A&P 400 (respiratory system) Flashcards

1
Q

repsiratory system

A

All of the structures involved in breathing (pulmonary ventilation) and external respiration

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2
Q

ppulmonary ventilationdefine

A

Pulmonary ventilation: airflow to/from the lungs

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3
Q

external respiration define

A

External respiration: gas exchange between the lungs and pulmonary circulation

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4
Q

respiration also inveolves

A

Respiration also involves internal respiration

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5
Q

internal respriation deinfe

A

gas exchange between systemic circulation and the tissues

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6
Q

respiraiton overview

A

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7
Q

homeostasis requires

A

a steady supply of O2

and constant elimination of CO2

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8
Q

Disruption?

A

= oxygen starvation & waste buildup

= rapid cell death

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9
Q

which 2 systems work together to make sure that our cells don’t die

A

respiratory system provides for gas exchange

cardiovascular system transports the respiratory gases

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10
Q

functions of repiratory system

1) external respiration,
2) ventilation,
3) protection (of air),
4) sound prodution,
5)smell/olfactory

A

extensive SA for gas exchange

move air from exchange surface of lungs along respiratory passageways

protecting respiratory surfaces from dehydration, temperature change, invasion of pathogens

produce sounds for speaking, singing, and other forms of communication

detecting odors via olfactory receptors in the superior portion of the nasal cavity

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11
Q

respiratory tract consists of

A

Nose

Pharynx
Larynx

Trachea

Bronchi
Bronchioles
Alveoli

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12
Q

what is the respiratory tract

A

branching passageway that carries air to/from gas exchange surfaces of the lungs

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13
Q

2 divisions of respiratory tract

A

​Conducting portion

​Respiratory portion

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14
Q

conducting portion of respiratory tract

(functional division)

A

Nasal cavity to larger bronchioles

No gas exchange

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15
Q

respiratory portion

(respiratory portion)

A

Smallest bronchioles (respiratory bronchioles) to alveoli

Where gas exchange occurs

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16
Q

what is another way the respiratory tract can be categorized / termed?

A

Can also divide into the upper respiratory tract and lower respiratory tract

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17
Q

functionally terming —>

A

nose, pharynx, larynx, trachea, bronchi, bronchioles

======>conducting portion

WHEREAS
bronchioles –> alveoli
====== RESPIRATORY PORITON

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18
Q

whereas for lower/uppre rt —>

A

nose/pharynx - Upper RT

larynx, trachea, bronchi, bronchioles, alveoli,
==== LOWER RT

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19
Q

What are anaotmical structures OF UPPER RT

A

Nose

Nasal cavity

Paranasal sinuses

Pharynx

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20
Q

what are functions OF URT

A

Filters (e.g. hairs), warms, and humidifies incoming air

Protects delicate lower tract

Reabsorbs heat and water in outgoing air

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21
Q

LOWER RT –> structures

A

Larynx

Trachea

Bronchi

Bronchioles

Alveoli

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22
Q

functions of LRT

A

Conducts air to and from gas exchange surfaces

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23
Q

Respiratory epithelia

A

… varies depending on where in respiratory tract

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24
Q

1) Respiratory mucosa

A

Lines the nasal cavity and superior pharynx

Also lines the superior portion of the lower respiratory tract
—> larynx, trachea, bronchi, etc.

—> ciliated columnar with goblet cells (mucus secretion)

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25
Q

2) Stratified squamous epithelium

A

Lines inferior portions of pharynx

—> oropharnx and hypopharynx (laryngopharynx)

—> protect from abrasion during swallowing ingested food

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26
Q

WHY INFERIOR PORTION OF PHARYNX STRATIFIED SQUAMOUS????

A

B/c food passes here briefly

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27
Q

3) Simple cuboidal or simple columnar

A

Lines the smaller bronchioles

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28
Q

note ciliated cells?

A

trap pathogens, propel debris upward

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29
Q

what about where not ciliated?

A

macrophages

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30
Q

4) Simple squamous epithelium

A

Forms gas exchange surfaces

Distance between air and blood in capillaries is less than 1 µm

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31
Q

1) RESPIRATORY MUCOSA

whre?
what tpye of cells?

A

Respiratory mucosa lines nasal cavity through large bronchioles

Pseudostratified ciliated columnar epithelium with mucous cells

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32
Q

Lamina Propria

A

underlying areolar tissue
(LOOSE CT)

( underneath respiratory mucosa)

supports respiratory epithelium

mucous glands in trachea and bronchi

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33
Q

mucous cells (different from mucous glands?)

A

b/w the…

Pseudostratified ciliated columnar epithelium with mucous cells

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34
Q

THE MUCOCILIARY ESCALATOR

A

Flow of mucus/trapped debris (VIA CILIA)

Sticky mucus produced by mucous cell and MUCOUS GLANDS

Traps debris particles

Moved by beating cilia

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35
Q

where does mucociliary escalator sweep the mucous?

A

Swept toward pharynx

Swallowed (to acids in stomach) or coughed out

Epithelial stem cells replace damaged/old cells

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36
Q

Anatomy of URT

A

..

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37
Q

nose

A

Nose is primary route for air entering respiratory system

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38
Q

what is trhe visible portion of nose?

A

External nose is the portion you can see

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39
Q

what are external NARES

A

Nostrils or external nares

Paired openings into nasal cavity

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40
Q

what is the structure of the extenral nose

A

Bony and cartilaginous structures make up the framework of the external nose

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41
Q

bony framework of nose

A

Dorsum of nose
(bridge) formed by two nasal bones

Maxilla and frontal bones also contribute

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42
Q

Cartilaginous framework of the external nose

A

NASAL CARTILAGES:
small, elastic cartilages extending laterally from bridge; help keep nostrils open

I.e.
Septal cartilage
Lateral nasal cartilage
Alar cartilage

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43
Q

nasal cavity (BORDERS)

A

superior border

inferior border

medial border

lateral border

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44
Q

supeior border

A

Superior border: ethmoid bone

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45
Q

inferior borer

A

Inferior border: hard palate, made of palatine bones and palatine process of maxillae

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46
Q

medial border

A

Medial border: nasal septum

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47
Q

latearl border

A

Lateral border: ethmoid bone, maxillae, lacrimal bones, palatine bones, and inferior nasal conchae bones

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48
Q

The nasal cavity

A

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49
Q

majority of nasal cavity is

A

Majority lined with respiratory mucosa

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50
Q

what does the nasal cavity anteiroly merge with

A

anteriorly merges with the external nares

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51
Q

what does nasal cavity posteriorly communicate with?

A

posteriorly communicates with the NASOPHARYNX through the CHOANAE (AKA internal nares)

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52
Q

choanae etymology

A

The term is a latinization from the Greek χοάνη, “choanē” meaning funnel.

The choanae ( sg. : choana), posterior nasal apertures or internal nostrils are two openings found at the back of the nasal passage between the nasal cavity and the pharynx

SINGULAR CHOANA

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53
Q

NASAL VESTIBULE

A

nasal vestibule lined with course hairs for filtering large dust particles

” The area just inside the nostril (nose opening) that leads into the nasal cavity. The nasal vestibule is supported by the cartilage of the nose and is lined with tissue that contains short, coarse hairs.”

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54
Q

functional divison of nasal cavity

A

Respiratory Region

olfactory portion

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55
Q

Respiratory Region

A

Larger, inferior region of nasal cavity

Lined w non-keratinized pseudostratified ciliated columnar epithelium with many goblet cells (respiratory mucosa)

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56
Q

Olfactory Region

A

Smaller, superior region of nasal cavity

Olfactory receptors near superior nasal concha

Have cilia, but no goblet cells

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57
Q

what is respiratory region of nasal cavity lined with (WHAT CELL TYPE???)

A

NON_KERATINIZED pseudostratified ciliated columnar epithelium

(WITH MANY GOBLET CELLS)

—> I.e.
respiratory mucosa

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58
Q

structure sof nasal cavity

A

Nasal septum:

Divides right and left nasal cavities

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59
Q

nasal septum formed by

A

Septal cartilage

Vomer

Perpendicular plate of the ethmoid

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60
Q

structures of the nasal cavity (continued)

conchae and meatuses

A

Superior, middle, and inferior nasal conchae (bones)

Superior, middle, and inferior nasal meatuses

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61
Q

what is the purpose of meatuses

A

Passages between nasal conchae

Swirl incoming air to trap small particles

Moves odorants to olfactory receptors

Warms/humidifies air

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62
Q

WHAT ABOUT THE Paranasal sinuses

A

Frontal, ethmoid, maxillary, and sphenoidal sinuses

Open into nasal cavity

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63
Q

functions of paranasal sinuses

A

Mucus secreted by sinuses moisten nasal cavity

Resonate sound

Lighten skull

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64
Q

what are NASAL POLYPS (structures related to paranasal sinuses)

A

outgrowths of mucous membranes

usually found around openings to paranasal sinuses

(not necessarily normal? Can be symptomatic)

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65
Q

what are the NASOLACRIMAL DUCTS?

A

the LACRIMAL sac drains tears from the eyes

the nasolacrimal duct carries tears from thelacrimal sacof the eye into the nasal cavityNw

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66
Q

basal tears

A

Basal tears are in your eyes all the time to lubricate, nourish and protect your cornea. Basal tears act as a constant shield between the eye and the rest of the world, keeping dirt and debris away.

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67
Q

reflex tears

A

Reflex tears are formed when your eyes need to wash away harmful irritants, such as smoke, foreign bodies or onion fumes.

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68
Q

emotional tears

A

Emotional tears are produced in higher quantities than basal tears. They may be the same amount or more than reflex tears. Unlike, basal and reflex tears, emotional tears can be held back by the individual voluntarily, and they can stop when they want to.

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69
Q

three types of tears

A

We cry to protect our eyes, to wash out irritants and because, well, we are moved to tears.

“There are three types of tears:
basal tears,
emotional tears
and reflex tears,”

explains David Silverstone, M.D., a professor of ophthalmology at the Yale School of Medicine.

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70
Q

Epiphora

A

Epiphora is the medical definition for having excess tears or watery eyes.

It’s caused by your eyes producing too many tears, or the tears in your eyes not draining away as they should.

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71
Q

AND SO… what is the purpose of the NASOLACRIMAL DUCTS/system

A

The purpose of the nasolacrimal system is to drain tears from the ocular surface to the lacrimal sac and, ultimately, the nasal cavity.

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72
Q

what happens if the nasolacrimal ducts are not functioning properly

A

EPIPHORA

Blockage of the nasolacrimal system can cause tears to flow over the eyelid and down the cheek; this condition is epiphora.

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73
Q

Epiphora etymology

A

late 16th century (in epiphora (sense 2)): via Latin from Greek epi ‘upon’ + pherein ‘to bear or carry’.

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74
Q

And so… WHY DO YOU GET runny nose after crying (rhinorrhea?)

A

When you cry, tears come out of the tear glands under your eyelids and drain through the tear ducts that empty into your nose. Tears mix with mucus there and your nose runs.

I.e.
They go through the NasoLacrimal Ducts

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75
Q

why does lacrimation take place in response to emotions? (emotional tears)

A

your limbic system — the part of your brain that regulates emotions — sends a signal to your brain’s message system to activate your lacrimal glands to produce tears.

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76
Q

note about lamina propria

A

Lamina propria (basement membrane) of nasal cavity has extensive network of vessels

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77
Q

what functions take place in nasal cavity?

A

Release heat to warm inhaled air

Water from mucus evaporates to humidify inhaled air

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78
Q

as a result of heating mechanism in nasal cavity

A

Air moving from nasal cavity to lungs:
—-> Heated to almost body temperature
—-> Nearly saturated with water vapor

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79
Q

On the other hand…
during exhalation:

A

The reverse process occurs during exhalation

—> mucosa reabsorbs heat and water; reduces heat loss and water loss to environment

—> Releases air (with CO2) – taking as much heat/water from released air as possible

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80
Q

WHAT IS something that eliminates these benefits?

A

Mouth breathing eliminates these benefits

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81
Q

Let’s discuss the pharynx

A

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82
Q

what two systems is the pharynx a part of?

A

Pharynx is shared by respiratory and digestive systems

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83
Q

what is the colloquial term for the pharynx?

A

Colloquially referred to as the throat

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84
Q

describe the pharynx

A

5 inch muscular tube from CHOANA (internal nares?) to cricoid cartilage

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85
Q

what is the pharynx lined with?

A

Lined with respiratory mucosa

–> except oropharynx and hypopharynx (laryngopharynx) – lined w/ stratified squamous

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86
Q

what is the function of the pharynx?

A

passage for food and air

resonating chamber for speech

lymphatic tissue (tonsil) to prevent the entry to the body
—> entry?? pathogens? ?

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87
Q

tonsils

(NOTE MALT —> mucosa associated lymphatic tissue)

A

The tonsils are lymph nodes in the back of the mouth and top of the throat. They help to filter out bacteria and other germs to prevent infection in the body.

A bacterial or viral infection can cause tonsillitis.

Strep throat is a common cause.

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88
Q

three regions of pharynx

A

1) Nasopharynx

2) ​Oropharynx

3) ​Laryngopharynx

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89
Q

Nasopharynx

A

superior part of the pharynx

Lined with respiratory mucosa

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90
Q

possibly, the oropharynx is the region with

A

non-keratinized stratified squamous epithelium

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91
Q

yes

A

“The stratified squamous epithelium of the oropharynx is continuous with the laryngopharynx”

“Anteriorly, the laryngopharynx opens into the larynx; whereas, posteriorly, it enters the esophagus.”

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92
Q

boundaries of the nasopharynx

A

From choanae to soft palate

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93
Q

what is a unique struture contained by the NASOpharynx

A

Has pharyngeal openings of the auditory tubes (EUSTACHIAN tubes)

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94
Q

what is another unique structure contained by the nasopharynx

A

Contains adenoids (pharyngeal tonsils)

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95
Q

adenoid etymology

A

aden = gland
oid

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96
Q

adenoids define

A

Adenoids are a patch of tissue that is high up in the throat, just behind the nose.

They, along with the tonsils, are part of the lymphatic system.

The lymphatic system clears away infection and keeps body fluids in balance.

The adenoids and tonsils work by trapping germs coming in through the mouth and nose.

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97
Q

eustachian etmyology

A

The Eustachian tube is named after the Italian anatomist Bartolomeo Eustachio (also spelled Eustachi and known by the Latin name Bartholomaeus Eustachius) who lived circa 1510-1574.

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98
Q

function of eustachian tubes

A

The primary function of the Eustachian tube is to equalize air pressure between the atmosphere and the middle ear.

Yawning and swallowing cause contraction of the muscles connected to the Eustachian tube, enabling the tube to open to small amounts of air.

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99
Q

why does airpressure need to be equalized?

A

The equalizing of middle ear pressure is crucial to the proper workings of the eardrum.

With equalized air pressure, the eardrum can vibrate appropriately and transmit sound.

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100
Q

OROPHARYNX****

A

middle part of the pharynx behind oral cavity

Lined with non-keratinized stratified squamous epithelium

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101
Q

boundaries of oropharynx

A

From soft palate to base of the epiglottis

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102
Q

glottis vs epiglotttis

A

The glottis opens into the windpipe and is responsible for the production of sound.

While the epiglottis is a cartilaginous flap on top of the glottis that prevents the food from entering the larynx.

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103
Q

Laryngopharynx

A

inferior part of the pharynx

Lined with non-keratinized stratified squamous epithelium

(NOTED ABOVE)

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104
Q

laryngopharynx boundaries

A

From epiglottis to cricoid cartilage

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105
Q

Anatomy of LRT

A

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106
Q

LARYNX

A

Cartilaginous tube that surrounds/protects glottis (“voice box”)

Connects the pharynx with the trachea

—> Anterior to C4 – C6

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107
Q

note term

A

laryngeal skeleton

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108
Q

what are the three large cartilages that make up the larynx

A

1) Epiglottis

2) Thyroid Cartilage

3) Cricoid Cartilage

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109
Q

an important note

A

even though epiglottis and laryngopharynx are at the same level, they are different structures

epiglottis itself is part of larynx

however, the laryngopharynx is simply at the same level of the epiglottis

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110
Q

1) EPIGLOTTIS

A

projects superior to glottis, forms lid over it

During swallowing the larynx elevates, the epiglottis folds back over glottis, and blocks entry into respiratory tract

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111
Q

2) THYROID CARTILAGE

A

Prominent anterior surface is laryngeal prominence (Adam’s apple)

Thyrohyoid ligament attaches it to hyoid bone; other ligaments attach it to epiglottis and smaller cartilages (e.g. cricoid)

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112
Q

thyroid etymology

A

shield shaped

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113
Q

3) CRICOID ETYMOLOGY

A

Forms complete ring around larynx

With thyroid cartilage, protects glottis and larynx

provides attachment for laryngeal muscles/ligaments (muscles that control voice pitch, sound production, and so on)

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114
Q

cricoid etymoloy

A

ring-shaped

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115
Q

what is the landmark use for a treacheostomy?

A

Cricoid cartilage (directly above “)

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116
Q

what is a tracheostomy for?

A

A tracheostomy is a surgically created hole (stoma) in your windpipe (trachea) that provides an alternative airway for breathing

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117
Q

tracheotomy vs tracheostomy?

A

The term “tracheotomy” refers to the procedure to make an incision (cut) into the trachea (windpipe).

The temporary or permanent opening itself is called a “tracheostomy.”

However, the terms are sometimes used interchangeably.

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118
Q

why would a tracheotomy be necessary>

A

Medical conditions that make it necessary to use a breathing machine (ventilator) for an extended period, usually more than one or two weeks.

Medical conditions that block or narrow your airway, such as vocal cord paralysis or throat cancer.

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119
Q

Other catilage structures (three other minor cartilaginous structures of larynx)

A

Arytenoid cartilages (2)

Corniculate cartilages (2)
(elastic cartilage)

Cuneiform cartilages (2)

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120
Q

arytenoid catilages function

A

change position & tension of vocal cords via synovial joint w cricoid cartilage

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121
Q

cuneiform cartilages function

A

support vocal folds and lateral epiglottis

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122
Q

what is the glottis

A

where air passes through larynx

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123
Q

what does glottis consist of?

A

Made of VOCAL FOLDS

and RIMA GLOTTIDIS
(opening between folds)

glottis=
“the part of the larynx consisting of the vocal cords and the opening [Rima glottidis] between them. It affects voice modulation through expansion or contraction.”

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124
Q

rima define

A

a long narrow opening, esp between the vocal cords and the cartilages at the back of the larynx.

“Rima is Latin for a narrow cleft, crack or slit”

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125
Q

Vocal Folds

(Also known as the vocal cords)

A

VOCAL FOLDS = tissue folds that contain vocal ligaments

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126
Q

how are sound waves produced?

A

Vibration of VOCAL FOLDS produce sound waves

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127
Q

how are the vocal folds opened and closed?

A

Opened/closed by rotation of ARYTENOID cartilages

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128
Q

PHONATION define

A

Phonation = sound production from larynx

Vibration of vocal cords produces sound waves

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129
Q

ARTICULATION define

A

modification of sounds by tongue, teeth, and lips

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130
Q

where does amplification (part of articulation?) occur?

A

Amplification and resonance occur in pharynx, oral and nasal cavities, and paranasal sinuses

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131
Q

how do sound dynamics take place? and what role does larynx play in sound dynamics?

A

3 components:

producing sound
pitch
volume

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132
Q

1) Producing sound

A

bands of elastic ligaments stretched between laryngeal cartilages

muscles contract
= cartilages move
= pulls ligaments tight
= stretched vocal folds out into airway
= rima glottidis narrows
= air passes through folds and they vibrate
= sound

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133
Q

2) Pitch

A

Depends on tension of vocal folds

 taut = rapid vibration = pitch

Androgens = thicker & longer vocal folds = lower pitch

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134
Q

3) Volume

A

Depends on the pressure of air

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135
Q

ventral, ventricular

A

late Middle English: from Latin ventriculus, diminutive of venter ‘belly’.

late Middle English: from Latin venter, ventr- ‘belly’ + -al.

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136
Q

ventricular folds of larynx

A

The ventricular folds, also known as the vestibular or false vocal folds are located above the true vocal folds and separated from them by the laryngeal ventricle

They are commonly referred as “false” vocal folds as they historically have been thought not to be directly involved in the production of “normal” voice.

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137
Q

ventricular folds funtion

A

aka false vocal cords

above true vocal cords

Space between = RIMA VESTIBULI

Useful for holding breath against thoracic cavity pressure

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138
Q

rima vestibuli vs rima glottidis

A

..

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139
Q

epithelium of larynx

A

depends on location:

1) superior to vocal fold
= non-keratinized stratified squamous epithelium (RECALL, UP TO CRICOID, LARYNGOPHARYNX IS STRATIFIED SQUAMOUS)

2) inferior to vocal fold
= pseudostratified ciliated columnar epithelium with goblet cells (respiratory mucosa)

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140
Q

THE PASSAGE OF AIR **

A

Trachea
—> Main Bronchi
—> Lobar Bronchi
—> Segmental Bronchi
—> Bronchioles
—> Terminal bronchioles to pulmonary lobules

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141
Q

passage of air via…

A

The trachea, bronchi, and bronchial branches convey air to and from lung gas exchange surfaces

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142
Q

trachea (windpipe) — at levels of…

A

Starts at C6 and ends at T5 by branching into bronchi

5 inches long
1 inch in diameter

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143
Q

esophagus vs trachea?

A

Lies in front of the esophagus

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144
Q

note the trachial cartilages

A

Has 15–20 C-shaped tracheal cartilages

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145
Q

what is function of tracheal cartilage?

A

Prevent collapse and overexpansion

allow esophagus to expand slightly into tracheal space

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146
Q

why does esophagus expand into trachea?

A

The hyaline cartilage in the tracheal wall provides support and keeps the trachea from collapsing.

The posterior soft tissue allows for expansion of the esophagus, which is immediately posterior to the trachea.

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147
Q

CARINA OF TRACHEA

A

ridge at the base of the trachea that separates the openings of the right and left main bronchi

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148
Q

carina define

A

a cartilage situated at the point where the trachea (windpipe) divides into the two bronchi.

etymology:
“keel”

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149
Q

note significant feature of structure/function of trachea (in the region of CARINA)

A

highly innervated mucosa

very sensitive cough reflex to prevent choking
—> prevent food/debris reaching bronchi

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150
Q

how are ends of c shaped tracheal catilages connected?

A

ELASTIC LIGAMENTS

as well as, TRACHEALIS (muscle)

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151
Q

what does contraction of trachealis do?

A

Contraction of trachealis narrows trachea; restricts airflow

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152
Q

why/when does tracheal diameter change?

A

Trachealis = how

why?
Tracheal diameter changes often, mostly controlled by sympathetic stimulation which increases airflow

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153
Q

note again tracheal cartilage shape/structure vs swallowing and esophagus

A

Tracheal cartilages are incomplete posteriorly allowing for expansion when swallowing

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154
Q

layers of mtrachea

A

mucosa

sub-mucosa

fibromuscular membrane

adventitia

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155
Q

1) mucosa (of trachea)

A

pseudostratified ciliated columnar epithelium with goblet cells (respiratory mucosa)

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156
Q

2) sub-mucosa (of trachea)

A

loose CT with seromucous glands

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157
Q

seromucous glands

A

release a mixture of mucus and antibacterial compounds. This mixture also serves to humidify and warm the air before it gets to the lungs.

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158
Q

3) fibromuscular membrane (with smooth muscle & elastic CT – INCLUDING TRACHEALIS mm)

(layers of trachea)

A

allow tracheal diameter change during inhalation/exhalation

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159
Q

4) adventitia (CT)

(layers of trachea)

A

binds trachea to other organs

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160
Q

Bronchi

A

..

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161
Q

main bronchi (s. bronchus)

aka primary bronchi

A

First division of bronchi

Right and left bronchus go into each lung

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162
Q

how do right and left main bronchi differ?

A

(Due to position of heart)

Right bronchus wider, at a steeper angle, and shorter than left

= foreign objects in trachea often go into it

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163
Q

why right/left bronchi different?

A

“The left lung has to accommodate the heart, which is positioned slightly towards the left side of the thoracic cavity. This anatomical arrangement causes the left bronchus to be more horizontal and curved to navigate around the heart.”

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164
Q

do bronchi have cartilaginous rings as well?

A

Have complete cartilaginous rings

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165
Q

note internal lining of bronchi

A

Lined with respiratory mucosa

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166
Q

Lobar Bronchi

(aka SECONDARY bronchi)

one lobar bronchi goes to each…

A

one goes to each lobe of the lung

(5 FIVE lobar bronchi)

—> 3 lobes on right
—> 2 lobes on left

(superior, middle, inferior lobes on right)

(superior, inferior lobes on left)

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167
Q

cartilage vs smooth muscle for lobar bronchi?

A

Smooth muscle encircles lumen and increasingly replaces cartilage

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168
Q

lobar bronchi internal lining

A

Also lined with respiratory mucosa

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169
Q

Segmental bronchi

(aka TERTIARY bronchi)

HOW MANY PER LUNG?

A

Each lung has approximately 10 segmental bronchi

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170
Q

what does each tertiary bronchus supply?

A

Each one supplies triangular shaped unit of lung

(BRONCHOPULMONARY segment)

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171
Q

bronchopulmonary segments

A

divisions of each LOBE

“A bronchopulmonary segment is a portion of lung supplied by a specific segmental bronchus and its vessels”

“These arteries branch from the pulmonary and bronchial arteries, and run together through the center of the segment.”

“Veins and lymphatic vessels drain along the edges of the segment.”

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172
Q

BRONCHIOLES

cartilage vs smooth muscle?

A

No cartilage; thick smooth muscle

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173
Q

what does HYALINE cartilage do for BRONCHI and TRACHEA

A

A layer of hyaline cartilage supporting the tracheal rings surrounds the submucosa.

The hyaline cartilage layer is sturdy but flexible and prevents the collapse of the trachea during expiration.

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174
Q

bronchioles – histology (LINED WITH…)

A

Ciliated simple columnar epithelium w goblet cells

& Ciliated simple cuboidal epithelium w/o goblet cells
(club cells or Clara cells)

recall:
simple cuboidal/columnar lines smaller bronchioles

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175
Q

Club cells (Clara cells)

A

Club cells, also known as bronchiolar exocrine cells,[1] are low columnar/cuboidal cells with short microvilli, found in the small airways (bronchioles) of the lungs.[2] They were formerly known as Clara cells.

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176
Q

broncholdilation

A

Sympathetic nervous system (NE/E) causes bronchodilation

—> increases airflow

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177
Q

bronchoconstriction

A

Parasympathetic nervous system causes bronchoconstriction

—> Decreases airflow

—> Histamine, asthma attack, allergies

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178
Q

extreme bronchoconstriciton

A

Extreme bronchoconstriction can occur during allergic reactions such as ASTHMA

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179
Q

lobes –> bronchopulmonary segments –> lobules

A

3 lobes (right lung)
+ 2 lobes (left lung)
= 5 lobes

right primary bronchus
= steep, wider, shorter

left primary bronchus
= angled, narrower, longer
(angled and longer to get around heart, narrower b/c less space)

In general, each lung has 10 segments
(TEN BRONCHOPULMONARY SEGMENTS)

Internally, each lobe further subdivides into hundreds of lobules.

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180
Q

bronchioles

—> TERMINAL BRONCHIOLES

—> Respiratory bronchioles

A

Bronchioles open into short segments called terminal bronchioles, which are thin-walled branches of the bronchioles.

Terminal bronchioles transition into respiratory bronchioles.

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181
Q

Respiratory bronchioles are lined by two types of epithelial cells:

A

(SAME AS bronchioles)

—> ciliated columnar cells and club cells (also known as Clara cells)

___NOTE THAT CLASS NOTES SAY THAT TERMINAL BRONCHI HAVE NON-CILIATED cells –> macrophage action instead

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182
Q

what do terminal—>respiratory bronchioles lead to?

A

Terminal bronchioles lead to PULMONARY LOBULES (for gas exchange)

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183
Q

i.e.

A

one main bronchus per lung

2 + 3 lobar bronchi per lobe

10 segmental bronchi (on each side) per BRONCHOPULMONARY segment

then many terminal/respiratory bronchioles PER lobule

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184
Q

terminal bronchioles

A

Many terminal bronchioles

Each terminal/respiratory bronchiole supplies a pulmonary lobule

Smooth muscle (no cartilage) = airway patency vulnerable to muscle spasms

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185
Q

terminal bronchioles –> LINING (histology

A

Non-ciliated simple columnar epithelium

macrophages remove debris (no cilia to move mucous)

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186
Q

respiratory bronchioles…

(according to class notes)

A

Many, many respiratory bronchioles

Simple cuboidal & simple squamous epithelium
—> AGAIN DIFFERENT FROM ABOVE
(follow classnotes)

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187
Q

respiratory bronchioles are…

A

First place where external respiration can occur, although limited

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188
Q

external vs internal repiration

A

Internal respiration occurs in the body tissues, where cells release carbon dioxide and take in oxygen from the blood.

External respiration occurs in the lungs or gills and occurs when the body takes in oxygen from the atmosphere and releases carbon dioxide.

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189
Q

review… (THE BRONCHIAL TREE)

A

Trachea: larynx to main bronchi in mediastinum

Main bronchi: one to each lung; cartilage rings are complete

Lobar bronchi: 3 in right lung, 2 in left; one per lobe

Segmental bronchi: branch to give rise to bronchioles
(one per bronchopulmonary segment)

Bronchioles

Terminal bronchioles

Respiratory bronchioles

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190
Q

review anatomy

A

Structural Division:

Upper Respiratory Tract
vs.
Lower Respiratory Tract

*

Functional Division:

Conducting Region
vs.
Respiratory Region

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191
Q

URT

A

nose, nasal cavity & pharynx

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192
Q

LRT

A

larynx, trachea, bronchi & lungs

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193
Q

Conducting region

A

nose, pharynx, larynx, trachea, bronchi, bronchioles, & terminal bronchioles

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194
Q

respiratory region (where gas exchange occurs)

A

respiratory bronchioles, alveolar ducts, alveolar sacs, & alveoli

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195
Q

gross anatomy of lungs

A

..

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196
Q

Each lung divided into lobes

A

Right lung (3): superior lobe, middle lobe, inferior lobe

Left lung (2): superior lobe and inferior lobe

(Each lobe has multiple bronchopulmonary segments)
—> 10 on right?
—> 9 on left?

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197
Q

right lung vs left lung

(SIZE)

A

Right lung is slightly shorter d/t liver

Left lung is 10% smaller d/t heart

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198
Q

how does lung form lobes?

A

DEEP FISSURES

Each lung is cone shaped and divided into lobes by deep fissures

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199
Q

right lung fissures

A

Right lung

horizontal fissure between superior/middle lobes;

oblique fissure between middle/inferior lobes

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200
Q

left lung fissures

A

oblique fissure between superior/inferior lobes

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201
Q

gross anatomy of lungs

(cone shaped)

A

Apex (tip) extends to superior border of first rib

Concave base rests on diaphragm

Cardiac notch—left lung; accommodates pericardium/heart

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202
Q

Root of lungs

A

dense connective tissue; fixes positions of bronchi, major nerves, blood vessels, and lymphatics

CONTAINS HILUM (?)

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203
Q

Hilum (of lungs)

A

medial depression on each lung

Allows passage of main bronchus, pulmonary vessels, nerves, lymphatics

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204
Q

hilum etymology

A

‘little thing, trifle’

“a depression or fissure where structures such as blood vessels and nerves enter an organ”

205
Q

grooves on surface of lungs?

A

Grooves on surface of lungs mark positions of great vessels

206
Q

PLEURA (p. plurae)

recall:
“Pleura, pericardium, and peritoneum are all examples of serous membranes.”

A

Visceral pleura

Parietal pleura

207
Q

pleura are

A

serous membrane sacs surrounding the lungs

208
Q

Visceral pleura

A

covers outer surfaces of lungs

209
Q

Parietal pleura

A

covers inner surface of thoracic wall; extends over diaphragm and mediastinum

210
Q

Pleural cavity

(same principle as pericardial cavity)

A

potential space between visceral and parietal layers of pleural sac

Contains pleural fluid that reduces friction of the lungs against the wall

211
Q

Conditions involving the pleural cavity

(Any may cause partial or complete lung collapse)

A

Pneumothorax

Hemothorax

Hydrothorax

Empyema

212
Q

Pneumothorax

A

pleural cavity fills with air

common cause is chest trauma

213
Q

Hemothorax

A

pleural cavity fills with blood

214
Q

Hydrothorax

A

collection of serous fluid

m/c cause is cardiac failure

215
Q

pleural effusion

and

pericardial effusion

A

pericardial effusion —> cardiac tamponade (?)

pleural effusion —> hydrothorax

216
Q

Empyema

A

em = in
puon = pus

Pus in the pleural cavity

m/c cause is pneumonia

217
Q

partial or complete lung collapse (?)

A

Any may cause partial or complete lung collapse

=
Pneumothorax
Hemothorax
Hydrothorax
Empyema

218
Q

lung collapse

A

“A collapsed lung occurs when air escapes from the lung. The air then fills the space outside of the lung between the lung and chest wall. This buildup of air puts pressure on the lung, so it cannot expand as much as it normally does when you take a breath. The medical name of this condition is pneumothorax.”

219
Q

Pulmonary lobules contain:

A

A terminal bronchiole

Venule, arteriole, lymphatics, capillaries

Multiple alveolar sacs

220
Q

pulmonary lobules are…

A

Pulmonary lobules are wrapped in elastic CT

(expand and return to original size when filled with air)

221
Q

note

A

Each terminal bronchiole branches into multiple respiratory bronchioles

222
Q

Respiratory bronchioles lead to

A

alveolar ducts,

which lead to alveolar sacs made of alveoli (sing. alveolus)

223
Q

external respiration occurs in

A

respiratory bronchioles and alveoli

224
Q

Pulmonary alveoli

A

~150 million alveoli (singular, alveolus) per lung; give lungs an open, spongy appearance

Surrounded by extensive capillary network for gas exchange

225
Q

pulmonary alveoli – surrounded by

A

Surrounded by elastic fibers—expansion/recoil aids air movement

Each alveolar duct ends in clusters of alveoli (alveolar sacs, or alveolar saccules)

226
Q

alveolar sacs vs lobules

A

A primary pulmonary lobule is defined as the lung unit distal to the respiratory bronchioles. It is significantly smaller than an acinus, and is composed of alveolar ducts, alveolar sacs and alveoli.

227
Q

Alveolar epithelium

(Three major cell types)

A

​Type 1 Pneumocytes

Type 2 ​Pneumocytes

Roaming alveolar macrophages

228
Q

​Type 1 Pneumocytes

A

simple squamous epithelium

thin, delicate, sites of gas diffusion

229
Q

Type 2 ​Pneumocytes

A

produce surfactant: oily secretion; reduces surface tension of water in alveoli to prevent collapse

230
Q

Roaming alveolar macrophages

A

locate and phagocytize particles that could clog the alveoli

231
Q

Blood air barrier

A

where gas exchange occurs between blood and alveolar air

aka alveolar–capillary membrane or respiratory membrane

232
Q

three layers of blood-air-barrier

A

1) Alveolar cell layer (epithelium)

2) Fused basement membranes (alveolar and capillary)

3) Capillary endothelium

233
Q

Blood air barrier…

A

Minimal distance separating air and blood (average ~0.5 µm) allows for rapid diffusion

Large total surface area (70 - 100 m2 ) also allows for a large amount of diffusion

234
Q

CLASS TWO

A

….

235
Q

pulmonary ventilation (breahting)

A

air movement in/out of lungs

Maintains ALVEOLAR VENTILATION
–> air movement in/out of alveoli

236
Q

respiraiton

A

Two integrated processes: EXTERNAL respiration and INTERNAL respiration

237
Q

external respiration

A

exchange of gases between blood, lungs, and external environment

gas diffusion occurs across BLOOD AIR BARRIER between alveolar air and alveolar capillaries

238
Q

INTERNAL RESPIRATION

A

occurs between blood and tissues

Absorption of oxygen from blood into tissues

Release of carbon dioxide by tissue cells into blood

239
Q

respiration vs ventilaiton

A

Respiration and ventilation are two different things. Ventilation is mechanical and involves the movement of air. Respiration is physiologic and involves the exchange of gases in the alveoli (external respiration) and in the cells (internal respiration).

240
Q

how do abnormalities affecting external respiration affect internal respiration?

A

Abnormalities affecting external respiration affect gas concentrations in interstitial fluids and cellular activities

241
Q

hypoxia

A

Hypoxia = low tissue oxygen levels

Severely limits metabolic activities

242
Q

anoxia

A

Anoxia = no oxygen supply

Much of damage caused by heart attacks and strokes is the result of localized anoxia

243
Q

physiology of pulmonary respiration

A

..

244
Q

Pressure

A

Molecules in a gas bounce around independently

When contained, collisions with container wall cause pressure

More collisions = higher pressure

245
Q

Boyle’s law and pressure

A

Boyle’s law
= More collisions occur when molecules are in smaller container

= Pressure is inversely related to volume (P = 1/V)

I.e.
Decreased volume = more collisions = higher pressure

Increased volume = less collisions = lower pressure

246
Q

Pressure and diffusion

A

diffusion:
the net movement of molecules from an area of greater concentration to an area of lesser concentration

I.e.
Molecules move down their concentration gradient

**

Likeiwse with pressure:
—> Gases will move from an area of high pressure to low pressure

—> Gases will move down their pressure gradient

247
Q

what is direciton of air into or out of lungs determined by?

A

Atmospheric pressure and intrapulmonary pressure

Atmospheric pressure is the pressure of air around us

Intrapulmonary pressure is the pressure inside respiratory tract, usually measured at the alveoli

248
Q

where is intrapulmonary pressure measured?

A

@ ALVEOLI

249
Q

therefore, pulmonary ventilation is determined by

A

Pulmonary ventilation involves changing volume of the thoracic cavity

250
Q

which structures alter the shape and space in the thoracic cavity?

A

Movements of the DIAPHRAGM and RIB CAGE (E.g. levator costarum)

—> change the volume of the thoracic cavity, which expands or compresses the lungs (changes lung volume)

Change in volume = change in pressure (Boyle’s Law)

251
Q

the steps involved in pulmonary ventilation

A

Start of a breath

During inhalation

During exhalation

(Volume and Pressure Changes During Pulmonary Ventilation)

252
Q

Start of a breath

A

Pressures inside and outside thorax are identical; no air movement

Expanding thoracic cavity expands lungs:
(DIAPHRAGM contracts, increases space in lungs –> also note action of levator costarum and other mm.)

253
Q

what happens when thoracic cavity expands

A

Parietal pleura attached to thoracic wall; visceral pleura to lungs

Pleural fluid forms bond between layers d/t surface tension

254
Q

DURING INHALATION

A

Thoracic cavity enlarges

Increased volume causes decreased pressure

Pressure inside lungs drops below atmospheric pressure (Poutside > Pinside)

Air moves into lungs from an area of high pressure to low pressure

255
Q

DURING EXHALATION

A

Thoracic cavity decreases in volume

Decreased volume causes increased pressure

Pressure inside lungs increases above atmospheric pressure (Poutside < Pinside)

Air is forced out of the lungs from an area of high pressure to low pressure

256
Q

in other words, during inhalation intrapulmonary pressure is…

A

negative

Negative intrapulmonary pressure pulls air into lungs

—> Intrapulmonary pressure < atmospheric pressure

257
Q

and during exhalation, intrapulmonary pressure is

A

POSITIVE

Positive intrapulmonary pressure pushes air out of lungs

Intrapulmonary pressure > atmospheric pressure

258
Q

respiratory muscles

A

May be involved with inhalation (inspiratory muscles) or exhalation (expiratory muscles

259
Q

breathing can either be

A

quiet or forced

260
Q

quiet breathing

A

Quiet breathing is normal breathing

261
Q

forced breathing

A

Forced breathing is laboured breathing

262
Q

quiet breahting occurs via

A

Active inhalation via primary inspiratory muscles

Passive exhalation via elastic recoil of tissues, not by muscle action

263
Q

what about forced breathing

A

Force breathing requires accessory respiratory muscles

I.e.
requires contribution from all repsiratory muscles (?)

–> also, exhalation is no longer passive

264
Q

inspiratory muscles

A

primary vs accessory inspiratory uscles

265
Q

primary inspiratory muscles

A

Primary inspiratory muscles used for quiet inhalation

266
Q

ACCESSORY inspiratory muscles

A

used for forced inhalation

267
Q

primary inspiratory mm

A

Diaphragm
external intercostals

268
Q

what is the ratio/percentage of contribution of diaphragm vs external intercostals (PRIMARY inspiratory muscles)

A

Diaphragm does ~75 % of movement
—> Flattens floor of thoracic cavity

External intercostals do ~25 % of movement
—> elevate ribs and pull out

269
Q

Note now the ACCESSORY inspiratory muscles (during forced inhalation)

A

Sternocleidomastoid

Scalenes

Pectoralis minor

Serratus anterior

270
Q

what exactly do the accessory inspiratory muscles do?

A

Increase speed/amount of rib movement to move more air when needed (tissue oxygen demands not met by primary inspiratory muscles)

In other words,
when you are very active, your regular “QUIET” inspiration is not providing adequate oxygen to tissue

—> forced inhalation is required to create greater speed/amount of rib movement to generate greater pressure difference, to let more air into the lungs, more quickly

271
Q

expiratory muscles

A

There are no primary (“quiet”) expiratory muscles

Quiet exhalation is a passive process done by elastic recoil

272
Q

during quiet exhalation

A

Diaphragm relaxes
—> dome moves superiorly

External intercostals relax
—> ribs move down

Passive elastic recoil caused by:
—> stretched elastic fibres
—> inward pull of surface tension from alveolar fluid (??)

273
Q

inward pull of surface tension from alveolar fluid

A

??

274
Q

accessory expiratory mm

A

Internal intercostals
—> depress ribs (?)

transversus thoracis
—> depress ribs (?)

external oblique, internal oblique,

rectus abdominis

275
Q

what do abdominal muscles do during forced exhalation

A

Abdominal muscles push diaphragm upward

—> possibly via decreased abdominal cavity volume pushing organs against diaphragm (?)

Decrease thoracic cavity volume quickly

Allow greater pressure change and faster airflow out of lungs

276
Q

FACTORS AFFECTING PULMONARY VENTIATION

A

Surface Tension

Compliance

Airway Resistance

277
Q

1) Surface tension

A

Water molecules attracted to each other more strongly than to air molecules
—> “this is why soap bubbles collapse inward and burst” (?)

Thin layer of alveolar fluid coats luminal surface of alveoli
—> Responsible for 2/3 of elastic recoil of lungs
—> Must be overcome during each inhalation

Surfactant (from type 2 pneumocytes)
—> reduces surface tension below simple water

278
Q

what substance is responsible for reducing surface tension in lungs?

A

Surfactant (from type 2 pneumocytes)

279
Q

when is surfactant first produced in developing fetus?

A

Surfactant is not produced until 24th – 28th week of development

280
Q

Note (N)RDS

A

Recall:
premature infants have decreased surfactant

= ^ surface tension = alveoli collapse = great effort to open alveoli with each inhalation

This leads to something called RDS (respiratory distress syndrome)

281
Q

Tx of (N)RDS

A

Tx: intubation, ventilation, artificial surfactant

282
Q

2) COMPLIANCE (factors affecting pulmonary ventilation)

A

Compliance = the ability of the lungs and chest wall to expand

283
Q

what happens during increased compliance

A

lungs & chest wall expands easily

elastic stretches easily and elastic recoil is not strong making exhalation more difficult

Seen with some OBSTRUCTIVE LUNG DISEASES
—> Like EMPHYSEMA

284
Q

increased lung compliance – emphysema

A

Compliance is increased in obstructive lung disease like pulmonary emphysema, less in asthma and at a minor degree in chronic bronchitis.

In emphysema, the elastic recoil is decreased (as a result of increased compliance – or rather, decreased elastic recoil CAUSES increased compliance) and the P-V curve is shifted up and left. This is due to the loss of elastic tissue as a result of alveolar wall destruction.

285
Q

What about decreased compliance

A

lungs & chest wall difficult to expand

This is restrictive lung disease
–> Pulmonary fibrosis (asbestosis, TB, etc.)
–> Pneumothorax
–> Pleural effusion
–> Chest wall injury or trauma
–> Scoliosis
–> Respiratory distress syndrome (RDS)
–> Obesity and pregnancy

286
Q

restrictive lung diseases

A

Restrictive lung diseases - fibrosis and interstitial lung disease: In interstitial lung diseases, the lung and/or chest wall compliance has become decreased. Therefore there is an increased tendency for the lungs to collapse.

287
Q

why is INCREAESD compliance causing OBSTRUCTIVE lung disease

A

decreased elastic recoil means that air is no exiting as effectively

–> I.e. it is obstructing continued passage/cycling of air

288
Q

why is decreased compliance related to RESTRICTIVE lung disease?

A

low compliance means there is restriction of tissue to even let air in to begin with.

In other words, even if recoil mechanism is intact in itself, the fibrosed tissue of lungs simply don’t expand to begin with

289
Q

3) AIRWAY RESISTANCE (factors affecting pulmonary ventilation)

A

..

290
Q

airway resistance is

A

the resistance of the respiratory tract to airflow during inhalation and exhalation

291
Q

under normal circumstances, during inhalation & exhalation, what happens to the resistance within the bronchioles?

A

d/t pressures:

—> Bronchioles expand during inhalation = decreased resistance

—> Bronchioles narrow during exhalation = increased resistance

292
Q

which type of lung diseases are characterized by INCREASED airway resistance?

A

Obstructive lung diseases

E.g.
Asthma

Chronic Obstructive Pulmonary Disease (COPD)
—> Chronic bronchitis
—> Emphysema

293
Q

a final review of restrictive lung disease definition

A

Restrictive lung diseases include diseases that make it hard for the lungs to expand and fill with air (low compliance)

294
Q

final review of obstructive lung disease definition

A

Obstructive lung diseases include disease that make it hard for people to expel air from the lungs (increased resistance)

—> increased airway resistance
—> increased compliance / reduced recoil

**

EXTRA:
WHY DOES COPD (e.g. chronic bronchitis) INCREASE AIRWAY RESISTANCE?

—> Expiratory flow limitation is a key characteristic in chronic obstructive pulmonary disease (COPD). Increased airway resistance occurs due to bronchoconstriction, destruction of elastic tissue in the airways, and mucus hypersecretion from goblet cells caused by irritation of the epithelium.

ALSO:
“More severe degrees of emphysema resulted in a marked increase in total airway resistance due almost entirely to the increase in the peripheral airway component.”
(?????)

295
Q

E.g. obstructive lung disease

A

Chronic Obstructive Pulmonary Disease (COPD)
E.g.
-> Chronic bronchitis
-> Emphysema

Asthma

296
Q

Again – examples of RLD

A

Pulmonary fibrosis (asbestosis, TB, etc.)

Pneumothorax

Pleural effusion

Chest wall injury or trauma

Scoliosis

Respiratory distress syndrome (RDS)

Obesity and pregnancy

297
Q

again – OLD e.g.

A

COPD (Chronic bronchitis, Emphysema)

Asthma

298
Q

COPD is

A

General term for progressive disorder of the airways that restricts airflow and reduces alveolar ventilation

299
Q

which two types of COPD frequently occur together?

A

Chronic bronchitis
+
Emphysema

300
Q

Chronic bronchitis

A

Long-term inflammation and swelling of bronchial lining; leads to overproduction of mucus

Frequent cough, lots of sputum can clog airways, increasing resistance, reduced efficiency
—> INCREASED AIRWAY RESISTANCE

Cigarette smoking most common cause
—> Also other environmental irritants

301
Q

Emphysema

A

Chronic, progressive condition

Alveolar walls are damaged
—> Loss of elastic tissues increases compliance

Loss of respiratory surface area restricts oxygen absorption (shortness of breath, intolerance of physical exertion

Strongly linked with CIGARETTE smoking

302
Q

note pattern

A

emphysema increases 2) COMPLIANCE

chronic bronchitis 3) INCREASES AIRWAY RESISTANCE

—> both contribute to the OBSTRUCTIVE nature of the lung disease

303
Q

ASthma

A

aka asthma bronchitis

Characterized by conducting passageways that are extremely sensitive to irritation

Airways respond by constricting smooth muscles along bronchial tree, edema/swelling of mucosa, increased mucus

Breathing difficult; resistance markedly increased

304
Q

triggers of asthma

A

Triggers include allergies, toxins, exercise

305
Q

Breathing patterns

A

..

306
Q

Eupnea

A

normal variation in breathing rate and depth (12 to 18 breaths per minute)

307
Q

Apnea

A

temporal cessation of breath (sleep apnea)

a-
-pnoe

308
Q

dyspnea

A

painful, difficult, or laboured breathing (shortness of breath, SOB)

309
Q

Tachypnea

A

rapid breathing rate (> 20 breaths per minute)

310
Q

bradypnea

A

Bradypnea is a symptom in which your breathing rate is lower than expected for your age and activity level.

311
Q

costal breathing

A

upward & outward movement of chest during contraction of intercostals

312
Q

diaphragmatic breathing

A

abdomen moving outward when contracting diaphragm

(b/c contraction of diaphragm reduces volume of abdominal cavity while increasing volume of thoracic cavity

313
Q

modified breathing patterns

A

..

314
Q

coughing

A

deep inspiration, closure of rima glottidis & strong expiration blasts air out to clear respiratory passages

315
Q

sneezing

A

muscles of expiration spasmodically contract, pushing air out of nose and mouth

316
Q

hiccupping

A

spasmodic contraction of diaphragm & quick closure of rima glottidis produce sharp inspiratory sound

317
Q

yawning

A

significant amount of inhaled air followed by quick exhalation

318
Q

valsalve (maneuver)

A

forced expiration against closed rima glottidis

(increases abdominal pressure)

319
Q

sobbing

A

many convulsive inhalations (where rima glottidis prematurely closes, letting in only a little air) & a long exhalation

320
Q

lung volumes and pulmonary function tests

A

..

321
Q

lung volumes

A

..

322
Q

how are respiratory voluesm measured?

A

SPIROMETER

spiro- = breath

323
Q

what shows the results of spirometer?

A

spirogram

What is Spirogram? Spirogram is the graphical record of lung capacities and lung volumes using a spirometer.

324
Q

which groups are lung volume larger generally?

A

males

taller people

younger people

325
Q

terms related to lung volume

A

tidal volume

inspiratory reserve volume

expiratory reserve volume

residual volume

minimal volume

326
Q

tidal volume

A

Amount of air moved in or out of lungs during single respiratory cycle at rest (normal quiet breathing)

Averages 500 mL

327
Q

what percentage of tidal volume actually reaches respiratory zone?

(I.e. zone where gas exchange can actually take place)

A

70% reaches respiratory zone for external respiration (350ml)

30-35% remains in conducting airways = anatomic (respiratory) dead space (150ml)

328
Q

anatomic (respiratory) dead space

A

Dead space is the volume of air that is inhaled that does not take part in the gas exchange,

because it either remains in the conducting airways or reaches alveoli that are not perfused or poorly perfused.

It means that not all the air in each breath is available for the exchange of oxygen and carbon dioxide.

329
Q

inspiratory reserve volume

A

Amount of air you can breathe in beyond tidal volume

(with forced inspiration)

330
Q

expiratory reserve volume

A

Amount of air you can exhale beyond tidal volume (after normal (quiet?) exhalation)

(forced exhalation (?))

331
Q

residual volume

A

Amount of air left in lungs after maximal exhalation (1200 mL)

presumably after forced exhalation

332
Q

minimal volume

A

Amount of air in the lungs if they were allowed to collapse

Included in residual volume

Cannot be measured in a healthy person
–> collapsed lung is medical emergency

333
Q

lung capacities

A

..

334
Q

lung capacities can not be

A

Lung capacities cannot be measured directly but are calculated by taking sum of various respiratory volumes

335
Q

terms related to lung capacities

A

inspiratory capacity

vital capacity

functional residual capacity

total lung capacity

336
Q

inspiratory capacity

A

VT + IRV

tidal volume + inspiratory reserve volume

—> I.e. volume of air with forced INHALATION

“Amount of air you can inhale after normal exhalation” (??)

337
Q

vital capacity

A

ERV + VT + IRV

expiratory reserve volume + tidal volume + inspiratory reserve volume

I.e.
“Maximum amount of air you can move in or out of lungs per cycle”

338
Q

functional residual capacity

A

ERV + residual volume

I.e.
Amount of air remaining in lungs after complete quiet cycle

339
Q

total lung capacity

A

Vital capacity + residual volume

Total volume of lungs

340
Q

total lung capacity in male vs female

A

Averages 6000 mL in adult males, 4200 mL in adult females

341
Q

Pulmonary function test

(PFT)

A

Pulmonary function tests (PFT) measure volume, capacities, and rates of flow

342
Q

Force Vital Capacity (FVC) (test)

A

measures how much air you can forcibly exhale after taking a deep breath

343
Q

Forced expiratory volume (FEV) (test)

A

This is the amount of air expired during the first, second, and third seconds of the FVC test (FEV1, FEV2, FEV3)

344
Q

Forced expiratory flow (FEF) (test)

A

This is the average rate of flow during the middle half of the FVC test

345
Q

Peak expiratory flow rate (PEFR) (test)

A

This is the fastest rate that you can force air out of your lungs

346
Q

effects of aging and smoking on lungs

A

..

347
Q

respiratory function vs age

A

All aspects of respiratory function decrease with age

As elastic tissue deteriorates, vital capacity decreases

Arthritis stiffens rib joints, reducing compliance and maximum respiratory minute volume

348
Q

(features of) emphysema is normal for…

A

Some degree of (features of) emphysema is normal for people over age 50

Extent varies widely with exposure to cigarette smoke and other irritants

Respiratory function declines more with more years of smoking

349
Q

Lung cancer

A

aggressive class of malignancies

Derived from epithelial cells in conducting passages, mucous glands, alveoli

350
Q

when are SSx of lung cancer present?

A

Signs/symptoms often not present until tumors restrict airflow or compress adjacent structures

—> Chest pain, shortness of breath, cough/wheeze, weight loss

351
Q

which cancer causes most deaths per year

A

lung cancer

Causes more deaths per year than any other type of cancer

352
Q

how often is lung cancer as a result of cigarette smoking

A

85–90 percent of lung cancer cases are direct result of cigarette smoking

353
Q

what effect does smoking have on lung tissue

A

..

354
Q

cigarette smoke contains

A

Cigarette smoke contains several carcinogens (cancer-causing agents)

355
Q

what do mucous and cilia do in normal respiratory epithelium?

A

Mucus and cilia in normal respiratory epithelium clean inhaled air

356
Q

what do carcinogens do?

A

Irritants/carcinogens in smoke cause progressive series of changes in the epithelium

357
Q

dysplasia

A

Cells damaged, and functional characteristics change

Cilia damaged and paralyzed—causes local buildup of mucus

Epithelium becomes
less effective at
protecting deeper,
delicate parts of
respiratory tract

358
Q

Metaplasia

A

Tissue changes structure

Stressed respiratory surface converts to stratified epithelium

—> Protects underlying layers but not deeper parts of tract

—> May be reversed if stimulus is removed
before further damage

359
Q

neoplasia and anaplasia

A

Neoplasia: Growth of abnormal cells forms a cancerous tumor (neoplasm)

Anaplasia: most dangerous stage
—> loss of differentiation/specialization of cells
—> Cells become malignant and metastasize to other parts of body

360
Q

is dysplasia reversible?

A

yes

361
Q

is metaplasia reversible?

A

yes

362
Q

is neoplasia and anaplasia reversible?

A

no (?)

363
Q

DAY 3

A

….

364
Q

Gas laws

A

principles that govern the movement and diffusion of gas molecules

365
Q

Boyle’s law (gas law)

A

(P1V1=P2V2)

Pressure and volume have an inverse relationship

determines direction of air movement during pulmonary ventilation

366
Q

____ is a mixture of gases

A

the atmosphere

367
Q

total atmoshpere pressure at sea level

A

760 mm Hg

368
Q

what is PARTIAL PRESSURE

A

Partial pressure (P) = pressure exerted by single gas in a mixture

369
Q

Dalton’s law

A

All the partial pressures of gases added together equal the total pressure exerted by the gas mixture

370
Q

where else does Dlaton’s law apply?

A

also applies to gas in the respiratory tract

371
Q

what varibale changes gas mixture

A

LOCATION ( in respiratory tract)

Gas mixture inside respiratory tract varies by location

372
Q

air when inhaled (location)

A

Inhaled air gets moistened and warmed

373
Q

air in alveoli (lcation)

A

In alveoli, it mixes with air remaining from previous breath

374
Q

what about exhaled air (location)

A

Exhaled air mixes with air in anatomic dead space

375
Q

how does (changing) gas mixture affect partial pressures of (changing) components?

A

As gas mixture varies, so do the partial pressures of its component gases

376
Q

Henry’s law

A

At a given temperature, the amount of a particular gas in solution is directly proportional to the partial pressure of that gas above the liquid

(*Also dependent on the solubility that gas in the solution)

“Henry’s law is a gas law that states that the amount of dissolved gas in a liquid is directly proportional to its partial pressure above the liquid.”

HENRY’S LAW AND BREATHING:

“The main application of Henry’s law in respiratory physiology is to predict how gasses will dissolve in the alveoli and bloodstream during gas exchange. The amount of oxygen that dissolves into the bloodstream is directly proportional to the partial pressure of oxygen in alveolar air.”

377
Q

External respiration & pressure

A

..

378
Q

blood in pulmonary capillaries

A

Blood arriving in pulmonary capillaries has lower PO2 and higher PCO2 than in alveolar air

—> Oxygen has been used in the tissues

—> Carbon dioxide has been created in the tissues and released in the blood

379
Q

Diffusion between alveolar gas and pulmonary capillaries:

A

Increases blood PO2 (oxygen enters blood)

Decreases PCO2 (carbon dioxide leaves blood)

380
Q

respiratory gas movement –> diffusion?

A

The actual exchange of gases occurs due to simple diffusion.

“Gas exchange during respiration occurs primarily through diffusion. Diffusion is a process in which transport is driven by a concentration gradient. Gas molecules move from a region of high concentration to a region of low concentration.”

381
Q

Internal respiration & presure

A

..

382
Q

what happens to PO2 of blood leaving lungs (via pulmonary veins)

A

PO2 of blood leaving lungs in pulmonary veins DROPS SLIGHTLY***** when it mixes with blood from capillaries around conducting passageways;

still higher than PO2 of interstitial fluid

Oxygen diffuses to interstitial fluid

383
Q

PCO2 in tissues (internal respiration)

A

PCO2 higher in tissues/interstitial fluid than in blood

Carbon dioxide diffuses from tissues into blood

384
Q

What do we do with the oxygen transferred into cells?

A

cellular respiration

= using oxygen inside the cell to create ATP

385
Q

Gas transport in blood

A

..

386
Q

Oxygen transport in blood

—> Each 100 mL of blood leaving alveoli carries ____

A

~20 mL oxygen

387
Q

what percentage/amount of O2 is dissolved in plasma? (when transported in blood)

A

Only ~0.3 mL (1.5 percent) is dissolved in the plasma

388
Q

what about the remaining 98.5%

Remaining 19.7 mL (98.5 percent) is bound to

A

is bound to IRON IONS in heme units of hemoglobin (Hb)

389
Q

Each hemoglobin molecule is made of four

A

globular proteins

390
Q

each globular protein with

A

with one heme unit

391
Q

each heme unit

A

iron ion

392
Q

Thus, how many O2 molecules can each Hb molecule hold?

A

4 heme units

4 molecules of O2

393
Q

what is oxyhemoglobin? (HbO2)

A

a bright red substance formed by the combination of hemoglobin with oxygen, present in oxygenated blood.

394
Q

why is carbon monoxide dangerous?

A

Carbon monoxide (CO) is dangerous because it also bind to heme units, making them unavailable for O2 transport

—> HIGHER AFFINITY FOR HEME UNITS —> harder to get off

395
Q

Hemoglobin saturation

A

Percentage of heme units containing bound oxygen at any moment

396
Q

Oxygen-hemoglobin saturation curve

A

graph showing hemoglobin saturation at different partial pressures of oxygen

397
Q

WHAT DOES SHAPE OF oxygen-hemoglobin saturation curve REPRESENT??

A

Shape reflects hemoglobin’s increased affinity for oxygen with each oxygen molecule bound

—> Increases steeply until it plateaus near saturation

—> Hemoglobin is > 90 percent saturated with oxygen when PO2 is above 60 mm Hg

398
Q

what is saturatin of hemoglobin in blood when entering SYSTEMIC CIRCUIT

A

~97 % saturated

PO2 is 95 mm Hg

399
Q

Hb saturation of blood LEAVING tissues

A

Hemoglobin in blood leaving body tissues is ~75 % saturated

PO2 is 40 mm Hg

400
Q

WHAT ABOUT BLOOD IN ACTIVE (SKELETAL) MM?

—> what is the Hb saturation like?

A

Hemoglobin in blood in active muscle is only ~20 % saturated

Large amounts of oxygen being released to tissue

PO2 is only ~15–20 mm Hg

401
Q

how is Hb saturation measured?

why is it measured?

A

measured to determine respiratory function

measured using a PULSE OXIMETER

402
Q

pulse oximeter deifne?

A

an oximeter that measures the proportion of oxygenated hemoglobin in the blood in pulsating vessels ********Ie»»»»> ARTERIES,

especially the capillaries of the finger or ear.

403
Q

what is ideal hemoglobin saturaiton?

A

An ideal hemoglobin saturation or SpO2 is between 96% and 99%

—> recall this measurement is from arteries —> not veins

404
Q

what Hb saturaitons (from oxygenated blood) is problematic?

A

An SpO2 of 90-95% requires investigation

An SpO2 of 80-89% requires urgent medical treatment

An SpO2 of < 80% is potentially fatal

405
Q

SpO2 ????

A

Serum Pressure = Sp

406
Q

Shifting the oxygen-hemoglobin saturation curve

A

A shift in the curve represents a change in the affinity for O2

a shift to the right (red curve) means oxygen is being more easily released from hemoglobin

a shift to the right (blue curve) means oxygen is more tightly bound to hemoglobin

407
Q

WHAT IS SHIFT IN O2-Hb Saturation curve caused by?

A

1) pH changes

2) temperature changes

3) changes in the partial pressure of CO2 (PCO2)

4) changes in the concentration of 2,3-bisphosphoglycerate (B P G)

408
Q

1) Blood pH and shift in O2-Hb Saturation curve

A

..

409
Q

via which EFFECT does blood pH affect O2-Hb saturation curve?

A

via BOHR EFFECT

410
Q

bohr effect

A

H+ binds to hemoglobin & alters it, decreasing the Hb affinity for O2

pH decreases (ACIDIC): saturation curve shifts to the right
(lower affinity)

pH increases (BASIC): saturation curve shifts to the left
(higher affinity)

411
Q

2) TEMPERATURE vs O2-Hb saturation curve

A

Higher temperature leads Hb to release oxygen more readily (lower affinity)

Especially important in
active tissues
(generate heat)

412
Q

3) PCO2 vs O2-Hb Saturation curve?

A

Increased PCO2 will shift the curve to the right
(DECREASED AFFINITY)

413
Q

NOTE THAT 1) & 3) actually enhance one another –> interdependeant

A

recall that increase in CO2 causes decrease in pH —> both subsequently LOWER the affinity for O2

414
Q

consider that 2) is ALSO closely related to 1) & 3)

In ohter words, all three are interdependent in a way
—> pH, temperature, CO2

A

I.e. INCREASE in metabolism

==== INCREASE in temperature (e.g. exercise)
+ increase in CO2
—> DECREASE in pH

ALL = DECREASE IN O2 AFFINITY

415
Q

FETAL HEMOGLOBIN

A

416
Q

fetal Hb structure

A

slightly different structure compared to adult Hb

417
Q

fetal Hb affinity for O2 compared to adult Hb

A

It has a higher affinity for O2 (a left shift)

418
Q

what is the function of higher affinity for O2 in fetal Hb?

A

This higher affinity allow fetal RBCs to pull more oxygen from the mother as it binds it more strongly

419
Q

how much more O2 does featl Hb carrry compared to adult Hb?

A

Carries up to 30% more oxygen compared to adult hemoglobin

420
Q

note again – carbon monoxide

A

Has a higher affinity for Hb than O2 (200x higher than O2)

Therefore, even small concentrations of CO decreases O2 carrying capacity

421
Q

carbon monoxide poisoning and HYPOXIA — SSx

A

headache,
dizziness,
weakness,
nausea,
vomiting,
chest pain,
confusion

422
Q

Carbon Dioxide transport

A

..

423
Q

where is CO2 genreated?

A

in peripheral tissues

424
Q

how is CO2 generated?

A

Carbon dioxide is generated by AEROBIC metabolism

425
Q

whre does CO2 need to go?

A

needs to be transported to the lungs for removal

426
Q

how is CO2 transpotrted in bloodstream?

THREEE WAYS&&&&&

A

1) Dissolved in plasma (~7 %, limited solubility in plasma)

2) Bound to hemoglobin in RBCs (~23 %)
—> Resulting compound is carbaminohemoglobin (HbCO2)

3) Converted to bicarbonate ion, HCO3− (~70 %)

427
Q

carbaminohemoglobin

A

This carbaminohemoglobin is formed by the reaction between carbon dioxide and an amino (-NH2) residue from the globin molecule,

a compound of hemoglobin and carbon dioxide, and is one of the forms in which carbon dioxide exists in the blood.

428
Q

what happens to majority of CO2 in blood ????

(70%)

A

Converted to bicarbonate ion, HCO3− (~70 %)

429
Q

BICARBONATE BUFFER SYSTEM

A

(in response to rise in pH)

CO2 + H2O
—-> H2CO3 (hydrogen donor = acid)
—-> H+ + HCO3-
—-> HCO3- goes to kidneys

(in response to fall in pH)
HCO3- + H+
—-> H2CO3
—-> CO2 + H2O
—-> CO2 goes to lungs

430
Q

note agian conversion of CO2 to CARBONIC ACID (H2CO3)

(i.e. CO2 + H2O)

A

Most carbon dioxide entering blood (~70 %) converts to carbonic acid (then Bicarbonate ion)

431
Q

WHICH*** ENZYME causes conversion of CO2 + H2O into CARBONIC ACID?

A

CARBONIC ANHYDRASE

432
Q

carbonic anhydrase

A

Carbonic anhydrases (CAs) catalyze a reaction fundamental for life: the bidirectional conversion of carbon dioxide (CO2) and water (H2O) into bicarbonate (HCO3−) and protons (H+)

433
Q

anhydrase

A

anhydrous + -ase

434
Q

what then happens to cabronic acid?

A

dissociates into bicarbonate and hydrogen ions

H2CO3 ↔ HCO3– + H+

435
Q

and what about bicarbonate (HCO3-) ions?

A

Bicarbonate ions (HCO3–) exchanged (leave cell) for an extracellular chloride ion (Cl–)

436
Q

WHERE DOES HYDROGEN ION GO

(AFTER CARBONIC ACID BECOMES HCO3- + H+)

A

Hydrogen ion (H+) binds to Hb, forming HbH+

Why (?)
—> Hb molecules function as pH buffers

437
Q

CHLORIDE SHIFT

A

PROCESS WHERE Bicarbonate ions (HCO3–) exchanged (leave cell) for an extracellular chloride ion (Cl–)

438
Q

where does bicarbonate ion go?

A

pissed out if excessive

As long as renal function is maintained, excess bicarbonate is excreted in the urine fairly rapidly.

439
Q

so again, H2O + CO2 —> H2CO3 —> H+ & HCO3-

—> WHAT HAPPENS TO H+ ??
—> WHAT HAPPENS TO HCO3- ??

A

H+ binds to Hb —> HbH+ (Hb acting as a pH buffer)

HCO3- leaves cell via CHLORIDE SHIFT (Chloride ion enters RBC, HCO3- leaves cell)

—> pissed out if excess

440
Q

HALDANE EFFECT ???

A

Deoxygenation of blood increases its ability to carry CO2

Conversely, oxygenated blood has a reduced capacity to carry CO2

This helps RBCs exchange CO2 for O2 in the lungs (external respiration) and exchange O2 for CO2 in the tissues (internal respiration)

441
Q

Haldane effect (wiiepdia)

A

The Haldane effect is a property of hemoglobin first described by John Scott Haldane, within which oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin, increasing the removal of carbon dioxide. Consequently, oxygenated blood has a reduced affinity for carbon dioxide.

442
Q

so let’s review form the start (THE (3) WAYS OF CO2 tranpsort in blood)

—> When CO2 ENTERS from tissue

A

1) CO2 diffuses into bloodtream

2) 93% diffuses into RBC

3) 7% DISSOLVES in plasma

4) of the 93%, 23% binds to Hb (CARBAMINOHEMOGLOBIN = HbCO2)

5) the remaining 70% converted to CARBONIC ACID — via Carbonic anhydrase

6) the carbonic acid dissociates into H+ & bicarbonate ion (HCO3-) — This is done via bicarbonate buffer pathway

7) the H+ then binds to Hb (Hb acts as pH buffer)

8) the HCO3- leaves RBC (in exchange for Chloride ion entering) — done via process called CHLORIDE SHIFT

9) HCO3- is pissed out if excess

443
Q

chloride shift

A

Chloride shift (also known as the Hamburger phenomenon or lineas phenomenon, named after Hartog Jakob Hamburger) is a process which occurs in a cardiovascular system and refers to the exchange of bicarbonate (HCO3−) and chloride (Cl−) across the membrane of red blood cells (RBCs).

444
Q

gas exchange —> AT THE ALVEOLI

A

1) Hb + O2 (from alveoli)

2) HCO3- ENTERS RBC (REVERSE reaction)
—> HCO3- + H+ —> Carbonic acid (H2CO3)

3) H2CO3 —> CO2 +H2O

4) thus, CO2 DIFFUSES to alveoli and out lungs

—> Note that this reverse process is best to counter-act drop in pH (bicarbonate BUFFER pathway)

5) ADDITIONALLY, the carbaminohemoglobin releases the CO2
—> CO2 from HbCO2 is released out of lungs

445
Q

RESPIRATORY CENTRES AND REGULATION

A

..

446
Q

respiratory centre

A

..

447
Q

where is the main component of automatic respiration located?

A

MEDULLA

448
Q

which part of brain modifies signals of the medulla?

A

Spontaneous rhythmic discharge of MEDULLARY NEURON is modified by neurons in the PONS

449
Q

medullary respiratory centre (consists of)

A

1) Dorsal respiratory group/inspiratory center (DRG)

2) Ventral respiratory group (VRG)

3) Pre-Botzinger Complex

450
Q

Pontine respiratory group (consists of)

A

1) apneustic centres

2) Pneumotaxic centres

451
Q

apneustic etymology

pneumotaxic etmyology

A

a- (un)
-pneustikos (breathing)

pneumo- (lung/breath)
-taxis (arrangement)

452
Q

the medullary (lower) respiratory centre

A

Most basic control

453
Q

what do pacemaker cells in the MEDULLA OBLONGATA effect* ??

A

Pacemaker cells in medulla oblongata generate cycles of contractions in DIAPHRAGM

454
Q

the significance of respiratory rhythmicity and MEDULLARY centres

A

Paired respiratory rhythmicity centers establish pace of respiration by adjusting pacemaker cells and coordinating other respiratory muscles

455
Q

Dorsal respiratory group (of Medullary respiratory centre)

A

Mainly concerned with inspiration

Inspiratory center of DRG controls lower motor neurons to primary (QUIET) inspiratory muscles (external intercostals, diaphragm)

—> intercostal nn to external intercostals
—> phrenic nn to diaphragm

During normal breathing, active for 2sec, inactive for 3sec

456
Q

which group of medullary respiratory centre is responsibly for quiet (primary) inspiration ?

A

Dorsal respiratory group

457
Q

how many seconds is DRG active, vs inactive

A

During normal breathing, active for 2sec, inactive for 3sec

458
Q

what feedback causes DRG respones to vary?

A

Dorsal respiratory group varies response through input from:

—> Chemoreceptors detecting O2, Co2, and pH (via CO2) levels in blood/CSF

—> Baroreceptors that detect pressure/stretch monitor stretch of lung wall

459
Q

2) VENTRAL respiratory group (VRG) of medullary respiratory centre)

A

Mainly associated with forced breathing

Functions only when breathing demands increase and accessory (SECONDARY) respiratory muscles are involved

460
Q

WHAT activates VRG?

A

the DRG

—> via feedback that indicates loss of homeostasis that DRG can not resolve on its own (?)

461
Q

3) Pre-Bӧtzinger complex in medulla (3rd component of MEDULLARY respiratory centre)

A

Rhythm maker that send input to DRG

Essential to all forms of breathing but poorly understood

462
Q

WHAT ELSE DOES THE VRG control?

A

MUSCLES OF EXHALATION

—> (Accessory)

—> recall there are no primary exhalation mm

463
Q

PONTINE RESPIRATORY GROUP

— what do??

A

IT MODIFIES **** (medulla nervous output)

Transmit nerve impulses to the DRG

Modifies the rhythm of breathing by adjusting nerve output from the medullary respiratory centers

464
Q

what are the TWO NUCLEI in the pons

A

1) APNEUSTIC CENTRE

2) PNEUMOTAXIC CENTRES

465
Q

1) apneustic centres

what do they do?

A

Promote inhalation by stimulating DRG

466
Q

WHAT STRUCTURE GIVES FEEDBACK TO APNEUSTIC CENTRES?????

A

VAGUS NERVE

Degree of stimulation adjusted based on sensory information from the vagus nerve about lung inflation

467
Q

2) PNEUMOTAXIC CENTRE

what do they do???

A

Inhibit apneustic centers

Promote passive or active exhalation

—> opposite to apneustic centres

468
Q

ALSO – what does increased pneumotaxic output do??

A

shortens inhalation duration (= faster respiratory rate)

469
Q

i.e. pneumotaxic either

A

INHIBITS INSP

or SHORTENS INSP

—> faster respiration**

470
Q

pneumotaxic output —> WHAT ABOUT DECREASED RATE?

A

Decreased output slows pace and increases depth of respiration

471
Q

pneumotaxic +++

A

faster breathing

472
Q

pneumotaxic —

A

slower breathing

473
Q

regulation of repsiratory centres

A

…***

474
Q

what locations does feedback/input come from to regulate respiratory centers

A

1) Cerebral cortex (LANGUAGE, MEMORY, EMOTION, REASONING)

2) Hypothalamus (HUNGER/THIRST, SEX DRIVE, BP, TEMP, MOOD)

3) Limbic system (EMOTION, SEXUAL STIM, MEMORY)

4) Chemoreceptors

5) Baroreceptors (mechanoreceptors)

6) proprioceptors

475
Q

1) cerebral cortex

A

voluntarily change or stop breathing

to keep out gases or water

476
Q

what does incerasing PCO2 & H+ in blood do?

A

H2O + CO2 –> H2CO3 –> H+ & HCO3-

increasing PCO2 & H+ in blood strongly stimulates DRG and sends impulses down nerves to resume breathing

477
Q

increasing PCO2 & H+ in blood strongly stimulates DRG and sends impulses down nerves to resume breathing

WHICH NERVES???

A

phrenic nerve

& intercostal nerves

478
Q

i.e. if you hold your breath till you faint

A

if you hold your breath until you faint, you will then resume breathing

(intercostal and phrenic nerve reflex)

479
Q

chemoreceptors

A

Central and peripheral chemoreceptors detect chemical changes in the blood/CSF

480
Q

most important factor / chemoreceptor

A

Under normal conditions, PCO2 is the most important factor influencing respiration

481
Q

what percentage rise of PCO2 in arteries doubles RESP RATE

A

Rise of only 10 percent in arterial PCO2 doubles respiratory rate

482
Q

PO2 ?

A

PO2 levels have to drop below 60 mm Hg before triggering respiratory centers

483
Q

CENTRAL CHEMORECEPTORS

A

Central chemoreceptors located in the medulla oblongata of CNS

484
Q

function of central chemoreceptors?

A

monitor PCO2 and H+ in cerebrospinal fluid

485
Q

PERIPHERAL CHEMORECEPTORS

A

Peripheral chemoreceptors are a part of PNS

—> monitor PCO2, PO2, & H+ in blood

486
Q

location of periheral chemoceptors?

A

aortic bodies

carotid bodies

487
Q

chemoceptors in aorta

A

aka aortic bodies

in wall of aortic arch close to aortic baroreceptors

488
Q

aortic bodies via WHICH NERVE???

A

VAGUS NERVE (CNX)

489
Q

chemoreceptors in carotid

A

aka carotid bodies

—> in wall of L/R common carotid arteries, close to carotid sinus baroreceptors

490
Q

carotid bodies via WHICH NERVE???

A

part of glossopharyngeal nerve (CN IX)

491
Q

HYPERCAPNIA

A

“too much”
kapnos = “smoke”

A slight increase in PCO2 (and thus H+) is called hypercapnia

492
Q

hypercapnia mc d/t

A

hypoventiliation or obstructive diseases like COPD

493
Q

what happens in response to hypercapnia

A

stimulates central and peripheral chemoreceptors

DRG activated, and hyperventilation occurs (rapid & deep breathing)
—> wasn’t DRG only concerned with quiet breathing (????)
—> perhaps b/c DRG stimulates VRG (which activates accessory breathing muscles)

—> Helps expel excess CO2

494
Q

HYPOCAPNIA

A

A decrease in PCO2 (<40 mmHg) is called hypocapnia

Most commonly caused by hyperventilation (eg. anxiety)

495
Q

what happens in response to HYPOCAPNIA

A

central & peripheral chemoreceptors not stimulated

no impulses sent to DRG

DRG sets its own pace until CO2 accumulates and PCO2 increased to 40 mmHg

496
Q

what about in response to decrease in OXYGEN?

Hypoxia

A

A decrease in PO2 (100-50 mmHg)

peripheral chemoreceptors stimulated

DRG activated, inspiration occurs to bring in more O2

497
Q

BAROCEPTORS (mechanoceptors)

HERING-BREUER REFLEX

A

detect lung expansion with stretch receptors (baroreceptors) in walls of bronchi & bronchioles

send inhibitory signal to DRG via vagus nerves (CN X)

activated when tidal volume > 1500ml (remember, TV = 500mL at rest)

—> Called the Hering-Breuer reflex

498
Q

PROPERIOCEPTORS

A

Ventilation increases even before the need for O2 increases

proprioceptors of joints and muscles activate DRG

upper motor neurons in primary motor cortex also activate DRG

499
Q

VARIATIONS IN VENTILATION & RESPIRATION DURING EXERCISE

A

..

500
Q

Pulmonary ventilation adjusts to meet body’s changing oxygen needs

A

..

501
Q

what varies?

A

Varies number of breaths/minute (respiratory rate)

and volume moved per breath (tidal volume—VT)

502
Q

respiratory rate

adult vs child average/resting rate

A

Respiratory rate (f)= Number of breaths/minute

Normal adult resting range: 12–18 breaths/minute

Average for children: 18–20 breaths/minute

503
Q

respiratory minute volume

A

Respiratory minute volume (VE) = Volume of air moved per minute

respiratory rate x tidal volume = RESPIRATORY MINUTE VOLUME

504
Q

as cardiac output increases

A

pulmonary perfusion increases

505
Q

O2 diffusing capacity during exercise

A

O2 diffusing capacity increased 3X the rate at rest (rate that O2 diffuses from alveolar air to blood)

—> d/t more pulmonary capillaries maximally perfused

506
Q

NOTE INITIAL ABRUPT BREATHING INCREASE VIA NEURAL CHANGES

(perhaps even before increased activity)

A

1) Proprioception

2) limbic anticipation

3) primary motor cortex

507
Q

VS.

gradual breathing increase with moderate exercise due to chemical & physical changes

A

1) decreased PO2

2) increased PCO2

3) increased temperature

508
Q
A