A&P Exam III - Pulmonary I Flashcards
Respiration
Exchange of gases between the atmosphere, blood and cells
3 processes required for respiration
Ventilation (breathing)
External (pulmonary) respiration
Internal (tissue) respiration
How does the cardiovascular system assists the respiratory system?
By transporting gas
Structurally: respiratory system is divided into 2 parts:
- Upper resp. System
2. Lower resp. System
Functionally: resp system are divided into 2 zones:
- Conduction zone
2. Respiratory zone
Conduction zone :
Dead space up to terminal bronchioles
Resp. zone:
Gas exchange in alveoli
The upper respiratory system consist of:
The nose, paranasel sinuses, pharynx and associated structures
The lower respiratory system consist of:
The larynx, trachea, bronchi and lungs
The Mallampati score I, II, III, IV
Class I: Full visibility of tonsils, uvula and soft palate
Class II: Visibility of hard and soft palate, upper portion of tonsils and uvula
Class III: Soft and hard palate and base of the uvula are visible
Class IV: Only hard palate visible
Thorax
Bones and cartilage protect contents
12 pairs on ribs:
- True ribs (1-7) directly attached to sternum
via costal cartilage
- False ribs (8-10) indirectly attached
- Floating ribs (11-12) not attached to
sternum
-Supernumerary ribs (extra)
- Cevical ribs - elongation of transverse
process of 7th cervical vertebra (0.5%)
incidence)
- Lumber rib - elongation of transverse
process f lumbar vertebra, less
common
Allow flexibility for movement that is needed for ventilation to occur
- Oblique orientation of rib allows for
elevation of the rib cage involved with lung
expansion
Manubrium
Upper most part of the sternum
Suprasternal notch (jugular)
- Trachea lies posterior to and in line with jugular notch.
- Same horizontal plane as second thoracic vertebra, signifies midpoint of trachea and a ideal location for the distal tip of the endotracheal tube
Sternal angle (of Louis)
Where manubrium joins the body of the sternum.
- Bifurcation of the trachea (carina) occurs at
this level (T4-T5)
Manubriosternal joint
Hinge- like joint between manubrium and body of sternum.
- Allows hinge- like forward movements of
sternum during inspiration and backward
movements during expiration
Upper Airway - Nose
Functions:
Warms, cleans, humidifies inhaled air
-detects Oder
-resonating chamber that amplifies the
voice
Bony and cartilaginous support
-Superior half: nasal bones medially and
maxillae laterally
- inferior half: lateral and alar cartilages
- Ala nasi: flared portion shaped by dense
CT forms lateral walls of each nostril
Structure of the Respiratory System: Structurally
Respiratory system is divided into 2 parts:
1) . Upper respiratory system
2) . Lower respiratory system
Structure of the Respiratory System:
Functionally
Respiratory system are divided into 2 zones:
1) . Conducting zone (dead space up to terminal bronchioles)
2) . Respiratory zone (gas exchange in alveoli)
Nasal Cavity
*Extends from nostrils to posterior nares
*Vestibule : dilated chamber inside ala nasi
-stratified squamous epithelium, vibrissae
(guard hairs)
*Nasal septum divides cavity into right and left chambers called nasal fossae.
Nasal Conchae and Paranasal sinuses
- turbinates and sinuses warm, clean and moisten air for the lungs
Nasal Conchae
3 folds of tissue on lateral wall of nasal fossa-mucous membrane supported by thin scroll-like turbinate bones
3 types of Conchae
Superior, Middle, and Inferior nasal conchae
Meatuses
- Narrow air passage beneath each conchae
- Narrowness and turbulence ensure air contacts mucous membranes
2 Type of nasal cavity mucosa
- olfactory mucosa (lines roof of nasal fossa)
- respiratory mucosa (lines rest of nasal cavity with ciliated pseudostratified epithelium
Defensive role of mucosa
- mucus traps inhaled particles
- bacteria destroyed by lysozyme and IgA
Mucus is from
Goblet cells
Cilia Function
Sweep debris - laden mucus into pharynx to be swallowed
Cilia Location
respiratory epithelium
Erectile tissue
Venous plexus that rhythmically engorges with blood and shifts flow of air from one side of fossa to the other once or twice an hours to prevent drying
Erectile tissue location
Inferior concha
Spontaneous epistaxis
Most common site is inferior concha
3 part of pharynx
- ) Nasopharynx
- ) Oropharynx
3) . Laryngopharynx
Nasopharyngeal (pseudostratified epithelium)
-posterior to choanae, dorsal to soft palate
- receives auditory tubes and contains
pharyngeal tonsil
-90 degree downward turn traps large particles (>10nm)
Oropharynx (stratified squamous epithelium)
-space between soft palate and root of tongue, inferiorly down to hyoid bone, contains palatine and lingual tonsils
Laryngopharynx (stratified squamous)
-hyoid bone to level of cricoid cartilage
Lower airways
Glottis
Epiglottis
Glottis
- Part of Larynx
- Vocal cords and opening between
Epiglottis
- Part of Larynx
- Flap of tissue that guards glottis, directs food and drink to esophagus
Infant Larynx
- higher in throat, forms a continuous airway from nasal cavity that allows breathing while swallowing
- by age 2, more muscular tongue forces larynx down
Larynx located : adults and children
- Adults C3-C6
- Children C3-C5 (superior)
Nine Cartilage of Larynx
- Epiglottic cartilage - most superior
- Thyroid cartilage - largest ; forms laryngeal prominence
- Cricoid cartilage - connects larynx to trachea
- Arytenoid cartilages (2)- posterior to thyroid cartilage
- Corniculate cartilages (2)- attached t o arytenoid cartilages like a pair of little horns
- Cuneiform cartilages (2) - support soft tissue between arytenoid and epiglottis
Narrowest portion of pediatric Larynx
- newer studies say glottis opening
- older studies say cricoid
Extrinsic muscles (suprahyoid muscles)
- ) stylohyoid
- ) mylohyoid
- ) diagstric
Extrinsic muscles of the larynx
•Connect larynx to hyoid bone, elevate larynx during swallowing up and forward
Extrinsic muscles (infrahyoid muscles)
1) omohyoid
2) sternothyroid
3) thyrohyoid
4) sternohyoid
Muscles of the laryngeal inlet
-Aryepiglottic: narrows inlet, closes glottis
- Oblique aretynoid: narrows inlet, closes glottis
- Together, the aryepiglottic and oblique arterynoid act as a purse-string sphincter during swallowing
-Thyroepiglottic: widens inlet
Intrinsic Mucles
rotate corniculate and arytenoid cartilages adducts (tightens: high pitch sound) or abducts (loosens: low pitch sound) vocal cords
Intrinsic Muscles involved with movement of true cords
- Cricothyroid
- Thyroarytenoids
- Lateral cricoarytenoids
- Transverse aryternoids
- Oblique arytenoids
- Posterior cricoarytenoids
Cricothyroid
-tense vocal cords
•ONLY intrinsic muscle to lie outside the cartilaginous framework of the larynx
Thyroarytenoids
-relax vocal folds
•Vocalis m.: part of the thyroarytenoids, adjusts tension of cords
Lateral cricoarytenoids muscles
: adducts cords, closes (slide 24)
Transverse arytenoids
adducts cords, closes
Oblique arytenoids
-adducts cords, closes
Posterior cricoarytenoids
-abducts vocal cords & folds, opens
•ONLY ABDUCTOR muscle of vocal cords
Larynx blood supply
•supplied via the external carotids & subclavian arteries and internal jugular vein
Innervation of the larynx
by cranial nerve X (Vagus nerve)
Interior Branch of Superior laryngeal nerve
-provides sensation for upper portion of the larynx down to and including upper half of the vocal cords
Recurrent laryngeal nerve (sensory)
transmits sensation below the true cords and half of the lower cords
Motor
Fibrocartilaginous tube, approximately 10-20cm long and 12mm in diameter
Trachea
Begins at the end of the larynx (C6) and extends to T5-T6
Trachea
begins /extends
Begins at the end of the larynx (C6) and extends to T5-T6
Trachea supported by
16-20 C-shaped rings of cartilage with smooth muscle posteriorly
Carina
the lower most portion of the trachea where it divides into primary bronchi
Trachea lined with
ciliated pseudo stratified epithelium
ciliated pseudostratified epithelium function
functions as mucociliary escalator
lungs produce how much mucous per day
100ml
Turbulent flow helps
trap precipitate
Mucociliary escalator mechanism impaired by
endotracheal intubation and volatile anesthetics
Cilia remove______ mucus
contaminated
Conduct Zone
- Secondary (labor) bronchi
- Segmental Bronchi
- Terminal Bronchioles
secondary (labor) bronchi
- Bronchospasm occurs here
- Three on the right, two on the left (related lobes)
Terminal bronchioles
- Diameter of 1mm and contain NO cartilage
- Relatively thick smooth muscle wall compared to lumen
- Can contract during asthma attack no goblet cells
Broncial circulation suppled by
systemic circulation
Anatomic shunting due to bronchial circulation
area of the lung where there is perfusion but no ventilation
Bronchial Innervation (sensory and motor)
via Vagus
Bronchial Innervation (sympathetic)
Epi/NE»_space;> bronchodilation
Respiratory Zone composed of:
Acinus (terminal respiratory unit)
Bronchial Innervation (parasympathetic)
Ach»>bronchodilation
Acinus composed of
- respiratory bronchioles
- alveolar ducts
- alveoli
Alveoli are formed
-birth to age 4, they continue to maximally expand until age 8
Alveoli # in adult
300 million
Alveoli shape
polygon shape
-maximizes surface area
Alveoli surrounded by
1000 pulmonary capillaries each
Type 1 alveolar cells type
squamous
Type 1 alveolar cell form/involved
from wall of alveoli and involved with gas exchange
Type II alveolar cells type
cuboidal
Type II alveolar cells secrete ____
surfactant
Type II alveolar cells can differentiate
into type I cell when needed
What happens to alveolar cells in pulmonary fibrosis?
-In a chronically injured lung (e.g. pulmonary fibrosis), alveolar epithelium is lined entirely by type II cells, limiting gas exchange
Alveolar macrophages
eliminate foreign debris
Alveolar pores
- pores of Kohn
- are openings in the walls between adjacent alveoli
Alveolar Pores (Pores of Kohn) function
allow for collateral ventilation
Alveoli collapse primarily prevented by:
- surfactant
- alveolar pores
- interdependence
If an alveolus start to collapse …
the surrounding alveoli are stretched and then recoil exerting expanding forces in the collapsing alveolus to open it
Lungs shape
cone shape
Lungs occupy all of thoracic cavity except
Mediastinum
Right lung # of lobes
3
Left lungs # of lobes
2
Which lung of more narrow? R or L?
Left is more narrow than the right
Lungs innervation
- innervated by the pulmonary plexus
- sympathetic fibers T2-T6
- parasympathetic fibers from the Vagus
Lung pain receptors
few to no pain receptors in lung
T/F- There is a normal perfusion and ventilation (V/Q) difference between the two lungs b/c of the different surface areas
True
The right lungs has 3 lobes and receives ____% of the CO
60%
Parasympathetic fibers produce _____ of the airways and increase _____
_ construction
-mucus
serous membranes that line the thoracic cavity and cover the lungs
pleural membranes
pleural fluid: amount/function
10cc produced per lung prevents function in pleural cavity
attached to outer surface of the lungs, parietal pleura line the wall of the thoracic cavity
Visceral pleura
Breathing (pulmonary ventilation)
- one cycle of inspiration and expiration
- quiet respiration- at rest
- forced respiration- during exercise
Flow of air in and opt of lungs requires
a pressure difference between air pressure within lungs and outdoes body
Diaphragm
Dome-shaped muscle that forms the floor of the thorax and separates the thoracic cavity and the abdominal
cavity
Diaphragm accounts for _____ tidal volume
most
Diaphragm separated into
2 halves = hemidaphragms
-Right hemidiaphragm is higher than the left (heart pushes left side down; liver raises rightsize)
Major diaphragmatic foramina
- Vena cava foramen
- esophageal hiatus (esophagus and vagus nerve pass through; site of hiatal hernia)
Diaphragm Innervation
-supplied by paired phrenic nerves
-C3-5 (C4 provides 70% of contribution)
-Allows for half of the diaphragm to continue working if one side is damaged
-Motor AND sensory nerves.
•Sensory diaphragmatic pain referred to the shoulder areas
Major factors affecting the position of the diaphragm:
- Recoil of lungs
- Thoracic viscera pressure (e.g. CHF)
- Abdominal viscera pressure (e. g. pregnancy)
- Abdominal muscle activity (contraction pushes diaphragm upward)
Diaphragm movement during normal breathing
- 1-2cm normal tidal breathing
- 7-13cm with deep breathing
The diaphragm accounts for _____% of normal tidal volume respiration
60-75%
External intercostal muscles oriented
obliquely forward and downward
External intercostal muscles responsible for up to of tidal volume that enters lungs during normal breathing at reat
25%
External intercostal muscles during inspiration
left up the ribs
Internal intercostal muscles oriented
backward and downward
internal intercostal muscles oriented
backward and downward
internal intercostal muscle assist in
expiration by pulling the ribcage down
At rest, when the diaphragm is relaxed, alveolar pressure is ___ to atmospheric pressure, and there is ____ air flow.
- equal
- no air flow
Factors affecting Ventilation
- surface tension
- elastic recoil
- compliance
Surface tension
inwardly directed force in the alveoli which must be overcome to expand the lungs during each inspiration
Elastic recoil
decrease the size of the alveoli during expiration
compliance
ease with which the lungs and thoracic wall can be expanded
