Respiratory i

Question 1

Major function of respiratory system

Answer 1

Respiration: duh

• supply blood with O2 for cellular respiration and dispose of CO2 which is a waste of cellular respiration
• 4 processes involving respiratory and circulatory system
• also functions in olfaction and speech

Question 2

4 processes of respiratory system function

Answer 2

Respiratory System

• Pulmonary ventilation = movement of air into and out of lungs
• External respiration = O2 and CO2 exchange between lungs and blood

Circulatory System:

• Transport = O2 and CO2 in blood
• Internal respiration = O2 and CO2 exchange between systemic blood vessels and tissues

Question 3

Airways: structural and functional

Answer 3

Upper Respratory structures
-nose, nasal cavity, and pharynx (naso-, oro-, laryngo-)

Lower Respiratory structures
-larynx, trachea, bronchi, bronchioles, alveoli

Respiratory zone
-respiratory bronchile, alveolar duct, alveoli
Conduction zone
-everything else

Question 4

Definition of the dif zones

Answer 4

Respiratory zone = site of gas exchange
Conducting zone = conduits to gas exchange sites –> cleanses, warms, humidifies air

Diaphragm and other respiratory muscles promote ventilation

Question 5

Nose

Answer 5

Func:

• provides airway for respiration
• moistens and warms entering air
• filters and cleans inspired air
• serves as resonating chamber for speech
• houses olfactory receptors

Anatomy
-nasal cavity within and posterior to external nose –> divided by midline nasal septum –> posterior nasal aperatures (choanae) open into nasopharynx –> roof = ethmoid and sphenoid bones –> floor = hard and soft palates

Question 6

Nasal vestibule and the rest of the nasal cavity

Answer 6

Nasal vestibule = nasal cavity superior to nostrils –> vibrissae (hairs) filter coarse particles from inspired air

Rest of nasal cavity lined with mucous membranes: olfactory and respiratory mucosa

Question 7

Olfactory and Respiratory mucosa

Answer 7

Olfactory mucosa contains olfactory epithelium

Respiratory mucosa

• pseudostratified ciliated columnar epithelium
• mucous and serous secretions contain lysozyme and defensins
• cilia move contaminated mucus posteriorly to throat
• inspired air warmed by plexuses of capillaries and veins
• sensory nerve endings trigger sneezing

Question 8

Nasal conchae and nasal meatus

Answer 8

Nasal conchae: superior, middle, and inferior

• protrude medially from lateral walls
• increase mucosal area
• enhance air turbulence

Nasal meatus = groove inferior to each concha

Question 9

Function of structures within nose during breathing

Answer 9

During inhalation, conchae and nasal mucosa filter, heat , and moisten air

During exhalation these structures reclaim heat and moisture

Question 10

Paranasal sinuses

Answer 10

In frontal, sphenoid, ethmoid, and maxillary bones

-lighten skull, secrete mucus, help to warm and moisten air

Question 11

Pharynx

Answer 11

Muscular tube from base of skull to C6

• connects nasal cavity and mouth to larynx and esophagus
• composed of skeletal muscle

There regions: naso-, oro-, laryngo-

Question 12

Larynx

Answer 12

Attaches to hyoid bone; opens into laryngopharyx; continuous with trachea

Func

• provides patent airway
• routes air and food into proper channels
• voice producetion: houses vocal folds

Question 13

Nine cartilages of larynx

Answer 13

• All hyaline except epiglottis
• Thyroid cartilage with laryngeal prominence (adam’s apple)
• Ring-shaped cricoid cartilage
• paired arytenoid, cuneiform, and corniculate cartilages
• Epiglottis = elastic cartilage which covers the laryngeal inlet during swallowing –> covered in taste bud-containing mucosa

Question 14

Vocal ligaments

Answer 14

In larynx –> deep to laryngeal mucosa

• attach arytenoid cartilages to thyroid cartilage
• contain elastic fibers

-form core of vocal folds (true vocal cords) –> glottis = opening between vocal folds –> folds vibrate to make sound as air rushed up from lungs

Vestibular folds (false vocal cords)
-superior to vocal folds --> no part in sound production --> help to close glottis during swallowing

Question 15

Epithelium of larynx

Answer 15

superior portion - stratified squamous epithelium

Inferior to vocal folds - pseudostratified ciliated columnar epithelium

Question 16

Voice production

Answer 16

• speech = intermittent release of expired air while opening an dclosing glottis
• pitch determined by length and tension of vocal cords
• loudness depends upon force of air
• chambers of pharynx, oral, nasal, and sinus cavities amplify and enhance sound quality
• sound is “shaped” into language by muscle of pharynx, tongue, soft palate, and lips

Question 17

Valsalva’s maneuver

Answer 17

glottis closes to prevent exhalation

• abdominal muscles contract
• intra-abdominal pressure rises
• helps to empty rectum or stabilizes trunk during heavy lifting

Question 18

Trachea: definition and layers

Answer 18

Windpipe from larynx into mediastinum

3 layers

1. mucosa = ciliated pseudostratified epithelium with goblet cells
2. submucosa = CT with seromucous glands
3. Adventitia = outermost layer made of CT tissue; encases C-shaped rings of hyaline cartilage

Question 19

Tracheal cartilage and muscle

Answer 19

Trachealis

• connects posterior parts of cartilage rings
• contracts during coughing to expel mucus

Carina

• spur of cartilage on last, expanded tracheal cartilage
• point where trachea branches into two main bronchi

Trachealis muscle along posterior

Question 20

Bronchi and subdivisions

Answer 20

Air passages undergo 23 orders of branching –> bronchial tree

From tips of bronchial tree –> conduction zone structures –> respiratory zone structures

Question 21

Conducting zone structures of Bronchi

Answer 21

• Trache goes into right and left main (primary) bronchi
• Each main bronchus enters hilum of one lung (right is wider, shorter, and more vertical)
• Each main bronchus branches into lobar (secondary) bronchi –> 3 on right; 2 on left –> each supplies one lobe
• Each lobar bronchus branches into segmental (tertiary) bronchi –> divide repeatedly
• Branches get smaller and smaller –> bronchiles are less than 1 mm diameter and terminal bronchioles are less than 0.5 mm diameter

Question 22

structural changes as bronchi branching occurs

Answer 22

• cartilage rings become irregular plates –> in bronchioles elastic fibers replace cartilage
• epithelium changes from pseudostratified columnar to cuboidal; cilia and goblet cells become sparse
• relative amount of smooth muscle increases –> allows constriction

Question 23

Lungs

Answer 23

• Right lung = superior, middle, inferior lobes separated by oblique and horizontal fissures
• Left lung = superior and middle lobes separated by oblique fissure

-Bronchopulmonary segments (10 right, 8-10 left) separated by CT septa (if diseased, can be individually removed)

Lobules = smallest subdivisions visible to naked eye; served by bronchiles and their branches

Question 24

Respiratory zone

Answer 24

-Begins as terminal bronchioles –> respiratory bronchioles –> alveolar ducts –> alveolar sacs

Alveolar sacs contain clusters of alveoli

• 300 mil alveoli make up most of lung volume
• sites of gas exchange

Question 25

Respiratory membrane

Answer 25

Alveolar and capillary walls and their fused basement mambranes --> 0.5 um thick --> gas exchange across membrane by simple diffusion Alveolar walls = simgle layers of squamous epithelium (type 1 alveolar cells) Scattered cuboidal type II alveolar cells secrete surfactant and antimicrobial proteins

Question 26

Alveoli

Answer 26

- Surrounded by fine elastic fibers and pulmonary capillaries - Alveolar pores connect adjacent alveoli --> equalize air pressure throughout lung - Alveolar macrophages keep alveolar surfaces sterile --> 2 million dead macrophages/hour carried by cilia --> throat --> swallowed

Question 27

Progression of epithelium thinning in bronchi

Answer 27

Pseudostraified ciliated columnar epithelium up to and including lobar bronchi Simple ciliated columnar epithelium in segmental bronchi and large bronchioles Simple ciliated cuboidal epithelium in small, terminal, and respiratory bronchioles (progressive loss of cilia) Simple squamous epithelium in alveolar ducts and forms alveoli

Question 28

Pulmonary circulation

Answer 28

-low pressure; high volume Pulmonary arteries deliver systemic venous blood to lungs for oxygenation -branch profusely; feed into pulmonary capillary networks Pulmonary veins carry oxygenated blood from respiratory zones to heart Lug capillary endothelium has enzymes that act on substances in blood (e.g. angiotensin-converting enzyme activates blood pressure hormone)

Question 29

Bronchial arteries

Answer 29

Provide oxygenated blood tp lung tissue - arise from aorta and enter lungs at hilum - part of systemic circulation (high pressure; low volume) - supply all lung tissue except alveoli - bronchial veins anastomose with pulmonary veins --> pulmonary veins carry most venous blood back heart

Question 30

Pleurae

Answer 30

Thin, double-layered serosa; divides thoracic cavity into two pleural compartments and mediastinum Parietal pleura on thoracic wall, superior face of diaphragm, around heart, between lungs Visceral pleura on external lung surface Pleural fluid fills slitlike pleural cavity --> provides lubrication and surface tension --> assists in expansion and recoil

Question 31

Boyle's Law

Answer 31

The pressure of a gas is inversely proportional to its volume at a given temp

Question 32

Dalton's law

Answer 32

The partial pressure of a gas in a mixture of gases is the percentage of the gas in the micture

Question 33

Henry's Law

Answer 33

The concentration of a gas dissolved in a liquid is equal to the partial pressure of the gas over the liquid times the solubility coefficient of the gas

Question 34

Mechanisms of breathing

Answer 34

Pulmonary ventilation = inspiration: gas flows into lungs + expiration: gases exit lungs

Question 35

Pressure relationships in thoracic cavity

Answer 35

Atmospheric pressure = pressure exerted by air surrounding body -760 mm Hg at sea level = 1 atmosphere Respiratory pressure is described relative to Patm - negative respiratory pressure is less than Patm - Positive respiratory pressure is greater than Patm - Zero respiratoy pressure is equal to Patm

Question 36

Intrapulmonary pressure

Answer 36

Also called intra-alveolar pressure --> Ppul - pressure in alveoli - fluctuates with breathing - always eventually equalizes with Patm

Question 37

Intrapleural pressure

Answer 37

Pip - pressure in pleural cavity - fluctuates with breathing - always a negative pressure (less than Patm and Ppul) - fluid level must be minimal (its pumped out by lymphatics, but if it accumulates --> positive Pip pressure --> lung collapse) Negative Pip caused by opposing forces - Two inward forces promote lung collapse: elastic recoil of lungs decreases lung size and surface tension of alveolar fluid reduces alveolar size) - one outward force tends to enlarge lungs: elasticity of chest wall pulls thorax outward