Respiratory system

Question 1

Divisions of respiratory system

Answer 1

Conducting portion and respiratory portion

Question 2

Function of conducting portion

Answer 2

Delivers air to lungs

Question 3

Function of respiratory portion

Answer 3

Structures within lungs where oxygen is exchanged for carbon dioxide in the blood

Question 4

Parts of the conducting portion

Answer 4

nose, nasopharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles

Question 5

Function of conducting portion

Answer 5

warms, moistens, and filters the air

Question 6

Nasal cavity parts

Answer 6

vestibule, olfactory segment, respiratory segment

Question 7

nostril openings

Answer 7

nares (outer portion, thin skin)

Question 8

First internal nasal cavity

Answer 8

vestibule

Question 9

Vestibule

Answer 9

First internal nasal cavity. Lined by nonkeratinized stratified squamous epithelium. Lining changes to pseudostratified ciliated columnar epithelium posteriorly. Contains vibrissae (short hairs) to filter out large particles. Vascular lamina propria contains seromucous glands

Question 10

Short hairs in the vestibule

Answer 10

vibrissae

Question 11

olfactory epithelium location

Answer 11

located in roof of nasal cavity on sides of the nasal septum and on the superior nasal conchae
very small region in humans

Question 12

What epithelium layer is present in the olfactory epithelium and what cells are present?

Answer 12

Pseudostratified columnar epithelium contains olfactory cells, supporting (sustentacular) cells, and basal cells

Question 13

What is present in the lamina propria of the olfactory epithelium?

Answer 13

many vains and nonmyelinated nerves and Bowman’s glands

Question 14

Olfactory cells

Answer 14

bipolar nerve cells; 30-60 day life span; bulbous apical projection (olfactory vesicle) with modified cilia

Question 15

Olfactory cilia

Answer 15

very long, nonmotile cilia, extend over the olfactory epithelium surface. The proximal 1/3 contains the 9 doublet +2 microtubule pattern, but the distal 2/3 has 9 peripheral singlet microtubules around a central pair. They function as odor receptors

Question 16

Supporting cells

Answer 16

Sustentacular cells - have apically located nuclei with many microvilli and a prominent terminal web. Physical and metabolic support to olfactory cells

Question 17

Basal cells

Answer 17

in contact with basal lamina - do not extend to surface. Incomplete cell layer. Regenerative (stem) cell for other cells in olfactory epithelium

Question 18

Bowman’s glands

Answer 18

produces thin, watery secretion. Released onto the olfactory epithelium via ducts.

Question 19

1) Odorous substances are dissolved in secretions detected by ____.

Answer 19

olfactory cilia

Question 20

2) _____ flush surface and prepare the odor receptors to receive new stimuli.

Answer 20

Secretions

Question 21

Nasopharynx

Answer 21

posterior continuation of the nasal cavities
Becomes the oropharynx at the level of the soft palate
Lined by respiratory epithelium
Contains mucous and serous glands in the lamina propria, and abundant lymphoid tissue - includes nasopharyngeal tonsil (adenoids)

Question 22

Larynx

Answer 22

Connects pharynx with trachea.
Wall supported by hyaline cartilages (thyroid, cricoid, and lower part of arytenoids) and elastic cartillages (epiglottis, corniculate, and tips or arytenoids)
Contains striated muscle, connective tissue, and glands within its wall

Question 23

Vocal cords

Answer 23

Consist of skeletal muscle (vocalis), vocal ligament (band of elastic fibers) and a covering of stratified squamous nonkeratinized epithelium

Question 24

Vestibular folds

Answer 24

Lie superior to vocal cords. Folds of loose connective tissue containing glands, lymphoid aggregations, and fat cells. Covered by stratified squamous nonkeratinized epithelium

Question 25

Respiratory system parts:

Answer 25

``` Trachea, Extrapulmonary bronchi, Intrapulmonary bronchi, Secondary bronchi, Tertiary bronchi, Bronchioles, Terminal bronchioles, Respiratory bronchioles, Alveolar duct, Alveolar sac, Alveolus ```

Question 26

Trachea

Answer 26

Walls supported by C-shaped hyaline cartilages. Open ends face posteriorly. Smooth muscle (trachealis) extends between the open ends of these cartilages. Has dense fibroelastic connective tissue between adjacent C-rings. Permits trachea elongation during inhalation

Question 27

smooth muscle of trachea

Answer 27

trachealis

Question 28

skeletal muscle in vocal cords

Answer 28

vocalis

Question 29

Trachea layers

Answer 29

mucosa (epithelium and lamina propria), submucosa, cartilage, and adventitia

Question 30

The lamina propria ends and the submucosa begins with a poorly defined _____. (trachea)

Answer 30

Elastic membrane

Question 31

Tracheal epithelium

Answer 31

Ciliated pseudostratified columnar epithelium. | Ciliated, mucous, brush cells, small granule cells, and basal cells

Question 32

Brush cell

Answer 32

columnar cell with blunt microvilli on surface. Basal portion may be in contact with afferent nerve ending - function as receptor cell

Question 33

Small granule cell

Answer 33

Similar in size and location to basal cells. Contains dense granules - catecholamine or other polypeptide hormones. These cells are members of the diffuse endocrine system (APUD-amine precursor uptake and decarboxylation). Also known as bronchial cells of Kulchitsky

Question 34

Basal cell

Answer 34

Reserve stem cell for epithelium

Question 35

Primary bronchi

Answer 35

2 primary bronchi, one for each lung. Structurally similar to trachea, but cartilage rings and spiral bands of smooth muscle completely encircle bronchi Right primary bronchus path more vertical than left - foreign objects more likely to lodge in right side if they reach bronchus.

Question 36

Intrapulmonary bronchi

Answer 36

Arise from subdivisions of primary bronchi. Divide many times. Gives rise to secondary (lobar) and tertiary (segmental) bronchi. Irregular cartilage plates in their walls. Lined by respiratory epithelium. Contain spiraling smooth muscle bundles - separates lamina propria from the submucosa - seromucous glands present

Question 37

Bronchi layers

Answer 37

mucosa (similar to trachea), muscularis (smooth muscle layer), submucosa, cartilage layer, adventitia

Question 38

Primary bronchioles

Answer 38

Lack glands in submucosa, walls have smooth muscle rather than cartilage plates. Diameter of 1 mm or less. Epithelium varies from ciliated columnar with goblet cells in the larger airways to ciliated columnar with Clara cells in the smaller passages. Divide to form several terminal bronchioles after entering the pulmonary lobules

Question 39

Terminal bronchioles

Answer 39

Lack glands in submucosa. Walls contain smooth muscle - no cartilage plates. Most distal part - conducting portion of the respiratory system. Diameter less than 0.5 mm. Simple cuboidal epithelium - contains mostly Clara cells, some ciliated cells, and no goblet cells

Question 40

Clara cells

Answer 40

dome-shaped apical surface - no cilia. Cells can divide. Secrete glycosaminoglycans (protect bronchiolar lining?), and metabolize airborne toxins - cytochrome P-450 enzymes present in the smooth ER

Question 41

Respiratory bronchioles

Answer 41

Transition to respiratory portion of lung Simple cuboidal lining - Clara cells and some ciliated cells proximally and primarily clara cells distally. Occasionally brush cells and dense-core granule cells Bronchiole walls interrupted by alveoli

Question 42

Alveolar ducts

Answer 42

Passageway leads from the respiratory bronchioles. Walls consist of adjacent alveoli separated from one another by an interalveolar septum Most distal portion of the respiratory system to contain smooth muscle - present in the walls at the openings of adjacent alveoli. Lined by a simple squamous epithelium consisting of type I and type II pneumocytes.

Question 43

Alveolar sacs

Answer 43

Outpouchings of numerous alveoli located at distal end of the alveolar duct

Question 44

Alveoli

Answer 44

Site of oxygen and carbon dioxide diffusion between air and the blood, Pouch-like evaginations (about 200 um diameter) in respiratory bronchiole walls, alveolar ducts and alveolar sacs Have elastic fibers at openings and many reticular fibers in the walls Separated from each other by ineralveolar septa - may contain 1 or more alveolar pores (for pressure equalization between alveoli) Lined by a simple squamous epithelium of type I and type II pneumocytes

Question 45

Type I pneumocytes

Answer 45

Cover 95% of alveolar surface. Cytoplasm may be less than 80 nm in thickness. Form tight junctions with adjacent cells. Not able to divide

Question 46

Type II pneumocytes

Answer 46

Cuboidal shape, usually found near septal intersections Apical cytoplasm contains short microvilli Form tight junctions with adjacent cells Contain cytoplasmic lamellar bodies which is a storage inclusion for pulmonary surfactant - lowers alveolar surface tension Can divide and regenerate both types of alveolar pneumocytes Also called type II alveolar cells, great alveolar cells, granular pneumocytes, and septal cells.

Question 47

Interalveolar septum

Answer 47

Partition between two adjacent alveoli. Outer surfaces of alveoli covered by simple squamous epithelium (type I pneumocytes) Thicker regions contain many elastic and reticular fibers Contains continuous capillaries in its central (interior) region Accomodates the blood-gas barrier, which separates the alveolar airspace from the capillary lumen

Question 48

Blood-gas barrier

Answer 48

Thinnest regions are 0.2 um or less in thickness Type I pneumocyte and surfactant layer Fused basal lamina of pneumocytes and capillary endothelial cells Endothelium of continuous capillaries

Question 49

Pulmonary surfactant

Answer 49

Surfactant functions to reduce alveolar surface tension - permits easy alveolar expansion and prevents alveolar collapse during expiration (SP-A; hydrophilic glycoprotein, SP-B, SP-C; hydrophobic glycoproteins), a phospholipid called DPPC (dipalmitoyl-phospholipidcholine), plus cholesterol

Question 50

Lung macrophages

Answer 50

In normal conditions, 70-85% of the cells in the airways are alveolar macrophages (dust cells) - phagocytic - clean up debris, bacteria, etc. Macrophages also found in interstitial septal connective tissue and can move from septa to alveoli and back.

Question 51

Inflammatory conditions will result in an increase in number and activation for _______.

Answer 51

Both types of macrophage

Question 52

Hyaline membrane disease

Answer 52

Neonatal respiratory distress syndrome not the same as ARDS Observed in premature infants Lack of adequate amounts of pulmonary surfactant (made by type II cells after 35th week of gestation) Characterized by labored breathing due to difficulty expanding the alveoli - because of high alveolar surface tension Can be treated if detected before birth, administer glucocorticoids - induce surfactant synthesis

Question 53

Emphysema

Answer 53

Destruction of respiratory bronchioles in smokers (centriacinar) and respiratory bronchioles, alveolar ducts, and alveolar walls in alpha1-antitrypsin deficiency (panacinar). Formation of cyst like sacs - reduce gas exchange surface area Decreased lung elasticity - lungs can't recoil adequately during expiration. Lungs eventually expand and enlarge the thoracic cavity ("Barrel chest") Associated - cigarette smoking and/or substances that inhibit alpha1-antitrypsin (protein that protects lungs from elastase produced by neutrophils) Can be hereditary - result from defective alpha-1-antitrypsin produced by liver. Possibility for gene therapy treatment with recombinant alpha1-antitrypsin

Question 54

Pulmonary edema

Answer 54

Fluid leaks into interstitial tissue and alveoli. May be due to 1) Left ventricle dysfunction (cardiogenic) that causes dilation of pulmonary capillaries and increase in hydrostatic pressure. 2) Destruction of endothelial lining due to bacteria (endotoxin), trauma, or other agents (water-near drowning, chemical agents)

Question 55

Acute Respiratory Distress Syndrome

Answer 55

.

Question 56

Asthma

Answer 56

Constriction of bronchiolar smooth muscle. Associated with difficult air expiration, mucus accumulation in airways, & inflammatory cell infiltration. Often progressive & associated with allergic reactions. (allergen causes mast cell degranulation, release of histamine & other substances). Treated with epinephrine & isoproterenol or other bronchiolar smooth muscle relaxants.

Question 57

Cystic fibrosis

Answer 57

defective chloride ion channel prevents movement of chloride (out of the cell), mucus is thick, traps bacteria

Question 58

Lung pleura

Answer 58

Visceral layer of pleura consists of thin mesothelial layer attached to lung. This layer "seals" the lung. Under mesothelium is connective tissue layer with blood vessels, lymphatics, and nerves. Parietal pleura lines the lung cavity.

Question 59

Disorders of the pleura

Answer 59

hydrothorax (fluid in the pleural cavity) | pneumothorax (air in the pleural cavity)