exam 2 14

Question 1

primary function of lungs?

Answer 1

gas exchange

Question 2

supportive function of gas exchange

Answer 2

mucocillary clearance

air conditioning

regulation of airflow

heat exchange

Question 3

what kind of lungs for a squamate?

Answer 3

•Squamates (lizards, snakes) don’t have diaphragms, instead use axial musculature that they also use for movements, so they often can’t breath while running!

Question 4

turtle lung structure

Answer 4

• Some have a layer of muscle surrounding their entire lungs
• Others have diaphragm-like structure

Question 5

O₂ and CO₂ move by ___, from an area of high to low partial pressure

Answer 5

simple diffusion

Question 6

Answer 6

A = alveolar duct

B = capillaries

C = individual alveoli

Question 7

Answer 7

pneumocyte= alveolar type 1 cells

blue= cytoplasm of an endothelial cell

arrows = blood gas barrier

Question 8

Ficks law

Answer 8

Vgas= A/T (D)(P₁-P₂)

The amount of gas that moves across a sheet is:

• Proportional to the area of the sheet•Inversely proportional to its thickness
• P1 is the partial pressure on one side, P2 on the other
• A=area
• V= flow (V is volume, the ^• means over time, so vol over time is flow, right?)
• D = diffusion, a constant, how big and how soluble the molecule is

Question 9

CO₂ diffuses ___ than O₂ – it’s MW is similar, but it is way more soluble

Answer 9

20x faster

Diffusion constant is higher than O2 (ficks law)

Question 10

conducting airway

Answer 10

•Trachea → mainstem bronchi → lobar bronchi → segmental bronchi → → → terminal bronchioles (smallest without alveoli)

Question 11

Answer 11

bronchus (can see cartilage and alveolar)

blue= pulmonary artery (deoxygenated)

red= pulmonary vein (oxygenated)

Question 12

Answer 12

smaller bronchi/bronchioles (smooth = no cartilage= deeper airway) and alveoli

Question 13

what blood vessel type runs along conducting airway

Answer 13

arteries-

veins will branch off earlier and do their own thing

Question 14

holes in alveolar

Answer 14

pores of kohn- function unknown

air bypass hurt alveoli

tissue repair- crawl

Question 15

Answer 15

alveolar ducts

Question 16

•Progression of ____ in larger airways to simple cuboidal and squamous in the alveoli

Answer 16

pseudostratified columnar

Question 17

respiratory epithelium is found ___

Answer 17

conducting airway

Question 18

alveolar epithelium is found

Answer 18

respiratory zone

alveoli- where gas exchange takes place

Question 19

conducting airways has what type of epithelium

Answer 19

respiratory epithelium

Question 20

4 types of cells in conducting airway

Answer 20

• Basal Cells
• Ciliated Cells
• Goblet Cells
• Club cells

Question 21

basal cells are found in __ and act as __

Answer 21

conducting airway

stem cell

Question 22

___ act as the stem cells in conducting airway

Answer 22

basal cell

Question 23

Answer 23

goblet cells

mucous producing

•Mucins fill and expands the apical portion of the cell, forcing the nuclei to the basal position and giving it a goblet shape

Question 24

Answer 24

ciliated cells

• “multiciliated” or “motile ciliated” ∼300 motile cilia into the periciliary layer
• Critical for propelling the mucus layer up the airway
• “Mucocilliary clearance”
• Terminally differentiated

Question 25

\_\_\_\_ beat in unidirection to move stuff out of lungs. this is called \_\_\_

Answer 25

ciliated cells mucocillary clearance

Question 26

what does it mean when ciliated cells are terminally differentiated?

Answer 26

can not turn into anything else can't reproduce or change

Question 27

mucociliary clearance

Answer 27

sweeps particles out of lungs

Question 28

club cells

Answer 28

* Cuboidal, non-ciliated * Produce “secretoglobins” AKA “uteroglobins”, thought to have innate immune functions * Also produce some **surfactant** proteins * Expression of **cytochrome p450** enzymes allows for detoxification of xenobiotics * In mice, these can serve as a **stem cell** in smaller airways that lack basal cells. Unclear in other species

Question 29

cub cells produce ___ thought to have innate immune functions

Answer 29

“secretoglobins” AKA “uteroglobins”, thought to have innate immune functions

Question 30

club cells produce __ to help with detoxification of xenobiotics

Answer 30

cytochrome p450

Question 31

what works as stem cells in mice in smaller airways

Answer 31

club cells no basal cells in smaller airways, club cells will take over the job

Question 32

ionocytes

Answer 32

Unknown function, but express high levels of **CFTR(cystic fibrosis),** thought to regulate mucous viscosity and thus mucociliary clearance

Question 33

tuft cells

Answer 33

Unknown function, hypothesized to modulate Th2 immune responses (i.e. allergy, parasites)

Question 34

neuroendocrine cells

Answer 34

Modulate Th2 immune responses (i.e. allergy, parasites) *How are these different from tuft cells? Good question.* Recently demonstrated to act as oxygen sensors

Question 35

what type of cells in respiratory zone?

Answer 35

alveolar type 1 and alveolar type 2 cells alveolar macrophages

Question 36

where gas exchange happens

Answer 36

alveolar type 1 cells- very thin- very big

Question 37

\_\_\_ cells are large, squamous•Cover 95% of lung surface area•Ultrathin•Facilitate gas exchange between air and blood

Answer 37

alveolar type 1 cells

Question 38

alveolar type II cells

Answer 38

* Cuboidal, non-ciliated, possess lamellar bodies * Produce surfactant proteins and phospholipids * Facultative Stem / Progenitor Cell!

Question 39

main function of alveolar type II cells

Answer 39

produce surfactant

Question 40

what type of cell acts as stem cells in alveolar epithelium?

Answer 40

alveolar type 2- usually makes surfactant but in times of need can act as a stem cell

Question 41

function of pulmonary surfactant

Answer 41

•Decreases surface tension preventing the alveolar sac from collapsing

Question 42

pulmonary surfactant are made in __ and secreted by \_\_

Answer 42

lamellar bodies type 2 alveolar cells

Question 43

surfactant is hydrophilic. True or false

Answer 43

false hydrophobic- type C most hydrophobic protein in the body- helps increase rate and spread of surfactant phospholipids over the surface of the lung

Question 44

why have alveolar macrophage

Answer 44

no ciliated cells to get particles out macrophages will eat anything bad left over

Question 45

Answer 45

**Pulmonary artery** •Thin wall•Less smooth muscle (still more than a vein though!)•Low pressure, 1/8 of systemic BP **Systemic artery (e.g. leg)** •Very thick wall•Lots of smooth muscle

Question 46

capillary bed formation in frog lungs

Answer 46

intussusceptive angiogenesis (make pillars to increase surface area

Question 47

bronchial circulation

Answer 47

•A smaller vessel, the **bronchial artery,** arises from the aorta (1% of cardiac output) and supplies oxygenated blood to the conducting airways to feed their metabolic functions **provides oxygenated blood to conducting airway**