Respiratory Histology

Question 1

cilia

Answer 1

small, hairlike structures that beat upward to carry mucus dust, and aspirated food into the throat (where it can then be expectorated or swallowed)

help protect against aspiration pneumonia

Question 2

respiratory epithelium

Answer 2

tissue lining most of respiratory tract

composed mostly of ciliated, pseudostratified, columnar cells, also contains goblet cells

Question 3

ciliated

Answer 3

containing cilia at top (apical side) of cell

Question 4

pseudostratified

Answer 4

cells appear to be in layers, but are actually all attached to basement membrane (floor of epithelial tissue)

Question 5

columnar

Answer 5

taller than they are wide

Question 6

goblet cells

Answer 6

mucus producing cells present in epithelium

mucus helps trap debris to be more easily removed by cilia

Question 7

stratified squamos epithelium

Answer 7

layered, flattened tissue lining nasal cavities

Question 8

squamos

Answer 8

“flattened”

Question 9

simple squamos epithelium

Answer 9

single-layer tissue lining the smaller bronchioles that allows for gas exchange

Question 10

3 major cell types within alveoli

Answer 10

1. type I alveolar cells
2. type II alveolar cells
3. alveolar macrophages

Question 11

surfactant

Answer 11

lipoprotein that covers luminal surface of alveoli to keep them from sticking together during exhalation

premature babies often can’t make surfactant yet which is why they can have breathing probs

Question 12

how surfactant works

Answer 12

walls of alveoli constantly kept moist w/water
water molecules attract each other, so an be difficult for alveoli to inflate into their open circular structure
surfactant breaks up water molecules so that alveoli can open

Question 13

type I alveolar cells

Answer 13

95% of alveolar epithelium

form the thin, simple squamos epithelium in junction with capillaries

Question 14

type II alveolar cells

Answer 14

5% of alveolar epithelium, dispersed throughout type 1 cells
produce & secrete pulmonary surfactant
can divide to replace damaged type 1 cells

Question 15

alveolar macrophages

Answer 15

not part of the epithelial tissue
most abundant cell in alveoli
phagocytize toxic particles/allergens/pathogens – primary immune defense system for alveoli

Question 16

hemoglobin molecule

Answer 16

4 polypeptide chains folded around heme (iron containing group)

250 million hemoglobin molecules are present in each red blood cell

Question 17

oxyhemoglobin

Answer 17

formed when oxygen combines w/hemoglobin to be transported to tissues from alveoli

Question 18

carbaminohemoglobin

Answer 18

combo of hemoglobin & CO2 in tissues that helps remove ~30% of CO2 from tissues back to alveoli (via bloodstream)

Question 19

bicarbonate ion

Answer 19

responsible for transporting most of CO2 from tissues back to alveoli (via bloodstream)

created via carbonic anhydrase enzyme combining CO2 & H2O