Biology Chapter 6: The Respiratory System

Question 1

What is the path of air through the lungs?

Answer 1

1. Drawn in through the nares
2. Through nasal cavity and pharynx
3. Filtered by nasal hairs and mucous membranes
4. Goes through larynx and then the trachea
5. Trachea divides into to bronchi
6. Those divide into bronchioles —> Alveoli

Question 2

What are aveoli?

Answer 2

Small sacs that interface with the pulmonary capillaries, allowing gasses to diffuse across a one-cell-think membrane.

Question 3

What is surfactant?

Answer 3

Reduces surface tension at the liquid-gas interface, preventing collapse.

Question 4

What are the 2 pleura & space?

Answer 4

Visceral (adjacent to lung)
parietal (lines chest wall)
intraplueral (lies between the two and contains fluid

Question 5

How do the lungs expand?

Answer 5

diaphragm and external intercostal muscles expand the thoracic cavity, increasing the volume of the intrapleural space, decreasing the intrapleural space. This expands the lungs, dropping their pressure and drawing in air from the environment – negative-pressure breathing

Question 6

Passive exhalation?

Answer 6

relaxation of the muscles of inspiration and elastic recoil of the lungs allow the chest cavity to decrease in volume, reversing the pressure differentials seen in inhalation

Question 7

Active exhalation?

Answer 7

internal intercostal muscles and abdominal muscles can be used to forcibly decrease the volume of the thoracic cavity pushing out air.

Question 8

What is a spirometer?

Answer 8

can be used to measure lung capacities and volume

Question 9

What is total lung capacity?

Answer 9

The maximum volume of air in the lungs when one inhales completely.

Question 10

What is residual volume?

Answer 10

The minimum volume of air in the lungs when one exhales completely

Question 11

What is tidal volume?

Answer 11

The volume of air inhaled or exhaled in a normal breath

Question 12

What is expiratory reserve volume?

Answer 12

The volume of additional air that can be forcibly exhaled after a normal exhalation

Question 13

What is inspiratory reserve volume?

Answer 13

the volume of additional air that can be forcibly inhaled after a normal inhalation

Question 14

What is the ventilation center?

Answer 14

a collection of neurons in the medulla oblongata that regulates ventilation

Question 15

What do chemoreceptors do in the ventilation center do?

Answer 15

They respond to carbon dioxide concentrations, increasing respiratory rate when there are high concentrations of carbon dioxide in the blood (hypercarbia or hypercapnia)

Question 16

How do the lungs perform gas exchange?

Answer 16

Through diffusion

Question 17

How do the aveoli and the capillaries assist in thermoregulation?

Answer 17

Vasodilation and vasoconstriction of capillary beds

Question 18

What helps to filter the incoming air?

Answer 18

vibrissae, mucous membranes, mucociliary escalator

Question 19

What do lysozomes do?

Answer 19

In nasal cavity and saliva - attack peptidoglycan cell walls of gram-positive bacteria

Question 20

What do macrophages do?

Answer 20

can engulf and digest pathogens and signal to the rest of the immune system that there is an invader

Question 21

What are mucosal surfaces covered with>

Answer 21

IgA antibodies

Question 22

What are mast cells?

Answer 22

Have antibodies on their surface that can promote the release of inflammatory chemicals – allergic reactions too.

Question 23

What happens when pH decreases?

Answer 23

respiration rate increases to compensate by blowing off carbon dioxide. This causes a left shift in the buffer equation, reducing hydrogen ion concentration.

Question 24

What happens when pH increases?

Answer 24

respiration rate decreases to compensate by trapping carbon dioxide. This causes a right shift in the buffer equation increasing hydrogen ion concentration.