Respiration

Question 1

Alveoli

Answer 1

microscopic air sacs containing blood vessels, moist membranes allow for gas diffusion

Question 2

taking air in

Answer 2

inspiration

Question 3

expelling air

Answer 3

expiration

Question 4

average rate of breathing

Answer 4

14-20 breaths per minute

Question 5

Path through respiratory system

Answer 5

nasal/oral cavity
pharynx
larynx (voice box)
trachea (wind pipe)
bronchi (primary, secondary, tertiary)
bronchioles
alveoli

Question 6

nasal cavity

Answer 6

• air enters nostrils
• hair filters particles
• air is warmed and moistened
• moist, mucous secreting epithelium (moistens air, helps trap dust/dirt, covered in cilia)

Question 7

epithelium

Answer 7

tissue that secretes mucous (found in nasal cavity), covered in cilia

Question 8

Pharynx

Answer 8

• begins behind nasal cavity
• extends to epiglottis
• passageway for food and air

Question 9

Larynx

Answer 9

voice box, contains vocal cords, cartilaginous

Question 10

Trachea

Answer 10

• wind pipe
• tube enforced with cartilage to keep airway open during inhalation

Question 11

Why is the trachea enforced with cartilage?

Answer 11

cartilage prevents trachea from collapsing during inhalation (inhalation caused by suction from the movement of diapragm that would collapse trachea otherwisse)

Question 12

Bronchi

Answer 12

• branches at end of trachea
• enters lungs
• continues to branch (primary, secondary, tertiary)
• ends in respiratory bronchioles

Question 13

Alveoli

Answer 13

• region of gas exchange
• air on one side, blood capillaries on other (2 cells thick)
• moist layer of fluid (surfactant) between air and alveolar membrane (inside of alveoli)

Question 14

Surfactant

Answer 14

moist layer of fluid between air and alveolar membrane that breaks surface tension, preventing alveoli from collapsing

Question 15

role of cilia

Answer 15

• particles trapped in mucus above cilia
• cilia sweep out particles

Question 16

respiration rate

Answer 16

breaths per minute

Question 17

medulla oblogata role

Answer 17

sends signals to adjust levels of oxygen present in body by changing breath rate

Question 18

air flow & pressure in lungs

Answer 18

• air flow due to pressure differences
  
  • low pressure causes air to flow out
  • high pressure causes are to leave

Question 19

role of muscles

Answer 19

muscles cause pressure differences (muscles compress = high pressure, muscles relax/give more room for lungs = low pressure)
- diaphragm
- intercostal muscles (between ribs)
- external - quiet breathing (expiration is passive process)
- internal - deep breathing (expiration is an active process)

Question 20

Mechanism of Inspiration

Answer 20

• chemoreceptors (aorta & carotid) detect high CO2 (as HCO3-) or H+
• sends signal to medulla oblongata which sends signal to muscles
• diaphragm contracts (flattens) and intercostal muscles contract (ribs move up & out), increasing volume of thoracic cavity
• lungs expand to decrease pressure inside
• air flows inside to equilize the low pressure

Question 21

Mechanism of Expiration

Answer 21

• stretch receptors activated by expanded lungs
• medulla oblonagta stops sending signal to muscles & muscles return to shape
• thoracic volume decreases, pressure increases
• pressure greater than outside, air is forced out

Question 22

low pressure

Answer 22

caused by larger space (contraction of muscles), causes air to flow in

Question 23

high pressure

Answer 23

caused by smaller space, causes air to flow out

Question 24

muscles during inhalation

Answer 24

diaphragm flattens, intercostal muscles move rib up and out

Question 25

muscles during expiration

Answer 25

diaphragm relaxes back to dome shape, intercostal muscles move rib down & in