GASEOUS EXHANGE

Question 1

gaseous exchange

Answer 1

the exchange of O2 and CO2 in the alveoli(external) and at cellular level(internal)

Question 2

requirements of efficient gas exchange

Answer 2

1. have lots of alveoli for increase in SA for max gas exchange
2. alveoli have thin epithelium cells for rapid and sufficient diffusion
3. mucous is produced so O2 and CO2 dissolves in the moisture
4. well ventilated to allow proper flow of air in and out of the respiration system
5. is protected by pleura, ribs and sternum

Question 3

function of nasal cavity

Answer 3

1. mucous from goblet cells and cilia trap dirt and sweep it out of the nose
2. keeps cavity moist and removes and destroys pathogens
3. blood capillaries warm incoming air

Question 4

function of larynx

Answer 4

contains vocal chords where air passes over them and makes them vibrate in order to produce sound

Question 5

function of ribs

Answer 5

protect the lungs from injury

Question 6

function of right bronchus

Answer 6

takes air to the right lung

Question 7

function of pharynx

Answer 7

connects the nasal cavity with the larynx and is lined with mucous membranes

Question 8

function of epiglottis

Answer 8

closes trachea when swallowing to prevent choking

Question 9

function of trachea

Answer 9

C-shaped cartilage rings that keep trachea open and is lined with ciliate epithelial cells to remove mucous

Question 10

function of left bronchus

Answer 10

takes air to left lung

Question 11

function of pleura

Answer 11

each lung is lined with a double pleura membrane which provides protection

Question 12

function of diaphragm

Answer 12

seperates abdominal and thoracic cavity and aids in breathing

Question 13

function of bronchioles

Answer 13

tubes that branch off from bronchus and then take air to the alveoli

Question 14

function of alveoli

Answer 14

1. are one cell layer thick which increases SA and then allows for gas exchange
2. is humid because of mucous

Question 15

gas exchange in the lungs

Answer 15

1. capillaries surrounding the alveolus have a high concentration of CO2 and low concentration of O2
2. the air in alveolus have a high concentration of O2 and a low concentration of CO2
3. this concentration gradient allows for diffusion to occur
4. O2 dissolves in the moisture lining the alveolus and diffuses into the bloodstream
5. the CO2 then diffuses out of the bloodstream into the alveolus
6. O2 forms a loose combination of haemoglobin to form oxyhaemoglobin

Question 16

gas exchange in the tissues

Answer 16

1. blood in the capillaries reaching the tissues has a high concentration of O2 and a low concentration of CO2
2. tissues fluid has a higher concentration of CO2 and a lower concentration of O2
3. this concentration gradient allows for diffusion to occur
4. O2 diffuses into the tissue fluid, then into the cells
5. CO2 diffuses out of the cells into the tissue fluid then into the blood
6. cell resp causes the consumption of O2 and production of CO2

Question 17

exhalation

Answer 17

when air is pushed out of the lungs

Question 18

inhalation

Answer 18

when air moves into the lungs

Question 19

what occurs during exhalation

Answer 19

1. diaphragm relaxes and moves upwards
2. intercoastal muscles relax
3. ribcage moves down and inward
4. volume of thoracic cavity decreases
5. air pressure in lungs increases relative to the outside air pressure

Question 20

what occurs during inhalation

Answer 20

1. diaphragm muscle contracts and moves downwards
2. intercoastal muscles between ribs contract
3. ribcage lifts up and pushes outwards
4. the volume of the thoracic cavity increases
5. air pressure in the lungs decreases as the chest volume increases

Question 21

homeostasis

Answer 21

the process of maintaining a constant, internal environment within narrow boundaries, despite changes taking place internally and externally

Question 22

strenuos physical activity increases the bodies need for energy, what does it result in?

Answer 22

1. CO2 levels in the blood increases above normal levels
2. receptor cells in carotid artery in the neck are stimulated
3. cells send impulses to the medulla oblongata in the brain
4. medulla oblongata stimulates breathing muscles and heart
5. breathing muscles contract more actively- increasing the rate and depth of breathing and the heart beats faster
6. more CO2 is taken to and exhaled from the lungs
7. the CO2 levels in the blood returns to normal