respiration physiology

Question 1

cellular respiration

Answer 1

within cells oxygen breaks down glucose to generate ATP
co2 is generated and must be removed from the cell
therefore there’s gas exchange

Question 2

lung structure

Answer 2

right:
- 3 lobes: superior, middle and inferior
- sup and mid separated by horizontal fissure and sup and inf by oblique

left:
- 2 lobes: superior and inferior
- separated by oblique fissure
- cardiac notch on superior- bottom left corner

apex at top of both

Question 3

bronchial tree order

Answer 3

larynx
trachea
2 main bronchi
2nd bronchus
3rd bronchus
bronchiole

Question 4

what’s conducting and respiratory zones

Answer 4

c: trachea
1st bronchus
2nd bronchus
3rd bronchus
terminal bronchiole

r: respiratory bronchiole
alveolar duct
alveolar sacs
alveoli

Question 5

features of the bronchial tree

Answer 5

goblet cells
ciliated cells
glands
hyaline cartilage
smooth muscle
elastic fibres

Question 6

goblet cells
ciliated cells
glands
hyaline cartilage
smooth muscle
elastic fibres

Answer 6

• produce mucus
• waft mucus back up
• secretion of mucus (along with goblet to trap particles) and serous fluid (contains enzymes to kill bacteria)
• c shaped rings around trachea to provide rigidity
• support airway structure and relax/ contract in response to airway
• allow stretching

Question 7

respiratory air flow

Answer 7

air naturally flow from high pressure to low pressure

movement of air in/out of lungs is caused by pressure difference between:
air in mouth (atmos pressure) and air in alveoli

Question 8

pressure changes in lungs (inhalation and exhalation)

Answer 8

I: pressure is lowered in alveoli by increasing lung volume

the pressure inside the alveoli is lower than atmshereric pressure- air enters the lungs

E: pressure is raised in alveoli by decreasing lung volume

pressure inside alveoli is higher than atmospheric pressure- air leaves lungs

Question 9

movement of structures during breathing

Answer 9

I: rib cage expands and muscles contract and diagphram contract (increases volume of lungs and resp for 75% of the air that enters the lungs)

E: rib cage smaller and muscles relax an diaphragm relaxes

Question 10

external intercostal muscles

Answer 10

• helps elevate the ribs and expand the thoracic cavity in inhalation
• rbs move outwards and upwards= increase volume in lungs
• respoible for 25% of air that enters lungs

Question 11

accessory muscles of breathing

Answer 11

used during forceful breathing

INHALTION:
- sternocleidomastoid muscle: elevates sternum
- scalene muscles: elevate upper ribs
- pectoralis minor: expand rib cage by elevating the 3rd through 5th ribs

EXHALATION:
- internal intercostal muscles: bring ribs down
- transverse thoracis: pull rubs down
- abdominals and oblique: pull ribs down, compress abdominal contents- pus diaphragm up

Question 12

intrapleural pressure

Answer 12

pressure that exists between the 2 pleural layers of the pleural cavity
always lower than atmospheric pressure
prevents natural tendency of lung to collapse

Question 13

alveoli

Answer 13

gas exchange:
- lungs contain about 300 million alveoli
- surface area available is 70 square metres
- narrow pulmonary capillaries and thin resp membrane = rapid diffusion

structure:
type ONE: squamous cells lining the walls
type TWO: cuboidal epithelium that secrete alveolar fluid (surfactant)

Question 14

gas exchange

Answer 14

diffusion is movement of material from high to low conc
conc of gases measured as partial pressures
greater the difference in partial pressure, greater rate of diffusion

Question 15

role of surfactant in alveoli

Answer 15

• reduce surface tension
• increase stability
• reduce collapse likelihood

Question 16

oxygen transport

Answer 16

o2 doesn’t dissolve in water easy
- 1.5% of the o2 inhaled dissolve in plasma
- 98% carried by haemoglobin
haemoglobin increases o2 carry capacity by 70 times

Question 17

haemoglobin structure

Answer 17

contains iron atom that binds to oxygen

Question 18

heme unit binding oxygen

Answer 18

pulmonary capillaries:
high partial pressure of oxygen
oxygen binds to haemoglobin

tissue capillaries:
low partial pressure of oxygen
oxygen unloaded from heme units

Question 19

cooperative binding

Answer 19

when first oxygen binds, haemoglobin shape changes to make binding 2nd oxygen easier

in tissue, pp of oxygen is low making it harder for Hb to bind to oxygen so shape changes slightly

shape change= next binding is easier

as sites get used up, binding of oxygen is hard since its really saturated (lungs)

graph is sigmoidal as one o2 molecule make it easier for the affinity of another

Question 20

factors affecting haemoglobin affinity for oxygen

Answer 20

acidity
pp of co2
temp
biphosphoglycerate

Question 21

acidity

Answer 21

as ph drops, affinity of Hb for o2 decreases

• metabolically active tissues produce lactic and carbonic acid (lower ph)
• hydrogen ions bind to Hb decreasing affinity for oxygen

Question 22

pp of co2

Answer 22

of pp of co2 rises, Hb releases o2 more readily

• co2 binds to Hb decreasing affinity for o2
• pp of co2 and pH are related- low blood ph results from high pp of co2

Question 23

temp

Answer 23

temp increases= more o2 unloading from Hb

• in metabolically active tissues a lot of heat is released

Question 24

biphosphoglycerate

Answer 24

BGP binds to Hb that causes o2 to be less tightly bound

• formed in rbc when they breakdown glucose to form ATP (glycolysis)

Question 25

release of O2 in tissues

Answer 25

decreased pH
increased co2
increased temp
BGP

(all cause greater release of o2 from Hb at same pp)

Question 26

uptake of o2 in alveoli

Answer 26

increased pH
decreased co2
lower temp

(all cause greater uptake of o2 from Hb at same pp)

Question 27

co2 transport

Answer 27

dissolved co2 in blood plasma (10%)

as carbamino compounds bound to protein in blood majority bound to haemoglobin (30%)

bicarbonate ions in blood plasma (70%)

Question 28

carbon monoxide poisoning

Answer 28

200 times greater affinity for Hb that o2

reduce oxygen carrying capacity of the blood

without urgent admission of pure o2, CO poisoning is fatal