Ch. 13 Regulation of Gas Transfer Flashcards Preview

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Flashcards in Ch. 13 Regulation of Gas Transfer Deck (72)
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1

the rate of blood perfusion of the respiratory surface is related to ....

the requirements of the tissues for gas transfer

2

the amount of O2 delivered to the respiratory surface must equal ...

the amount taken away from the blood

3

the ventilation to perfusion ratio in humans is

1 b/c the O2 contnet of blood is approximately that of air

4

the ventilation to perfusion ratio in fish is

10:1 to 20:1

water over gills:blood over gills

5

to compensate for a decrease in PO2 in air or water...

ventilation increases

and vice versa

6

why can the pattern of capillary blood flow change in gills and lungs

maintain equal blood and inhalent flow over the respiratory surface

7

how does hypoxic vasoconstriction of blood vessels in the lung help to maintain an ideal ventilation to perfusion ratio?

low alveolar O2 level causes vasoconstriction so blood doesnt flow to this area of the respiratory surface

8

neuronal regulatuion of breathing 2 types

pattern generator

rhythm generator

9

pattern generator

sets depth and amplitude of each breath

10

rhythm generator

controls breathing frequency

pre-Botzinger complex in brain stem

11

medullary respiratory center

sends signals to spinal motor neurons that control the diaphragm and intercostal muscles

12

Hering-Breuer reflex

reflex to prevent overinflation of the lungs

pulmonary stretch receptors sense over-stretching during large breaths and inhibit the vagus nerve

13

phrenic nerve

affects diaphragm via inspiratory neuronal activity

14

inspiratory neuronal activity

controls muscles of inspiration

15

amphibian and reptile episodic breathing

intrinsic property of brainstem

16

fluxes in O2 and CO2 levels in animals lead to ______ changes in ventilation

reflex

17

two types of receptors that affect rate and depth of breathing

carotid bodies

aortic bodies

18

carotid bodies and aortic bodies are ____________ that measure changes in __ and ____

chemoreceptors, O2, CO2, and pH

19

"central" chemoreceptors CSF

in medulla

respond to decreases in pH of CSF (high CO2) detect H+

accurate b/c no buffer system in CSF

20

peipheral chemoreceptors monitor

arterial blood

21

do peripheral chemoreceptors react to high CO2 or low pH

they think low pH, not the actual CO2 level

22

carotid body chemoreceptors respond greater to...

pH/CO2 changes

leads to inc ventilation via medullary resp center

23

increases in _____________ and _______ can also stimulate carotid chemoreceptors, and stimulation of the carotid nerve causes release of _____

temperature, osmolarity, ADH

24

in mammals does CO2 or O2 dominate breathing rate

CO2

25

in aquatic vertebrates does CO2 or O2 dominate breathing rate and why

O2

O2 is limiting in water b/c less soluble and concentration fluctuates a lot more

26

fish exposed to high O2...

reduce breathing until there is a high PCO2 in blood

27

CO2 effect on mammal pulmonary stretch receptors

reduces their inhibitory effect to increase depth of breathing and lung ventilation

28

lung irritant receptors

stimulation by mucous or dust causes bronchioconstriction and coughing

29

type J receptors in the lungs

stimulation causes a feeling of breathlessness

responds to increased interstitial fluid (pulmonary edema)

30

hypoxia definition

reduced oxygen levels