12

Question 1

chemoreception

Answer 1

when chemicals bind to chemoreceptors and activate action potential in sensory neurons

Question 2

Gustation

Answer 2

Sense of taste

Question 3

Olfaction

Answer 3

sense of smell

Question 5

when odorants reach the mucous layer in the roof of nose they bind to membrane bound receptor proteins, activating

Answer 5

olfactory receptor neurons

Question 6

axons from these neurons project up to the:

Answer 6

olfactory bulb

Question 7

part of the brane where olfactory signals are processed and interpreted

Answer 7

olfactory bulb

Question 8

intracellular peripheral membrane proteins closely associated with trans transmembrane signal receptors

Answer 8

G proteins

Question 9

when G proteins are activated by a signal receptor they trigger the production of

Answer 9

second messenger

Question 10

what are second messengers

Answer 10

-small, non protein signalling molecule or ion
-links the receipt of an extracellular signal to the production of an intracellular signal

Question 11

3 steps of G-protein-coupled signalling

Answer 11

1. a signalling molecule binds to its membrane receptor
2. the associated G-protein exchanges GDP for GTP and splits into two parts
3. the active G protein subunit activates a nearby membrane enzyme and catalyzes the production of a second messenger.

Question 12

signal transduction in odorant receptors

Answer 12

1. odorant binding to an odorant receptor causes conformational change in the odorant receptor protein
2. this change in conformation activates G proteins which diffuses through the cytoplasm and activates adenylyl cyclase
3. adenylyl cyclase converts ATP to cAMP.
4. cAMP open cAMP gated Na/Ca2+ channels
5. cAMP gated channels open and sodium and calcium flows in.
6. calcium opens calcium gated cl channels causing efflux of Cl.
7. neuron is depolarized
8. sodium gated channel opens and sodium flows in generating action potential

Question 13

each olfactory receptor neuron expresses __ type of odorant receptor

Answer 13

1

Question 14

each odorant receptor respond to different odorants with varying affinity.

Answer 14

true

Question 15

receptors of the same type project to distinct regions in the olfactory bulb called:

Answer 15

glomeruli

Question 16

how does the brain identify specific smells?

Answer 16

by interpreting the intensity and pattern of activation of specific glomeruli

Question 17

chemicals secreted into the environment and cause a physiological and behavioural change in members of the same species.

Answer 17

pheromones

Question 18

pheromone receptors are localized in

Answer 18

vomeronasal organs (VNO).

Question 19

sensory organs in the nasal region of some animals distinct from the olfactory bulb

Answer 19

vomeronasal organs

Question 20

how to calculate the partial pressure of a gas

Answer 20

multiple the fractional composition of that gas by the total pressure exerted by the entire mixture.

Question 21

pressure of a particular gas in a mixture of gases is called

Answer 21

partial pressure

Question 22

it is harder to breathe at high altitudes because

Answer 22

the partial gradient between the atmosphere and your lung is small

Question 23

_______ states that the rate of diffusion of a gas depends on 5 parameters

Answer 23

Fick’s law of diffusion

Question 24

the five parameters in fick’s law of diffusion

Answer 24

1. solubility of gas
2. temperature
3. surface area for diffusion
4. differences in partial pressures across the gas exchange surface
5. thickness of the barrier in diffusion

Question 25

Rate of diffusion =

Answer 25

k x A x (P2 - P1)/D k = diffusion constant A = area for gas exchange D = distance of diffusion

Question 26

Five major steps of gas exchange

Answer 26

1. Ventilation 2. diffusion at the respiratory surface 3. Circulation 4. Diffusion at the tissues 5. Cellular respiration

Question 27

ventilation

Answer 27

movement of air through a specialized gas exchange organ

Question 28

Diffusion at the respiratory surface

Answer 28

where oxygen moves from the air or water into the blood and CO2 moves from the blood into the air or water.

Question 29

Circulation

Answer 29

transport of dissolved CO2 and O2 throughout the body via the circulatory system

Question 30

Diffusion at the tissues

Answer 30

O2 moves from blood into tissues and CO2 moves out if the tissues into blood.

Question 31

Cellular respiration.

Answer 31

the cell’s use of O2 to produce co2. leads to high Co2 and low o2 levels in the tissues

Question 32

respiratory system

Answer 32

collection of cells, tissues, and organs responsible for gas exchange.

Question 34

ram ventilation

Answer 34

when fish force water through their gills by opening their mouths

Question 35

the stiff flap over fish gills is called

Answer 35

operculum

Question 36

most fish ventilate by

Answer 36

opening and closing their mouths and operculum to create a pressure gradient

Question 37

structure of gill

Answer 37

gill filaments extend from each gill arch and each gill arch contains thousands of sheet like gill lamellae

Question 38

structure of lung in the order that each component branches out

Answer 38

Trachea bronchi bronchioles alveoli

Question 39

alveoli consists of (from the air side to the blood side)

Answer 39

- a thin aqueous film - epithelium of alveolus - extracellular matrix material(ECM) - the wall of a capillary

Question 40

humans ventilate their lungs by

Answer 40

changing pressure within their chest cavity.

Question 41

change in volume of lung is caused by a downward motion of a thin muscular sheet called the:

Answer 41

diaphragm

Question 42

each lung is surrounded by a pleural sac which is composed of

Answer 42

two layers of cells with small space between them

Question 43

inhalation

Answer 43

during inhalation, the diaphragm moves down and the pressure in the chest cavity is lowered, causing the lungs to expand and air to move in.

Question 44

exhalation

Answer 44

as diaphragm relaxes, the chest cavity volume decreases, and air is exhaled. - passive process driven by the elastic recoil of the lungs and chest wall as the diaphragm and rib muscle relax. - it can become energy demanding during exercise

Question 45

functions of brain stem

Answer 45

information relay, autonomic control of the heart, lungs, digestive system.

Question 46

the mammalian rate of breathing is controlled by the

Answer 46

medullary respiratory centre

Question 47

how does the body deal with increased CO2 conc

Answer 47

Increased CO2 react with water in the blood and cerebrospinal fluid to form carbonic acid H2CO3, which dissociates in to H+ and bicabonate ion HCO3. the release of hydrogen ions lowers the blood and CSF pH, which is sensed by specialized chemoreceptors which stimulate CNS control centers to increase breathing rate.

Question 48

blood is a fluid connective tissue consisting of cells in a watery extracellular matrix called:

Answer 48

plasma

Question 49

the blood is composed of

Answer 49

plasma platelets white blood cells red blood cells

Question 50

Platelets

Answer 50

cell fragments that minimize blood loss.

Question 51

white blood cells

Answer 51

part of the immune system

Question 52

red blood cells

Answer 52

transport of CO2 and O2

Question 53

red blood cells contain an oxygen carrying molecule called

Answer 53

hemoglobin

Question 54

composed of four polypeptide chains, each of which binds to a non protein group called heme

Answer 54

hemoglobin

Question 55

each heme contains an iron ion that can bind to an

Answer 55

oxygen molecule

Question 56

the oxygen-hemoglobin equilibrium curve plots the

Answer 56

percentage saturation of hemoglobin vs the partial pressure of oxygen in tissues

Question 57

decreases in pH alter hemoglobins conformation and causes a ___ shift in the hemoglobin curve

Answer 57

right

Question 58

temperature increase decrease oxygen affinity and causes a _____ shift

Answer 58

right

Question 59

fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin therefore

Answer 59

more oxygen is needed to supply tissues

Question 60

______ _______ in red blood cells catalyzes the formation of carbonic acid from carbon dioxide in water.

Answer 60

carbonic anhydrase

Question 61

CO2 that diffuses into red blood cells is converted to

Answer 61

bicarbonate ions and protons.

Question 62

most CO2 is transported in blood in the form of

Answer 62

bicarbonate ions

Question 63

parietal cells have a high concentration of the enzyme _____ ______ and ______

Answer 63

carbonic anhydrase, mitochondria

Question 64

where is carbonic anhydrase found?

Answer 64

in red blood cells

Question 65

importance of red blood cells for two reasons

Answer 65

1. the protons produced by the carbonic anhydrase reaction induce the Bohr shift, which makes hemoglobin more likely to release oxygen. 2. the Pco2 in blood drops when CO2 is converted to bicarbonate, favouring entry of CO2 into red blood cells

Question 66

proton generated from the conversion of co2 to bicarbonate binds to ______

Answer 66

hemoglobin

Question 67

diffusion of CO2 out of the alveoli

Answer 67

1. hydrogen ions leave their binding sites on hemoglobin 2. hydrogen ions react with bicabonate to form CO2 3. CO2 diffuses into the alveoli anf is exhaled from the lungs

Question 68

reactions to synthesize HCO3 occur in the:

Answer 68

RBC

Question 69

HCO is exchanged for Cl in the plasma at the ____

Answer 69

tissues

Question 70

Cl is exchanged for HCO3 in the plasma at the ____

Answer 70

alveoli