8.1-8.5 transport in animals

Question 1

what are the stages of the cardiac cycle ?

Answer 1

-atrial systole
-ventricular systole
-diastole

Question 2

describe diastole

Answer 2

the chambers relax and the semi-lunar valves close.the atria fill up with blood and the atrio-ventricular valves open allowing blood to passively flow into the ventricles

Question 3

describe atrial systole

Answer 3

the walls of the atria contract pushing blood into the ventricles. the volume of the aura decreases and the pressure increases

(coincides with ventricular diastole)

Question 4

describe ventricular systole?

Answer 4

the ventricular walls contract pushing blood out of the heart through the aorta or pulmonary artery. the volume of the ventricles decrease and the pressure increases

(coincides with atrial diastole)

Question 5

what is cardiac output?

Answer 5

the volume of blood pumped out by the heart per unit of time

Question 6

what is the equation for cardiac output?

Answer 6

CO = heart rate x stroke volume

Question 7

what is stroke volume?

Answer 7

the volume of blood pumped out of the heart in one cardiac cycle

Question 8

what is cooperative binding in haemoglobin?

Answer 8

when the first oxygen molecule binds to haemoglobin it undergoes a conformational change to stabilise the molecule and increase the affinity for oxygen making it easier for the oxygen molecule to bind

the first oxygen molecule is the hardest to bind

Question 9

what is the oxygen dissociation curve?

Answer 9

shows the relationship between the partial pressures of oxygen in the blood and the saturation of haemoglobin with oxygen

as partial pressure increases so does the saturation of the haemoglobin with oxygen until they are fully saturated

Question 10

what is partial pressure?

Answer 10

the concentration of a gas in a given volume

Question 11

what type of curve is the oxygen dissociation curve?

Answer 11

sigmoid ( s shape )

Question 12

what is the bohr effect?

Answer 12

as the partial pressure for carbon dioxide increases, haemoglobin gives up more oxygen causing the oxygen dissociation curve to shift right.

Question 13

what is the importance of the bohr effect?

Answer 13

-it allows oxygen to bind more readily to the haemoglobin in the lungs where there is low CO2 pressures
-in active tissues with high CO2 partial pressures and low O2 partial pressures allowing oxygen to offload more readily

Question 14

does fetal or adult haemoglobin have a higher affinity for oxygen?

Answer 14

fetal

Question 15

what is tachycardia?

Answer 15

when the heart beat is too fast ( resting heart beat over 100 bpm )

Question 16

what is bradycardia?

Answer 16

when the heartbeat is too slow ( resting heart beat below 60 bpm )

Question 17

what is an ectopic heartbeat?

Answer 17

when the heartbeat is followed by a pause

Question 18

what is fibrillation of the heart?

Answer 18

when there is an irregular heart beat - can result in death

Question 19

what is the chloride shift ?

Answer 19

cl- ions move into erythrocytes to prevent electrical imbalance from the build up of H+ ions due to the dissociation of carbonic acid

Question 20

what 3 ways can C02 be transported in the bloodstream?

Answer 20

-a small % dissolves into the plasma
-binds to haemoglobin forming carbaminohaemoglobin
-transported as bicarbonate (HCO3 -)

Question 21

how does CO2 form HCO3 -?

Answer 21

CO2 + H2O –> H2CO3
H2CO3<=> HCO3 - + H+

the H+ binds with Hb to form haemoglobinic acid so the H+ doesn’t effect the pH

Question 22

What is the purpose of an electrocardiogram ( ECG ) ?

Answer 22

to monitor and investigate the electrical activity of the heart

Question 23

what is the big peak on a ECG?

Answer 23

The depolarisation of the ventricles- ventricular systole.

(it is the largest wave due to having the latest muscle mass )

Question 24

what protects the heart in the chest cavity?

Answer 24

the pericardium= tough fibrous sac

Question 25

what is an intrinsic rhythm?

Answer 25

when the heart beats around 60 times a minute

Question 26

what are the stages of heart action ?

Answer 26

1. the sinoatrial node initiates a wave of depolarisation making the atria contract 2. non-conducting tissue prevents the wave going straight to the ventricles and slows it down 3. the wave is passed through the atrioventricular node which is stimulated and passes the wave of excitation to the bundle of his 4. excitation is carried along the purine tissue and fibres which branch up and across the ventricles 5. the ventricles are depolarised causing them to contract from the apex upwards, pushing blood out of the heart

Question 27

what are the key components of heart activation in chronological order?

Answer 27

-sinoatrial node -non-conducting tissue -atrioventricular node -purkyne tissue -purkyne fibres

Question 28

describe and explain the structure of an artery

Answer 28

-narrow lumen (0.4-2.5 cm) to maintain high blood pressure -tunica extrema contains collagen to prevent damage -tunica media contains smooth muscle and elastic fibres to maintain and withstand high blood pressure and pulses -tunica intima is made of endothelial cells which is smooth t reduce friction

Question 29

describe and explain the structure of a vein

Answer 29

-contains valves to prevent the back flow of blood under the low blood pressure -larger lumen increase the volume of blood transported as blood pressure is lower and decreases the friction for blood -thinner muscle in the tunica media as it doesn't need to withstand high blood pressure

Question 30

describe and explain the structure of a capillary

Answer 30

-one endothelial cell tack to provide a short diffusion path in the lungs for gas exchange -contains pores for plasma to diffuse out of the capillary to form tissue fluid -tiny lumen to slow down the flow of blood for diffusion

Question 31

what are the two loops in a double circuitry system called?

Answer 31

pulmonary circuit and systemic circuit

Question 32

what are the components of an insects respiratory system ?

Answer 32

-spiracles controlled by sphincters -trachae -tracheoles -tracheol fluid

Question 33

describe the structure of trachea in an insects respiratory system

Answer 33

up to 1mm in diameter and lined with spirals of chitin for strength

Question 34

describe the structure of tracheoles in an insects respiratory system

Answer 34

around 0.6 to 0.8 micrometers in diameter with no chitin ( so freely permeable ).

Question 35

how do larger insects increase gas exchange?

Answer 35

-mechanical ventilation ( air is pumped in ) -collapsible enlarged trachea or air sacs act as reservoirs

Question 36

what is the role of tracheol fluid in insects?

Answer 36

they are at the ends of tracheoles and use osmosis to leave the tracheoles to increase the surface area available for gas exchange during times of high oxygen demand

Question 37

what is counter-current blood flow?

Answer 37

when the flow of blood and water run in opposite directions in fish for maximum efficiency of gas exchange as it maintains a diffusion gradient for oxygen

Question 38

how does water flow inwards in fish?

Answer 38

the buccal cavity lowers increasing the volume and decreasing the pressure of the buccal cavity casing water to rush in. as the buccal cavity closes water rushes into the opercular cavity as volume of the buccal cavity decreases and pressure increases

Question 39

how does water flow out of a fish?

Answer 39

the operculum opens which increases the pressure of the opercular cavity causing water to rush out

Question 40

what structure incase the surface area in the gills?

Answer 40

lamellae and gill filaments

Question 41

describe the structure and function of the lamellae in the gill

Answer 41

circular disks in the gill filament which is the main site of gas exchange