Module 3

Question 1

blood flow

Answer 1

the volume of blood flowing through: vessel, or organ circuit

BF = P/R

Question 2

blood pressure

Answer 2

force exerted on a vessel wall by blood in its own vessel

moves from an area of high to low pressure

Question 3

systemic blood pressure

Answer 3

• highest in aorta

- steepest drop in arterioles

Question 4

arterial blood pressure

Answer 4

volume of blood forced into elastic arteries by ventricular contraction

Question 5

systolic pressure

Answer 5

peak pressure generated in large arteries when ventricles contract

Question 6

diastolic pressure

Answer 6

pressure in large arteries when ventricles relax

Question 7

pulse pressure

Answer 7

systolic pressure - diastolic pressure

Question 8

what is the goal of the circulatory system

Answer 8

to maintain blood flow

Question 9

Mean Arterial Pressure (MAP)

Answer 9

MAP = COXR

Question 10

resistance

Answer 10

measure of friction

Question 11

Total Peripheral Resistance (TPR)

Answer 11

• blood viscosity
• blood vessel length
• blood vessel diametre

Question 12

viscosity

Answer 12

thickness of fluid

Question 13

blood vessel length

Answer 13

resistance to flow > as length >

Question 14

blood vessel diametre

Answer 14

greater contact = > friction => resistance

> diametre = contact = < friction = < resistance

Question 15

vasoconstriction

Answer 15

< diametre

which > resistance = < BF

Question 16

vasodilation

Answer 16

> diametre

which < resistance = > BF

Question 17

list 3 ways blood vessel diametre is altered

Answer 17

• protrusions
• vasoconstriction
• vasodilation

Question 18

Capillary Blood pressure

Answer 18

35 mmhg at arterial end
15 mmhg at venous end

• low pressure due to thin walls and permeability

Question 19

last the 5 structures of venous return

Answer 19

1. valves
2. muscular pump (pushes blood towards heart)
3. respiratory pump (pressure change in breathing moves blood to heart)
4. pulsation (in arteries)
5. venoconstriction (of tunica media under sympathetic control)

Question 20

list the 3 methods of regulation of BP

Answer 20

1. Cardiac Output
2. Total Peripheral Resistance
3. Blood Volume

Question 21

Regulation of BP - CO

Answer 21

• rapid
• short term
• > SV or HR = > BP

Question 22

Regulation of BP - TPR

Answer 22

• rapid
• short term
• vasoconstriction > BP
• vasodilation < BP

Question 23

Regulation of BP - Blood Volume

Answer 23

• slower
• long term
• renal and endocrine mechanisms
• auto regulation
• neural regulation
• renal mechanisms
• endocrine regulation

Question 24

Regulation of BP - Blood Volume - Auto Regulation

Answer 24

tissues regulate their own BP + F in response to:

• diametre
• opening/closing of pre capillary sphincters

Question 25

Regulation of BP - Blood Volume - Neural regulation

Answer 25

- cardiovascular centres + ANS - cardio inhibitory < - cardioacceleratory < - vasomotor (change in diametre)

Question 26

Regulation of BP - Blood Volume - Renal Mechanisms list 2

Answer 26

1. direct | 2. indirect

Question 27

Regulation of BP - Blood Volume - Renal Mechanisms - Direct

Answer 27

rate of urine formation determined by BP e.g. > BP = > flow to kidneys = > filtration = > urine = < BV + Bp

Question 28

Regulation of BP - Blood Volume - Renal Mechanisms Indirect

Answer 28

``` Hormones - RAAS = < pressure = angiotensin 2 = - vasoconstriction - aldosterone secretion - ADh - Thirst which all increase pressure ```

Question 29

Endocrine regulation - autoregulation

Answer 29

changes in patterns of BF within capillary beds

Question 30

Endocrine regulation - list receptors

Answer 30

- baroreceptors | - stretch receptors

Question 31

baroreceptor reflex - > stimulation

Answer 31

> BR stimulation = < CO - peripheral vasodilation = < BP, venous return, CO

Question 32

baroreceptor reflex - < stimulation

Answer 32

< BR stimulation = > CO - sympathetic stimulation via cardioacceleratory - peripheral vasoconstriction

Question 33

carotid sinus reflex

Answer 33

monitors and protects blood flow to the brain

Question 34

aortic reflex

Answer 34

monitors + maintains blood flow in systemic circuit

Question 35

Capillary exchange - bulkflow | what is it and where does it move through

Answer 35

moves across capillary walls by bulk - out at arterial end - in at venous end moving through: - intracellular clefts - fenestrations - sinusoids

Question 36

hydrostatic pressure

Answer 36

- fluid pushing against tissue wall - to move fluid and small solutes through intracellular clefts/fenestrations - out of the capillaries

Question 37

colloid osmotic pressure

Answer 37

force related to tonicity | - pulling force back into capillaries at venous end

Question 38

list the 4 pathways of exchange for : - respiratory gases - nutrients - waste

Answer 38

1. lipid soluble across plasma 2. water soluble through intracellular clefts 3. small water soluble through fenestrations 4. large molecules in pinocytotic vessicles

Question 39

compensated shock

Answer 39

< 30% loss baroreceptor reflex - intense sympatehtic - intense vasoconstriction

Question 40

progressive shock

Answer 40

>35% of blood volume lost - ischaemic tissue damage - inadequate BP + BF = death

Question 41

hypovolaemic shock

Answer 41

- large scale loss | - eg haemorrhage

Question 42

hormones that increase BP

Answer 42

- adrenalin - nor adrenalin - angiotensin 2 - aldosterone - adh

Question 43

hormones that decrease BP

Answer 43

- ANP