Cardiovascular Physiology Part 3

Front 1

Blood flow

Back 1

Volume of blood flowing through any tissue/min

Determined by pressure and resistance

F = P/R

Front 2

Resistance depends on

Back 2

1. Vessel length

2. Viscosity of blood

3. Radius of arteruoles

Front 3

Radius of arterioles

Back 3

Most import control of blood flow

Controlled by smooth muscle innervate by SNS

Front 4

2 types of intrinsic arterioles radius

Back 4

1. Myogenic regulation

2. Metabolic regulation

Front 5

Myogenic regulation

Back 5

When smooth muscle is stretched it contracts (if pressure/flow increase arterioles constrict to limit flow/keep amount of blood the same)

E.g. standing up blood rushes to feet, so feet vasoconstrict

Front 6

Nitric oxide

Back 6

Increases blood flow to organ

Released by endothelial and hemoglobin

- when O2 and pH decrease and CO2

increases (aka. More ATP used by

cells)

Front 7

Endothelins

Back 7

Decrease blood flow to organs (vasoconstriction)

Released by endothelial cells if metabolism is low

Front 8

Types of extrinsic regulation of Caterpillar radius

Back 8

1. Neural regulation

2. Hormonal regulation

Front 9

SNS and artiolar radius

Back 9

1. Vasoconstriction

2. Venoconstriction

3. Causes release of epi

Doesnt impact brain!

Front 10

Epinephrine impact on arterioles radius

Back 10

1. Vasoconstriction of skin, viscera, ect.

2. Vasodilation of heart skeleton muscle, liver, ect (opposes SNS, = overall no change)

Front 11

Angiotensin II

Back 11

Hormone that causes vasoconstriction

Front 12

ADH

Back 12

Hormone that causes vasoconstriction

Front 13

Histamine

Back 13

Hormone that causes vasodilation

Front 14

Pulse pressure

Back 14

Systolic pressure - diastolic pressure

Front 15

Mean arterial pressure

Back 15

Average blood pressure through cardiac cycle

MAP = dist. P + 1/3 pulse P

Front 16

MAP factors

Back 16

1. Cardiac output

2. Total peripheral resistance (a.k.a. arterioles radius)

3. Blood volume

Front 17

Baroreceptors reflexes

Back 17

Short term changes

stretch receptors (monitor MAP) in

1. Carotid sinus (brain bp)

2. Aortic arch (systemic bp)

Front 18

Baroreceptors impulses

Back 18

Go to medulla

Causes decrease in SNS and decreases CO

Front 19

Chemoreceptors

Back 19

Respond to pH, CO2 and O2

1. In aortic arch

2. In carotid sinus

Called bodies

Regulate respiration and affect bp

Front 20

Increase in chemoreceptors signals

Back 20

From increase metabolism

Causes

1. Increase in SNS

2. Increase in Epi

3. Vasoconstriction (increase CO)

Side effect = increase MAP

Front 21

Epinephrine effect on MAP

Back 21

Increase force of contraction

Increase CO

Increase MAP

Front 22

Rein-angiotensin system

Back 22

Starts: plasma angiotensinogen (protein in blood)

Ends with angiotensin II

Front 23

Angiotensin I

Back 23

Formed from plasma angiotensinogen by rein (enzyme from kidney)

Makes angiotensin II when exposed to angiotensin converting enzyme

Front 24

Angiotensin II causes

Back 24

1. Increase vasoconstriction (MAP)

2. Increase Aldosterone & ADH (increase blood volume & MAP)

Front 25

Atrial natriuretic peptide

Back 25

Decreases aldosterone & ADH

Increase urine production & decreases blood volume (decrease MAP)

Front 26

Capacitance vessels

Back 26

Large veins

Front 27

Resistance vessels

Back 27

Arterioles