Cardiovascular system compensation

Question 1

What role does innervation of the heart play

Answer 1

1. it modulates the output so the nerves can change contractility and heart rate

Question 2

What type of nerves supply the heart?

Answer 2

autonomic nerves

Question 3

How can the sympathetic nervous system best be defined?

What affect does this have on the heart?

Answer 3

Fight flight or freeze

Inc contractility and HR

Question 4

How is the parasympathetic nervous system described. What affect does this have on the heart?

Answer 4

Rest and digest

Decrease in contractility and HR

Question 5

What affect does the sympathetic nervous system have on blood vessels?

Answer 5

Vasoconstrict to non essential organs: GI tract, Reproductive tract, Skin, kidney (everything else)
Vasodilation to essential organs: working skeletal muscle, heart (also brain)

Question 6

What is the origin and exit of the sympathetic sympathetic nervous system?

Answer 6

Both originate in CNS but exit different:
1. Sympathetic nerves exit from spinal cord: Thoracolumbnar segments: only thoracic and lumbar portions of spinal cord: T1- L2

Question 7

Talk about sympathetic nervous system and ganglion

Answer 7

Short PRE ganglionic fibres that travel to a ganglion and synapse with a post ganglionic fibre

Question 8

What is the sympathetic supply to the heart?

Answer 8

From the sympathetic ganglia C5 - T3

NOT THE SAME AS SPINAL C5 and T3!!!!

Question 9

Where is the anatomical origin of the parasympathetic nervous system

Answer 9

1. Craniosacrel origin
   Because the preganglionic fibres from para exit from either cranial nerves in brain stem or sacral spinal segments.
   Cranial nerves are 3, 7, 9, 10 (vagus nerve which supplies the throacic viscera)

Question 10

Which vessels are most responsible for altering blood flow to a tissue in the systemic circulation

Answer 10

1. Arterioles

Question 11

What effect will a generalised vasodilation have on cardiac output and why?
What if just arteriole dilation

Answer 11

First = most common
1. decrease preload as making vessels wider:. reduce hydrostatic pressure:. reduce pressure leading into heart
2. Reduced preload reduces cardiac output as reduces EDVV:. reduced V filling:. reduces SV
CO = SV X HR
ALSOOOOO
1. arteriole dilation = decreased afterload = inc CO
2. because dec AL = reduced ESVV as bigger pressure gradient (pressure in arteries is lower than the pressure V generates so more blood moves out = less left in V at end of Systole)
therefore higher ejection fraction, higher SV, higher CO

Question 12

What effect will a generalised vasoconstriction have on cardiac output and why?

Answer 12

1. inc CO as inc preload as dec size of container = inc Hydrostatic pressure = inc pressure supplying V
2. Decrease CO as inc afterload = reduced ventricular emptying - less blood moves out.

Question 13

What BV does the parasympathetic nervous system innovate?

Answer 13

ONLY genital and coronary, other effects on BV is due to lack of sympathetic stimulation rather than direct parasympathetic effect”

Question 14

What receptors do the blood vessels that are innovated by the parasympathetic nervous system have?

Answer 14

M3 CHOLINERGIC

Question 15

What heart receptor is associated with the para

Answer 15

M2 CHOLINERGIC

Question 16

What receptors do the blood vessels have that are innovated by the sympathetic nervous system

Answer 16

alpha 1, 2, Beta 2 adrenergic receptors

Also M3 CHOLINERGIC

Question 17

What receptors does the heart have that is innovated by the sympathetic nervous system?

Answer 17

beta 1 adrenergic on cardiac myocytes and nodal tissue

Question 18

What is nodal tissue?

Answer 18

a unique type of tissue that has both muscular adn nervous characteristics adn can be found at the SAN and AVN. Responsible for coordinating the cardiac cycle

Question 19

What are the 5 systems that manage BP during exercise

Answer 19

1. Metabolic autoregulation of blood flow
2. Psychogenic response
3. Exercise reflex
4. Baroreflex
5. Skeletal muscle and Respiratory pumps

Question 20

How deos the psychogenic response affect the body

Answer 20

1. Inc sympathetic activity, dec para
2. inc CO: inc HR, contractility, conduction speed
3. Increased TPR (total pulmonary resistance): vasoconstriction of non-essential organs, inc preload
4. inc blood pressure
5. this is a graded response and continues throughout exercise, changing degree

Question 21

What is the exercise reflex?

Answer 21

1. mechanical- to do with activity of joint and muscle by receptors which tell train how hard you are working
2. Modifies the degree of autonomic activity
3. feedback system

Question 22

What is the respiratory pump?

Answer 22

1. increase depth and rate of breathing helps pump blood due to physical expansion adn contraction of chest = squishes and stretches vessels in chest = inc preload

Question 23

What is the skeletal pump

Answer 23

1. veins squashed more = emptying veins = push blood back to heart = fill more readily = inc preload

Question 24

What is the baroreflex?

Answer 24

1. monitors blood pressure

Question 25

Preganglionic fibres of the parasympathetic nervous system are from these segments:

Answer 25

Craniosacral

Question 26

Preganglionic fibres of the sympathetic nervous system are from these segments:

Answer 26

Thoracolumbar

Question 27

What is the effect of alpha 1 & 2 adrenergic activation on arterioles? Sympathetic

Answer 27

1. Vasoconstriction

2. Purpose: increase TPR, decreases blood flow to organs

Question 28

What type of neurotransmitter do adrenergic sympathetic nervous system release

Answer 28

1. Circulating noradrenaline: in blood stream = fight or flight response
2. “local” noradrenaline: adreanaline from sympathetic neurones (acts directly on nearby receptor

Question 29

What is the effect of alpha 1 & 2 adrenergic activation on veins? Sympathetic

Answer 29

1. Vasoconstriction

2. Purpose: move venous blood towards heart: increase preload

Question 30

What is the effect of beta 1 adrenergic activation on Cardiac myocytes, including nodal tissue. Sympathetic

Answer 30

1. Inc HR
2. Faster conduction
3. Shorter refractory period
4. inc contractility
   PURPOSE = inc cardiac output

Question 31

What is the effect of beta 2 adrenergic activation on coronary and skeletal muscle arterioles. Sympathetic

Answer 31

1. Vasodilation

PURPOSE = increased coronary and skeletal muscle blood flow

Question 32

What is the effect of M2 Cholinergic receptors on cardiac myocytes, mainly SAN adn AVN- less direct innovation of ventricular cells

Answer 32

1. Ach
2. oppo to B1: dec HR, slower conduction, longer refracotyr, dec contractility
   PURPOSE: decrease CO

Question 33

What is the effect of M2 Cholinergic receptors on sympathetic nerve endings at ventricular cells

Answer 33

1. Ach
2. inhibits release of noradrenaline frm sympathetic nerves
   PURPOSE= counteracts sympathetic effect on ventricular cardiomyocytes

Question 34

What is the effect of M3 receptors on the coronary arteroiles

Answer 34

1. Ach
2. Vasodilation
   PURPOSE: inc coronary blood flow (slightly)

Question 35

What is the effect of M3 receptors on the genital arteroiles

Answer 35

1. Ach
2. Vasodilation
   PURPOSE: engorgement and erection

Question 36

What is the effect of M3 receptors on the Skeletal muscle

Answer 36

1. Ach
2. Vasodilation
   PURPOSE: increased skeletal and muscle blood flow

Question 37

Broadly what are the 4 points to remember about para/ sym and Cholinergic vs adrenergic

Answer 37

1.*Parasympathetic NS tends to reduce
cardiac output and BP.
2. Sympathetic NS tends to increase cardiac
output and BP.
3. Cholinergic receptors respond to
acetylcholine from the presynaptic
neurone.
4. Adrenergic receptors respond to
noradrenaline from the presynaptic
neurone, and circulating noradrenaline or
adrenaline from the adrenal gland