Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CVR > CVR 16 Cardiac Output > Flashcards

CVR 16 Cardiac Output Flashcards

1
Q

Define CO, CI

A

cardiac output - output of ventricle 5-7 litres / min

cardiac index - output of ventricles per m2 - 3-5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where gets the most CO blood?

A

Liver and kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

SNS innervation to heart?

A

T1-4 via cervical and stellate with nt’s of NA and adrenalin on adrenergic receptors. Primarily Beta 1 on heart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Supply to heart arise in the ____ from dorsal
motor nucleus of ____ and nucleus ambiguus
routed via ganglia on surface in heart.
• Neurotransmitter _____ on cholinergic
receptors
– ________

A

medulla
vagus
Ach
muscarinic M2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

PNS “vagal tone”: tonic discharge dominant at
rest with SNS _____ called - ____________

SNS response: tonic discharge, increased/
dominant in stress with PNS inhibition: +
___________

A

inhibition
positive chronotrophic effect
negative chronotriophic effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What effect does Ach have on the pacemaker?

A

increasing outward K

Decreasing slow inward Ca and Na

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ach– decreases slope of _______ of SA node
potential increasing time required to reach
threshold

A

phase 4 RMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What effect does NA have on the pacemaker

A

increases pacemaker rate by increasing all 3 currents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

NA– increases slope of phase ______ of SA node
potential decreasing time required to reach
threshold

A

Phase 4 RMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the MOA of B1 blockers and Atropines

A

beta blockers like atenolol lower heart rate and contractility.

Atropine block M2 muscarinic Ach receptors heart rate increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is preload?

A

Preload includes all factors which determine VEDV or

ED fibre length of ventricular muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What determines blood volume?

A

Renin angiotensin aldosterone

ADH

Atrial natriutice peptide ANP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the determinants of contractility?

A

Sarcomere - muscle fibre length / starlings law

Sympathetic NS - increase contract

Parasympathetic NS - minimal negative

Hormones - Insulin, Thyroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

1.In the relaxed state (low Ca2+) binding of
_____ to _____ is blocked- as myosin binding
sites on actin are covered by ______

  1. When AP leads to increased Ca2+ , Ca2+
    binds to _____ causing tropomyosin to
    move & resulting in exposure of ______
    binding sites to _____
  2. Myosin binds to _____, followed by
    ratcheting action of myosin head group
    which shortens sarcomere as actin & myosin
    slide past each other
  3. ____ and _____ are released
  4. Binding of ATP to myosin head group
    causes detachment of actin & myosin
A

actin to myosin
tropomyosin

troponin
myosin
actin

ADP and Pi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

increase in _____ results in increase in SV & CO

• decrease in ______ results in decrease in SV & CO

A

VEDV

VEDV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Unlike skeletal muscle, cardiac sarcomeres have an optimum length that is
_____ than their resting length so increasing the _____ brings the
sarcomeres closer to optimum length

A

Greater

VEDV

17
Q

What is Starlings law of the heart?

A

•The force of contraction depends on initial fibre length

18
Q

measure of force of contraction: _________

• measure of initial fibre length: ____________

A

CO SV EF

LVEDV LVEDP

19
Q

What is a positive inotropic agents role on calcium

A

Beta agonists cause myocytes contract faster and more strongly

20
Q

What are inotropic agents

A

Beta 1 agonist SNS stimulation

Digitalis - inhibit Na K pump increasing Calcium intracellular

21
Q

What can diminish the amount of calcium intracellular ie negative inotropic agents

A

hypoxia ischemia, beta blockers, calcium channel blockers

22
Q

What is afterload

A

Force opposing cardiac muscle shortening
& ejection of blood during ventricular contraction

ventricular wall & arterial
impedance

23
Q

What is Ficks principle

A

amount of 02 going into lungs and alveoli must equal that in the pulmonary veins

24
Q

•Larger than normal VEDV (“enlarged” hearts) seen in patients
with cardiomyopathy can compensate somewhat in the early
stages for the reduced contractility that occurs in this condition
because stretching of the ventricular muscle cells:

A

Decreases influx of calcium during ventricular repolarisation

  • B. Enhances reuptake of calcium by sarcoplasmic reticulum
  • C. Decreases influx of calcium during ventricular depolarisation
  • D. Changes the overlap of thick and thin filaments
  • E. Improves conduction among muscle cells

CVR (43 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions