Unit 1 Day 1 Flashcards Preview

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Flashcards in Unit 1 Day 1 Deck (30)
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1
Q

Function of CV System

A
  • provide cells with nutrients and to exchange oxygen

- to maintain homeostasis

2
Q

Series Arrangement Circulatory

A

-blood flow in L and R heart is arranged in series, and therefore must be closely matched

3
Q

Parallel Arrangement Circulatory

A
  • systemic circulation is primarily in parallel

- changes in metabolic demand or blood flow to one organ does not affect other organs

4
Q

4 Chambers of Heart R to L

A
  • right atrium
  • right ventricle
  • left atrium
  • left ventricle
5
Q

4 Vessels of Heart R to L

A
  • superior/inferior vena cava
  • pulmonary artery
  • pulmonary vein
  • aorta
6
Q

4 Valves of Heart R to L

A
  • tricuspid
  • pulmonary
  • mitral (bicuspid)
  • aortic
7
Q

MIcrocirculation Arrangement

A
  • arterioles to capillaries to venules

- blood flow determined by pressure and regulated by arterioles and precapillary sphincters

8
Q

Function of Lymphatic System

A
  • carries fluid from interstitial space to blood supply

- filters interstitial fluid in lymph nodes

9
Q

Flow Equation

A

Q = deltP/R

  • Q is flow (vol/time)
  • deltP is pressure difference
  • R is resistance
10
Q

Poiseuille’s Equation

A

Q = deltP [(pi r^4)/(8nl)]

  • Q is flow
  • r is radius
  • l is length of vessel
  • deltP is pressure difference
  • n is viscosity of blood
11
Q

Pulsatile Flow

A
  • heart beat produces pulsatile flow
  • pulse pressure is dampened in arterial system
  • flow is continuous in capillaries
12
Q

Vascular Compliance

A

C = deltV/deltP

  • C is compliance
  • deltv is change in volume
  • deltP is change in pressure
  • compliance represents the elastic properties of vessels
13
Q

LaPlace’s Law

A

T = (deltP x r)/u

  • T is tension (or wall thickness)
  • deltP is transmural pressure
  • r is radius
  • u is wall thickness
14
Q

Fick’s Principle

A

Xused = Xi - Xo

  • Xused is amount used
  • Xi is initial amount
  • Xo is final amount
  • can be used to determine transcapillary efflux
  • needs more info
15
Q

Starling’s Equation

A

Flux = k[(Pc - Pi) - (PIc - PIi)]

  • flux is net movement across capillary wall
  • k is constant
  • Pc is capillary hydrostatic pressure
  • Pi is interstitial hydrostatic pressure
  • PIc is capillary oncotic pressure
  • PIi is interstitial oncotic pressure
  • net hydrostatic pressure tends to be outward (filtration)
  • net oncotic pressure tends to be inward (reabsorption)
  • balance between hydrostatic and oncotic pressure in capillary bed determines the direction of transcapillary transport
16
Q

Unique Cellular Properties of Cardiac Muscle

A
  • 2-3 billion cardiac muscle cells
  • striated (like skeletal muscle)
  • not under direct neural control
  • shorter, narrower, and richer in mitochondria than skeletal muscle cells
  • ATPase activity of cardiac muscle is slower than skeletal muscle but faster than smooth muscle
  • Ca2+ binding to troponin regulates actomyosin interaction
17
Q

Cross-Bridge Cycle

A
  • rest state- no Ca2+, weakly bound, non-force generating
  • transition state-Ca2+ bound, XB weakly bound, non-force generating
  • active state-Ca2+ bound, XB strongly bound, force generating
  • active state- no Ca2+, XB strongly bound, force generating
18
Q

Length-Tension Relationship (Frank-Starling) of Cardiac Muscle

A
  • intrinsic mechanism by which the heart adapts to changes in preload
  • violation of Starling’s Law corresponds to heart failure
  • the effect of increasing preload on increasing force of contraction
  • length-tension relationship: inc. volume in ventricle and cells stretch
  • greater preload = greater force generated

Mechanisms Behind L-T Relationship

  • extent of overlap
  • change in sensitivity of myofilament to calcium
  • inc. calcium release
  • cardiac titin isoform is very stiff, resists stretch
19
Q

Sarcomeric changes associated with heart failure

A
  • contractile function is depressed in heart failure

- needs update

20
Q

Cardiac Output

A
  • volume of blood pumped per min by L ventricle
  • CO = heart rate x stroke volume = 5 L/min
  • stroke vol = vol blood pumped per beat
21
Q

4 Phases of Cardiac Cycle

A
  1. diastole
  2. isovolumetric contraction phase
  3. ejection phase
  4. isovolumetric relaxation phase
22
Q

End Diastolic Pressure-Volume Relationship Phase (EDPVR)

A
  • pressure-volume relationship during filling of heart BEFORE contraction
  • represents the PRELOAD on the heart
23
Q

Preload

A
  • length to which a muscle is stretched before shortening
  • for L ventricle, preload ~ end diastolic volume
  • inc. in preload = inc. in stroke volume
24
Q

Afterload

A
  • the load against which a muscle contracts
  • for L ventricle, afterlaod ~ aortic pressure
  • inc. in afterload = dec. in stroke volume
25
Q

Systolic Pressure-Volume Relationship (SPVR)

A
  • afterload

- pressure-volume relationship at peak of isomeric contraction

26
Q

PV Loop Diagram

A
  • diagram of pressure and volume during cardiac cycle

- see an example

27
Q

Stroke Volume

A

-volume of blood pumped per beat

28
Q

Stroke Work

A
  • energy per beat in Joules
  • corresponds to area inside PV loop diagram
  • NOT same for L and R sides of heart- L heart does more work
29
Q

Pulse Pressure

A

-difference between systolic and diastolic pressure points

30
Q

Contractility

A
  • inotropy
  • length-independent mechanism
  • most obviously regulated via sympathetic nervous system stimulation
  • inc. in contractility = inc. in stroke volume