Brainscape's Knowledge GenomeTM

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


See full index

BMSC 207 > Cardiovascular 5 > Flashcards

Cardiovascular 5 Flashcards

1
Q

Sympathetic modulation of contraction (SV): 4 steps

A
  1. Phosphorylation of CA2+ channels increases calcium conductance during an AP
  2. Phosphorylation of ryanodine receptors enhances sensitivity to Ca2+, increasing release of Ca2+ from SR
  3. Increases rate of myosin ATPase (binds faster)
  4. Phosphorylation of SERCA increases speed of CA2+ reuptake, increasing Ca2+ storage
    -that can be used for next contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Increasing sarcomere length increases

A

Force of Contraction (SV)

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

2 Reasons why increasing sarcomere length will increase force of contraction

A
  1. Increases the Ca2+ sensitivity of Myofilaments
    -a stretched sarcomere has a decreased diameter, can reduce distance Ca2+ needs to diffuse
    -increases probability of cross bridging
  2. Additional tension on stretch activated Ca2+ channels
    -increases Ca2+ entry from extracellular space
    -increasing Ca2+ induced Ca2+ release
    -increases tension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The degree of myocardial stretch prior to contraction is known as

A

The preload on the heard
-load on ventricles before contraction
Increase preload= increase contractility

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

Frank- Starling Law of the Heart

A

Stroke volume increases with increasing EDV

The amount of force developed by cardiac muscle of ventricle (SV) depends on the initial stretch oof the ventricle walls (ventricular filling)

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

How is EDV determined

A

Normally by Venous return
-increased venous return increase venous pressure
-results in increased atrial filling and leading to increased ventricle filling

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

Factors affecting Venous Return: (3)

A
  1. Skeletal Muscle Pump
  2. Respiratory Pump
  3. Sympathetic Constriction of Veins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does the Skeletal Muscle Pump affect venous Return

A

Skeletal muscle activity compresses veins in the extremities, pushing blood back to the heart
-increased muscle activity of the extremities can increase venous return
-through one way valves it returns
-pressure in veins usually low at rest

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

How does the Respiratory Pump affect Venous Return

A

During inspiration, the chest expands and diaphragm moves down
-creates a subatmoshperic pressure in the thoracic cavity
-draws blood into the vena cava that exist within
Basically makes thoracic cavity bigger and creates a negative reassure to stretch internal viscosities more
-also during inspiration veins in the abdomen are compressed -forces blood back to the heart

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

How does sympathetic constriction of veins affect Venous Return

A

-decreases their volume squeezing blood back towards the heart
-Fromm norepinephrine -pressurized blood to increase return

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

What is after load

A

The end load against which the heart contracts to eject blood

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

3 factors that affect SV of the heart

A

Preload. After load, COntractility

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

How is afterload determined

A

By the combination of the EDV and the pressure in the outflow artery, prior to contraction

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

Afterload can be increased how

A

Increased arterial blood pressure, decreased aortic compliance, chronic hypertension, echocardiography, altered ejection fraction

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

Hypertrophy in the Ventricles means

A

The muscle around it (wall) gets thicker
-this causes the ventricles to lose elasticity and compress the coronary arteries
-results in a lower SV as the ventricle can’t stretch to fill

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

Heart rate is determined by

A

The rate of depolarization in autorhytmic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Cardiac Output is determined by:

A

Heart rate and Stroke volume
-about 5L/min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Heart rate decreases due to

A

Parasympathetic innervation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Heart rate increases due to

A

Sympathetic innervation and epinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Stroke Volume is determined by

A

Force of contraction in ventricular myocardium

21
Q

Stroke Volume is influenced by

A

Contractility, EDV, Afterload

22
Q

Contractility is increased by

A

Sympathetic innervation and epinephrine

23
Q

EDV varies with affect from

A

Venous return
-respiratory pump and skeletal muscle pump

24
Q

An increase in afterload causes a what in SV

A

A decrease in SV

25
Q

Each side of the heart…

A

Functions as an independent pump and loop

26
Q

Elastic systemic arteries are a pressure reservoir that

A

Maintain blood flow during ventricular relaxation

27
Q

The arterioles are the site of

A

Variable resistance
-choose where blood is constricted to or allowed to

28
Q

Gas exchange between the blood and cells takes place

A

ONLY at the capillaries

29
Q

Systemic veins serve as

A

An expandable volume reservoir
-half the blood in the body sits in the systemic veins

30
Q

Progressive branching of vessels pathway:

A

Aorta> Arteries > Arterioles > Capillaries > Venules ? Veins > Vena cavas

31
Q

All vessels contain what inner layer

A

An inner layer of thin endothelial cells
-can be wrapped in a combination of elastic tissue, smooth muscle, or fibrous tissue

32
Q

Endothelial Cells are important in: (4)

A

Secreting Paracrines
Regulation of BP
Blood Vessel Growth
Absorption of Materials

33
Q

In most vascular smooth muscle, there is always a state of

A

Partial contraction
-can be influenced by neurotransmitters, hormones, paracrines (Sympathetic Input)
-these bind receptors, resulting in increased cystitis Ca2+ release, causing contraction

34
Q

Systemic circuit begins with

A

The aorta (single), branches off to major arteries

35
Q

Arteries walls breakdown:

A

Walls are both stiff and springy (pressure reservoir)
-thick smooth muscle layer and large amount of elastic and fibrous connective tissue

36
Q

Arteries branch into

A

Arterioles
-that mainly have vascular smooth muscle

37
Q

Microcirculation

A

Smallest place where circulation takes place
-arterioles, capillaries, venules
-across you have metarterioles which are bypass vessels (also for WBCs)

38
Q

Capillaries breakdown

A

-smallest venules in the CV system
-majority of exchange of O2 between blood and interstitial space happens
-single think endothelial layer surrounded by basal lamina (extra cellular matrix)
-gases normally passively diffuse across endothelial cells

39
Q

Capillaries are linked by

A

Interendothelial junctions -also aid in transport of small solutes and water
-they are like tight junctions (transmembrane proteins that link adjacent cells together)
-

40
Q

What are Fenestrations in Capillaries

A

Membrane lined pores running through them to allow the transport of substances between plasma and interstitial fluid

41
Q

Capillaries are often surrounded by

A

Pericytes (BBB)
-periocytes and astrocytes
-prevents substances from the plasma to interstitial fluid of the brain (which is good)

42
Q

Main types of Capillaries: (3)

A
  1. Continuous Capillary
  2. Fenestrated Capillary
  3. Discontinuous (sinusoidal) Capillary
43
Q

Continuous Capillaries

A

Most common
-seen in brain
-thicker endothelial cells that don’t contain fenestrations
-only allow passage of water and small ions through intercellular junctions
-least amount of transport

44
Q

Fenestrated Capillaries

A

-found in Kidneys, GI Tract
-thin endothelial cells-perforated with fenestrations (pores)
-small molecule passage
-increased amount of transport

45
Q

Discontinuous Capillaries

A

-least common
-found in liver, spleen, bone marrow
-lack a basal membrane
-large open fenestrations
-gaps between endothelial cells
-large proteins for large gap

46
Q

Methods of Transport in Capillaries: (3)

A
  1. Transcellular Transport
  2. Paracellular transport
  3. Transcytosis
47
Q

Transcelluar Transport in Capillaries

A

-diffusion or osmosis across endothelial cell membrane
-gases, small lipid soluble molecules, water (aquaporin channels)
-some facilitated diffusion

48
Q

Paracellular Transport in Capillaries

A

-diffusion through inter endothelial junctions, pores, or fenestrations
-water, small water soluble, small polar molecules

49
Q

Transcytosis in Capillaries

A

-combo of endocytosis, vesicular transport, and exocytosis
-transport macromolecules (bigger) across endothelial cells

BMSC 207 (15 decks)

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