L13

Question 1

What is the purpose of the elastic systemic Arteries?

Answer 1

These are a pressure reserve that maintains blood flow during ventricular relaxation

Question 2

Arterioles are the site of variable resistance, what do they do to maintain this resistance/decrease it?

Answer 2

Arterioles adjust their diameter

Question 3

What do systemic veins serve as?

Answer 3

These serve as an expendable volume reserve

Question 4

What side of the heart allows for material exchange?

Answer 4

The right side of the heart

Question 5

What two components do blood vessels have? What are their function?

Answer 5

Blood vessels contain smooth muscle and elastic fiberous connective tissue:

Smooth muscle: regulates pressure
Elastic tissues: returning to normal state after stretch

Question 6

Wall thickness varies in different vessels, the more ____ the vessel is, the ____ exchange of materials take place.

Answer 6

The more thin the vessel is, the greater exchange of material takes place

Question 7

What is the inner most layer of blood vessels made of? What are the five function?

Answer 7

The inner most layer is endothelium which:

• acts as a barrier
• secretes paracrine factors
• regulates blood pressure
• regulates vessel growth
• regulates absorption

Question 8

What is muscle tone?

Answer 8

This is a state of partial contraction, there is always a contraction occurring in blood vessels.

Question 9

Describe the characteristics of arteries

Answer 9

• these are a key component in elasticity
• act as a pressure reservoir
• has a thick layer of vascular smooth muscles
• lots of elastic and fiberous tissues

Question 10

Describe the characteristics of arterioles

Answer 10

• site of variable resistance
• part of microcirculation
• less elastic and more muscular
• several layers of smooth muscle that act for constriction and relaxation

Question 11

Describe the characteristics of metarterioles

Answer 11

• branches of arterioles
• partial smooth muscle layer
• controls if blood goes into capillaries, acts as a bypass mechanism
• precapillary sphincters open and close to direct blood flow

Question 12

What occurs during ventricular contraction? What is the beginning phase?

Answer 12

• contraction of the ventricles pushes blood into elastic arteries causing a stretch
• beginnings phase is ventricular contraction

Question 13

What occurs during ventricular relaxation? What’s the beginning phase?

Answer 13

• elastic recoil in the arteries maintain driving pressure during ventricular diastole
• beginning phase is isovolumetric relaxation

Question 14

When precapillary sphincters _______, blood flows through the capillary into the blood

Answer 14

Relax/dilate

Question 15

When precapillary sphincters _______, blood flow bypasses capillaries completely and flows to metarterioles

Answer 15

Constrict

Question 16

What is the primary site of interstitial fluid and blood exchange?

Answer 16

The capillaries

Question 17

Describe the characteristics of the capillary walls

Answer 17

• more thin, less area to cross means more efficient
• lacks smooth muscles
• flat layer of endothelium
• basal lamina

Question 18

Describe the characteristics of pericytes

Answer 18

• highly branched contractile cells associated with capillaries
• contribute to capillary impermeability
• secrete paracrine factors that promote vascular growth and differentiation
• MORE PERICYTES for a more secure area so it doesnt leak.

Question 19

What is angiogenesis?

Answer 19

This is the development of new blood vessels (can cause spreading of a disease)

• necessary for normal development
• enhances heart and skeletal muscle blood flow

Question 20

What is angiogenesis controlled by? What’s it inhibited by?

Answer 20

It is controlled by cytokines and promoted by vascular endothelial factor and fibroblast growth factors.
- its inhibited by angiostatin and endostatin

Question 21

What is pulse pressure?

Answer 21

Pulse pressure measures strength pressure wave produced by ventricular contraction

Systolic pressure- diastolic pressure

(This decreases over distance due to friction)

Question 22

What is mean arterial pressure? What are the two types?

Answer 22

Diastolic pressure + 1/3 pulse pressure

This represents the driving force. There are two types:

Hypotension- lower than normal MAP
Hypertension- higher than normal MAP

Question 23

Volume of blood in arteries is determined by _______ and flow out

Answer 23

Is determined by input (cardiac output)

Question 24

As arterial volume increases ______ increases

Answer 24

Pressure increases. This applies both ways. As arterial volume decreases pressure decreases.

Question 25

If flow exceeds flow ____ (of) aorta then blood volume ______ and MAP increases

Answer 25

Out, increases | Vice versa can occur

Question 26

Blood volume is relatively constant, change in blood volume affects blood pressure in the following ways: Blood volume ____, pressure ______, / Blood volume ____, pressure _____

Answer 26

Increases, increases / decreases, decreases

Question 27

MAP is determined by 4 factors, list them.

Answer 27

1. Blood volume 2. Effectiveness of heart as pump 3. Resistance of the system to blood flow 4. Distribution of blood between arteries/veins

Question 28

Blood pressure control includes _____ responses from cardiovascular system and _____ responses from the kidneys

Answer 28

Rapid, slower

Question 29

Arterioles have a resistance that is influenced by what?

Answer 29

Local and systemic control mechanisms (local control, sympathetic control, reflexes, hormones)

Question 30

What do myogenics autoregulation adjust?

Answer 30

These adjust the blood flow which allows for vascular smooth muscles to regulate its own state of contraction.

Question 31

Paracrine signals influence vascular smooth muscles, list more of their characteristics

Answer 31

- these secrete NO, which is a major signal in hypertension (which blocks airway) - kinins and histamines are a potential vasodilator - metabolic influences causes active vs reactive hypermia

Question 32

What is hypermia? What are the two types?

Answer 32

This is a locally mediated increase in blood flow. Active hypermia- direct matching of blood flow to increased metabolism Reactive hypermia- follows a period of decreased blood flow

Question 33

Neural and hormonal signals have three types:

Answer 33

- atrial nativertic peptide (this occurs in contraction) - angiotensin II - vasopressin (ADH)

Question 34

Characteristics of sympathetic control on vascular smooth muscle

Answer 34

- adrenal medially releases epinephrine into blood - epinephrine binds to alpha and beta receptors - binds alpha receptors with very low affinity—> vasoconstriction Binds beta 2 receptors on vascular smooth muscles of heart, liver and sketch muscle arteries which causes—> vasodilation

Question 35

What is arteriole diameter controlled by?

Answer 35

Tonic release of norepinephrine

Question 36

Blood distribution ____ according to metabolic need of individuals tissues

Answer 36

Varies

Question 37

Two factors that govern distribution of blood

Answer 37

Local control mechanism and homeostatic reflexes

Question 38

The flow in aorta is equal to _____ in all arterioles due to branching

Answer 38

The flow

Question 39

What do individual arterioles regulate on their own?

Answer 39

They regulate their own flow by compensation in remaining arteries

Question 40

What is the importance of the Cardiovascular Control Centre?

Answer 40

It’s contains the baroreceptor reflex that controls blood pressure, these produce continuous tonic action potential

Question 41

Wha triggers the baroreceptor flex? Explain how.

Answer 41

Orthostatic hypertension triggers this reflex, this decreases in blood pressure due to postural change. Failure to compensate may lead to lack of O2 delivery.

Question 42

What is the intrinsic rate of the heartbeat modulated by?

Answer 42

This is modulated by sympathetic and parasympathetic neurons. The blood vessel diameter is under tonic control by the sympathetic division

Question 43

Difference between continuous and fenstrated capillaries

Answer 43

``` Continuous= have a leaky junction Fenstrated= larger pores ```

Question 44

Describe what happens with velocity of the blood flow in capillaries

Answer 44

- constant rate of flow, velocity of flow is higher in smaller diameter tubes - velocity of blood flow is lowest in capillaries - total cross sectional area of capillaries is primary determinate of velocity

Question 45

___ flow in artery system, ___ flow in capillaries and venules

Answer 45

Fastest, slowest

Question 46

Exchange between plasma and interstitial fluid occur by what?

Answer 46

Paracelluallar pathways and endothelial transport

Question 47

Describe movement by diffusion

Answer 47

This is small dissolved solutes and gases that depend on lipid solubility and concentration gradients

Question 48

Describe the vesicular transport method

Answer 48

This carries large solutes and proteins via transocytosis

Question 49

Describe what occurs during filtration

Answer 49

- this is where fluid movement is out of capillaries - this had pressure laterally or against gradients - if hydrostatic pressure increases (or is greater) filtration occurs - caused by hydrostatic pressure—> which decreases with distance

Question 50

Describe what happens during absorption

Answer 50

- Fluid movement into capillaries - caused by colloid pressure - due to presence of proteins in fluid that attract back into system

Question 51

Net filtration at atrial end occurs when _______ | Net absorption at Venus end occurs when______

Answer 51

Hydrostatic pressure> osmotic colloid | Hydrostatic pressure

Question 52

A net average of ___L per day of fluid is filtered out of the capillaries

Answer 52

3

Question 53

An increase in hydrostatic pressure ______ | A decrease in colloid osmotic pressure ______

Answer 53

Forces fluids out of capillary | Forces fluids into capillary

Question 54

What is Edema?

Answer 54

This is an accumulation of fluid in the intestinal space. Inadequate drainage of Lymph or filtration greater than absorption.