Chap 21 Blood Vessels

Question 0

What is an embolus?

Answer 0

Something that travels through the bloodstream, lodges in a blood vessel and blocks it ( embolism)

Ex: detached blood clot, clump of bacteria, air

Question 1

How are arteries and veins different?

Answer 1

Arteries are made to withstand pressure, muscular, elastic

Veins have valves to prevent back flow not built for high pressure

Question 2

What is a cerebrovascular accident?

Answer 2

It’s a stroke… An interruption of the blood supply to any part of the brain

Question 3

Describe the two kinds of artieries

Answer 3

Elastic: high content of elastic fibers in the aorta and branches. Works like a pressure reservoir

Muscular: smooth muscle tissue. Adjust the rate of blood flow through vasodilation and vasoconstriction

Question 4

What happens when blood first enters the Aorta?

Answer 4

It stretches when it receives the blood then retracts. The retracting gives an extrA pulse if pressure to push the blood further

Question 5

What is atherosclerosis?

Answer 5

Fatty material collects along the walls of arteries. This fatty material thickens hardens and may eventually block the arteries.

Question 6

How does a blood clot form in an artery?

Answer 6

Plaque breaks off of the wall of the artery exposing colleges which calls the platelets which forms a clot

Question 7

What is an aneurysm?

Answer 7

Abnormal widening or ballooning of a portion of an artery due to weakness in the wall if a blood vessel

Question 8

Describe capillaries

Answer 8

Smallest blood vessel thinnest

Connect arterial outflow to venous return

Exchange between blood and interstitial fluid which surrounds body tissue

Question 9

How does blood flow through the capillaries

Answer 9

One blood cell through at a time

More surface area which allows for rapid exchange between rbc and interstitial fluid

Blood slows significantly through capillaries, allows for efficient exchange

Question 10

Describe the different types of capillaries

Answer 10

Continuous: most capillaries - exchange between o2 and co2

Sinusoids: giant holes… Found in the liver spleen and red bone marrow… Filters out old rbc’s

Fenstrated: found in the kidneys… Lots of holes helps filter a good amount of water

Question 11

How do the capillaries control movement?

Answer 11

There are sphincter muscles around the capillaries squeezing or relaxing to push the blood through or constrict it

Question 12

Describe capillary exchange

Answer 12

Movement of substances between blood and interstitial fluid

Diffusion: high to low concentration of o2
Most important, works with o2 and co2

Bulk flow: through the kidneys
Regulate blood volume

Question 13

Explain the relationship between velocity and area in blood flow

Answer 13

The less area the more velocity

The greater the area the less velocity

Question 14

Describe veins

Answer 14

Not designed to withstand high pressure

More numerous than arteries ( blood reserves)

Superficial- very susceptible to pressure changes

Deep - completely surrounded and protected by skeletal muscle

Valves prevent backflow

Question 15

What are varicose veins?

Answer 15

Swollen twisted and sometimes painful veins that have filled with an abnormal collection of blood

Valves no longer work properly so there is backflow

Question 16

What is phlebitis?

Answer 16

Inflammation of veins

Question 17

What are hemorrhoids?

Answer 17

Swollen veins in the anal canal

Too much pressure on the veins in the pelvic and rectal area

Question 18

Where do you find the greatest volume of blood?

Answer 18

Systemic veins and venules

Question 19

What is blood pressure?

Answer 19

Contraction of ventricles

Systolic bp: highest bp in arteries during contraction

Diastolic: lowest bp during relaxation

Question 20

How many pulse points are in the body

Answer 20

9

Question 21

Explain blood pressure (mean arterial pressure)

Answer 21

The average between systolic and diastolic

Map = co x r

R= vascular resistance

Question 22

What is vascular resistance and what are the 3 aspects of it?

Answer 22

Opposition to blood flow

1. Size of lumen ( area where blood passes)
2. Blood viscosity ( thickness, rbc/volume
3. Total length of blood vessels (area)

Decrease of lumen = increase of vascular resistance

Increase of resistance = increase of cardiac output

Increase of viscosity = increase in resistance = increase in mean arterial pressure

Question 23

Explain the different kinds of hypertension

Answer 23

Benign: extended period of high bp

Malignant: sudden and rapid development of extremely high bp > than 200/140

Essential: high bp with no known cause

Question 24

Explain congestive heart failure

Answer 24

Hypertension over a long period of time leads to CHF

Caused by myocardial infarction, mitral insufficiency, CAD (coronary artery disease) hypertension

If left side fails=pulmonary edema

If right side fails = peripheral edema (arms and legs swelling)

Question 25

In venous return explain the skeletal muscle pump

Answer 25

For the deep veins contraction of the skeletal muscle presses on the veins an forces the blood upward toward the heart. The valves close to prevent back flow. When the muscle relaxes blood enters the vein but only from the arterial side.

Question 26

In venous return explain the role of the respiratory pump.

Answer 26

Breathing in causes negative pressure in the thorax causing a suction effect… This means the pressure gradient pushing blood towards the right atrium is increased, thus more blood returns to the heart. Therefore inspiration leads to an increase in venous return.

Question 27

In the cardiovascular center, what nerve impulses are input?

Answer 27

From higher brain centers: cerebral cortex, limbic system, and hypothalamus

From proprioceptors: monitor joint movements

From baroreceptors: monitor blood pressure

From chemoreceptors: monitor blood acidity H+, CO2, and O2

Question 28

In the cardiovascular center what are the output effectors?

Answer 28

Vagus nerves (parasympathetic)= decreased heart rate

Cardiac accelerator nerves (sympathetic) = increased heart rate and contractility

Vasomotor nerves (sympathetic) = blood vessels vasoconstriction

Question 29

In neural regulation of blood pressure, what are the three reflexes that affect this?

Answer 29

Baroreceptor reflexes

Carotid sinus reflex (internal carotid)

Aortic sinus reflex

Question 30

Explain how baroreceptor reflexes work

Answer 30

Baroreceptors are found in the carotid and aortic sinus reflexes

They are pressure sensitive receptors that respond to changes in blood pressure

Question 31

What is the function of the carotid sinus reflex?

Answer 31

Monitors changes in blood pressure to the brain

Question 32

What is the function of the aortic sinus reflex?

Answer 32

It monitors pressure changes to the systemic circuit

Question 33

What are chemoreceptors extremely sensitive too?

Answer 33

Carbon dioxide levels

Question 34

What happens when you faint and what are the causes?

Answer 34

Decreased blood flow to the brain, results in a temporary loss of consciencness

Causes: dehydration, psychological factors, shock, drugs and alcohol, standing up suddenly

Question 35

What is shock?

Answer 35

Condition where the tissues in the body don’t receive enough oxygen and nutrients

This ultimately leads to cellular death, progressing to organ failure and finally to whole body failure and death

Four types : hypovolemic, cardiogenic, obstructive, and anaphylactic

Question 36

How does aging affect the cardiovascular system?

Answer 36

Decrease in compliance of aorta

Decrease cardiac muscle fiber size and strength

Decrease CO and HR

Increase LDL, CAD, congestive heart failure