Mareib A&p Chapter 19

Front 1

Arteries and veins are composed of what three "tunics?"

Back 1

1) Tunica interna
2) Tunica media
3) Tunica externa

Front 2

What's the innermost layer of a vein or artery called?

Back 2

Tunica interna

Epithelial layer that forms a smooth inner surface that is good for blood flow...smooth blood flow is laminar

Front 3

What's the second deepest layer of a vein or artery called?

Back 3

Tunica media (it's also the second most superficial. It lies in the middle)

a layer of smooth muscle that can be used to adjust blood vessel radius altering blood flow.

Front 4

What's the outermost layer of a vein or artery called?

Back 4

Tunica externa

a loose network of collagen fibers that support the vessels

Front 5

What are the three types of blood vessels?

Back 5

Arteries, Veins, Capillaries

Front 6

What do arteries do?

Back 6

Arteries carry blood away form the heart
Have thick muscle walls
high pressure vessels
small lumen
located deep

Front 7

What do veins do?

Back 7

Veins carry blood toward the heart

Front 8

What do capillaries do?

Back 8

Capillaries contact tissue cells and directly serve cellular needs

Front 9

In what order do the vessels move away from and back to the heart?

Back 9

elastic arteries, muscular arteries, arterioles, capillaries small veins, large veins

Front 10

What two factors determine blood pressure near the heart?

Back 10

1) How much the elastic arteries close to the heart can be stretched
2) the volume of blood forced into them at any time.

Front 11

What vessels are the resistance vessels? What is the significance of the resistance vessels reducing pressure?

Back 11

The resistance vessels are the arterioles. These vessles can adjust radius therefore can adjust blood flow.

Front 12

What are the three structural types of capillaries?

Back 12

1) Continuous

2) Fenestrated (from the latin "fenestra," meaning "window")

3) sinusoidal (noun = sinusoids)

Front 13

What are the elastic (conducting) arteries?

Back 13

Thick-walled arteries near the heart; the aorta and its major branches

Front 14

What arteries are described as "thick-walled arteries near the heart; the aorta and its major branches?"

Back 14

The elastic, or conducting, arteries

Front 15

What four characteristics make the elastic (conducting) arteries unique?

Back 15

1) Large lumen allow low-resistance conduction of blood

2) All three tunics contain elastin

3) They can withstand and normalize large fluctuations in pressure

4) They allow blood to flow fairly continuously through the body

Front 16

What's another word for elastic arteries?

Back 16

Conducting arteries

Front 17

What's another term for conducting arteries?

Back 17

Elastic arteries

Front 18

What's another term for muscular arteries?

Back 18

Distributing arteries

Front 19

What's another term for distributing arteries?

Back 19

Muscular arteries

Front 20

What do muscular (distributing) arteries do?

Back 20

They deliver blood to body organs

Front 21

What two physical properties make muscular (distributing) arteries unique?

Back 21

1) Thick tunica media with more smooth muscle and less elastic tissue

2) Active in vasoconstriction

Front 22

What are arterioles?

Back 22

The smallest of arteries; arteries that lead to the capillary beds

Front 23

What arteries are the smallest, and lead to capillary beds?

Back 23

Arterioles

Front 24

What important task are arterioles charged with?

Back 24

Controlling flow of blood to the capillary beds by vasoconstriction and vasodilation

Front 25

What are the smallest blood vessels?

Back 25

Capillaries

Front 26

What three physical properties make capillaries unique?

Back 26

1) They only have one tunic -- the tunica interna

2) The tunica interna is only one cell thick

3) They allow RBC's to flow through the capillary wall, one at a time.

Front 27

Where are continuous capillaries common?

Back 27

skin and muscles

Front 28

What are three physical properties that describe the continuous capillaries found in skin and muscles?

Back 28

1) They have endothelial cells that provide an uninterrupted lining

2) Adjacent cells are held together with tight junctions

3) There are intercellular clefts of unjoined membranes that allow the passage of fluids

Front 29

What special function do continuous capillaries in the brain serve?

Back 29

They make up the blood-brain barrier

Front 30

What physical property makes continuous capillaries in the brain unique?

Back 30

The endothelia of these capillaries are completely joined by tight junctions (no clefts).

Front 31

What two types of stimuli control blood flow at the capillary bed?

Back 31

1) Vasomotor nerve impulses

2) Local chemical changes

Front 32

What two factors result in blood pressure?

Back 32

Blood flow and resistance. That's pressure for you.

Front 33

Describe systemic pressure.

Back 33

1) Highest in the aorta

2) Declines throughout length of pathway

3) It's 0 mm Hg in the right atrium

Front 34

Where does the steepest change in blood pressure occur?

Back 34

Arterioles

Front 35

Arterial BP reflects what two factors of arteries close to the heart?

Back 35

1) Elasticity

2) Amount of blood forced in

Front 36

Blood pressure in elastic arteries near the heart is ____, meaning it rises and falls

Back 36

Pulsatile

Front 37

Define systolic pressure

Back 37

Amount of pressure exerted on arterial walls during ventricular contraction

Front 38

Define diastolic pressure

Back 38

The lowest level of arterial pressure during a ventricular cycle

Front 39

What term describes arterial blood pressure during ventricular contraction?

Back 39

Sytolic pressure

Front 40

What's a term defined as "the difference between systolic and diastolic pressure?"

Back 40

Pulse pressure

Front 41

What's MAP?

Back 41

"Mean arterial pressure." This is the figure that REALLY matters when considering amount of blood flow to tissues.

Front 42

What's an easy way to estimate MAP?

Back 42

MAP = diastolic pressure + 1/3 pulse pressure

Front 43

What range does capillary BP usually fall into?

Back 43

20-40 mm Hg

Front 44

What's desirable: low capillary BP or high capillary BP.

Why?

Back 44

Low capillary BP -- high BP would rupture the tiny fragile walls.

Low BP is sufficient to force filtrate out into interstitial space and distribute nutrients, gases, and hormones between blood and tissues.

Front 45

What two phenomena assist the venous system in returning blood to the heart, seeing as how venous BP is insufficient to do so?

Back 45

1) Respiratory pump - local veins are squeezed during breathing, suck blood toward the heart

2) Muscular pump - contraction of skeletal muscles "milk" blood towards the heart

Front 46

What prevents backflow during venous return?

Back 46

valves, dummy.

Front 47

What five factors influence blood pressure in general?

Back 47

1) Heart rate
2) Blood volume
3) Cardiac output (CO)
4) Resistance
5) Viscosity

Front 48

What branch of the autonomic nervous system increases activity in relation to the heart in order to stimulate increased heart rate?

Back 48

Sympathetic

Front 49

What two factors are the most important factors in creating resistance in a blood vessel?

Back 49

1) Size of vessel (smaller means more pressure)

2) Smoothness of vessel (rougher means more pressure)

Front 50

What's a term for narrowing of blood vessels?

Back 50

vasoconstriction

Front 51

What kinds of drugs can cause vasoconstriction, thus increasing BP?

Back 51

antihistamines, naphazoline nitrate, tetrahydrozoline hydrochloride

Front 52

What's a common vasodilator that can decrease BP and help prevent heart attacks?

Back 52

Nitroglycerin

Front 53

Does anemia increase or decrease blood pressure?

Back 53

If it is anemia due to low RBC concentration, it will decrease blood pressure

Front 54

What artery do we use to measure blood pressure? What artery is our "benchmark?"

Back 54

brachial artery

Front 55

BP in other blood vessels is ____ than arterial BP.

Back 55

Lower

Front 56

What's the average BP in a healthy adult?

Back 56

120/80 mm Hg

(systolic comes first, diastolic comes last)

Front 57

What two factors are the main causes of hypertension (high BP)?

Back 57

1) Heart pumping with excessive force

2) Arterioles become narrower

Front 58

What's hypotension?

Back 58

Low blood pressure -- and it's usually a good sign. Unless, of course, it's chronic and due to malnutrition, addison's disease, or hypothyroidism.

Also, if it's acute, it's the clearest sign of circulatory shock

Front 59

What's the vasomotor center?

Back 59

The vasomotor center is a cluster of sympathetic neurons in the medulla that oversees changes in blood vessel diameter. Innervates SMOOTH MUSCLE, especially in arterioles

Front 60

What's the cardiovascular center?

Back 60

The vasomotor center plus the cardiac centers in the medulla that together regulate BP by altering CO and blood vessel diameter

Front 61

What's a baroreceptor?

Back 61

It's a receptor that can detect changes in blood pressure and communicate messages about these changes to the brain

Front 62

What are the types of baroreceptors?

Back 62

High pressure arterial baroreceptors and low pressure (cardiopulmonary) baroreceptor

Front 63

Describe the chain of events that occurs when BP strays higher than nominal levels.

Back 63

1) Baroreceptors detect the change, setting off the baroreceptor reflex

2) Cardioregulatory center increases parasympathetic stimulation of the heart while decreseaing sympathetic stimulation

3) Simultaneously with number 2, the vasomotor center decreases sympathetic stimulation of blood vessels

4) Stroke volume decreases, thus CO decreases. Vasodilation occurs, decreasing pressure. BP is reduced

Front 64

What prominent chemicals increase blood pressure?

Back 64

1) Adrenal medulla hormones (epinephrine and norepinephrine)

2) Antidiuretic hormone (ADH) is a vasoconstrictor

3) Angiotensin II (released by kidney and is INTENSE as a vasoconstrictor)

4) Endothelium and prostoglandin-derived growth factor (PDGF) are vasoconstrictors

Front 65

What chemicals decrease blood pressure?

Back 65

1) Atrial natriuretic peptide (ANP)

2) Nitric oxide (NO) - brief but potent vasodilator

3) histamine, prostacyclin, kinins -- inflammatory chemicals in general

4) Alcohol, since it inhibits antidiuretic hormone (ADH)

Front 66

What chain of events occurs when blood pH strays higher than nominal levels? (this is often caused by a decrease in blood CO2)

Back 66

1) CHEMORECEPTOR REFLEX: chemoreceptors in the medulla oblongata detect the pH change

2) Vasomotor center decreases sympathetic stimulation of blood vessels and the cardioregulatory center increases parasympathetic activity while decreasing sympathetic stimulation of the heart.

3) Vasodilation occurs and CO decreases, because the body knows that low CO2 levels mean that too much blood is traveling to the lungs and thus decreases BP

Front 67

What chains of events occur when blood pH strays lower than nominal levels? (often caused by an increase in CO2 or a large decrease in O2)

Back 67

1) CHEMORECEPTOR REFLEX: Carotid and aortic bodies have chemoreceptors that detect the change. This reflex increases sympathetic stimulation of blood vessels and increased respiration rate (which in turns increases sympathetic stimulation of the heart and decreases parasympathetic stimulation of the heart). Vasoconstriction occurs and increases resistance while CO increases, increasing BP.

2) CHEMORECEPTOR REFLEX in the medulla oblongata -- cardioregulatory cetner increases CO by decreasing parasympathetic stimulation of the heart and increasing sympathetic stimulation

3) CNS - ISCHEMIC RESPONSE - chemoreceptors sense the pH change and the vasomotor increases sympathetic stimulation of blood vessels, constricting them and creating more resistance

FINALLY increased BP and CO cause more blood flow to lungs, fixing the problem, we hope.