A&p Lecture 26

Front 1

What blood vessels determine the resistance and capacity of the cardiovascular system, respectively.

Back 1

The arterioles determine resistance and veins determine capacity.

Front 2

How can sympathetic stimulation change the resistance or capacity?

Back 2

increase resistance by vasoconstriction of arterioles
decrease capacity of the system by vasoconstriction of veins

Front 3

What is the equation for mean arterial pressure (MAP)?

Back 3

cardiac output X stroke volume

Front 4

What two locations is the capacity of the venous system very large?

Back 4

Skin, gastrointestinal tract

Front 5

After a hemorrhage, the capacity of the venous system is ________?

Back 5

reduced

Front 6

What three locations in the body does a "venous pump" work?

Back 6

1. Plantar pump of the feet
2. Muscular pump of the legs
3. Respiratory pump of the lungs pressuring the thoracic cavity.

Front 7

Describe the bloodflow going through a capillary bed.

Back 7

Terminal arterioles lead into the capillary bed and reach the precapillary sphincter. Blood flows throught the capillary to the non-muscular venules, then to the muscular venules.

Front 8

The endothelial cells in the brain and retina are _______ _______

Back 8

tightly packed

Front 9

The endothelial cells in the skin, muscle, lungs, GI tract, and kidney are _______ _______

Back 9

slightly packed

Front 10

The endothelial cells in the capillaries of the liver, bone marrow, and spleen are ______ _____.

Back 10

loosely packed

Front 11

What are the 3 ways that materials are moved in and out of the capillaries?

Back 11

Diffusion, Pinocytosis, Filtration

Front 12

What is the main force that drives fluid OUT of the capillary?

Back 12

hydrostatic pressure

Front 13

What is the main force that draws fluid into the capillaries?

Back 13

protein osmotic pressure

Front 14

What is edema?

Back 14

Tissue swelling caused when an abnormal excess of fluid builds up in the interstitial space.

Front 15

What are the 4 components of edema?

Back 15

1. Increased venous hydrostatic pressure.
2. Reduced plasma osmotic pressure.
3. Increased interstitial fluid osmotic pressure.
4. Blocked lymphatics.

Front 16

What is a pulmonary edema?

Back 16

When pressure in the capillaries in the lungs rises and the alveoli become too wet. Possible cause: left ventricle failure. Results in death very quickly.

Front 17

What are 4 factors that regulate blood flow through the capillaries.

Back 17

1. Carbon dioxide content
2. Oxygen content
3. Low pH
4. Other agents

Front 18

Name 4 vasoconstrictors.

Back 18

1. Noropinephrine/epinephrine
2. Angiotensin II
3. Vasopressin
4. Endothelin

Front 19

Name 2 vasodilators.

Back 19

1. Nitric Oxide
2. Histamine

Front 20

What is sympathetic vasoconstrictor tone?

Back 20

A constant blood vessel tone that is maintaned by the sympathetic nervous system. This in turn maintains the total peripheral resistance.

Front 21

Describe angiogenesis.

Back 21

growth of new blood vessels that is regulated by angiogenic factors.

Front 22

Name 4 situations in which angiogenesis is important.

Back 22

1. Development of blood vessels in blood-deficient tissue.
2. In deep wounds, angiogenic factors promote blood vessel growth to supply oxygen to healing tissues.
3. During embryonic development.
4. During the menstrual cycle.

Front 23

Name the 4 factors that determine mean arterial blood pressure.

Back 23

1. Cardiac output
2. Total peripheral resistance.
3. Capacity of the veins and venules.
4. Blood volume in circulation

Front 24

What are the two basic processes / systems that determine blood pressure?

Back 24

1. sympathetic nervous system
2. Renin-angiotensin-aldosterone system

Front 25

What organ does the R-A-A system work?

Back 25

kidneys

Front 26

Describe the process of the R-A-A system.

Back 26

Release of renin from kindeys-->angiotensin I forms from angiotensinogen in the blood-->conversion of angiotensin I to angiotensin II--> angiotensin II induced release of aldosterone

Front 27

What is the purpose of the R-A-A system?

Back 27

vasoconstriction and retention of water and salt

Front 28

Describe the baroreceptor reflex.

Back 28

The baroreceptors in the carotid arteries sense a drop in arterial pressure and initiate a sympathetic reflex that vasoconstricts blood vessels and increases heart rate and myocardial contractility.

Front 29

Describe the Central Nervous System Ischemic Response.

Back 29

This happens when blood pressure has dropped dangerously low and blood isn't reaching the brain. Peripheral blood vessels constrict so tightly that they completely close and the kidneys completely stop urine production.