chapter_161

Blood Vessels & Circulation

Chapter 16

Question 1

Name the five types of blood vessels. Arteries Arterioles Capillaries Venules veins

Question 2

At any one time, most of your blood, 60% is found in the veins and venules.

Question 3

Define Vasoconstriction- decrease in the

diameter of the lumen of a blood vessel. Vasodilation- the smooth muscle fibers

relax to increase the lumen diameter.

Question 4

Which tissues have no capillaries? Epithelial Cornea Lens of eye

Question 5

List three functions of blood vessels. Carries blood away from the heart to the

tissues and returns it to the heart. Exchange of substances between blood

and body cells. Nutrients and oxygen go from the blood to

the tissues. Wastes from the tissues go into the blood.

Question 6

Name five substances that can enter and leave the capillaries by simple diffusion. Oxygen Carbon dioxide Glucose Amino acids hormones

Question 7

Define Bulk flow- a passive process by which

large numbers of ions, molecules or particles move together in the same direction.

Capillary blood pressure- the pressure of blood against the walls of capillaries pushes fluid out of the capillaries into the interstitial fluid.

Question 7

Define Blood colloid osmotic pressure- an

opposing pressure, fluid is pulled INTO the capillaries (blood proteins create the blood’s osmotic pressure)

Reabsorption- water and solutes move via bulk flow from the interstitial fluid into the blood capillary

Question 8

The lumen of a vein is wider than that of a corresponding artery.

Question 9

Normal systole is 120. Normal diastole is 80.

Question 10

If greater than 10% of total blood volume is lost, this is life threatening.

Question 11

Name three causes of vascular resistance. Explain each. Size of lumen- this changes from moment

to moment. Blood viscosity- ratio of RBC to plasma Total blood vessel length- the greater the

length the more friction (200 miles per extra pound of body fat)

Question 12

Define Proprioreceptors- monitor movement of

joints and muscles. Baroreceptors- monitor changes in

pressure and stretch in the walls of blood vessels.

Chemoreceptors- monitor the concentration of various chemicals in the blood.

Question 13

The Vagus (X) nerve decreases heart rate.

Question 14- omit

Question 15

Define Hypoxia- lowered oxygen availability Acidosis- increase in H+ concentration Hypercapnia- excess carbon dioxide

Question 16

List and explain the four hormone systems that regulate blood pressure and blood flow. Renin-angiotensin-aldosterone RAA

system Epinephrine and norepinephrine Antidiuretic hormone Atrial Natriuretic Peptide (ANP)

Renin-angiotensin-aldosterone RAA system Decrease blood flow to the kidneys or decrease

in blood pressure triggers Kidney cells to secrete renin Renin and angiotensin converting enzyme

(ACE) produce the hormone angiotensin II which raises the blood pressure by vasoconstriction.

Angiotension II stimulates the secretion of aldosterone, this increases the reabsorption of sodium and water by the kidneys. Increases blood volume and blood pressure.

Epinephrine and norepinephrine

These hormones increase cardiac output Increase the rate and force of heart

contractions Causes vasoconstriction of arterioles

and veins in the skin and abdominal organs.

Antidiuretic hormone

ADH is released in response to dehydration or decreased blood volume.

ADH causes vasoconstriction which increases blood pressure

ADH is also called vasopressin.

Atrial Natriuretic Peptide (ANP)

ANP is released by the cells of the heart ANP lowers blood pressure by

vasodilation, loss of salt and water from the blood into the urine

ANP reduces blood volume

Question 17

Autoregulation- the ability of a tissue to automatically adjust its blood flow to match its metabolic demands.

Question 18

Name the two general stimuli that contribute to autoregulation and explain. Physical changes-

warming promotes vasodilation Stretching of smooth muscle causes it to contract

Vasodilating and vasoconstricting chemicals- Many cells release chemicals that alter the blood

vessel diameter WBC, platelets smooth muscle fibers,

macrophages and endothelial cells release the vasodilator nitric oxide.

Question 19

Define pulse- the alternate expansion and elastic recoil of an artery after each contraction of the left ventricle.

Question 20

The radial artery at the wrist is most commonly used to feel the pulse.

Question 21

Name three other sites where you can feel your pulse. Dorsalis pedis (instep of foot) Brachial artery Common carotid Politeal artery

Question 22

What is the normal pulse rate? 70-80 bpm

Tachycardia? 100 bpm, rapid resting heart

Brachycardia? 60 bpm, slow resting heart

Question 24

The device used to measure blood pressure is a sphygmomanometer. Normal blood pressure is 120/80.

Question 25

Define shock- failure of the cardiovascular system to deliver enough oxygen and nutrients to meet cellular metabolic needs.

26. Seven causes of shock

Loss of body fluids Hemorrhage Dehydration Burns Excessive vomiting Diarrhea sweating

27. Symptoms of shock

Systolic less than 90 Rapid resting heart Weak, rapid pulse Cool, pale skin Sweating Reduced urine

Altered mental state due to lack of oxygen to the brain

Thirst nausea

Go through Figures 16.8-16.14

Question 28

How is hypertension defined? Name three lifestyle changes in managing hypertension.

Hypertension- persistently high blood pressure

Lifestyle changes- lose weight, limit alcohol, exercise, reduce salt intake, don’t smoke, manage stress, watch potassium, calcium and magnesium levels.

Question 29

Define aneurysm. What happens if it is untreated?

Aneurysm- a thin weakened section of the wall of an artery

Untreated- massive hemorrhage, shock, pain, stroke and even death.

Matching answers

L, K, J, I, H, G, F, E, D, C, B, A

The end.

Question 23

What rate is tachycardia?