Circulatory System

Question 1

Blood

Answer 1

-composed of water, solutes, and other elements in fluid connective tissue

Question 2

Blood vessels

Answer 2

• tubules of different sizes that transport blood

Question 3

Heart

Answer 3

• muscular pump providing the pressure necessary to keep blood flowing

Question 4

Arterial and venous systems

Answer 4

• consist of three layers:
  Innermost tunica intima
  Tunica media (smooth muscle cells and elastic fibers)
  Outer tunica adventitia

Question 5

Elastic arteries

Answer 5

• aortic and major branches
• largest vessel in the arterial system
• stretches when blood is forced out of heart and recoil under low pressure

Question 6

Muscular arteries

Answer 6

• includes arteries that branch off of the elastic arteries
• higher proportion or smooth muscle and fewer elastic fibers
• regulate blood flow by vasoconstriction / vasodilation

Question 7

Arterioles

Answer 7

• tiny vessels that lead to capillaries
• tunica media is thin, almost all smooth muscle
• vasoconstriction / vasodilation and control blood flow to capillaries

Question 8

Venules

Answer 8

• tiny vessels that exit capillary beds
• thin walls
• empty blood into larger vein

Question 9

Veins

Answer 9

• wide lumen valves prevent back flow of blood

- carry blood back to heart

Question 10

Blood pt. 2

Answer 10

• carrying raw materials to cells and removing waste
• stabilize internal pH and hosts infection fighter
• adults = 5 quarts of blood
• composed of red, white cells, platelets, and plasma (which = half of blood volume)
• plasma contains proteins, ions, glucose, amino acids, hormones, and dissolved gases.

Question 11

Red blood cells

Answer 11

• transport oxygen to cells.
• form in the bone marrow
• live for 4 months
• constantly being replaced by fresh cells

Question 12

White blood cells

Answer 12

• defend the body against infection
• remove waste
• lymphocytes, neutrophils, monocytes, eosinophils, and basophils

Question 13

Platelets

Answer 13

• fragments of stem cells

- function blood clotting

Question 14

Heart

Answer 14

• muscular pump made of cardiac muscle tissue
• four chambers, each half contains both an atrium and ventricle
• halves are separated by a valve
• has its own coronary arteries
• functions by contracting and relaxing
• atrial contractions fills the ventricles
• ventricular contraction empties them

Question 15

Cardiac cycle: diastole phase

Answer 15

• blood flows through superior and inferior vena cava
• through atrioventricular valve (tricuspid) to the right ventricle
• sinoatrial node (SA pacemaker) on right atrium sends electrical impulses carried by purkinje fibers to the rest of the atrium, stimulating it to contract and fill the right ventricle with blood
• impulse from SA node goes through the atrioventricle node, which signals the right ventricle to contract (systole phase)

Question 16

Cardiac cycle: systole phase

Answer 16

• tricuspid valve closes
• pulmonary semilunar valve opens
• blood pumped out the pulmonary artists to lungs
• blood returning from lungs fills the left atrium (2nd diastole)
• SA triggers the mitral valve to open and blood fills left ventricle (2nd systole)
• mitral valve closes and the aortic semilunar valve opens
• left ventricle contracts, blood out through aorta to the rest of the body

Question 17

Types of circulation: coronary

Answer 17

• blood enters the coronary arteries which branch off the aorta, supply major arteries, which enter heart with O2 blood
• deO2 blood returns to the right atrium through the cardiac veins which empty into coronary sinus

Question 18

Types of circulation: pulmonary

Answer 18

• between heart and lungs
• deO2 blood flows from right ventricle to the lunges via pulmonary arteries
• O2 blood flows back to the left atrium via pulmonary veins

Question 19

Types of circulation: systemic

Answer 19

• flow of blood to the entire body with the exception of coronary and pulmonary
• aorta to the carotid arteries, subclavian arteries, common iliac arteries, and renal arteries
• returns to heart via jugular veins, subclavian veins, common iliac veins, and renal veins
• empties into superior and inferior vena cava
• portal = flow to digestive system to liver then to heart
• renal = between heart and kidney

Question 20

Blood pressure

Answer 20

• fluid pressure generated by the cardiac cycle

Question 21

Arterial blood pressure

Answer 21

• transports O2 poor blood to lungs and O2 rich blood to the body tissues
• arteries turn into smaller arterioles which contract and expand based on signals
• arterioles are adjustments made in blood delivery to specific area based on body system communication

Question 22

Capillary beds

Answer 22

• diffusion sites for exchange between blood and interstitial fluid
• single layer of endothelial cells
• merge into venules which turn into larger veins, which goes back to the heart