Exam 2 Circulatory system basics

Question 1

What are the causes of a heart attack?

Answer 1

A heart attack is a blocked or reduced blood supply to the hear through the coronary artery.

Plaque formation and atherosclerosis contributes to heart attacks from a low nutrient supply.

Question 2

Atherosclerosis

Answer 2

The interior of an artery that is narrowed because of lipid deposition and inflammation.

Question 3

Hypertension

Answer 3

When your blood pressure is constantly raised above the normal rates, creating more work for the heart and arteries. This creates more room for strokes or major health problems.

it is measures in millimeters of mercury (mm Hg) and shown as a fraction with the top number being the systolic number and the bottom being the diastolic number.

Question 4

Blood pressure

Answer 4

The force exerted by the blood vessels and arteries as the heart pumps and pushed the blood into the vessels.

Question 5

Functions of the capillaries

Answer 5

Capillaries form branching networks exchanges oxygen, nutrients, and waste between body cells and the blood.

There are more capillaries than small arteries.

Blood is divided into small channels, slowing it down

Question 6

Functions of veins

Answer 6

• Veins carry blood towards the heart
• Lowers strength: expandable; holds a larger volume of blood
• Blood in veins exerts less pressure than blood in arteries: loses most of its propulsive force after it circulates through the body; only able to return to the heart because of skeletal muscles; has valves to prevent backwards blood flow.

Question 7

Functions of arteries

Answer 7

Arteries carry blood away from the heart: has thicker muscular walls; carries high pressure blood from the heart
- thick layer of smooth muscle tissue allows for arteries to regulate blood flow by changing in diameter

Question 8

Cardiac cycle

Answer 8

• Relaxed atria fill. Fluid pressure opens AV valves and blood flows into the relaxed ventricles
• Atrial contraction squeezes more blood into the still-relaxed ventricles
• As blood flows into the arteries, pressure in the ventricles declines and the aortic and pulmonary valves close
• Ventricles start
  to contract and the rising pressure pushes the AV valves shut. A further rise in pressure causes
  the aortic and pulmonary valves
  to open.

Question 9

Coordination of the heart beat

Answer 9

Made of special pacemaker cells.
Coordinate the muscle tissue to beat correctly
Timing of the heart beat begins with special pacemaker called sinoatrial node
Atrioventricular node transmits the stimulus to contract the ventricles
Atria contract together, then the ventricles contract together
Lub sound is closing of the atrioventricular valves; dup sound is closing of the semilunar valves

Question 10

Valves in the heart

Answer 10

Keep blood flowing in one direction
Between the atrium and ventricle on each side
Atrioventricular (AV) valves
Tricuspid
Bicuspid( Mitral)
Valves between the ventricle and the artery of each side
Semilunar valves
pulmonary
Aortic