heart

Question 1

human heart

where? surrounded by?

Answer 1

• size of human fist
• located in middle of chest
• protected by breastbone and vertebral column
• surrounded by fluid filled sac called pericardum

Question 2

how many chambers in mammalian hearts? how do they work?

Answer 2

• 4
• blood flows from atrium to ventricle

Question 3

double pump system

Answer 3

• mammalian hearts called this bc 2 contractions force blood through body in 2 diff. directions at the same time
• right side pumps to lungs
• left pumps to body

Question 4

name the heart valves

Answer 4

• 2 atrioventricular valves
• aortic valve
• pulmonary valve

Question 5

atrioventricular valves

what do they do

Answer 5

• tricuspid and mitral
• prevent blood from entering atria when heart beats

Question 6

aortic valve

Answer 6

prevents blood from moving from aorta to left ventricle when heart not beating

Question 7

pulmonary valve

Answer 7

prevents blood from moving from pulmonary artery into right ventricle when heart not beating

Question 8

pulmonary circuit

Answer 8

• right atrium and ventricle
• receive and pump oxygen-poor blood to lungs

Question 9

systemic circuit

Answer 9

• left atrium and ventricle
• receive and pump oxygen-rich blood to body

Question 10

lubb dubb sound caused by…

Answer 10

• lubb: atrioventricular valves closing as ventricles contract
• dubb: pulmonary and aortic valves closing as ventricles relax

Question 11

heartbeat

Answer 11

• initiated in cluster of cells in right atrium called sinoatrial node (SA)
• “pacemaker”
• gives signals to set normal rhythm of heartbeat, which reach atrioventricular node

Question 12

Purkinje fibers

Answer 12

• line the septum and heart muscles from the atrioventricular node
• conduct impulses for heartbeat

Question 13

ECG/EKG

Answer 13

• electrocardiograph
• heartbeat is electrically simulated
• electrodes detect heart activity through body

Question 14

cardiovascular diseases

Answer 14

• athersclerosis: buildup of plaque in arteries
• coronary heart disease: atherosclerosis of arteries that provide heart muscle (leads to heart attack)
• stroke: atherosclerosis in arteries supplying brain