Chapter 20

Question 1

All large organisms must transport materials through the body involving 3 steps:

Answer 1

1. Dissolve essentials in water (i.e., plants = sap, animals = blood)
2. Have vascular elements (tubes) leading to all regions.
3. Power required to move the fluid throughout the body.

Question 2

Heart is located in the

Answer 2

mediastinum (area from sternum to the vertebral column between lungs)

Question 3

Apex -

Answer 3

directed anteriorly, inferiorly and to the left

Question 4

Base -

Answer 4

directed posteriorly, superiorly and to the right

Question 5

Anterior surface -

Answer 5

deep to the sternum and ribs

Question 6

Inferior surface -

Answer 6

rests on the diaphragm

Question 7

Right border -

Answer 7

faces right lung

Question 8

Left border (pulmonary border) -

Answer 8

faces left lung

Question 9

Heart has 2 surfaces:

Answer 9

anterior (superior) and inferior

Question 10

heart has 2 borders:

Answer 10

right and left

Question 11

Fibrous pericardium

Answer 11

dense irregular CT

protects and anchors the heart, prevents overstretching

Question 12

Serous pericardium

Answer 12

thin delicate membrane
contains :
parietal layer-outer layer
pericardial cavity with pericardial fluid
visceral layer (epicardium)

Question 13

epicardium

Answer 13

visceral layer of serous pericardium

Question 14

myocardium

Answer 14

cardiac muscle layer is the bulk of the heart

Question 15

Endocardium

Answer 15

chamber lining & valves

Question 16

Cardiac muscle fibers swirl

Answer 16

diagonally around the heart in interlacing bundles

Question 17

Sulci -

Answer 17

grooves on surface of heart containing coronary blood vessels and fat

• coronary sulcus
• anterior interventricular sulcus
• posterior interventricular sulcus

Question 18

Right atrium receives blood from 3 sources:

Answer 18

superior vena cava, inferior vena cava and coronary sinus

Question 19

Right atrium also:

Answer 19

Interatrial septum partitions the atria
Fossa ovalis is a remnant of the fetal foramen ovale
Tricuspid valve

Question 20

Tricuspid valve does:

Answer 20

Blood flows through into right ventricle

has three cusps composed of dense CT covered by endocardium

Question 21

Right Ventricle

Answer 21

Papillary muscles (raised bundles of cardiac muscle)
Chordae tendineae
Interventricular septum
Pulmonary semilunar valve

Question 22

Chordae tendineae

Answer 22

cords between valve cusps and papillary muscles

Question 23

Interventricular septum

Answer 23

partitions, ventricles, septum

Question 24

Pulmonary semilunar valve

Answer 24

blood flows into pulmonary trunk

Question 25

Left Atrium:

Answer 25

Forms most of the base of the heart
Receives blood from lungs - 4 pulmonary veins (2 right + 2 left)
Bicuspid valve

Question 26

Bicuspid valve:

Answer 26

: blood passes through into left ventricle
Has two cusps
LAMB
Left Atrioventricular, Mitral, or Bicuspid valve

Question 27

Left Ventricle:

Answer 27

Forms the apex of heart
Chordae tendineae anchor bicuspid valve to papillary muscles
Aortic semilunar valve

Question 28

Aortic semilunar valve:

Answer 28

blood passes through valve into the ascending aorta

just above valve are the openings to the coronary arteries

Question 29

Myocardial Thickness and Function

Answer 29

Thickness of myocardium varies according to the function of the chamber
Atria are thin walled, deliver blood to adjacent ventricles

Question 30

Ventricle walls are much thicker and stronger, why?

Answer 30

right ventricle supplies blood to the lungs (little flow resistance)
left ventricle wall is the thickest to supply systemic circulation

Question 31

Myocardium of left ventricle is

Answer 31

much thicker than the right.

Question 32

Fibrous Skeleton of Heart includes:

Answer 32

Dense CT rings surround the valves of the heart, fuse and merge with the interventricular septum
Support structure for heart valves
Insertion point for cardiac muscle bundles
Electrical insulator between atria and ventricles
prevents direct propagation of AP’s to ventricles