Chapter 20 Flashcards Preview

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Flashcards in Chapter 20 Deck (32):
1

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

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.

2

Heart is located in the

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

3

Apex -

directed anteriorly, inferiorly and to the left

4

Base -

directed posteriorly, superiorly and to the right

5

Anterior surface -

deep to the sternum and ribs

6

Inferior surface -

rests on the diaphragm

7

Right border -

faces right lung

8

Left border (pulmonary border) -

faces left lung

9

Heart has 2 surfaces:

anterior (superior) and inferior

10

heart has 2 borders:

right and left

11

Fibrous pericardium

dense irregular CT
protects and anchors the heart, prevents overstretching

12

Serous pericardium

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

13

epicardium

visceral layer of serous pericardium

14

myocardium

cardiac muscle layer is the bulk of the heart

15

Endocardium

chamber lining & valves

16

Cardiac muscle fibers swirl

diagonally around the heart in interlacing bundles

17

Sulci -

grooves on surface of heart containing coronary blood vessels and fat
-coronary sulcus
-anterior interventricular sulcus
-posterior interventricular sulcus

18

Right atrium receives blood from 3 sources:

superior vena cava, inferior vena cava and coronary sinus

19

Right atrium also:

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

20

Tricuspid valve does:

Blood flows through into right ventricle
has three cusps composed of dense CT covered by endocardium

21

Right Ventricle

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

22

Chordae tendineae

cords between valve cusps and papillary muscles

23

Interventricular septum

partitions, ventricles, septum

24

Pulmonary semilunar valve

blood flows into pulmonary trunk

25

Left Atrium:

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

26

Bicuspid valve:

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

27

Left Ventricle:

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

28

Aortic semilunar valve:

blood passes through valve into the ascending aorta
just above valve are the openings to the coronary arteries

29

Myocardial Thickness and Function

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

30

Ventricle walls are much thicker and stronger, why?

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

31

Myocardium of left ventricle is

much thicker than the right.

32

Fibrous Skeleton of Heart includes:

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