Heart

Question 1

layers of heart

Answer 1

• tunica intima: endocardium
• tunica media: myocardium
• adventitia: epicardium

Question 2

endocardium

Answer 2

• lined by endothelium that is continuous with vessels that enter the heart
• subendothelial layer: collagen, dense fibroelastic CT
• subendocardial: loose CT connected to myocardium; blood vessels, nerves, & purkinje fibers

Question 3

myocardium

Answer 3

cardiac muscle tissue with deep (circular) & superficial layers (spiral)

Question 4

epicardium

Answer 4

• outermost layer formed by mesothelial cells

- inner layer of loose CT & adipose tissue, coronary blood vessels

Question 5

fibrous skeleton

Answer 5

skeleton composed of dense irregular CT

Question 6

septum membranaceum

Answer 6

fibrous portion of IV septum

Question 7

annuli fibrosi

Answer 7

fibrous rings around origins of pulmonary arteries, aorta, & atrioventricular canals

Question 8

trigona fibrosa

Answer 8

fibrous tissue between arterial foramina & atrioventricular canals

Question 9

atrioventricular valves

Answer 9

tricuspid &mitral; connected to papillary muscles of ventricles by fibrous cords called chordae tendineae

Question 10

semilunar valves

Answer 10

between ventricles & aorta & pulmonary arteries

Question 11

what kinds of tissue layers do valves have?

Answer 11

dense and loose CT surrounded by endothelium

Question 12

sinoatrial node

Answer 12

pacemaker of heart; contains modified cardiac muscle cells around nodal artery

Question 13

atrioventricular node

Answer 13

lies beneath endocardium in right atrium; forms common stem called bundle of His

Question 14

atrioventricular bundle of His

Answer 14

formed by purkinje fibers; penetrates skeleton & branches to left & right

Question 15

purkinje fibers

Answer 15

modified muscle cells that are filled with glycogen