Histology

Question 1

Coverings of the heart (pericardium) from superficial to deep

Answer 1

Fibrous pericardium: dense irregular connective tissue

serous pericardium: parietal layer. mesothelium (sheet of mesothelial cells on a basement membrane)

pericardial cavity: fluid filled

visceral layer of serous pericardium: mesothelium

Question 2

fascia adherens

Answer 2

help cells move as one by connecting their actin filaments

Question 3

macula adherens (desmosomes)

Answer 3

help prevent cells from pulling apart by connecting intermediate filaments

Question 4

purkinje fibers

Answer 4

made of specialized modified cardiomyocytes

• larger in size
• need lots of stored energy

Question 5

Question 6

Answer 6

Ventricularis/atrialis = Layer rich in elastin at the inflow surface. Elastin facilitates rapid recoil to close the valve quickly. Lined on the outside with endothelium.

Spongiosa = Central core of loose CT with loosely arranged collagen and elastic fibers. Dampens vibrations from valve closing.

Fibrosa = Dense irregular connective tissue at the outflow surface that is an extension of the fibrous skeleton. Lined with endothelium on the outside. Note: cordae tendineae in AV valves are extensions of the fibrosa.

Inflow surface: ventricularis or atrialis. Depending on where the blood is coming from. Lots of eleastic fibers to snap valve back in place.

Question 7

Internal elastic lamina present in

Answer 7

small arteries but not arterioles

Question 8

tunica media in arteriole vs small artery

Answer 8

small artery: 4-10 layers of smooth muscle

arteriole: 1-3 layers of smooth muscle

pre-capillary sphincter= smooth muscle enlargement in the areriole.

Question 10