Histology

Question 1

What are the roles of the cardiovascular system?

Answer 1

• Transport of oxygen and nutrients to the tissues
• Transport of CO2 and other metabolic waste from the tissues.
• Temperature regulation.
• Distribution of hormones and immune cells.
• Reproductive function in males: penile erection

Question 2

What is tunica intimate made of?

Answer 2

single layer of squamous epithelial cells termed endothelial cells supported by a basal lamina and a thin layer of connective tissue

Question 3

What is tunica media made of?

Answer 3

smooth muscle.. thickness of tunica media varies dramatically

Question 4

What is tunica adventitia made of?

Answer 4

supporting connective tissue

Question 5

What separates the tunica intima and media?

Answer 5

elastic tissue called the internal elastic membrane

Question 6

What separates the tunica media and adventitia?

Answer 6

elastic tissue called the external elastic membrane

Question 7

How do elastic arteries get their nutrient supply?

Answer 7

vasa vasorum

Question 8

What are the layers in an arteriole?

Answer 8

little smooth muscle, no adventitia

Question 9

What are the layers in a capillary?

Answer 9

endothelial cells and a basal lamina

Question 10

What are pericytes and where are thy found?

Answer 10

outside the basal lamina of capillaries

connective tissue cells that have contractile properties

Question 11

What are the there types of capillaries?

Answer 11

Continuous capillaries: found in muscle, connective tissue, lung, skin and nerve
Fenestrated capillaries: found in mucosa of gut, endocrine glands and glomeruli of kidney
Sinusoidal or discontinuous capillaries: large gaps in walls, found in liver, spleen and bone marrow

Question 12

What are post-capillary venues made of?

Answer 12

endothelial cell-lined and contain a thin layer of connective tissue and occasional pericytes

Question 13

When does a post-capillary venue become a venule?

Answer 13

when they acquire intermittent smooth muscle cells in the tunica media layer

Question 14

What are the layers in a vein?

Answer 14

thin tunica media with a few layers of smooth muscle, thick adventitia in large veins

Question 15

What are the three layers of the heart?

Answer 15

• endocardium
• myocardium
• epicardium

Question 16

What is the structure of the endocardium?

Answer 16

endothelium
basal lamina
thin layer of collagen fibres
layer of dense connective tissue
subendocardium containing loose connective tissue and impulse conducting parts

Question 17

What is the structure of the myocardium?

Answer 17

bundles and layers of contractile carina muscle fibres, individual muscle fibres surrounded by connective tissue and rich network of capillaries

Question 18

What do intercalated discs do?

Answer 18

attach cells and allow the spread of electrical activity

Question 19

What is the structure of the epicardium?

Answer 19

single layer of flattened mesothelium, basal lamina and fibroelastic connective tissue and sometimes adipose tissue

Question 20

What is the purpose of the fibrous skeleton on the heart?

Answer 20

support the valves
provides attachment for cardiac muscle fibres
electrically isolate the atria and the ventricles

Question 21

What is the structure of heart valves?

Answer 21

endothelial layer with basal lamina over all surface
lamina fibrosa is extension of the fibrous skeleton
no blood vessels
tendinous cords and papillary muscles

Question 22

What are the three types of cardiac muscle cells?

Answer 22

contractile
pacemaker
conducting

Question 23

What is the structure of pacemaker cells?

Answer 23

smaller than normal myocytes
pale
few myofibrils
little glycogen
no T tubule system

Question 24

What is the structure of the conducting cells in the Purkinje fibres?

Answer 24

larger than normal cells
found in subendocardial layer deep to the endocardium
lots of glycogen
no T tubules and no intercalated discs
pale

Question 25

What does interstitial fluid contain?

Answer 25

contains ions, lipids, proteins and occasional cells

Question 26

What is the role of lymph nodes?

Answer 26

immune surveillance to check for antigens

Question 27

How is flow maintained in the lymph system?

Answer 27

hydrostatic pressure from voluntary muscles and valves in the vessels