Lecture 20 9/25/23

Question 1

What are the characteristics of the endocardium?

Answer 1

-simple squamous
-practically the same as endothelium
-lines the four chambers of heart

Question 2

What is a hemangiosarcoma?

Answer 2

malignant tumor of the endothelial/endocardial cells of the heart

Question 3

What are the characteristics of the heart valves?

Answer 3

-thin connective tissue core
-covered with endocardial cells

Question 4

What are the two types of tissue in the myocardium?

Answer 4

-cardiac muscle
-perkinje fibers

Question 5

What are the characteristics of cardiac muscle?

Answer 5

-striated
-branched
-intercalated discs
-central nuclei

Question 6

What are the characteristics of perkinje fibers?

Answer 6

-lots of glycogen
-transmit electrical signals throughout heart

Question 7

What is the cardiac skeleton?

Answer 7

four fibrous rings that provide structure for the heart/its chambers

Question 8

Which animal has a cartilaginous cardiac skeleton?

Answer 8

cats

Question 9

Which animal has an osseous cardiac skeleton?

Answer 9

cattle

Question 10

What is the epicardium?

Answer 10

tissue on the outside of the heart

Question 11

What are the characteristics of the epicardium?

Answer 11

-contains adipose tissue and coronary arteries/veins/nerves
-covered with mesothelium on the very outermost surface

Question 12

How can endothelium and mesothelium be differentiated?

Answer 12

-knowing the location that you are looking at
-seeing adipose tissue typically indicates mesothelium

Question 13

What are the characteristics of the pericardial sack?

Answer 13

-parietal pericardium
-thin collagen layer with mesothelium on both sides
-may contain adipose tissue

Question 14

What is the function of the mesothelium?

Answer 14

producing pericardial and pleural fluids

Question 15

Which fluid is on each side of the pericardial sac?

Answer 15

-pericardial fluid on the inside
-pleural fluid on the outside

Question 16

What substances are typically contained within the lymphatic vessels?

Answer 16

-lymph fluid
-lymphocytes

Question 17

What are the characteristics of lymphatic vessels?

Answer 17

-thin-walled
-have valves
-normally no erythrocytes

Question 18

What are the characteristics of the lymphatic capillaries?

Answer 18

-blind-ended
-fluid flow towards heart only
-discontinuous endothelial cells and basement membrane

Question 19

What is the function of the lymphatic capillaries?

Answer 19

to constantly pick up fluid, protein, and cells from the interstitium and return them to the circulatory system

Question 20

Why do lymphatic vessels appear empty on microscopy?

Answer 20

the lymphatic fluid is clear and cannot be seen

Question 21

How can lymphatic vessels and veins be distinguished microscopically?

Answer 21

-veins will contain blood and appear pink/red inside
-lymphatic vessels do not contain blood and will appear empty inside

Question 22

Why are the lymphatic capillaries composed of discontinuous endothelial cells?

Answer 22

to allow cells to move through the capillaries

Question 23

What do the lymphatic capillaries feed into?

Answer 23

larger lymphatic vessels

Question 24

What are the characteristics of the larger lymphatic vessels?

Answer 24

-pass through lymph nodes
-empty into large veins near the heart

Question 25

Which lymphatic vessel is the largest?

Answer 25

thoracic duct

Question 26

Why is the lymphatic system important?

Answer 26

tumor cells will use the lymphatic vessels to metastasize