Circulatory system

Question 1

State the layers of tunics present in large blood vessels from interior to exterior.

Answer 1

intima, media, adventitia

Question 2

Define vasa vasorum

Answer 2

smaller vessels branching through the adventitia and outer part of media of large vessels. NOTE: veins have more than vasa vasorum.

Question 3

What makes up the tunica intima?

Answer 3

Endothelium + underlying sub endothelial connective tissue (+ elastic lamina in larger vessels)

Question 4

Tunica media

Answer 4

Smooth muscle (primary component) + external elastic lamina - where present

Question 5

Tunica adventitia

Answer 5

Fibroelastic connective tissue (dense irregular CT with small amounts of elastic fibers)

Question 6

State the classes of arteries.

Answer 6

Large (elastic), medium (muscular), and small (arterioles)

Question 7

Describe the external and internal elastic lamina of elastic vessels.

Answer 7

Internal is incomplete, there is no distinct external elastic lamina

Question 8

What type of nerve innervate muscular arteries?

Answer 8

Postganglionicsympathetic

Question 9

Describe the external and internal elastic lamina of muscular arteries.

Answer 9

Internal is well developed, thick external elastic lamina at edge of tunica media

Question 10

Diameter of arterioles

Answer 10

Less than 0.5 mm

Question 11

Describe the internal elastic lamina of arterioles

Answer 11

It may or may not be present

Question 12

Smooth muscle layers in arteriole media

Answer 12

1 - 3

Question 13

What can pericytes differentiate into?

Answer 13

Fibroblasts or smooth muscle cells

Question 14

Describe a continuous (somatic) capillary.

Answer 14

Continuous endothelium and basal lamina. No fenestrae.

Question 15

Where are continuous capillaries located?

Answer 15

Muscle, connective tissue, CNS, exocrine pancreas, gonads

Question 16

Describe the basal lamina and endothelium of fenestrated (visceral) capillaries.

Answer 16

Basal lamina: continuous

Endothelium: attenuated large 60-80nm fenestrae with thin 4-6 nm diaphragms

Question 17

Where are fenestrated capillaries located?

Answer 17

Mucosa of GI tract, endocrine glands, renal, kidney, choroid plexus, ciliary body

Question 18

How are fenestrated endothelium in the glomerular capillaries unique?

Answer 18

No diaphragms

Question 19

Where are discontinuous (sinusoidal) capillaries found?

Answer 19

Liver and hemopoietic organs (bone, marrow, spleen)

Question 20

Type of capillary with an incomplete basal lamina and large gaps between cells

Answer 20

Discontinuous

Question 21

Do muscular venules have pericytes?

Answer 21

No.

Question 22

Do postcapillary venules have pericytes?

Answer 22

Yes.

Question 23

What size of veins have valves? What is the basic structure of these valves?

Answer 23

small - medium

paired, semilunar folds of the intima

Question 24

What is the purpose the specialized tunica media with sphincter at arteriovenous anastomoses? What happens when it is open/closed?

Answer 24

Control flow of blood through capillary bed
Closed shunt: arterial blood flows through capillary bed
Open shun: blood bypasses capillary bed

Question 25

What is the role of a precapillary sphincter?

Answer 25

Controls amount of blood flowing through microvascular beds.

Question 26

Lacteals

Answer 26

Important round of fat absorption in the intestine

Question 27

What site does lymph flow towards?

Answer 27

Veinous angles at base of neck.

Question 28

Do lymphatic vessels have a basal lamina?

Answer 28

No.

Question 29

What CT layer of skeletal muscle possesses lymphatics?

Answer 29

Perimysium (only one to have it)

Question 30

Smooth muscle cell proliferation that follows angioplasty procedure

Answer 30

Restenosis

Question 31

Ballooning of an artery due to weakness

Answer 31

Aneurysm

Question 32

Tortuous, dilated veins primarily in legs - result of fascial and valve failure.

Answer 32

Varicose veins

Question 33

Disease states associated with aneurysm

Answer 33

Atherosclerosis, syphilis, connective tissue disorders (Ehlers-Danos, Marfan's syndrome)

Question 34

What is prostacyclin produced from? What cells produces prostacyclin?

Answer 34

Arachidonic acid | Endothelial cells produce

Question 35

What is the physiological role of prostacyclin?

Answer 35

Inhibits platelet adhesion and clot formation

Question 36

What is the physiological role of nitric oxide?

Answer 36

Causes smooth muscle in the tunica media to relax = vasodilation

Question 37

What is the physiological role of endothelin-1?

Answer 37

Vasoconstrictor

Question 38

Describe the general regulation of inflammation mediated by macrophages.

Answer 38

Macrophages secrete TNF-alpha, IL-1 > expression of E-selectin induced > Neutrophils bind to selectins and extravasate through endothelium

Question 39

State the tunics of the heart (inner to outer)

Answer 39

Endocardium, myocardium, epicardium

Question 40

What heart layer contains Purkinje fibers?

Answer 40

Subendocardial CT of endocardium

Question 41

What are the layers of the myocardium? What are their courses?

Answer 41

Superficial: Spiral course around ventricle Deep: circular course

Question 42

What tissue types form the epicardium?

Answer 42

Mesothelium (outer layer) and loose CT with adipose (under mesothelium)

Question 43

Fibrous rings around the origins of the pulmonary artery, aorta, av canals.

Answer 43

Annuli fibrosi

Question 44

Fibrous tissue between the arterial foramina and the atrioventricular canals

Answer 44

Trigona fibrosa

Question 45

What tissue type makes up the fibrous skeleton of the heart?

Answer 45

Dense irregular CT

Question 46

What is the pacemaker of the heart?

Answer 46

SA node

Question 47

What cell type produces Purkinje fibers?

Answer 47

Modified muscle cells (filled with glycogen)

Question 48

What cells produce polypeptide hormones?

Answer 48

Atrial cardiac muscle cells and some cells in the interventricular septum

Question 49

What are the four hormones made by the ANP gene?

Answer 49

Long acting natriuretic (sodium) peptide Vessel dilator Kaliuretic Atrial natriuretic peptide (ANP)

Question 50

What causes the release of ANP? What is the effect of ANP?

Answer 50

Released in response to high BP. Increases sodium and H20 secretion from kidney.