Cardiovascular

Question 1

What is the function of arteries and veins?

Answer 1

arteries: convey blood from heart to tissues of the body.
veins: return blood from the tissues back to the heart

Question 2

How are lymphatic vessels are associated with CVS?

Answer 2

drain excess fluid from tissue and return it to the CVS

-run one-way from the tissues to the veins.

Question 3

What components make up the tunica intima. What type of epithelium tissue and where is it present?

Answer 3

-endothelium-simple squamous epithelium.
present in all blood vessels, lymphatic vessels, and heart cavities.
-basal lamina of all endothelial cells.
-subendothelial layer: areolar CT and smooth muscle.
1.) internal elastic membrane- a network of elastic fiber bands.

Question 4

Tunica media

Answer 4

composition variable (dependent upon vessel)- predominantly elastic membranes or circularly arranged smooth muscle depending on type of vessel, or mixture of both.

Question 5

Tunica adventitia

Answer 5

• usually longitudinally arranged collagenous tissue.

- large arteries and veins, contains blood vessels (vasa vasorum and nervi vasorum)

Question 6

microvasculature

Answer 6

consists of arterioles, cappillaries (area of exchange), emerging benules and arteriovenous anastomoses (AV shunts)

Question 7

what do Av shunts do? Where is it found?

Answer 7

contraction allows BF to capillary beds;relaxation causes less BF to capillary beds
-found in skin of finger tips, lips, nose, erectile tissue

Question 8

What is the function of AV shunt? where is its exception in this role?

Answer 8

thermoregulation

exception in erectile tissue

Question 9

Sympathetic Innervation

Answer 9

NE causes vasoconstriction in skin and vasodilation in arterioles in skeletal muscle

Question 10

Vasovagal syncope

Answer 10

emotional fainting (not always), can occur in urination, defecating. 
-arteries dilate (acute drop in BP), vagus nerve (parasympathetic) is stimulated causing bradycardia- person faints.

Question 11

postcapillary venule

Answer 11

endothelial cells respond to histamine (dilate) and serotonin (constrict).

• no tunica media, little smooth muscle.
• pericytes, basal lamina

Question 12

Muscular Venules

Answer 12

• endothelial cells
• basal lamina
• 1-2 layers of smooth muscle found in the T. media

Question 13

how are veins different than arteries?

Answer 13

walls are thinner, lumen is larger, internal and external elastic membranes are small and attenuated or absent.

Question 14

What is the function of arteriole?

Answer 14

major regulator of blood flow and peripheral resistance; control amount of blood that enters the capillaries

Question 15

Where are continuous capillaries found and describe is morphology.

Answer 15

found in lung, muscle, and CNS

• complete endothelial cells (no pores)
• many pinocytotic vesicles
• continuos basal lamina
• tight junctions is not complete-some leak (except CNS)
• pericytes

Question 16

Where are fenestrated capillaries found and describe is morphology.

Answer 16

found in endocrine glands, gi tract, glomeruli

• endothelial cells with POREs (80-100nm)
• diaphragm spans pores
• continuous basal lamina
• pericytes

Question 17

Where are discontinuous capillaries found and describe is morphology.

Answer 17

found in liver, spleen, bone marrow

• large gaps present (NO DIAPHRAGMs)
• incomplete or missing BASAL Lamina
• important so that RBCs can leave when needed.

Question 18

What are the 6 function of capillaries besides exchange in gases, glucose, aa, electrolytes.

Answer 18

In the endothelial cells

1. site of angiotensin 2 conversion
2. produce growth factors (EDGF)- proliferation of new blood vessels
3. inactive molecules
4. release nitric oxide, aka endothelial relaxing factors- causes vasodilation
5. anti-thrombogenic function: produces anticoagulants and vasodilators
6. serve as a barrier between blood and sub-endothelial tissue, protective mechanisms such as thrombus formation can occur here

Question 19

what type of molecules can endothelial cells in capillaries inactivate and what effect does it have on the blood vessels?

Answer 19

Norepinephrine, serotonin (mostly vasoconstrict)

Prostaglandins (mostly visodilator)

Question 20

Postcapillary venule responds to what molecules?

Answer 20

histamine and serotonin

Question 21

What is the morphological difference between postcapillary venule and muscular venule?

Answer 21

• muscular venules have 1-2 layers of smooth muscle in tunica media while postcapillary venule does not.
• postcapillary venule has pericytes.

Question 22

Describe the morphology of continuous capillaries and where in the body could it be found?

Answer 22

1. complete endothelial cells with no pores
2. many pinocytotic vesicles
3. continuous basal lamina
4. tight junctions isn’t complete-some leak (except CNS)
5. pericytes
6. found in muscle, lungs and CNS

Question 23

Describe the morphology of fenestrated capillaries and where in the body could it be found?

Answer 23

• endothelial cells with pores
• diaphragm spans pores
• continuous basal lamina
• pericytes
• found in endocrine glands, GI, glomeruli (specialization don’t have diaphragm)

Question 24

Describe the morphology of discontinuous capillaries and where in the body could it be found?

Answer 24

large gaps present (NO DIAPHRAGMS)
-incomplete or missing basal lamina
-found in liver, spleen, bone marrow;
a way for blood can pull and leave easily.