PATH - 9-25 - Circulatory/Cardiac Histology

Question 1

3 Types of Capillaries

B: Composition

Answer 1

– Continuous’

– Fenestrated’

– Discontinuous

B: 1 layer of endothelial cells with a basal lamina

Question 2

DESCRIBE THESE THREE TUNICA LAYERS IN THE VESSEL

A: Tunica Intima (3)

B: Tunica Media (3)

C: Tunica Adventitia (3)

Answer 2

A: Tunica Intima

• Endothelium
• [SubEndothelium connective tissue]
• [Internal Elastic Lamina]

B: Tunica Media

• Smooth Muscle
• Contains [elastic membrane lamina]
• [External Elastic lamina]

C: Tunica Adventitia

• [Dense Connective Tissue] and Fibroblast
• Vaso Vasorum in large vessels(Arteries AND Veins)
• -Veins have [Longitudinal smooth m. bundles in their Adventitia]*

Question 3

Endothelium

A: Composition

B: Function (3)

Answer 3

Endothelium:

A:Composed’of’single’layer’of’squamous’cells,’

B: Provides:

• permeable barrier,
• ‘angiogenesis,’
• release’of’single’molecules

Question 4

[Medium Sized Arteries] are also called ______ arteries because their wall is mostly ______.

B: Different from Large Artery by what 2 things?

Answer 4

[Medium Sized Arteries] are also called Muscular arteries because their wall is mostly smooth muscle.

B: Different from Large Artery by:

*[Internal and External Elastic Lamina] are well defined

*[Internal and External Elastic Lamina] LACK prominent vasovasorum

Question 5

A: Describe the small arteries (2)

B: Arterioles only have __ layers of smooth muscle with no _____ or _______

Answer 5

A:small arteries:

• Same as [medium muscle artery] but with NO EXTERNAL ELASTIC LAMINA
• Tunica media has fewer layers (3-6 of smooth m.)

B: Arterioles only have TWO layers of smooth muscle with no [Internal/External elastic lamina] / SubEndothelium

Question 6

Describe [Tunica Media] in Large Arteries (2)

Answer 6

Smooth’muscle’ cells’

+

‘Large’ quantity’of’elastic fibers’

Question 7

Describe [Tunica Media] in Muscle Medium Arteries

Answer 7

Multiple layers of smooth m. cells (6-40 layers)

Question 8

Describe [Tunica Media] in small Arteries

Answer 8

2- 6 layers of smooth m.

Question 9

Describe [Tunica Media] in Arterioles

Answer 9

2 layers of smooth m.

Question 10

Function of Large Arteries (4)

Answer 10

1. Conduct blood from heart
2. Accomodate pressure changes
3. Maintain continuous blood flow during Diastole
4. Wall Recoil

Question 11

Function of Muscle Medium Arteries

Answer 11

Distributing arteries

Question 12

Function of Small Arteries

Answer 12

Control and Modulation of [Blood Pressure]

Question 13

Function of Arterioles (2)

Answer 13

1. Controls blood flow to capillaries
2. Important in Regulating Blood Pressure

Question 14

Examples of Large Arteries (4)

Answer 14

1. Aorta
2. Subclavian
3. Carotid
4. iLiac Artery

Question 15

Coronary and Renal Arteries are what type of artery?

Answer 15

Muscle Medium Artery

Question 16

Veins have more [Tunica Media] or [Tunica Adventitia]?

Answer 16

[Tunica Adventitia]

Question 17

VENOUS VALVES

1. Contains folds in the [Tunical _____] of [_____ and _____ veins]
2. # of valves INC with _____ of vessel
3. Prevents _____
4. Also present in _____ vessels

Answer 17

1. Contains folds in the [Tunical Intima] of [medium and large veins]
2. # of valves INC with size of vessel
3. Prevents blood backflow
4. Also present in lymphatic vessels

Question 18

A: How is the Arterial lumen different from Venous lumen? (3)

B: Describe Lymphatic Vessel Composition (3)

Answer 18

A: Arterial Lumen = smaller / rounder / [Prominent Internal Elastic Lamina]

B: Lymphatic Vessels = [Large Lumens] + [Thin Walls (1 endothelium layer)] and [no continuous basement membrane]

Question 19

What 3 things are the Endocardium composed of?

Answer 19

• Simple Squamous epithelium (endothelium)
• Connective Tissue
• SubEndocardium which is in contact with cardiac muscle and contains nerves / Purkinjie Fibers /small vessels

Question 20

A: [Purkinje Fibers] are located in ______ in Clusters. There are ______ nuclei per Muscle cell and they stain ______due to fewer ______.

B: They are also the terminal branches of the _________

Answer 20

A: [Purkinje Fibers] are located in [Large modified Muscle Cells] in Clusters. There are 1-2 nuclei per Muscle cell and they stain [pale pink] due to fewer myofibrils.

B: They are also the terminal branches of the AV Bundle branches

Question 21

A: Which heart chamber has the thinnest myocardium and why?

B: Describe Smooth Muscle Cells (4)

C: Which layer of the heart Covers and Protects it?

Answer 21

A: R Atrium (due to low resistance to back flow)

B: Long/Slender Central Nuclei lying inside narrow fusiform cells but with No Cross Striations

C: EPICARDIUM

Question 22

Epicardium composition (3)

Answer 22

Epicardium is composed of

• Connective tissue w/nerves
• adipocytes
• Outer Layer Mesothelium —> Secretes pericardial fluid

Question 23

Describe the 3 Layers of a Heart Valve

Answer 23

A: Spongiosa= Endothelium that faces the Atrium

B: Fibrosa = Dense CORE of Connective Tissue

C: Ventricularis= Dense Connective Tissue with elastic and collagen fibers facing the ventricles

Question 24

What are the 3 main thing that make medium Veins different from Large Veins?

Answer 24

medium veins are:

1. Lumen is smaller
2. Vaso Vasorum is NOT prominent
3. DEC # of [longitudinal smooth m. bundles] in [Tunica Adventitia]

Question 25

Answer 25

Tunica Adventitia

Question 26

Answer 26

Vaso Vasorum

Question 27

Injury to the cells in the box would predispose a pt to what disease?

Answer 27

Atherosclerosis