Histology

Question 1

What are the three basic layer structures to the blood vessels

Answer 1

Tunica intima, Tunica media, Tunica adventitia (Inside to outside)

Question 2

Structure of the Tunica Intima

Answer 2

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

Question 3

Structure of the Tunica media

Answer 3

Tunica media, made up predominately of smooth muscle. Thickness of this layer varies tremendously.

Question 4

Structure of the Tunica adventitia

Answer 4

Tunica adventitia, made up of supporting connective tissue.

Question 5

What seperates the tunica intima and tunica media

Answer 5

Internal elastic membrane

Question 6

What seperates the tunica media and tunica adventitia

Answer 6

External elastic membrane

Question 7

What are elastic arteries?

Answer 7

The very largest arteries (e.g. aorta) are termed elastic arteries because they have many sheets of elastic fibres in their tunica media to provide elastic recoil.

Question 8

What is vasa vasorum?

Answer 8

In large vessels, only the inner part of the wall can obtain nutrients from the lumen, therefore these vessels will have their own vascular supply: the vasa vasorum.

Question 9

What are capillaries composed of

Answer 9

Capillaries are essentially composed of endothelial cells and a basal lamina.
They have a diameter of 4-8µm. (compare that to the dia. of an RBC - 7)

Question 10

What are pericytes

Answer 10

Pericytesare contractile cells that wrap around the endothelial cells that line the capillaries and venules throughout the body. They are found at intervals just outside basal lamina

Question 11

Three types of capillaries

Answer 11

Continuous, fenestrated and discontinuous

Question 12

What help control flow through the capillary network

Answer 12

Precapillary sphincters

Question 13

What has a thinner tunica media, artery or veins?

Answer 13

Veins

Question 14

Layers of the heart

Answer 14

Endocardium, myocardium and epicardium (Inside to outside)

Question 15

What does the subendocardium compose of

Answer 15

Subendocardium of loose connective tissue containing small blood vessels and nerves and the branches of the impulse conducting system such as Purkinje fibres

Question 16

Function of intercalated discs

Answer 16

Acts to attach cells but also allows spread of electrical activity

Question 17

Parts of the pericardium

Answer 17

Fibrous and serous pericardium

Question 18

What is the fibrous pericardium

Answer 18

Fibrous pericardium is a sac of tough fibrocollagenous connective tissue

Question 19

What is the serous pericardium made of

Answer 19

Serous pericardium is made up of a layer of simple squamous epithelium (termed mesothelium), backed by a basal lamina and connective tissue.

Question 20

What is the epicardium

Answer 20

The epicardium is the visceral layer of the serous pericardium

Question 21

Structure of heart valves

Answer 21

Layer of collagen and elastin fibres. A core of dense irregular connective tissue, called the lamina fibrosa, that is in continuity with the fibrous skeleton. The leaflets of the valves separating the atria from the ventricles (the mitral and tricuspid) are anchored to papillary muscles in the wall of the ventricle by collagenous strands called the chordae tendineae, which merge with the lamina fibrosa

Question 22

Types of cardiac muscle cells

Answer 22

Contractile muscle cells
Pacemaker cells
Conducting cells

Question 23

What is the size relation of purkinje fibres when compared of normal cardiac cells

Answer 23

Unlike the small pacemaker and bundle fibres, the Purkinje fibres are larger than normal cardiac muscle cells.

Question 24

What produces flow in lymphatic vessels

Answer 24

Lymphatic vessels have no central pump, but smooth muscle in walls, hydrostatic pressure in the tissue and compression of the vessels by voluntary muscle, combined with valves in the vessels, produces flow.