Histology

Question 1

Where is the most blood in the body?

Answer 1

Peripheral veins

Question 2

What is the inner, middle and outer layers of blood vessels?

Answer 2

1. Tunica intima
2. Tunica media
3. Tinica adventitia

Question 3

Describe the tunica intima?

Answer 3

Made up of single layer of squamosu epithelial cells termed endothelial cells (collectivly endothelium) supported by a basal lamina and thin layer of connective tissue.

Question 4

Describe the tunica media?

Answer 4

Made up of predominantly muscle (some areas elastic tissue). It varies and sometimes disapears.

Question 5

What is the tunica adventitia made from?

Answer 5

Supporting connective tissue

Question 6

What are the very largest arteries termed?

Answer 6

Elastic arteries

Question 7

What do elastic arteries have that provides elastic recoild?

Answer 7

Sheets of elastic fibres

Question 8

What are the elastic arteries own vascular supply called?

Answer 8

Vaso vasorum

Question 9

What does Verhoeff’s/Masson trichrome stain do to elastic fibres, collagen and smooth muscle?

Answer 9

Elastic fibres - black
Collagen - green
Smooth muscle cells - red

Question 10

What does the tunica intima extend to?

Answer 10

An internal elastic membrane

Question 11

What seperates the tunica media nad tunica adventitia?

Answer 11

External elastic membrane

Question 12

What does Modified van Gieson’s stain do to collagen, cytoplasm and elastin?

Answer 12

Collagen - red
Cytoplasm - yellow
Elastin - black

Question 13

What are capillaries essentially composed of?

Answer 13

Endothelial cells and a basal lamina

Question 14

What do capilarries often have ar intervals just outside the basal lamina?

Answer 14

Pericytes

Question 15

What are the three types of capillary?

Answer 15

1. Continuous capillaries
2. Fenestrated capillaries
3. Sinusoidal or discontinuous capillaries

Question 16

What types of capillaries are found in muscle, connective tissue, lung, skin and nerves?

Answer 16

Continuous capillaries

Question 17

What capillaries are found in mucosa of gut, endocrine glands and glomeruli of the kidney?

Answer 17

Fenestrated capillaries

Question 18

What capillaries lack basal lamina and have large gaps through which macromolecules, and in some cases even cells can pass. Found in liver, spleen and bone marrow?

Answer 18

Sinusoidal or discontinuous

Question 19

What are important sites for exchange e.g. cells moving into the tissue in inflammation?

Answer 19

Postcapillary venule

Question 20

In microvasculature, what are small arterioles connected to?

Answer 20

Postcapillary venules through a network of metarterioles, throughfare channels and capillaries

Question 21

What are composed of smooth muscle, found at the beginning of capillaries and help control flow through the network?

Answer 21

Precapillary sphincters

Question 22

What are the three layers of the heart from outside to inside?

Answer 22

Epicardium
Myocardium
Endocardium

Question 23

What does Azan trichrome stain nuclei, collagen and muscle?

Answer 23

Nuclei - red
Collagen - blue
Muscle - red

Question 24

What lines the entire inner surface of the heart, including the valves?

Answer 24

Endocardium

Question 25

What are the 4 features of the structure of the endocardium?

Answer 25

1. Endothelium 2. Basal lamina 3. Thin layer of collagen fibres 4. Layer of denser connective tissue

Question 26

What else is there present in the endocardium that is made of loose connective tissue, contaisn small blood vessels and nerves and the branches of the impulse conducting system?

Answer 26

Subendocardium

Question 27

What has this structure: bundles and layers of c ontractile cardiac muscle fibres, individual muscle fibres are surrounded by delicate, collagenous connective tissue with a rich network of capillaries?

Answer 27

Myocardium

Question 28

What has intervalated discs passing across the fibres at irregular intervals?

Answer 28

The myocardium

Question 29

What do intercalated discs allow?

Answer 29

Attachment of cells and spread of electrical activity

Question 30

What structure is this - on the surface of the heart, a single layer of flattened epithelium called mesothelium, basal lamina, fibroelastic connective tissue and in some places adipose tissue?

Answer 30

Epicardium

Question 31

Where are large branches of the coronary blood vessels found?

Answer 31

In the epicardium

Question 32

What are the two parts of the pericardium?

Answer 32

Fibrous and serious

Question 33

What is the name of a sac of tough fibrocollagenous connective tissue?

Answer 33

Fibrous pericardium

Question 34

What is made up of a layer of simple squamous epithelium (mesothelium), backed by a basal lamina and connective tissue. The serous pericardium lines the inner surface of the fibrous pericardium (where it is termed the parietal serous pericardium), and covers the surface of the heart (where it is termed the visceral serous pericardium)?

Answer 34

Serous pericardium

Question 35

What seperates the two mesothelial layers of the pericardium?

Answer 35

Thin pericardial cavity which contains serous fluid to help heart movement lubrication

Question 36

What forms the fibrous skeleton of the heart?

Answer 36

Bands of fibrous connective tissue around the heart valves, between the atria and between the ventricles

Question 37

What is the outer layer of heart valves?

Answer 37

Endothelial layer with basal lamina

Question 38

What do heart valves also have a layer of?

Answer 38

Collagen and elastin fibres

Question 39

What is a core dense connective tissue, that is in continuity with the fibrous skeleton?

Answer 39

Lamina fibrosa

Question 40

What are the leaflets of the valves seperating the atria from the ventricles (mitral and tricuspid) anchored by?

Answer 40

Collagenous strands called the chordae tendineae, which merge with the lamina fibrosa

Question 41

What cells are small, appear pale, have few myofibrils, little glycogen and no proper T-tubules system?

Answer 41

Pacemaker cells

Question 42

Where are Purkinje fibres found?

Answer 42

In the subendocardial layer just deep to the endocardium

Question 43

What fibres have abundant glycogen, no T-tubules, no intercalated discs and sparse actin and myosin filaments, which tend to be found at the periphery of the cells?

Answer 43

Purkinje fibres

Question 44

What structures distribute the excitatory activity such that ventricular contraction generally occurs from inferior to superior?

Answer 44

Purkinje fibres

Question 45

What do lymphatic capillaries begin as?

Answer 45

Blind sacs

Question 46

What does interstitial fluid contain?

Answer 46

Lipids, ins, proteins and occasional cells

Question 47

How do lymphatic vessels produce flow as they do not have a central pump?

Answer 47

Smooth muscles in walls, hydrostatic pressure in the tissue and compression of the vessels by voluntary muscle, combined with valves in the vessels, produces flow

Question 48

What two systems does the circulatory system consist of?

Answer 48

1. Cardiovascular system | 2. Lymphatic vascular system