Histology of Blood Vessels & Film

Question 1

What is blood vessels pathway

Answer 1

Arteries
Elastic arteries
Muscular arteries
Arterioles (to Terminal arterioles)
Meta Arterioles
Capillaries
Venules
Post capillary venule
Vein

Question 2

What are the 3 layers of blood vessels

Answer 2

Tunica Intima (inner)
Tunica Media
Tunica Adventitia (outer)

Question 3

What is tunica intima

Answer 3

Single layer of squamous epithelial cells supported by basal lamina & connective tissue

Question 4

What is tunica media

Answer 4

Smooth muscle layer with elastic fibres which thickness depends upon specific vessel

Question 5

What is tunica adventitia

Answer 5

Made of supporting connective tissue with elastic fibres and fibroblasts

Question 6

What separates tunica intima and tunica media

Answer 6

Internal Elastic membrane
(layer of elastic tissue)

Question 7

What separates the Tunica media from tunica adventitia

Answer 7

External Elastic membrane
(layer of elastic tissue)

Question 8

In large arteries what is smooth muscle in tunica media replaced with

Answer 8

Sheets of elastic arteries
= therefore called elastic arteries as provide elastic recoil

Question 9

What is the thickness of tunica media in arteries

Answer 9

Tunica media thickness is GREATER than the tunica adventitia thickness

Question 10

What is the thickness of tunica media in veins

Answer 10

Tunica media thickness is LESS THAN the tunica adventitia thickness

Question 11

What is vasa vasorum in large arteries

Answer 11

Vessels have their own blood supply

(only inner wall gets the nutrients from lumen)

Question 12

What are arterioles

Answer 12

Smallest division of muscular arteries

Question 13

How do arteries turn into arterioles

Answer 13

When smooth muscle is lost from tunica media until only 1 or 2 layers are left with almost no adventitia

Question 14

What is a terminal arteriole

Answer 14

Has no internal lamina & is covered by continuous smooth muscle cell coat

Question 15

What is meta arteriole and what does it turn into

Answer 15

Smooth muscle replaced by dis-continuous & non-contractile cells
(Called pericytes)
These terminate into Capillaries

Question 16

What are capillaries comprised of

Answer 16

Endothelial cells and basal lamina

Question 17

Where are capillaries absent

Answer 17

Cornea of eye

Hyaline cartilage

Epidermis of skin, hair & nails

Epithelial cells resting on basement membrane

Question 18

What are the 3 types of capillary

Answer 18

Continuous (No gaps)
Fenestrated (Small pores)
Discontinuous (Large gaps)

Question 19

Where are continuous capillaries found

Answer 19

Muscle
Nerves
Lung
Skin

Question 20

Where are fenestrated capillaries found

Answer 20

Gut mucosa
Endocrine glands
Kidneys

Question 21

Where are discontinuous capillaries found

Answer 21

Liver
Spleen
Bone marrow

Question 22

What are the different routes to get from small arteriole to
post-capillary venule

Answer 22

-Metarterioles
-Throughfare channels
-Capillaries
-Precapillary sphincters

Question 23

What are venules comprised of

Answer 23

Endothelial cell lines and contain thin layer of connective tissue

Question 24

When can a venule be classified

Answer 24

Once smooth muscle cells have been reacquired in tunica media

Question 25

What are venules important sites of

Answer 25

Exchange e.g. cells moving into tissue during inflammation

Question 26

What are veins comprised of

Answer 26

Thin layer of tunica media and obvious tunica adventitia

Question 27

Where does lymph vascular system transport tissue fluid to and how is flow controlled

Answer 27

Lymph taken to lymph nodes for immunological surveillance Flow maintained by smooth muscle, hydrostatic pressure in tissue and compression by voluntary muscles

Question 28

What are the components of blood

Answer 28

Formed elements 45% Plasma 55%

Question 29

What's classified as formed elements

Answer 29

Red cells Platelets White cells (Granulocytes or agranulocytes)

Question 30

What's classified as plasma

Answer 30

Water 90% Proteins Nutrients Salts

Question 31

What types of white blood cells are granulocytes

Answer 31

Neutrophils Eosinophils Basophils

Question 32

What type of white blood cells are agranulocytes

Answer 32

Lymphocytes Monocytes

Question 33

What is centrifugation

Answer 33

Separates components of blood depending on density Red cells densest and found of the bottom White cells next Plasma (liquid) is found at the top

Question 34

What is serum

Answer 34

Liquid remaining when clotting factors are removed first by the blood -Achieved by allowing blood to clot, removing clot before centrifugation

Question 35

What are erythrocytes

Answer 35

Red blood cells Biconcave discs about 7um in diameter

Question 36

Why are mature erythrocytes not true cells

Answer 36

Have no nucleus or organelles 1/3 volume taken up by haemoglobin

Question 37

What does cytoskeleton of red blood cells allow them to do

Answer 37

As its flexible they can deform and slip through spaces smaller than themselves

Question 38

How long do red blood cells last and what removes them

Answer 38

4 months Removed by spleen and liver

Question 39

What is a haematocrit

Answer 39

Proportion of blood that is red blood cells e.g. haematocrit of 40 = 40% of volume is cells and rest is plasma

Question 40

What are the proportions of 5 different leukocytes (White blood cells)

Answer 40

Neutrophils 40-75% Eosinophils 5% Basophils 0.5% Lymphocytes 20-50% Monocytes 1-5%

Question 41

What is a neutrophil

Answer 41

- Most common type of leukocyte - Cytoplasm has MANY granules however stain poorly - Prominent multi-lobed nucleus

Question 42

How long do neutrophils last

Answer 42

short lived - so even though they are abundant a significant proportion of bone marrow is devoted to their production

Question 43

When are neutrophils stimulated from inactive circulating state

Answer 43

e.g. Presence of bacteria by inflammation Enter tissue to be highly motile phagocytes

Question 44

What are eosinophils

Answer 44

- Bilobed nucleus - Granules contain hydrolytic enzymes which induce and maintain inflammation in allergic reactions & asthma -Important in fighting parasitic infection -Slightly larger than neutrophils

Question 45

What dye do eosinophils have affinity for

Answer 45

Red acidic dye eosin due to prominent cytoplasmic granules

Question 46

What are basophils

Answer 46

- Bilobed nucleus obscured by granules -Granules contain histamine, heparin & inflammatory mediators - Effector cells in allergic reactions

Question 47

What dyes do basophils have high affinity for

Answer 47

Basic dyes e.g. methylene blue due to prominent granules, staining intense blue/purple

Question 48

What are monocytes

Answer 48

- Numerous small lysosomal granules in cytoplasm - Largest cells circulating in blood - Non-lobed nucleus (kidney bean shaped)

Question 49

What do monocytes serve as

Answer 49

precursors of tissue macrophages Together form Mononuclear phagocyte system

Question 50

What are examples of mononuclear phagocytic system cells which reside in specific tissues and are not wanderers

Answer 50

Kupffer cells = Liver Microglia = Brain Langerhans's cells= Skin

Question 51

What are lymphocytes

Answer 51

- Round nucleus - Surrounded by thin rim of cytoplasm with no visible granules - B & T cells, both arise in bone marrow but T differentiate in thymus

Question 52

What do platelets play a key role in

Answer 52

Haemostasis which is the prevention of blood loss -Found on large numbers in the blood, small fragments (No nucleus)