HISTOLOGY

Question 1

what bone marrow cells produce platelets?

Answer 1

megakaryocytes

Question 2

what bones retain hemopoiesis?

Answer 2

vertebrae 
ribs
skull
pelvis
proximal femur

Question 3

what is the main site of hemopoiesis after birth?

Answer 3

bone marrow

Question 4

what are the three layers of a blood vessel? (from inner to outer)

Answer 4

tunica intima (inner)
tunica media (middle)
tunica adventitia (outer)

Question 5

describe the tunica intima (3)

Answer 5

inner layer of a blood vessel
a single layer of squamous epithelail cells (endothelium)
supported by a basal lamina and a thin layer of connective tissue

Question 6

describe the tunica media (3)

Answer 6

middle layer
predominantly smooth muscle, some elastic fibres
thickness of this layer varies

Question 7

describe the tunica adventitia (2)

Answer 7

outer layer

made up of supportive connective tissue

Question 8

what separates the tunica intima and the tunica media?

Answer 8

a layer of elastic tissue called the internal elastic membrane

Question 9

what separates the tunica media from the tunica adventitia?

Answer 9

a layer of elastic tissue called the external elastic membrane

Question 10

what is an elastic artery?

Answer 10

an artery in which a significant amount of the smooth muscle in the tunica media is replaced by sheets of elastic fibres

Question 11

what do sheets of elastic fibres in the tunica media allow?

Answer 11

elastic recoil

Question 12

why do large arteries have their own vascular supply and what is this called?

Answer 12

only the inner part of the wall can obtain nutrients from the lumen
the vasa vasorum

Question 13

how are arterioles formed?

Answer 13

arteries become smaller and lose smooth muscle from their tunica media

Question 14

what are arterioles important for?

Answer 14

controlling blood flow in a tissue

Question 15

describe the structure of capillaries (3)

Answer 15

composed of endothelial cells and a basal lamina
diameter of between 4 and 8 micrometers
they form networks

Question 16

what are the three types of capillaries?

Answer 16

continuous
fenestrated
discontinuous/sinusoidal

Question 17

where are continuous capillaries found? (4)

Answer 17

muscle, nerves, lungs and skin

Question 18

describe fenestrated capillaries

Answer 18

have small pores

found in the gut mucsosa, endocrine glands and the kidneys

Question 19

describe discontinuous capillaries

Answer 19

have large gaps

found in the liver, spleen and bone marrow

Question 20

describe venules (4)

Answer 20

10 - 30 micrometres in diameter
lined with endothelial cells, contain a thin layer of connective tissue
important sites for exchange
has intwrmittent smooth muscle cells in the tunica media

Question 21

describe the structure of a vein

Answer 21

tunica intima
tunica adventitia
thin but continuous tunica media, few layers of smooth muscle

Question 22

describe the structure of the largest veins

Answer 22

thick tunica adventitia which incorporates bundles of longitudinally oriented smooth muscle

Question 23

why do many veins have valves?

Answer 23

to prevent backflow of blood

Question 24

what is the lymph vascular system?

Answer 24

a system of relatively thin walled vessels that drain excess tissue fluid called lymph into the blood stream and to lymoh nodes for immunological surveillance

Question 25

how is flow maintained in the lymph vascular system?

Answer 25

smooth muscle in walls hydrostatic pressure in tissue compression of the vessels by voluntary muscle valves

Question 26

what is the second site of hemopoiesis?

Answer 26

liver and spleen (mainly the liver) as they are colonized with hemopoietic stem cells

Question 27

where is the earliest site of hemopoiesis?

Answer 27

in the yolk sac at about 3 weeks of development

Question 28

what is hemopoiesis?

Answer 28

the production of blood cells

Question 29

platelets

Answer 29

small cell fragments play a key role in preventing blood loss no nucleus granulated - granules contain coagulation factors

Question 30

what two main components make up blood?

Answer 30

formed elements | plasma

Question 31

lymphocytes

Answer 31

round nucleus thin cytoplasm with no granules arise in bone marrow participate in the specific immune response

Question 32

monocytes (6)

Answer 32

``` precursors to tissue macrophages predominent in loose connective tissye lysosomal granules in the cytoplasm largest blood cells non lobulated nucleus - kidney bean shaped some are resident to tissues ```

Question 33

describe basophils

Answer 33

granules in cytoplasm (affinity for basic dyes) bilobed nucleus granules contain inflammatory mediators degranulation leads to allergic reaction

Question 34

what is the rarest granulocyte?

Answer 34

basophils

Question 35

describe eosinophils

Answer 35

granulocytes granules stained red by eosin in cicrculation for 8-12 hours then live in tissues larger than a neutrophil bilobed nucleus induce and maintain an inflammatpry response

Question 36

describe a neutrophil (4)

Answer 36

contain granules in its cytoplasm multi lobed nucleus once activated, act as highly motile phagocytes abundant and short lived, significant proportion of the bone marrow is dedicated to their production

Question 37

what is the most common type of leukocyte?

Answer 37

neutrophil

Question 38

what is a leukocyte?

Answer 38

white blood cell

Question 39

how long do red cells last in circulation and how are they removed?

Answer 39

four months | removed by the spleen and the liver

Question 40

why do red cells have a network of flexible cytoskeletal elements?

Answer 40

to allow them to deform and slip through spaces smaller than themselves

Question 41

describe a red blood cell

Answer 41

biconcave disc 7 micrometers in diameter not a true cell as they contain no nucelus or organelles contain the protein haemoglobin

Question 42

what are erythrocytes?

Answer 42

red blood cells

Question 43

what is it called if clotting factors are removed from blood?

Answer 43

serum

Question 44

describe the separation of blood in a centrifuge

Answer 44

red cells are the densest and are found at the bottom of the tube white cells are on top of red cells plasma is found on top

Question 45

what are the two types of agranulocytes?

Answer 45

lymphocytes | monocytes

Question 46

what are the three types of granulocytes?

Answer 46

neutrophils eosinophils basophils

Question 47

what are the two types of white cells?

Answer 47

granulocytes | agranulocytes

Question 48

what makes up the formed elements of blood?

Answer 48

red cells white cells platelets

Question 49

what do all eukaryotic contain?

Answer 49

``` an outer membrane cytoplasm cytoskeleton membrane bound organelels inclusions ```

Question 50

what is the function of the cytoskeleton?

Answer 50

gives cell shape and fluidity, provides support and structure

Question 51

what is another name for the cell membrane?

Answer 51

the plasmalemma

Question 52

what is the cell membrane made up of?

Answer 52

amphipathic phospholipids

Question 53

describe the phosphilipid head

Answer 53

hydrophillic, faces outer and inner surfaces

Question 54

describe the phospholipid tail

Answer 54

hydrophobic fatty acid chain | faces the middle of the two layers

Question 55

what does the cell membrane contain?

Answer 55

integral proteins: receptors, channels, transporters, enzymes and cell attachment proteins peripheral proteins cholesterol

Question 56

what ways can proteins be embedded in the cell membrane?

Answer 56

some can diffuse laterally in the membrane | some are anchored

Question 57

what is endocytosis?

Answer 57

moving things into the cell

Question 58

what is exocytosis?

Answer 58

moving things out of the cell

Question 59

what does the cell membrane provide?

Answer 59

a barrier between the cell and the outside world

Question 60

what is an organelle?

Answer 60

a small intracellular organ that is essential for life

Question 61

what is an inclusion?

Answer 61

anything else in a cell that isnt essential for life

Question 62

how can inclusions get into cells?

Answer 62

synthesised by the cell | taken up from the extracellular environment

Question 63

what three types of protein filaments make up the cytoskeleton?

Answer 63

microfilaments | intermediate filaments

Question 64

microfilaments

Answer 64

made from actin

Question 65

intermediate filaments

Answer 65

made from six types of proteins, varied in different cell types

Question 66

microtubules

Answer 66

two tubulin protein subunits

Question 67

how do the filaments of the cytoskeleton attach to the membrane and each other?

Answer 67

by joining proteins to form a 3D internal scaffold inside the cell

Question 68

why are microfilaments a fluid part of the cytoskeleton?

Answer 68

actin molecules assemble into the filaments and can later dissociate

Question 69

what type of protein is actin?

Answer 69

globular