Histology

Question 1

histological features of skeletal muscle fibres (5)

Answer 1

striated
unbranched
multinucleated (syncytium formed)
long cylinders
peripheral nuclei just under sarcolemma

Question 2

CT around muscle fibre =
around fascicle =
around muscle =

Answer 2

fibre = endomysium
fascicle = perimysium
muscle = epimysium

Question 3

if cut transversely skeletal muscle fibres =

cardiac =

Answer 3

skeletal = cylindrical so all the same diameter
cardiac = taper therefore different diameters

Question 4

fibres in a motor unit are in the same site/scattered in a muscle?

Answer 4

scattered

Question 5

aerobic fibres resistant to fatigue and produce less force =

Answer 5

type I - slow twitch

Question 6

relatively uncommon skeletal muscle fibres

Answer 6

Type IIa - intermediate twitch

Question 7

succinate dehydrogenase stain result on type I , IIa, IIx fibres

Answer 7

I = dark purple
IIa = light purple
IIx = white

Question 8

cartilage is nourished by ___ because it is __

Answer 8

ECM diffusion

avascular

Question 9

___ mature to chondrocytes - live in __ in ECM. __+__ ECM

Answer 9

chrondroblasts
lacuna
secrete and maintain

Question 10

ECM in hyaline cartilage composition =

Answer 10

75% water
25% organic - 60% Type 2 collagen, 40% proteoglycan aggregates of GAGs bound to core protein and often linked to hyaluronan

Question 11

thicker and linear bundles = ___ collagen

Answer 11

Type 1

Question 12

finer and forms 3D meshwork = ___ collagen

Answer 12

Type 2

Question 13

grossly hyaline looks = \_\_+\_\_
found in (5)

Answer 13

translucent and blue white

articular surfaces, tracheal rings, costal cartilage, epiphyseal growth plates, foetal precursor to bone

Question 14

2 gross features of elastic cartilage =

Answer 14

light yellow and flexible

Question 15

bands of packed collagen I interlaced with rows of chondrocytes surrounded by a small amount of ECM
grossly = white =

Answer 15

fibrocartilage

Question 16

95% of Ca2+ in body is stored __

Answer 16

in bone

Question 17

locations of haemopoeisis in adults =

Answer 17

axial skeleton

girdles

Question 18

components of bone (4)

Answer 18

65% mineral (calciumhydroxypatitite crystals)
23% collagen
10% water
2% non collagen proteins

Question 19

outer shell of diaphysis = ___ bone

Answer 19

cortical

Question 20

epiphysis = __ bone

Answer 20

cancellous/trabecular

Question 21

cortical and trabecular bone are both ___

Answer 21

lamellar

Question 22

in cortical bone:

___ run through and branch to ___ = blood supply

Answer 22

Haversion canals

Volkmann’s canal

Question 23

lines often found around osteons in cortical bone = ___ due to remodelling

Answer 23

cement lines

Question 24

osteocytes in cortical bone have ___ that expand into ___ and pass nutrients cell-cell

Answer 24

dendrites

canaliculi

Question 25

in trabeular bone:
lacks ____ because struts are thin
osteocytes get nutrients from ___

Answer 25

lack haversian canals

marrow spaces

Question 26

osteoprogenitor cells are found ___ and are a pool of ___

Answer 26

on bone surfaces

reserve osteoblasts

Question 27

cells that form bone =

Answer 27

osteoblasts

Question 28

osteoblasts are found ___

they have plentiful __+__

Answer 28

on surface of developing bone

RER and mitochondria

Question 29

ostecytes are found __

Answer 29

trapped in the matrix of bone

Question 30

osteoclasts are ___ and ___
found on __
function =

Answer 30

large (>=40microns) multinucleated
bone surface
resorption

Question 31

osteoclasts are derived from ___

Answer 31

macrophage lineage of cells

Question 32

cutting cone in remodelling of bone =

Answer 32

osteoclasts drill in to bone > blood vessels form in tunnel and bring osteoblasts which lay down bone to line tunnel > continues until only Haversian canal remains

Question 33

collection of osteoclasts and blasts involved in remodelling of bone =

Answer 33

BMU

basic multicellular unit

Question 34

osteoblasts secrete __+++_ collectively known as ___ which becomes mineralised over time

Answer 34

collagen
GAGs
proteoglycans
other organic components of the matrix
= osteoid