Histology

Question 1

???

Answer 1

!!!

Question 2

muscle fibres
-no. of nuclei?
-term for a group of fibres
-name the connective tissue that covers: 
the whole muscle
the group of fibres
individual fibres
-explain the striated appearance

Answer 2

• multinucleated (nuclei in periphery under the cm)
• fasicle

-Epimysium
Perimysium
endomysium

-disks within a sarcomere of one myofibril are aligned with the next

Question 3

muscle fibre types

• what are the types
• features: contactility, metabolism, mitochondria, fatigue, force, colour

Answer 3

Type 1 and Type 2 A & B

Type 1:
slow contraction
oxidative metabolism
abundant mitochondria
resistant to fatigue
produce less force
'red'

Type 2:
A: relatively fast contraction
relatively resistant to fatigue

B:fast contracting
anearobic motabolism
Fatigue easily
produce greater force
"white"

Question 4

Describe cartilage and bone composition and nutrient supply

Answer 4

Cartilage
semi-rigid, deformable
permeable
avascular (diffusion through the extracellular matrix)

Bone
rigid
non-permeable
cells nourished by blood vessels pervading tissue

Question 5

Chondrocytes

• what are they
• what do they do

Answer 5

• cartilage cells, make up hyaline cartilage

- live in lacuna in the extracellular matrix and secrete and maintain the extracellular matrix

Question 6

name the 3 types of cartilage

-appearance

Answer 6

hyaline- blue/white, translucent on articular surfaces

elastic cartilage- light yellow + elastic fibres

Fibrocartilage- appears white, bands of densely packed type 1 collagen interspersed with rows of chondrocytes

Question 7

Bone

• what type of bone makes up the diaphysis
• what type of bone makes up the epiphysis
• functional unit of bone and its composition?
• what carries vessels through the bone?
• what do you call bone cells & how do they receive nutrients
• what are the lines around a functional unit of bone called
• acts as a reservoir for bone cells?
• what are osteoblasts
• what are osteoclasts

Answer 7

• cortical
• cancellous/trabecullar
• an osteon, composed of lamellae
• Haversion canals
• osteocytes, trapped within the extracellular matrix and receive nutrients via dendritic branches
• cement lines
• osteoprogeniter cells on the bone surface
• bone forming cells found on the surface of developing bone, lots of mitochondria & RER
• large multi-nucleated, responsible for bone resorption

Question 8

Remodelling

-describe the process

Answer 8

-osteoclasts congregate and drill into the bone
blood vessel grows into the bone bringing with it osteoblasts
they line the tunnel and put down new lamellar bone, this continues until a aversion canal forms
forms a basic multicellular unit

Question 9

Bone mineralisation

• involves what kind of crystals
• what do osteoblasts secrete
• collective term for the substances secreted

Answer 9

• Ca and Phosphate
• collagen, glycosaminoglycans, proteoglycans & other matrix components
• osteoid

Question 10

Bone laid down after break?

-subsequently replaced by?

Answer 10

• woven bone

- lamellar bone