Flashcards in MSK histology Deck (54):
What are the three types of muscle?
What is the plasma membrane of a skeletal muscle cell called?
Are skeletal muscles striated?
Are skeletal muscles branched or unbranched?
Are skeletal muscles multinucleate or uninucleate?
Where in the skeletal muscles do the nuclei lie?
What is the epimysium?
The connective tissue surrounding a muscle
What is the perimysium?
The connective tissue surrounding a muscle fascicle
What do we call the connective tissue which surrounds a single muscle fibre?
What are sarcomeres?
Smallest contractile elements in skeletal muscle
What are myofibrils?
Structure formed when loads of sarcomeres form end to end
Muscle fibres are composed of what?
Why does skeletal muscle appear striated?
Because of the alternating thick and thin filaments in the sarcomere
What is a motor unit?
One motor neurone (nerve) and all the muscle fibres which it innervates
What denotes fine muscle control in relation to the motor unit?
The smaller the number of muscle cells that the nerve innervates the more precise the control
What is the synapse between motor nerves and muscle cells called?
Describe the three subtypes of skeletal muscle cell
Type I (red) - slow contracting & aerobic, many mitochondria, low force, fatigue resistant
Type IIA - intermediate of other two subtypes, relatively fast contracting and fatigue resistant
Type IIB (white) - fast contracting & anaerobic, fatigue easily, minimal mitochondria, high force
Which of the three skeletal muscle subtypes is the least common?
Describe the vasculature of cartilage
How does the cartilage receive nutrients?
Diffusion through the extracellular matrix
Is bone permeable?
No - it's cartilage that is permeable
What do we call cartilage cells?
What do we call immature cartilage cells?
Where are chondrocytes found within the cell?
Nb - spelling similar to laluna but this is a structure found on your nail!
What is the major component of the extracellular matrix in cartilage?
What type of collagen is found in cartilage?
What type of collagen is found in most connective tissues?
What are the three subtypes of cartilage?
Which is the most common subtype of cartilage?
List some common sites where cartilage is found
Pre-bone ossification bones are cartilage
List some functions of bone
What is haemopoiesis?
Red blood cell production
In adulthood which bones remain involved in haemopoiesis?
Which type of collagen is found in bone?
Which type of bone morphology can be seen at the diaphysis?
Which type of bone morphology can be seen at the epiphysis?
What is the difference between cortical and trabecular bone?
Presence of spaces
Is bone avascular or vascular?
What do we call bone cells?
Where are the osteocytes found within the bone?
Name the two types of canals found within bone and the difference between them
Haversion canal - longitudinal
Volkman canal - horizontal
How does bone transfer nutrients from blood from one osteocyte to the other?
Osteocytes possess dendritic cell processes which run in canaliculi
What are cement lines in relation to bone?
Visible lines surrounding an osteon
What is an osteon?
Functional unit of bone
What cells do bone cells derive themselves from?
What are osteoblasts?
Cells which produce new bone
What are osteoclasts?
Cells which reabsorb old bone
What are osteocytes?
Cells trapped within bone matrix
What is the basic multicellular unit?
Osteoclasts and osteoblasts which participate in bone remodelling
Describe bone remodelling briefly
Osteoclasts drill down into bone -->
Blood vessels form and bring osteoblasts -->
Osteoblasts begin laying down new bone in this drilled tunnel -->
Only haversion and/or volkmans canals remain
What do osteoblasts need a good supply of to function normally?
What is osteoid?
Osteoblast secretion consisting of collagen, GAGs & other organic compounds which eventually becomes mineralised
What is woven bone?
Bone fibres which have been laid down in a haphazard manner in response to a break within the bone