Histology Flashcards
When referring to skeletal muscle cells, what does the term syncytial infer about the cell?
describe some elements of a skeletal muscle cell
It is multinucleated
striated, unbrached, multinucleated
Why are nuclei found at the periphery of skeletal muscle cells?
The cytoskeleton pushes them to the cell peripheries
The bundles muscle fibres are grouped into are called what?
Fascicles - muscle typically contains several
What is the term given to connective tissue around the muscle as a whole?
Epimysium
What is the term given to connective tissue around the individual fascicles?
Perimysium
What is the term given to connective tissue around a single muscle fibre?
Endomysium
What is a motor unit?
A single motor neurone and all of the muscle fibres it innervates
By definition a sarcomere extends between which consectutive points?
Between consecutive Z-lines
What are the types of skeletal muscle?
- Type I
- Type IIa
- Type IIb
What is type I muscle?
- Slow fibres
- Rely on oxidative metabolism
- Abdundant mitochondria and myoglobin
- Resistant to fatigue
- Produce less force
- Red in colour
What is type IIa muscle?
- Relatively fast
- Relatively resistant to fatigue
- Relatively uncommon
What is type IIb muscle?
- Fast
- Depend on anaerobic metabolism
- Few mitochondria and myoglobin
- Fatigue easily
- Produce more force
- White in colour
How are chondrocytes nourished?
Diffusion from the extracellular matrix
What is the space within the extracellular matrix that chondrocytes reside?
Lacuna
What are chondrocytes responsible for secreting and maintaining?
The extracellular matirx around them
What is the extracellular matrix comprised of?
- Water (75%)
- Type II collagen
- Proteoglycan aggregates
What are the three type of cartilage?
- Hyaline cartilage ( comes from the greek glassy)
- Fibrocartiliage
- Elastic cartilage
What is the most common form of cartilage?
Hyaline cartilage
By looking at a transverse section of a bone, two main bone types can be identified. What are these?
- Cortical bone (dense outer shell)
- Trabecular (cancellous) bone (fine inner meshwork)
What is the term given to cylindrical structures within bone composed of coincentric laminae?
Osteon - layers built on top of eachother and have a grain so are very strong like plywood
What are Volkmann’s canals?
Small channels in the bone that transmit blood vessels from the periosteum into the bone. They transmit blood between osteons
What are Haversion canals?
Small blood vessels within osteons and bone. They are interconnected by Volkmann’s canals
Which cells are responsible for bone resorption?
Osteoclasts
What are the bone forming cells?
Osteoblasts
What is the name given to a cell used to form bone that becomes trapped within the bone matrix?
Osteocytes
What does sarco mean?
Meat/ flesh
what does each muscle fibre contain?
many myofibrils, with each myofibril containing many sarcomeres
sarcomeres are the unit of contraction in a muscle fibre
what is the etymology of synovial?
synonym, ovial (egg white) put it togther you get “like egg white”
what is the diaphysis and epiphysis?
An outer shell of dense cortical bone makes up the shaft (diaphysis).
Cancellous or trabecular bone occupies the ends of the bone (the epiphyses). Cancellous bone is a fine meshwork of bone that looks a bit like the inside of an Aero bar.
