Histology Flashcards
Osteoprogenitor cells
located on bone surfaces, for example under the periosteum, these cells serve as a pool of reserve osteoblasts
Osteoblasts
bone forming cells found on the surface of developing bone. They have plentiful RER and prominent mitochondria.
Osteocytes
a bone cell trapped within the bone matrix.
Osteoclasts
large (up to 40µm or more) multinucleated cells. They are found on the surface of bone and are responsible for bone resorption.
Explain the histology of skeletal muscle cells?
- striated
- multinucleate (periphery)
- unbranched
Explain fascicles
- groups of skeletal muscle fibres
- covered by perimysin
What is epimysium
- connective tissue that surrounds the muscle
What is perimysium
- connective tissue around a single fascicle
What is Endomysium
-connective tissue that surrounds each muscle cell
Myofibrils are ___cellular
- intracellular
What is a sarcomere?
- Contractile elements of striated cells
- extended from one Z-line to another Z-Line
What are z-lines
- Anchors actin
What are m-lines
- Anchors myosin
What gives skeletal muscles it striated appearance?
- myofibrils z-lines held in registry
- perpendicular to the long axis
What is a motor unit?
- consist of one motor neurone and all the muscle fibres that it innervates
Describe type I muscle?
- relatively slow contracting fibres
- depend on oxidative metabolism
What colour are type I muscle cells?
- Red
What colour are type IIB muscle cells?
- white
- dependant on anaerobic metabolism
Describe histological appearance of cartilage
- semi-rigid
- permeable
- avascular
How does cartilage receive its nutrients?
- neighbouring vessels, nutrients enter through the extracellular matrix via diffusion
What colour does elastic cartilage appear?
- yellow
What colour is hyaline cartilage?
- Blue/white
Name given to the outer shell of dense cortical of bone?
- diaphysis
Name given to the cancellous or trabecular bone?
- epiphyses
How is bone created?
- osteoblasts secrete different materials and osteoid
- this osteoid then becomes mineralised to produce bone