Histology Flashcards
What are muscle fibres grouped into?
Fascicles
What is the connective tissue surrounding the muscle called?
Epimysium
What is the connective tissue around a single fascicle called?
Perimysium
What is the connective tissue around a single muscle fibre called?
Endomysium
Sarcomeres are built up to form?
A myofibril
What is a motor unit comprised of?
One motor neurone and all of the muscle fibres that it innervates - fewer the muscle fibres the finer the control
Where does the axon of the motor neurone branch?
Nearing its termination and each branch ends in a special type of synapse called the neuromuscular junction
What are the three types of skeletal muscle?
Type I, Type IIA and Type IIB
Tell me about skeletal muscle type I
Relatively slow contracting fibres that depend on oxidative metabolism. Abundant mitochondria, resistant to fatigue and produce relatively less force. “red” fibres
Tell me about skeletal muscle type IIA
Relatively fast contracting, reasonably resistant to fatigue, relatively uncommon
Tell me about skeletal muscle type IIB
Fast contracting fibres than depend on anaerobic metabolism. Few mitochondria, fatigue relatively easily and produce relatively greater force. “white fibres”
Is the cartilage permeable??
True
What are the cells in cartilage called?
Chondrocytes
chondroblasts when immature
Where do chondrocytes live?
Lacuna
What is the most common form of cartilage?
ECM (hyaline)
Tell me about Type I collagen
Most common form found in most connective tissue
Tell me about type II collagen
Finer, forms a 3D meshwork
What are proteoglycan aggregates made of?
GAGs - most commonly keratan sulphate and chondroitin sulphate
What are all the types of cartilage and tell me about them
Hyaline - blue white, translucent, most common form
Elastic - light yellow in colour
Fibrocartilage - hybrid between tendon and hyaline. Densely packed type I collagen - appears white
What is haemopoiesis?
Blood cell production
What are the two types of bone recognised by the naked eye
Cortical bone - outer shell, dense
Cancellous or trabecular bone - the end of bones, fine meshwork
What are the living bone cells called?
Osteocytes
Name the types of canals in bones
Haversion and Volkmann’s
What are cement lines?
Often visible surrounding the osteon - only found in osteons that have formed during remodelling