Histology Flashcards
Are skeletal muscle fibres branched?
No
Where are the nuclei of muscle fibres found within the cell when viewed under a microscope?
At the periphery
Protein strands displace them there
What is the cell membrane of a muscle fibre called?
Sarcolemma
What is a fascicle?
Group of muscle fibres
What is the name of the connective tissue surrounding a fascicle?
Perimysium
What is the name of the connective tissue surrounding a single muscle fibre?
Endomysium
What is the name of the connective tissue surrounding the muscle as a whole?
Epimysium
What is a sarcomere?
Functional unit of a muscle fibre - smallest unit of contraction
What is the name of a string of sarcomeres, end to end?
Myofibril
What colour are Type I muscle fibres?
Red
- aerobic
- high myoglobin content
What colour are Type IIx muscle fibres?
White
- anaerobic
List 4 features of cartilage
Deformable, semi rigid
Permeable
Avascular - nourishment via ECM
List 3 features of bone
Rigid
Impermeable
Cells nourished via blood vessels
What are the principle cells found in cartilage?
Chondrocytes
Where are chondrocytes found?
ECM within lacunae
State the function of chondrocytes
Secrete and maintain the ECM around them
State the composition of ECM in hyaline cartilage
75% water
25% organic material
List the 2 substances that comprise “organic material” in the ECM
60% Type II collagen
40% Proteoglycan aggregates e.g. keratan sulfate, chondrotoin sulfate
List the 3 types of cartilage found in the body
Hyaline cartilage
Elastic cartilage
Fibrocartilage
List 5 areas where hyaline cartilage may be found [most abundant type]
Articular surfaces Tracheal rings Costal cartilage Epiphyseal growth plates Bone precursor in foetuses
State the composition of bone
65% minerals
23% Type I collagen
10% Water
2% non-collagen proteins
List 2 types of bone that may be seen in section of a long bone
Cortical bone
Cancellous/trabecular bone
Which part of the bone is cortical bone found?
Dense shell
Makes up diaphysis
Which part of the bone is cancellous bone found?
Spongy bone
Occupies epiphyses
What are osteons?
Regions of concentric lamellae in cortical bone, bound by cement lines
Have a haversian canal in the center
What is a haversian canal?
Tubes in the centre of osteons
Have nerves and blood vessels running through
How do blood vessels within haversian canals communicate with osteocytes in lacunae?
Via canaliculi
What are Volkmann’s canals?
Communicate with haversian canals
Transmit blood from the periosteum to deeper parts of the bone
What are osteoprogenitor cells?
Reserve pool of osteoblasts
Found deep to periosteum
