Week 1 - D - Histology of Skeletal Muscle, Cartilage and Bone Flashcards
What type of muscle is unbranched, striated and multinucleated?
Skeletal muscle is unbranched, striated and multinucleated
Muscle fibres are bundled into groups called what? What is the predominant structure that makes up a muscle fibre?
Muscle fibres are bundled into groups called fasciles The predominant structure that makes up a muscle fibre are known as myofibrils
What is the connective tissue structure that surrounds each muscle fibre known as? What is the connective tissue structure that surounds each fasiscle known as? What is the conective tissue structure that surrounds the whole muscle known as/?+
Connective tissue surrounding each muscle fibre is known as the endomysium (overlies the muscle membrane known as the sarcolemma) Connective tissue surrounding each fascicle is known as the perimysium Connective tissue surrounding whole muscle is known as the epimysium
Nuclei in cardiac and smooth muscle cells are located centrally Where are the nuclei in skeletal muscle cells located?
The nuclei of seletal muscle cells are located at the periphery of the skeletal muscle cells just under the sarcolemma
What is the smallest contractile element in the striated muscle cell? When thousands of these contractile elements are placed end to end, what does it form?
Smallest contractile element in the striated muscle cells is the sarcomere Thousands of sarcomeres placed end to end form myofibrils Myofirbils are packed together to form a muscle fibre (muscle cell)
What does a motor unit consist of? The axon of the motor unit branches as it reaches its termination and each branch ends in a special synapse. What is this synapse known as?
A motor unit is a single alpha motor neurone and all the skeletal muscle fibres it innervates The alpha motor neurone branches as it reaches its termination to form neuromuscular junctions with the skeletal muscle fibres (only present in skeletal muscle)
What are the three types of skeletal muscle fibres?
Type 1 - slow oxidative (aerobic) Type IIa - fast oxidative (aerobic and anaerobic) Type IIb (or IIx) - fast glycolytic (mainly anaerobic)
What colour is given to each of the skeletal muscle fibre types? Which exercises are each of the skeletal fibre muscle types used in?
Type 1 - slow oxidative - aerobic - red fibres (used in walking) Type IIa - fast oxidative - aerobic and anaerobic - intermediate fibres (used in jogging) Type IIb/x - fast glycolytic - mainly anaerobic - white fibres (used in running)
Are cartilage and bone permeable?
Cartilage is permeable Bone is not permeable
What are cells found in cartilage known as? Whereabouts in cartilage are they found?
Cells found in cartilage are known as chondrocytes and they are found in spaces known as lacunae
What are the three types of cartilage and which is most common?
Hyaline cartilage Elastic cartilage Fibrocartilage Hyaline cartilage is the most common type of cartilage
Where is approximately 95% of the bodies calcium found? What is the site of haematopoeisis?
Approx 85% of the bodies calcium is found in the bone The site of haematopoeisis is the bone marrow
Fill in the blanks An outer shell of dense ??? makes up the shaft (diaphysis)? Trabecular bone or ??? occupies the ends of the bone (epiphyses)?
An outer shell of dense CORTICAL bone makes up the shaft (diaphysis) Trabecular bone or CANCELLOUS bone makes up the ends of the bone (epiphyses)
What are the living cells that bone contains known as? Where are these cells located in the bone?
The lviing cells in the bone are known as osteocytes and they are found in spaces known as lacunae in the bone
What are the 4 cells of the bone?
Osteoprogenitor cells Osteoblasts Osteocytes Osteoclasts
What is the function of the 4 bone cells?
Osteoprogenitor cells - serve as reserves for osteoblasts Osteoblasts -secrete matrix that will become new bone Osteocytes - formed when an osteoblast becomes embedded in the material it has secreted Osteoclasts - mutltinucleated cells responsible for bone resoprtion
What is the type of bone laid down during development or a break before normal lamellar bone is modelled? How is this type of bone remodelled into lamellar bone?
Woven bone is the type of bone laid down during development or after a break It is then remodelled into normal lamellar bone by being broken down by osteoclasts and reformed by new osteoblasts
