Histology Flashcards
How many nuclei do skeletal muscles have and where are they located?
Multinucleated
Located at the periphery of fibre
What is the connective tissue that surrounds the muscle as a whole called?
Epimysium
What is the name for the connective tissue around a single fasicle?
Perimysium
What is the name for connective tissue around a single muscle fibre?
Endomysium
The axon of the motor neurone branches as it nears its termination and each branch ends in a special type of synapse called what?
Neuromuscular junction
Name the three types of skeletal muscle fibres?
Type I
Type IIA
Type IIB
What type of muscle fibres are relatively slow contracting fibres that depend on oxidative metabolism, have abundant mitochondria, are resistant to fatigue and produce relatively less force (often called red fibres)?
Type I
What type of muscle fibre is an intermediate between the other two, relatively fast contracting but also reasonably resistant to fatigue and are relatively uncommon?
Type IIA
What type of muscle fibre has fast contracating fibres that depend on anaerobic metabolism, have few mitochondria, fatigue relatively easily and produce relatively greater force (often called white fibres because of lack of myoglobin)?
Type IIB
Are there blood vessels in cartilage?
No
How are cartilage cells nourished?
By difusion through the extracellular matrix
How are bone cells nourished?
By blood vessels that pervade the tissue
What are cells found in cartilage called?
Chondrocytes
chondroblasts when immature
Where do chondrocytes live?
Within a space in the extracellular matrix termed a lacuna
How does type II collagen differ from type I?
It is finer and instead of aggregating into linear bundles it forms a 3-dimensional meshwork
What are made up of GAGs (most commonly keratan sulfate and chondroitin sulfate) bound to a core protein and often linked to hyaluronan?
Proteoglycan aggregates
What colour is hyaline, elastic and fibrocartilage?
Hyaline - blue/white
Elastic - Yellow
Fibrocartilage - White
What type of cartilage has badns of densely packed type I collagen interleaved with rows of chondrocytes surrounded by small amounts of cartilagenous ECM?
Fibrocartilage
What type of cartilage is found on articular surfaces, tracheal rings, costal cartilage, epiphyseal growth plates and precursor in fetus to many bones?
Hyaline cartilage
What do bones store?
Calcium
What structures in the body carry out haemopoiesis (blood cell production)?
Bones
In utero where is blood produced?
In liver and spleen
Where is the site of haemopoiesis?
Bone marrow - axial and limb girdle
An outer shell of what makes up the shaft of a bone (diaphysis)?
Cortical bone
What type of bone occupies the end of the bone (epiphyses)?
Cancellous (aero bar) or trabecular
Where are Haversion canals found?
Bone
What cells are located on bone surfaces, for example under the periosteum, and serve as a pool of reserve osteoblasts?
Osteoprogenitor cells
What cells are bone forming cells found on the surface of developing bone, they have plentiful RER and prominent mitochondria?
Osteoblasts
What type of cell is a bone cell trapped within the bone matrix?
Osteocytes
What bone cells are large multinucleated cells, found on the surface of bone and are responsible for bone resorption?
Osteoclasts
What is the basic multicellular unit or BMU?
The collection of osteoclasts and osteoblasts that participate in the process of bone remodelling
In what process does this occur: osteoclasts congregate and begin to drill into the bone forming a tunnel, a blood vessel grows in the tunnel bringing with it osteoblasts which line the tunnel and begin laying down new lamellar bone, it continues until a Haversian canal remains?
Bone remodelling
What do osteoblasts secrete?
Osteoid - collagen, glycosaminoglycans (GAGs) and proteoglycans
