histology Flashcards
what are the bundles called that muscle fibres are grouped into
fascicles
what is epimysium
the connective tissue that surrounds the muscle as a whole
what is perimysium
the connective tissue around a single fascicle
what is endomysium
the connective tissue around a single muscle fibre
what are sarcomeres
the unit f contraction of the muscle cell, smallest contractile elements in the striated muscle cell
how long does a sarcomere extend
from one Z line to the next
what does a motor unit consist of
one motor neurone and all of the muscle fibres that innervates it
what is type 1 muscle fibre
- slow contracting that depend on oxidative metabolism
- mitochondria and myoglobin
- resistant to fatigue
what is type 2A fibres
- intermediate
- relatively fast
- reasonably resistant to fatigue
what is type 2B fibres
- fast contracting
- depend on anaerobic metabolism
- few mitochondria and less myoglobin
- fatigue easily
where are chondrocytes found
a space in the extracellular matrix called a lacuna
how is type II collagen different from type I
its finer and forms 3D meshwork
what are proteoglycan aggregates made up of
GAGs bound to a core protein and often linked to hyaluronan
colour of hyaline cartilage
blue-white and translucent
colour of elastic cartilage
light yellow
colour of fibrocartilage
white
examples of where hyaline cartilage is found
articular surfaces
tracheal rings
costal cartilage
epiphyseal growth plates
functions of bone
support levers protection calcium store haemopoiesis
what are the two types of bone
cancellous and cortical
what are cement lines
the lines that are often visible surrounding the osteon
does trabecular bone have haversian canals
no
what are osteoprogenitor cells
located on bone surfaces, for example under the periosteum, these cells serve as a pool of reserve osteoblasts
what are osteoblasts
bone forming cells found on the surface of developing bone.
what are osteocytes
a bone cell trapped within the bone matrix.
what are osteoclasts
large (up to 40µm or more) multinucleated cells. They are found on the surface of bone and are responsible for bone resorption.
what is the basic multicellular unit
the collection of osteoclasts and osteoblasts that participate in bone remodelling
how does bone remodelling work
In this process, a number of osteoclasts will congregate and begin to ‘drill’ into the bone, forming a tunnel. A blood vessel will grow into the tunnel bringing with it osteoblasts which line the tunnel and begin laying down new lamellar bone. This process continues until only the space of a Haversian canal remains.
what is osteoid
when the osteoblasts secrete collagen, glycosaminoglycans, proteoglycans and other organic components this matrix is called osteoid
