Muscles Flashcards
What are the functions of Muscle: myocyte
ATP used to generate force/ movement posture and heat
Describe Sketetal muscle
mostly voluntary or postural cylindrical/long/ striated multinucleic attached to bone via tendon 650 types
Longest muscle
Sartorius
Smallest muscle
Stepedius
Striation in skeletal muscle is caused by
myofibrils within cell
- thick and thin myofilaments overlap= striation
Structure of CT on skeletal muscle
Epimysium( around muscle) Perimysium (around fascicles) Endomysium (around myocyte) Saroelma (around myofibrils) Sarcoplasm (cytoplasm of myofibrils)
Structure of Skeletal muscles
fascicles
Myocyte
myofibrils
describe the structure of a myofilament
Linked by M line H band (only thick filament) I band (only thin filament) A band (all of thick filament Z disc- links via actin to corresponding sarcomere
What is the function on Titin
Links M line to Z line provides resting tension in I band (molecular spring)
In full contraction What occurs to the myofilament structures
A band exits
I band and H band no longer exits as there is overlapping in the sarcomere
Cardiac tissue structure
Straited branched
single nuclei
Fibres join ends via intercalated discs
involuntary
Intercalated disc have which junctions and their function
Desmosomes- bind filaments Provide adhesion in contraction
Gap junction: communication/ rapid communication
What junctions do you find in cardiac tissue
GAp and desmosomes
Smooth muscles description
Walls of hollow internal structures: intestines & bV short small Involuntary not striated single nuclei Dense bodies
Describe Smooth muscle contraction
Smooth muscle contracts via twist
= Intermediate filaments do not contract
Two main subdivisions of the NS
Central- spinal cord and brain (optic nerve)
Peripheral NS: sensory/ afferent division.
Motor efferent division
Functions of NS
homeostatsis
V movement
perception/ behaviour and memory
Activated groups in CNS
Sensory: CNS
Intagrative: memory
Motor: glans/ muscle: effector
Which cell is the longest in the body
Neurons
Describe the 2 types of nerves within the body
Neurons- large- concious and unconcious control
Neuroglia- supporting cell (small)
Describe the Structure of a Neuron
Has cell bodies Dendrites: receives inpulses axon: sends messages away axon mylinated high metabolic rate/ do not divide have mutipolar neurons
What are the 4 Neuron structures
Multipolar
bipolar
unipolar
anaxonic
Describe Multipolar neuron
Mutiple 2 or more dentrites
largest
found in CNS common
controls skeletal muscle
Bipolar neurons
Special nerve sensors
cell body found between dendrites and axons
rare
Unipolar neuron
cell body branches off to side
dendrites and axon are continuous
involved in sensory
long
Anaxonic Neuron
very rare
can not determine what is dendrite and axon
found in brain & special sense organs
Neuroglia function and location
CNS and PNS
does not send action potentials but can communicate
Physical structure of Nervous tissue repair framework undertake phagocytosis nutrient supply regulated interstitial fluid
What are the 4 classifications of CNS Neuroglia
Astrocytes
Ependymal cells
microglia
Oligodendrocytes
Astrocytes description
Blood brain barrier
Largest most numerous neuroglia- syncytium network
Oligodendrocyte
FORMS myelin sheath (protein lipid layer) in CNS
mylienated more than one neuron
Microglia
Phagocytic- protection
Ependymal cells
produce cerebrospinal fluid (CSF)
lines ventricles in brain/ central canal
have cilia and microvilli
mechanical buffer moves nutrients
What are the 2 type of PNS Neuroglia
Schwann cells- mylinated sheath
Satellite cells- supprt fluid exchange
