Exam 2 Flashcards
Sarcomere
basic structural and functional unit of skeletal muscle
Sarcolemma
Cell membrane of skeletal muscle fiber
Sarcoplasm
Cytoplasm of skeletal muscle
Sarcoplasmic reticulum
ER of skeletal muscle
Stores Calcium
Myosin
thick filament
Actin
thin filament
Z disk
where 2 sarcomeres connect
Endomysium
CT surrounding myofibrils
Perimysium
CT surrounding fascicle
Epimysium
CT surrounding entire muscle
H zone
M line
Only myosin is present
I band
Only actin is present
light bands
A band
Overlap of actin and myosin from end to end
dark bands
During contraction:
1) A band
2) H zone
3) I band
1) stays the same size
2) gets smaller
3) gets smaller
T-tubules
Important for conduction of electrical excitation
Muscle fiber
Sarcomeres laid end to end makes up muscle fibers
Structure of muscle biggest to smallest
Muscle Fascicle Muscle fiber (surrounded by sarcolemma) Myofibrils Filaments
Motor unit
One motor neuron and all the muscle fibers it innervates
Neuromuscular Junction (NMJ)
Where motor neuron and muscle meets
Creatine phosphate
energy available instantly
stores are depleted quickly so is only good for very short period of time
Aerobic cellular respiration
Requires oxygen
Produces 36 ATP per glucose
Anaerobic cellular respiration
2 ATPs per glucose
Lactic acid
Removal of lactic acid
Requires oxygen
Gets converted back to glucose and is stored
Endurance training
increases # of mitochondria
increases ability to get oxygen (lung volume, hemoglobin, etc.)
increases myoglobin
Muscle twitch
Contraction of muscle fiber in response to single stimulus
Tetany
Full contraction of muscle as strong as it can be
Muscle tone
state of partial contraction in resting muscles
need it to help you sit up and not flop over
keeps muscle ready to respond optimally
excitation of alternating motor units
need input from CNS
Isometric contraction
length of muscle stays the same
Isotonic contraction
tension in the muscle stays the same
Nerve
has motor and sensory info
Damage to dorsal root
no sensory info
movement is indirectly affected
Damage to ventral root
no movement
sensory info remains
Ganglion
cluster of cells in the periphery
Dorsal root ganglion
contains unipolar, sensory afferent neurons
Ventral root
carries motor info
cell bodies in CNS-ventral horn of spinal cord
Converging neuronal pathway
two or more neurons synapse on same neuron
allows info from more than one pathway to converge into one single pathway
Diverging neuronal pathway
axon from one neuron divides and synapse with more than one neuron
allows info to be transmitted in one pathway to diverge into two or more pathways
Choroid plexus
makes CSF
Acetylcholine at the NMJ increases permeability of the muscle cell membrane to
Sodium ions
Dorsal and ventral roots combine to form
spinal nerve
how many pairs of spinal nerves
31
Brachial plexus
C5-T1
supplies upper limb, shoulder, hand
Cervical plexus
C1-C4
phrenic nerve
supplies head and neck
Lumbosacral plexus
L1-S4
supplies lower limbs
Sacral and Coccygeal plexuses
sciatic nerve
large nerves
Arachnoid granulations
absorb CSF and put into general circulation
Cerebellum
coordinated movement
learning
Thalamus
relay center for all senses except smell
CN I
olfactory
CN II
optic
CN III
oculomotor
CN IV
trochlear
eye movement
CN V
trigeminal
chemosensory, innervates face
CN VI
abducens
eye movement
CN VII
facial
taste, tears, saliva, facial expression
CN IX
glossopharyngeal
swallowing, saliva, taste
CN X
vagus
controls PNS, smooth muscle of GI tract
CN XI
accessory
moving head and shoulders, swallowing
CN XII
hypoglossal
speech, swallowing
CN VIII
Vestibulocochlear