anatomy exam 3

what are the connective tissue wrappings around a muscle

epimysium, perimysium, endomysium

what does the epimysium surround

entire muscle

what does perimysium wrap

fascicles

what does endomysium wrap

muscle fibers (cells)

what is the structural levels of the muscle from biggest to smallest

muscle, fascicle, muscle fiber, myofibril, sarcomere, myofilaments

what is a fascicle

bundle of muscle fibers

what is a muscle fiber

muscle cell

how is a muscle fiber formed

fusion of myoblasts

what is a myofibril

bundle of proteins

what is a sarcomere

functional unit of a muscle
segment of myofibril

what are myofilaments

protein fibers

what are the components of muscle fibers

sarcolemma, sarcoplasm, transverse tubules, myofibrils, sarcoplasmic reticulum, cisternae

what is the sarcolemma

plasma membrane

what is the sacroplasm

cytoplasm

what is the transverse tubule (t-tubules)

Perpendicular to fibers
Allow action potential to travel throughout cell so all fibers can contract at once

what is the sarcoplasmic reticulum

Location where calcium is stored
Specialized smooth ER

what is the cisternae

Large chambers

what is the triad

2 cisternae + 1 T-Tubule

what are the parts of a sarcomere

M-line, Z-line, H-band, A Band, Zone of overlap, I band

what is the M-line

middle where myosin anchors

what is Z-line

end of sarcomere where actin anchors

what is H band

part in middle with only myosin
shrink during contraction

what is A band

where myosin is

what is zone of overlap

where myosin and actin overlap

what is I band

where actin is

where is T-tubule in perspective of sarcomere

Run perpendicular and are where I band and A band meet

what moves in contraction of sarcomere

Z- line, actin

what doesn't move in contraction of sarcomere

myosin

what are the steps of muscle contraction

Neurotransmitter (acetylcholine) released from synapse of neuron and binds to ligand gated Na+ channel on muscle cell.
Ligand gated Na+ channel open and Na+ enters the muscle cell causing it to depolarize
When muscle cell reaches threshold (-55 mV), voltage gated Na+ channels open and cell depolarizes more (+35 mV)
Sodium diffuses down T-tubule and potential reaches threshold (-55 mV) near sarcoplasmic reticulum
Voltage gated calcium channels on sarcoplasmic reticulum open and calcium released to t-tubule
Calcium travels to cisterne then to sarcomere
* when calcium is not present, tropomyosin is on actin covering the myosin binding sites*
Calcium binds to troponin causing tropomyosin to move exposing the myosin binding site
Cross bridge cycling

what are the steps of cross bridge cycling

Myosin head bound + myosin tail straight
ADP is lost
Power stroke occurs (Mysoin pulling actin toward center)
Myosin head bound + myosin tail bent
Gain ATP
Myosin head unbound + myosin tail bent
ATP → ADP
Myosin head unbound + myosin tail straight

how is contraction ended

Calcium is put back into sarcoplasmic reticulum using ATP

what are the stages of rigor mortis

2-7 hrs : sustained muscle contraction
1-6 days : contraction ceases

explain the cause of rigor mortis

Cellular breakdown causes Ca+ to be released from SR
Without ATP, myosin stuck in bound + bent configuration
leading to Sustained muscle contraction

what is muscle tension

how contracted a muscle is in a stable (postural) position

what determines muscle tension

starting length of sarcomer, frequency of stimulation, number of motor units in a muscle

explain the impact of starting legnth of sarcomer on muscle tension

Overly constricted
Actin overlaps and there isn’t any more room for actin to slide inwards

Overly stretched
Only a few myosin heads can reach the actin to attach

explain the impact of frequency of stimulation on muscle tension

How often a signal is sent to muscles from nervous system

what is the impact of motor units on muscle tension

Recruitment of more motor units increases tension

what is a motor unit

1 neuron + all associated fibers

what is the relationship between number of motor units, force, and control

More fibers per motor unit = more force + less control
Less fibers per motor unit = less force + more control

what is muscle hypertophy

Increase in size of muscle cells

what is muscle atrophy

Decrease in size of muscle cells

what is aplasia

Decrease in # of cells

what is hyperplasia

Increase in # of cells
precursor/ indication of cancer

what is metaplasia

Change in type of cells
precursor/ indication of cancer

what is penia

Lower than normal numbers

what are the 4 regions of the brain

cerebral hemisphere (cerebrum)
Diencephalon
Cerebellum
Brain Stem

what are the 4 lobes of the cerebral hemisphere

Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe

what are the parts of the brain stem

Midbrain
Pons
Medulla oblongata

what is gray matter in the CNS

nucleus

what is white matter in the CNS

tract

what is gray matter in the PNS

ganglion

what is white matter in the PNS

nerve

what is the arrangement of white and gray matter in the cerebral hemisphere

White matter inside
Grey matter outside

what is a gyri

ridge

what is a sulci

shallow grove

what is a fissure

deep groove

what is the central sulcus

shallow groove that divides the frontal and parietal lobes

what is the precentral gyrus

Primary motor cortex
Frontal lobe

what is the post central gyrus

Primary somatosensory cortex
Parietal lobe

what is the longitudinal fissure

Separates two hemispheres

what is the corpus callosum

Connects two hemispheres

what is the transverse cerebral fissure

Separates cerebrum and cerebellum

what side of the body does each hemisphere of the cerebrum control

contralateral

what is the function of frontal lobe

motor and judgement

what is function of parietal lobe

somatosensory

what is function of temporal lobe

hearing

what is function of occipital lobe

vision

what does the association cortex responsible for

Giving meaning, putting things together, naming

what cortex are in the frontal lobe

primary motor cortex (precentral gyrus), Premotor cortex (motor association cortex), broca's area, prefrontal cortex

what does the primary motor cortex do

initiates skeletal movement

what happens when theres damage to the primary motor cortex

paralysis

what does the premotor cortex do

Plans skeletal movement
Learned, repetitious, or patterned motor skills

what happens when damage to premotor cortex

no complex movement

what is broca's area

speech production

what is the motor map of frontal lobe

Lateral -Head/ cranial
Superior -Upper limb
Medial -Lower limb

what is function of prefrontal cortex

Higher level thinking

what cortex are in the parietal lobe

somatosensory cortex (postcentral gyrus), somatosensory association cortex

what is the function of the somatosensory cortex

First to receive sensory info

what happens when injury to somatosensory cortex

don’t receive sensory info (ex. Can’t feel)

what is function of somatosensory association cortex

Put sensory info together to identify them

what happens when injury to somatosensory association cortex

can’t put sensory info together (can’t identify object)

what is the sensory map of pariteal lobe

Lateral -Head/ cranial
Superior -Upper limb
Medial -Lower limb

what cortex are in occipital lobe

primary visual cortex, visual association cortex

what is function of primary visual cortex

Receives visual info

what occurs with damage to primary visual cortex

blindness

what is function of visual association cortex

Give info meaning/ identify and label object

what occurs with damage to visual association cortex

can’t comprehend what looking at

what cortex are in temporal lobe

primary auditory cortex, auditory association area

what is function of primary auditory cortex

hear beat, tone, sound

what is function of auditory association area

identify/ label sound

what is olfactory cortex

smell

what is gustatory cortex

taste

what is a commissure

white matter pathway where info crosses sides of body

what does decussate mean

action of info crossing

what are the parts of the limbic system

cerebrum, diencephalon, and midbrain

what are parts of diencephalon

thalamus, hypothalamus, amygdala, hippocampus

describe thalamus

Gateway into brain
All sensory info from body must go to thalamus and be sent to other areas
Made of many nucleus (clusters of cell body/gray matter)

describe hypothalamus

Control endocrine system
Hormone production
Made of many nucleus (clusters of cell body/gray matter)

what is amygdala responsible for

fear