Human Anatomy Exam 3

what are the three types of muscle

skeletal,cardiac,smooth

skeletal muscle

voluntary, striated

cardiac muscle

involuntary, striated

smooth muscle

walls of hollow organs (stomach), involuntary, nonstriated

excitability

ability to respond to a stimulus

conductivity

how well is stimulus transmitted among membrane

contractility

ability of muscle to shorten/decrease in length

extensibility

ability of muscle to lengthen

elasticity

ability of muscle to return to resting length

name 5 skeletal muscle functions

body movement, protection and support, regulating elimination of materials (spincteres at orifices), heat production, maitenence of posture

structural heirachy of a muscle (big to small)

whole muscle, muscle fascicle, muscle fiber, myofibrils, myofilaments

whole muscle

everything

muscle fascicle

sectional view segments

muscle fiber

muscle cell (contains myofilaments)

myofibrils

cyndrical inside muscle fibers elongated (80% of fiber volume) - contains myofilaments

myofilaments

alternnating bands on muscle myofibris (thick and thin)t

thick filament

bundles of myosin molecules

thin filaments

two strands of actin wound around each other (tropomyosin and troponin)

Tropomyosin

rope like protein, covering binding sites of actin

troponin

protein attaching to tropomyosin (has binding site 4 calcium)

three types of CT in muscles

endomysium,perimysium,epidysium

endomysium

CT surrounding each fiber (muscle cell)

perimysium

CT surrounding each fascicle

epidysium

CT above aka surrounding whole muscle

two types of muscle attachments

tendon, apponeurosis

tendon

connects muscle to another structure

aponeurosis

broad sheet of CT (top of head and abdomen)

sacrolemma

membrane surrounding muscle fiber

sarcoplasm

cytoplasm within muscle fiber

sarcoplasmic reticulum

smooth ER equivalent (stores calcium)

transverse tubercles

deep invaginations of the sarcolemma that extend into the sarcoplasm

sarcomere

structural and functional units inside a myofiber

I band

contains only thin filaments

A band

thick and thin filaments are present

H zone

only have thick filaments

M line

center of each H zone

sldiing filament theory

filaments do not shorten themselves but instead z discs slide over closer to m line

neuromuscular junction

where neuron meets muscle

synaptic knob

large ends of motor neuron

synaptic vesicles

small pouches containing neurotransmitters

synaptic cleft

space between synaptic knob and muscle fiber

motor end plate

wavy region just across cleft from neuron

ACH receptors

proteins that bind ACH on the motor end plate

motor units

single motor neuron and muscle fibers it controls

types of skeletal muscle fiber motor units

1, 2a, 2b

type 1

skeletal muscle fiber that is smallest, resistent to fatigue, produce submaxial contration, lots of mito, extensive capillaries

type 2a

intermediate skeletal muscle fiber

type 2b

largest skeletal muscle fiber, maximal contraction, but fatigue quickly, few mito, few capillaries

muscle hypertrophy

increase muscle size but not #

muscle atrophy

decrease in muscle size

muscle tone

some muscle fibers activated and some in resting state

isometric contration

muscle length does not change, can still fatigue

isotonic contraction

muscle length changes

concentric contraction

type of isotonic contraction, positive, decrease in length

eccentric contraction

type of isotonic contraction, negative, increase in length

agonist

prime mover

antagonist

opposes the agonist

synergist

helper muscle that assists agonist

fibromyalgia

unexplanable chronic pain

muscular dystrophy

inherited causing the muscle to degenerate/breakdown

myasthenia gravis

autoimmune attacking acetylcholine receptors on sarcolemma, weakness of muscle

cramps

involuntary painful sustained contractions of muscle

central ns

brain and spinal cord

peripheral ns

cranial nerves, spinal nerves, ganglia

collect info

function of ns; sensory receptors in PNS detect changes in envrionement relaying info to CNS

processess and evaluate info

CNS determines required response

initiate response

CNS initiates impulses that PNS carries effectors to react to changes in enviornment

effectors

muscle/glands

somatic sensory

info pulled out consciously

visceral sensory

info that is pulled in not consciously aquired

somatic motor

sending impuses out to voluntary effectors

automatic motor

sending impulses to involuntary effectors

neurons

communicate through impulses

name the parts of a neuron

cell body, dendrite, axon, axon hillock,

glial cells

assist neurons

axon hillock

connects cell body to axon

unipolar

one extension

bipolar

two extensions

multipolar

mult extensions

sensory (afferent neurons)

carry impuses from pns to cns

motor (efferent neurons)

carry impulses from cns to pns

interneurons

always inbetween, within cns, where processing occurs

three types of cns

astrocytes, ependymal,oligendrocytes

astrocytes

star shape, has perivascular feet wrapping around capillary - helps prevent toxins from leaving capillary and entering cns

ependymal

ciliated cuboidal epithelial cells that line ventricles of brain and central canal of spinal cord - help produce csf

oligodendrocytes

produce myelin (insulator for electrical activity) wrap themselves around the axons

satellite cells

regulate fluid compositiion around neuron cell bodies

neurolemmocytes/schwann cells

associated w/pns axons

myelination

each neurolemocytes wraps around an axon

endoneurium

wraps around a single axon

perineurium

wraps around a bundle of axons/fasicles

epineurium

surrounds whole muscle

three types of synapses

persynaptic neuron, synaptic cleft, postsynaptic neuron

persynaptic neuron

synaptic knobs at axon endings for sending a signal

synaptic cleft

space between presynaptic and postsynaptic

postsynaptic neuron

neuron after synapse

synapse

junction of neuron w/smth else

multiple sclerosis (ms)

myelin tissue is being attacked by immune system → slow communication,progression and symptoms

amyotropic lateral sclerosis (als)

neurodegenerative disease, loss of function leads to muscle weakness, atrophy, quick progression

meninges

ct layers