human anatomy exam #3

properties of muscle tissues

excitability

ability to respond to a stimulus

conductivity

ability to transmit electrical impulses along the cell membrane

contractibility

ability of a muscle to shorten

extensibility

ability of a muscle to lengthen (stretch!)

elasticity

ability of a muscle to return to its resting size after shortening or lengthening (bounce back to OG state)

muscle structural hierarchy

whole muscle

muscle fascicle

muscle fiber (muscle cells)

myofibrils

myofilaments

CT of skeletal muscle

endomysium

perimysium

epimysium

CT surrounding each individual muscle fiber

CT surrounding each fascicle

CT surrounding entire muscle

muscle attachments

tendon vs aponeurosis

CT that attaches muscle to something

broad flat sheet of CT (top of head or over abdomen)

sarcolemma

plasma membrane

sarcoplasm

cytoplasm

T-tubules

holes in sarcolemma that extend into sarcoplasm

carry impulses from sarcolemma to help stimulate muscle contraction

sarcoplasmic reticulum

right next to T-tubules

stores calcium and releases it

myofibrils

shorten which results in contraction of the muscle fiber

contain myofilaments= thick and thin

thick filaments

myosin

myosin heads

binding site for actin (they are mobile)

thin filaments

tropomyosin vs troponin

actin

covers the myosin binding sites

has calcium binding site

sarcomere

contains overlapping thick and thin filaments

one sarcomere spans from one Z DISC to the next

Z disc=borders of sarcomere

I band

contains ONLY thin filaments

A band

H zone vs M line

anywhere with thick filament (can overlap with thin)

ONLY where there is thick

center of the H zone (midline of sarcomere)

neuromuscular junction

between neuron and muscle fiber

components of neuromuscular junction

synaptic knob

expanded tip of neuron axon

synaptic vesicle

membrane sacs in synaptic knob filled with ACh

synaptic cleft

narrow SPACE separating synaptic knob and motor end plate

motor end plate

region of sarcolemma under synaptic knob

ACh receptors

proteins that bind ACh on the motor end plate

AChE

enzyme in synaptic cleft that breaks down ACh (prevents continuous stimulation of muscle)

muscle contraction

a nerve impulse causes Ach to be released in the synaptic cleft

it binds to receptors on motor end plate initiating a muscle fiber impulse

spread of impulse down T-tubules causes CA+ to leak into sarcoplasm

CA+ binds to troponin which exposes tropomyosin then myosin heads bind to actin's active sites

myosin pulls actin toward center of sarcomere and repeats

when impulse stops the CA+ goes back to sarcoplasmic reticulum, tropomyosin re-covers active sites, and the filaments slide back to their relaxed state

motor unit

a single motor neuron and the muscle fiber it controls

very specific only same type of fibers

Type 1

slow twitch fibers

smallest

aerobic

many mitochondria

Type 11a

intermediate

Type 11b

largest

anaerobic

fast twitch

a skeletal muscle contains ALL three fiber types but a motor unit can only contain ONE

muscle hypertrophy vs muscle atrophy

increases fiber size

decrease in size

muscle tone

constant tension even at rest

isometric vs isotonic

not changing in length (hold dumbells at 90 degrees)

muscles are changing in length

types of isotonic

concentric contraction vs eccentric contraction

muscle decreases in length

muscle is lengthening

agonist vs antagonist vs synergist

the main muscle producing movement

opposing muscle

helper muscle

fibromyalgia

unexplainable chronic muscle pain

muscular dystrophy

inherited disease with progressive deterioration of muscle tissue

myasthenia gravis

autoimmune disease

stops pathway from neuron to muscle fiber

cramps

involuntary pain

sustained contractions of a muscle

attachment of muscles of the head and neck

most attach to skull or hyoid bone

muscles of mastication

temporalis

masseter

attachments of sternocleidomastoid

attaches to the sternum

clavicle

mastoid process

erector spinae

3 groups

muscles help determine posture

iliocostalis (most lateral)

longissimus (intermediate)

spinalis (medial)

muscles involved with inhalation and exhalation

external intercostals

internal intercostals

diaphragm

diaphragm

most important muscle for breathing

dome shaped with a central tendon

muscles that move the glenohumeral joint

biceps brachii

deltoid

coracobrachialis

triceps brachii

teres major

lats

pectoralis major

rotator cuff muscles

subscapularis

supraspinatus

infraspinatus

teres minor

SITS

elbow flexors

biceps brachii

brachialis

brachioradialis

elbow extensors

triceps brachii

anconeus

flexor retinaculum

sheet of CT on wrist

carpal tunnel

space between carpal bones and flexor retinaculum

hip flexor muscles

iliacus

psoas major

sartorius

rectus femoris

muscles in the medial compartment of the thigh

adductor longus

pectineus

adductor brevis

gracilis

adductor magnus

muscles in the lateral compartment

tensor fascia latae, attaches to the iliotibial tract (band)

muscles of the posterior compartment that extend the thigh

biceps femoris

semimembranosus

semitendinosus

muscles of the anterior compartment that extend the knee

(called the quadriceps femoris)

rectus femoris

vastus lateralis

vastus medialis

vastus intermedius

CNS

brain and spinal cord

protected by skull and vertebral canal

responds to signals

PNS

detects changes

structure outside of CNS

cranial nerves, spinal nerves, ganglia

sensory nervous system

detects stimuli and transmits information from receptors to the CNS

somatic sensory vs visceral sensory

sensory input that is consciously perceived (eyes)

sensory input that is not consciously perceived (heart)

motor nervous system

initiates and transmits information from the CNS to the effectors

somatic vs autonomic motor

motor output that is voluntary/conscious

motor output that is involuntary/unconscious

neurons vs glial cells

transfer information (nerve cells)

support and protect neurons

axon hillock

region where the axon connects to the cell body

unipolar

single, short fiber branches like a T off of the axon

bipolar

2 processes and one axon

multipolar

many axons and a single cell body

neuroglia

(glial cells)

found in both CNS and PNS

capable of mitosis (neurons can't)

astrocytes

star shaped

help to form blood-brain barrier

prevents substances from entering CNS

supports doesn't send signals!

ependymal cells

line ventricles and help produce cerebrospinal fluid

microglia

immune cells

engulf debris

oligodendrocytes

CNS axons ONLY

wrap themselves around axons (spiders)

produce myelin

crucial with speed of neuron

satellite cells

regulate fluid around neuron cell bodies

schwann cells

PNS axons ONLY

not a spider

form myelin

saltatory conduction

an impulse jumps from one neurofibril node to another (the part where there is no myelin surrounding the axon)

continuous conduction

unmyelinated axons where the impulse doesn't jump it just goes straight through

nerve

bundle of neurons

3 types of CT around nerves

endoneurium

perineurium

epineurium

innermost (surrounds each axon)

surrounds each fascicle

surround the entire nerve

neuron pools

neurons that are grouped

many types that serve different functions

multiple sclerosis

autoimmune disease where the body attacks the myelin sheath

ALS

neurodegenerative disease affecting motor neurons

leads to atrophy

brain

gray matter vs white matter

most superficial (cerebral cortex)

myelinated & deep to gray matter

meninges

CT layers

-Epidural space

Dura mater

-subdural space

Arachnoid mater

-subarachnoid space-contains CSF

Pia mater- directly connected to surface of brain and spinal chord

dura mater

arachnoid mater

pia mater

most superficial (tough/strong)

spider web

thinnest and deepest, directly on the top of cerebral cortex

ventricles

cavities within the brain that contain cerebrospinal fluid

choroid plexus

produce and secrete CSF

functions of the CSF

buoyancy

protection

environmental stability (transports nutrients, removes waste from the brain)

blood brain barrier

regulates what substances can enter the brain

corpus callosum

connects the two hemispheres

broca's area vs wernicke's

motor speech

speech comprehension

Function of

frontal

parietal

temporal

occipital

insula

cognitive functioning and voluntary movement

sensory information

hearing

vision

taste & autonomic nervous system

primary motor cortex

in precentral gyrus

primary sensory cortex

in postcentral gyrus

diencephalon

relay station

epithalamus

thalamus

hypothalamus

epithalamus

pineal gland= secretes melatonin

habenular nuclei= visceral and emotional responses to odor

thalamus

relay center

Structure below hypothalamus

infundibulum= connects the pituitary gland and hypothalamus

brainstem

connects forebrain and cerebellum to spinal cord

midbrain

pons

medulla oblongata