Appendicular skeleton

First stage of muscle contraction

excitation

Which tissue types are electric

nervous and muscle

What is resting membrane potential?

positive charge outside of the cell (Na+), negative charge inside of the cell (PO4 3-)

What steps occur in excitation step

Frontal lobe sends signal through motor neuron, secretes ACh (neurotransmitter), attaches to sarcolema receptor

What is the second stage of contraction

excitation contraction-coupling

ACh ligand does what once it attatched to ACh receptors?

opens channel proteins causing depolarization by letting in Na+ ions

What happens in excitation: contraction-coupling stage?

depolarization, Na+ ions travel through t-tubules of cell to sarcoplasmic reticulum, SR releases Ca+, and Ca+ attached to troponin on actin

What is the third stage of contraction

contraction

What happens in the contraction stage

troponin removes tropomyosin, exposing active site on actin, allowing myosin to attach to actin.

ATP is required during which step of the contraction phase?

when the myosin pulls on actin, causing motion

When actin and myosin attach, that’s called forming a

crossbridge

When myosin pulls on actin, that’s called a

powerstroke

When all myosin fibers pull on actin simultaneously, that’s called a

contraction

The fourth stage of contraction is

relaxation

What happens during the relaxation stage

Frontal lobe stops motor neuron, AChE enzyme removes ACh from sarcolemma, closing channel protein. ATP breaks cross bridge, releasing actin from myosin, Ca+ gets reabsorbed into SR

Which step(s) of relaxation stage require ATP

breaking of actin-myosin crossbridge and re

What are the rotator cuff muscles

supraspinatus, infraspinatus, teres minor, subscapularis

What are the functions of the rotator cuff muscles

holds the ball and socket joint stable

When someone injures their rotator cuff, it’s usually the

supraspinatus

deltoid

biceps brachii

supraspinatus

infraspinatus

teres minor

teres major

triceps brachii

lateral head of triceps brachii

long head of triceps brachi

Mvmt of deltoid

abducts, flexes and extends arm

Mvmt of biceps brachii

supinates and flexes forearm

Mvmt of supraspinatus

stabilizes joint and assists abduction

Mvmt of infraspinatus

laterally rotates and stabilizes joint

Mvmt of teres minor

laterally rotates and stabilizes joint

Mvmt of subscapularis

adducts and rotates medially and stabilizes joint

Mvmt of teres major

adducts, extends, and rotates arm medially

Mvmt of triceps brachii (both lateral and long head)

extends forearm

Mvmt of ilacus

flexes thigh

Mvmt of psoas major

flexes thigh, flexes and laterally flexes vertebral column

Mvmt of sartorius

flexes abducts, and laterally rotates thigh/leg

Mvmt of Vastius lateralis

extends leg

Mvmt of rectus femoris

extends leg

Mvmt of Vastus medialus

extends the leg

Mvmt of gracilis

abducts, flexes, and rotates thigh medially

iliacus

psoas major

sartorius

rectus femoris

vastus lateralis

vastus medialus

gracilis

mvmt of gluteus maximus

extends, laterally rotates, abducts thigh

mvmt of biceps femoris

extends thigh, flexes leg

mvmt of semitendinosus

extends and flexes leg

mvmt of semimembranosus

extends and flexes leg

mvmt of iliotibial tract

abducts, flexes, and rotates thigh medially

iliotibial tract

biceps femoris

semitendinosus

semimembranosus

tibialis anterior

mvmt of tibialis anterior

dorsiflexes foot

mvmt of gastrocnemius

plantarflexes foot + flexes leg

mvment of soleus

plantarflexes foot

gastrocnemius

soleus

What is rigor mortis

when you die, muscles contract and can’t relax

Why does rigor mortis happen

No breathing, no ATP, Ca+ spills out causing contraction and muscle is stuck in that state

What kind of paralysis is rigor mortis

spastic