Ex Phys: Muscular system

skeletal muscle tissue

• has striations

• many nuclei per cell

• voluntary neural control

smooth muscle tissue

• no striations

• one nuclei per cell

• involuntary neural control

cardiac musle tissue

• has striations

• one nuclei per cell

• involuntary neural control

Hierarchy muscle structure (large to small)

• muscle

• muscle fascicles

• muscle fiber (cell)

• myofibrial

• myofilaments

muscle fiber surrounded by

sarcoiemma

myofilaments (two types)

• actin

• myosin

Sarcolemma

plasma membrane of a muslce fiber mainteining the integrity of the cell

Sarcoplasm

cytoplasm of a muscle fiber that contains organelles

nuclei

contains DNA, which determined cell structure and function

Sarcoplasmic Reticulum

smooth ER in a muscle fiber that stores calcium

Transverse tubules

extensions of the sarcolemma that penetrate into the sarcoplasm carrying electrical impules, which trigger the release of the calcium from the sarcoplasmic reticulum

myofibril

a bundle of myofilaments

myofilaments

threadlike contractile proteins that interact to produce contractions

sacromere

contractile unit of the muscle fiber

z line

end of sarcomere, actin is attached on both sides

I band

only actin

A band

spans the length of myosin

m line

center line of sacomere

Actin

• 2 strands arranged in a double helix

• troponin

• tropomyosin

• thin filament

myosin

• globular heads with a hinge point and fibrous tail

• thick filament

latent phase

action potential

no physical contraction

contraction phase

power stroke

relaxation phase

signal cut off

return to normal sacromere length

Muscle Interactions

• origin: do not move

• insertion: move towards origin during movement

• agonist: target muscle, main muscle proforming movement

• antagonist: opposing groups in a group of muscle

• synergist: assist agonist muscle

• isotonic: same tension, throughout muscle

• isometric: same length, no movement, muscle contract

naming muscles

• function

• shape

• relative position

• location

• site of attachment

• origin and insertion

• size

• orientation

myoglobin

muscles store oxygen using

Masseter

-zygomatic arch

-chewing

Temporalis

-temporal bone

-chewing

Diaphragm

-inhale and exhale

Trapezius

-shrug shoudler

-shape

-clavicle, spine, scapula

Pectorialis Major

-bench press, push ups

-clavicle, sternum, upper ribs

Deltoid

-clavicle, spine, scapula

-overhead press, lateral rasie

Rotator Cuff

• 4 muscles rotate the humerus and form a cudd around the shoulder joint, they help stabilize muscles of the shoulder joint

The four rotator cuff muscles

• Infraspinatus

• Subscapularis

• Supraspinatus

• Teres Minor

Psoas Major

-lumber vertebrae

-main hip flexor muscle

-walking

4 muscles in the quad

• rectus femoris

• vastus lateralis

• vastus medialis

• vastus intermedius

3 muscles in the hamstring

• biceps femoris

• semitendinsus

• semimembranosus

Rectus Femris

• quad

• leg extension

Vastus Lateralis

• quad

• deep squat

Vastus Medialis

• quad

• feet closer squat

Vastus Intermedius

• quad

• front squat

Biceps Femoris

• hamstring

• dead lift

Semitendinosus

• hamstring

• hamstring curl

Semimembranosus

• hamstring

• single leg pushes