hbs lesson 1.2 - muscular system

lessons 1.2.1 through 1.2.6 - still working on matching the parts to diagrams sorry!

skeletal muscle

this muscle is striated, has no branching, and uses voluntary movement. this muscle is attached to skeletal bone

cardiac muscle

this muscle is striated, has branching, and uses involuntary movement. this muscle is found only in the heart

smooth muscle

this muscle has no striations, minimal to no branching, and uses involuntary movement. this muscle is found in the lining of intestines and organs

what are the main functions of the muscular system?

movement of the body, heat, stabilization, posture, protection, movement of internal substances

abduction

movement away from midline

adduction

movement towards midline

flexion

bending

extension

straightening

elevation

rising, or moving upwards

depression

lowering, or moving downward

inversion

movement of the soles inward

eversion

movement of the soles outward

dorsiflexion

movement of the soles upward

plantar flexion

movement of the soles downward

pronation

movement of the palm upward

supination

movement of the palm downward

medial rotation

rotation towards the midline

origin

some bones may have multiple of these. this is the end part of the muscle that is attached to a relatively fixed in place bone

insertion

this is the end part of the muscle that is attached to a more mobile bone, it is the mobile part of the muscle

agonist

the muscle in a muscle pair that is used more during an exercise

antagonist

the muscle in a muscle pair that is used less during an exercise

anterior

front, or belly side

posterior

back

lateralis

side

maximus

largest

medius

middle

minimus

small

pectoralis major

• origin: clavicle and sternum

• insertion: humerus

• action: flex, extend, and adduct the shoulder

• location: superficial to chest

pectoralis minor

• origin: ribs number 3, 4, and 5

• insertion: scapula

• action: movement of the scapula

• location: deep to chest

brachialis

• origin: humerus

• insertion: ulna

• action: flexion of the elbow

• location: near the elbow

triceps

• origin: scapula

• insertion: ulna

• action: extension of the elbow

• location: the upper arm area

intercostals

• origin: superior edge of ribs

• insertion: inferior edge of ribs

• action: depression and expiration of the ribs

• location: between the ribs

excitablity

the ability to receive and respond to stimuli

contractibilty

the ability to shorten or thicken

extensibility

the ability to stretch or extend

elasticity

the ability to return to the original shape

epimysium

the outermost layer of connective tissue in skeletal muscle

perimysium

the middle layer of connective tissue in skeletal muscle

endomysium

the innermost layer of connective tissue in skeletal muscle

what is the first step of sliding filament theory?

the muscle sends out a signal to the brain, which releases acetylcholine

what is the second step of sliding filament theory?

the acetylcholine triggers the release of calcium ions from the sarcoplasmic reticulum

what is the third step of sliding filament theory?

calcium ions bind to troponin, which triggers tropomyosin to reveal the myosin binding sites. this whole process happens on the actin filament

what is the fourth step of sliding filament model?

the temporary cross-bridge is formed by myosin heads on the thick filament attaching to the myosin binding sites on the thin filament

what is the fifth step of sliding filament model?

the power stroke is when the myosin heads pull the actin strand towards the center of the sarcomere

what is the sixth (and final) step of sliding filament model?

ATP binds to the myosin heads to release them from the actin strand, myosin can now attach onto new aprts of the actin strand to continue towards the center

sarcomere

a single muscle tissue made up of two myofilaments, actin and myosin

actin

the thin filament in a sarcomere that contains tropomyosin and troponin

myosin

the thick filament in a sarcomere that contains “heads” that attach to binding sites

troponin

a protein that bonds with calcium ions to release a signal

tropomyosin

a protein that covers the myosin binding sites

articular cartilage

smooth, white tissue that allows bones to glide over each other

joint capsule

connective tissue capsule that encases bones within the joint

synovial cavity

space created within the joint capsule; filled with fluid

synovial membrane

soft tissue that lines the synovial cavity; secretes synovial fluid

synovial fluid

clear, thick, lubricating fluid; reduces friction during movement

bursa

a closed sac of synovial fluid; found in most synovial joints

ligaments

bands of connective tissue that support and strengthen the joint

ball and socket joint

a ball shaped joint that fits into a cone shaped socket

• complete range of motion; widest range of all joints

• found in the shoulder and hips

condyloid (ellipsoidal) joint

oval shaped surface that fits into an elliptical surface

• side to side and up and down movement

• found in the wrist

gliding joint

articulating surfaces, usually flat

• gliding, nonaxial movement

• found between wrist bones

hinge joint

spool-shaped surface that fits into a concave surface

• one plane about a single axis, like a door

• found in elbows, knees, ankles, and fingers

pivot joint

arch-shaped surface that rotates around a rounded pivot

• rotational movement

• found in the neck

saddle joint

a saddle-shaped surface that fits into a socket curved in an opposite direction

• like condyloid, similar to a rider in a saddle

• found in the thumb joint

difference between rotation and circumduction

rotation: movement about an axis

circumduction: conical movement where one end of the limb is stationary and the other end moves

what taping method should be used immediately after injury?

lymphatic drainage technique

goniometer

a device used to measure angles or the range of motion (ROM) in joints

what test is used to assess the state of the posterior cruciate ligament (PCL)?

posterior drawer test

what test is used to assess the state of the medial collateral ligament (MCL)?

valgus stress test

what test is used to assess the state of the lateral collateral ligament (LCL)?

varus stress test

the six muscle rules

Muscle(s):

1. must have at least 2 attachments and cross at least 1 joint

2. always pull to get shorter

3. origin doesn’t move, insertion moves

4. decreasing angle = flexor, increasing angle = extensor

5. work in opposing pairs

6. striations show direction of pull