unit 5 muscle system

what is the four functions of muscles

1. holds the body erect

2. makes movement possible

3. movement makes the body warm (85%)

4. aids with blood flow

three types of muscle tissue

1. skeletal muscle

2. smooth muscle

3. cardiac muscle

locations, striations, control and function of skeletal muscle?

attaches to bone

striations: yes

control is voluntary

function: move the whole body

location, striations, control and function of cardiac muscle?

located at the heart

has striations

involuntary control

function: contract heart to propel blood through the body

location, striations, control and function of smooth muscle?

located in the walls of hollow organs, blood vessels, and glands

striations: none

involuntary control

compress organs, ducts, tubes 

What is Adhesion? What is it caused by?

scar tissue that forms around the muscle and makes it hard to stretch.
caused by injury or surgery.  

What is Atrophy? What is it caused by?

Atrophy is poor muscle development.

Caused by disease or muscle wasting/lack of use.

What is Hypertrophy? What is it caused by?

Increase in Muscle Bulk

Caused by exercise or dangerously, steroids.

what are the terms for size for muscles?

vastus (huge)

Longus (long)

brevis (short)

what are the terms for shape for muscles

latissimus (wide)

teres (round)

what are terms of direction of fibers

transverse (across)

oblique (diagonal)

what are the terms for location of mucles

pectoralis (chest)

gluteus (buttock)

brachii (arm)

sub (underneath)

what are the terms for naming actions of muscles

flexor

extensor

adductor

what are the terms for naming divisions of muscles

bi (2)

tri (3)

quad (4)

what is the order of skeletal muscle tissue from Lg to Sm

muscle, fascicles, fibers, fibrils, microfibrils

what are tendons?

they attach muscles to the bone

what is the epimysium??

it is the outside layer of muscle

what is perimysium

it is the outside layer of a fascicle

what is the Endomysium?

it surrounds the muscle fibers

what happens to the bones when a muscle contracts at a joint?

a bone will stay stationary and the other bone moves

define origin of a muscle

the origin of the muscle is located on the stationary bone

define insertion of a muscle

the insertion of a muscle is located on the bone that moves

define action of a muscle

the action of a muscle is the movement occuring

what are the three categories of muscles based on their role in movement

agonist

antagonists

syngergists

define agonist

the agonist is the “superman” and primary mover. it is the main muscle that contracts (shortens) and creates the movement necessary to complete a task

define antagonist

the antagonist is the joker/opposite muscle of the agonist, and it relaxes (lengthens) whilst the agonist contracts

define synergist

it is the muscle that helps the agonist function, and it helps with movement and stabilizes the joint where the movement happens

agonist/antagonist pairs/ how to know which is which?

depending on the movement, the agonist is always the one to contract and initiate movement while the antagonist stretches and lengthens to allow it

what is three examples of an agonist/antagonist pair

biceps/triceps + quadriceps/hamstrings + back/chest

what are the three contraction types

isometric

eccentric

concentric

define isometric contraction

it is muscle contraction by no movement. ex: planks/wall sits

define concentric contraction

it is the muscle shortening while contraction happens

define eccentric contration

the lengthening of the muscle while contracting

what contraction occurs during the sit- up phase going up

concentric contraction

what type of muscle contraction happens to the hamstrings during the downwards motion of a deadlift

eccentric contraction

what type of muscle contraction occurs when holding a wall sit

isometric contraction

what type of muscle contraction happens to t he biceps brachii during downwards phase of a bar curl?

eccentric contraction

what is the rotator cuff

a group of muscles that surround the shoulder joint

abdominals

a group of muscles that form the front of your abdomen

quadriceps

group of muscles that form the front of your thigh

hamstrings 

group of muscles that form the back of your thigh

adductors

group of muscles that form the medial (inside of thigh)

glutes

group of muscles that form the buttocks

calves

group of muscles that form back of lower leg

what are the 4 quadriceps muscles and their actions

rectus femoris

vastus lateralis

vastus medialis

vastus intermedius

action: knee extensor + hip flexor

what are the three hamstring muscles and their action

bicep femoris

semitendinosus

semimembranosus

action: hip extension + knee flexion

what is the action of the biceps?

flexion of the elbow

what is the action of the triceps

extension of the elbow

what does muscle contraction strength depend on?

size: bigger fibers = more force
# of fibers: more fibers = bigger contraction

what else does it depend on?( muscle contraction pt2)

neuruomuscular efficiency: muscle memory

biomechanical factors: greater angle = bigger contraction

fast twitch vs slow twitch fibers

define fast twitch

quicker contraction, but wears out faster

good for quick extertion of power (short sprints + max reps)

gains muscle mass and strength

define slow twitch

contract slower but lasts longer

good for distance, more reps, longer-stronger

gains stamina and endurance

what does fiber types depend on?

genetics

types of exercise you do 

what does it mean to be a slow twitch athlete?

requires great stamina and longer, still stronger moves, and pacing, like a marathon runner

what does it mean to be a fast twitch athlete

powerful spikes of movement, but at the cost of lasting shorter like Serena Williams

why do muscles cramp?

altered neuromuscular control, dehydration, electrolyte depletion, poor conditioning, muscle fatigue, or heat exhaustion.

how do muscles grow

They grow by exercise, damaging your muscles, eating protein, and genetics. As well as aided by the cytokines that repair your muscles, and the satellite cells that create new muscle fibers. 

what is hypertrophy

increase in muscle bulk due to exercise or steroids

what is a spasm

sudden involuntary muscle contraction 

what is muscular dystrophy 

Genetically inherited disease causing progressive muscle degen + weakness + atrophy → cannot be cured but PT can help with walking, etc

what is muscles strain

Damage to the muscles/tendons + caused by overuse/stretching + has three grades

1. Minor tearing + can be played through (grade 1)

2. Need 4-6 weeks of rest + visible tear (grade 2)

3.  Severe tear / complete split “tore their hamstring” (grade 3)