PSK4U - Unit 2 (Muscular System)

Tissue

Masses of cells that have similar functions and form.

Muscle Tissue

Collection of cells that shorten during contraction, there fore creating tension that results in movement.

Over 600

How many muscles in the body?

Smooth, Cardiac, and Skeletal

What are the 3 main muscle groups?

Surrounding the internal organs

Smooth muscle is found where?

Involuntary

Smooth muscle is voluntary or involuntary?

Like dense sheets

Smooth muscle looks...

Found only in the heart

Cardiac muscle is found where?

Involuntary

Cardiac muscle is voluntary or involuntary?

Striated (light and dark strips)

Cardiac muscle looks...

Attached to bones and tendons

Skeletal muscle is found where?

Voluntary

Skeletal muscle is voluntary or involuntary?

Striated (light and dark strips)

Skeletal muscle looks...

Irritability

Ability of muscle to respond to stimulus

Contractibilty

Ability of muscle to shorten in length

Elasticity

Ability of muscle to stretch and return to normal position

Extensibility

Ability of muscle to extend in length

Conductivity

Ability to transmit nerve impulses

The muscular system and the nervous system

Complex Linkages are formed between which two systems?

Neuromuscular junction

Actual meeting point between between nervous system and muscular system

Acetylcholine (ACH)

Which chemical is released as a neurotransmitter?

It causes the muscle to contract

What does ACH do to the muscle?

Motor unit

1 Nerve cell and all of its connecting muscle fibres

Muscle twitch

Single nervous impulse and its resulting contraction (involuntary)

All or none law

When a motor unit is stimulated to contract it does so to its fullest potential (full out or not at all)

Action of Muscle

Flexion, extension, rotation, abduction, etc

Direction of fibres

Rectus (straight), transverse (across), etc

Location of muscle

Anterior, posterior, lateral, medial, intermediate, etc

Number of divisions

Number of heads (2 or 3)

Shape of muscle

Deltoid (Greek letter delta), Trapezius (trapezoid)

Point of attachment

Origins and inserts

Relative size

Maximus (largest), minimus (smallest), longus (long), brevis (short)

Isotonic and isometric

What are the two types of muscle contractions?

Isotonic Contraction

Muscle changes length as it contracts and moves a load

Concentric and eccentric

What are two types of isotonic contractions?

Concentric contraction

Muscle shortens as it contracts

Eccentric contraction

muscle contracts as it lengthens

Isometric contraction

Muscle has no change in length as it contracts

Skeletal muscles

Which muscle is arranged in opposing pairs?

Agonist

Prime mover

Antagonist

counteracts agonist

Synergists

Aids agonist by promoting same movement or becomes a joint stabilizer to reduce effort

Fixators

Immobilize one or more bones to form stable base

Origin

Point where muscle attaches to a more stationary bone

Insertion

Point where muscle attaches to a more moved bone

Frontalis

Orbicularis oculi

Temporalis

Zygomaticus

Orbicularis oris

Buccinator

Masseter

Triangularis

Sternocleidomastoid

Trapezius

Deltoid

Pectoralis Major

Latissimus dorsi

Serratus Anterior

External oblique

Internal oblique

Rectus abdominus

External intercostals

Internal intercostals

Teres major

Supraspinatus

Infraspinatus

Teres minor

Subscapularis

Spinalis

Longissimus

Ilocostalis

Triceps

Biceps

Brachialis

Pronator teres

Brachioradialis

Flexor carpi radialis

Palmaris longus

Flexor carpi ulnaris

Flexor digitorum superficialis

Extensor digitorum

Gluteus Maximus

Gluteus medius

Gluteus minimus

Satorius

Adductor longus

Gracilis

Vastus lateralis

Vastus medialis

Vastus intermedius

Rectus femoris

Gastrocnemius

Soleus

Peroneus

Tibialis anterior

Semitendinosus

Semimembranosus

Biceps femoris

Tensor fasciae latae