11PE Unit 1: Anatomy and Muscle Function

Superior

Closer to the head than another part

Inferior

Closer to the feet than another part

Anterior

Towards the front of the body

Posterior

Towards the back of the body

Medial

Towards the body's midline

Lateral

Away from the body's midline

Proximal

A body part closer to its attachment point

Distal

A body part further away from the point of attachment than another

Superficial

A body part closer to the surface of the body than another

Deep

A body part that is internal or further from the surface of the body than another

Palmer

The palm side of the hand

Plantar

The sole side of the foot

Sagittal Plane

Divides the body into left and right sections via a vertical line through the midline of the body

Transverse Plane

Divides the body into superior and inferior sections via a horizontal line through the midline of the body

Frontal Plane

Divides the body into anterior and posterior sections via a vertical line

Axial Skeleton

Provides the main support for the body and includes the skull, vertebral column and the rib cage

Appendicular Skeleton

Made up of the limb bones and their girdles

Joint

A part of the body where two or more bones meet

Fixed or Fibrous

No joint movement. Example- skull and pelvis.

Cartilaginous

Slight movement. Such as ribs and lumbar vertebrae.

Synovial

Large range of movement. Such as Thoracic vertebrae, hip and elbow. There are more synovial joints in the body than any other type of joint.

Pivot

Uniaxial joint that only allows the rotation of one bone around another such as top vertebrae.

Gliding

Occurs when flat bones glide past each other, usually in a biaxial manner, such as carpals/ tarsals.

Ball and Socket

Occurs where a rounded bone head articulates with a cup-shaped cavity, allowing flexion, extension, adduction, abduction, etc. Examples such as shoulder and hip.

Hinge

A uniaxial joint allowing flexion and extension, such as knee and elbow.

Saddle

Occurs where a concave and convex bone surface align, usually biaxial, allowing flexion, extension, circumduction, adduction, and abduction, such as carpo-metacarpals joint of thumb.

Condyloid

Very similar to hinge joint but also allows slight rotation, is biaxial, allowing flexion, extension, adduction, abduction, circumduction, such as wrist.

Flexion

Where the angle of the joint decreases, such as the knee joint in the downwards phase of a squat.

Extension

When the angle of a joint increases, such as the knee joint when kicking a footy.

Abduction

Movement of a body part away from the midline.

Adduction

Movement of a body part towards the midline.

Rotation

Rotation occurs when a bone turns on its own axis within the joint.

Medial rotation

Rotation towards the middle of the body.

External rotation

Rotation away from the midline of the body.

Circumduction

When a limb moves in a circular fashion.

Supination

When the forearm is rotated turning the palm of the hand facing up.

Pronation

When the forearm is rotated while the palm of the hand faces downwards.

Dorsiflexion

When the toes point up towards the sky.

Plantar Flexion

When the toes are pointing towards the floor.

Inversion

Sole of the foot turns inwards

Eversion

Sole of the foot turns outwards

Cardiac Muscle

Make up the walls of the heart, Involuntary

Smooth Muscle

Found in blood vessels and walls of intestines, Involuntary

Skeletal Muscle

Muscles that are attached to bone, Voluntary muscles

Tendons

Attach muscle to bone, Situated at the end of muscle, Cross across joint- helping with movement and stability

Origin

Where muscle attaches to stable bone (usually a flat bone)

Insertion

The area that is pulled by the action of the muscle

Reciprocal Inhibition

The process of muscles working in pairs (agonist and antagonist) to produce movement

Agonist

Muscle that contracts, creating the movement/ prime mover

Antagonist

Muscle that lengthens/ relaxes

Fascicles

You need a lot of fascicles to make up a muscle

Muscle Fibre

Muscle fibre are made from Myofibril

Epimysium

Structure that wraps around outside of the entire muscle- muscle pillowcase

Perimysium

Wraps around a bundle of muscle fibre

Endomysium

Wraps around a single muscle fibre

Sarcomere

Smallest unit of muscle contraction, One sarcomere is one z disc to another z disc

M line

Middle line of the sarcomere

H zone

Space in middle of sarcomere, decreases as muscle contracts, increases when muscle relaxes

Myosin

A thick protein filament

Actin

A thin protein filament

Crossbridge

Are formed when myosin attaches to actin to pull z discs closer together

Sliding Filament theory

The process of the crossbridge pulling on the myosin and actin filaments, pulling the Z discs closer together, causing the myosin and actin to slide past each other.

Contraction

Z discs are pulled closer to the M zone, causing the H zone to decrease.

Extension

Z discs pull away from the M line, causing the H zone to increase.

how does the brain create movement

Brain sends message along motor neurons via spinal cord to muscle to create movement

Sensory neurons

Detect signal.

what make up motor neurons

Cell body

Dendrites= receives impulses

Axon= Away from cell body towards muscle

Brain

Sends message along motor neurons via spinal cord to muscle to create movement.

Motor unit

Motor neurons + muscle fibre.

Fine movements

Require less motor units are needed to fire for contraction.

Large movements

Require more motor units need to fire for contraction.

All or Nothing Principle

States that when an electrical impulse reaches a certain threshold, all fibres in a motor unit will contract at the same time and as forcefully as possible.

Intensity of Muscle contractions

Varying the number of motor units stimulated and varying the frequency which the impulses arrive at the motor unit.

Slow Twitch

-type 1a

- aerobic

- red

- small fibre size

-large resistance

- low force production

fast twitch 2a

- anaerobic (long term)

- red

- medium fatigue resistance

- medium fibre size

- high force production

fast twitch Type 2B

- white

- large fibre size

- very high force production

- low fatigue resistance

-anaerobic (short term) activities.

Isoinertial

Muscle length changes during muscle contraction

concentric- muscle that shortens

eccentric- muscle that lengthens

isometric

force produced with no change in muscle length