Unit 1 SEHS IB HL

Anatomical Position

Body erect, Feet slightly apart, Palms facing forward, Thumbs point away from body (BFPT)

Superior

above or nearer to the head

Inferior

below or further away from the head

Proximal

nearer to a limb attachment (joint)

Distal

further away from a limb attachment (joint)

Posterior

closer to the back

Anterior

closer to the front

Internal

away from the surface, inside

External

nearer or on the surface, outside

Lateral

futher away from the midline

Medial

closer to the midline

Intermediate

between two structures

6 Functions of the Skeleton

Protects vital organs, supports and maintains posture, providing attachment for muscles, storing and releasing minerals, haemopoesis (RBC production), energy storage

Axial Skeleton

consists of the skull, rib cage, and vertebral column

Axial Skeleton main function

Protection

Appendicular Skeleton

Consists of the limbs and limb girdles that are attached to the axial skeleton

Appendicular Skeleton function

Movement

Sagittal Plane

splits body into left and right halves

Frontal Plane

splits body into front and back halves

Transverse Plane

splits body into top and bottom halves

Sagittal Plane movements

running, squats, bicep curls

Frontal Plane movements

Jumping jacks, lateral raises, cartwheels

Transverse Plane movements

Ballet spin, golf swing

Elevation

moving upwards

Depression

moving downwards

Protraction

back moving forwards

Retraction

back moving backwards

Dorsiflexion

flexion of the ankle joint (toes up)

Plantarflexion

extension of the ankle joint (toes down)

Eversion

Toes out, ankle rolls in

Inversion

Toes in, ankle rolls out

Pronation

Medial radio-ulnar movement (holding soup)

Supination

Lateral radio-ulnar movement (pouring soup)

Anthropometry

the study of human body measurements

Anthropometry helps performance by optimizing 4 factors

Aerodynamics, Balance, Leverage, range of motion

Ergonomics

Taking body structure and biomechanics into consideration when designing products

Bone structures are made of

a mix of protein (collagen) and minerals (calcium/phosphate)

Epiphysis

End of a long bone

Diaphysis

Shaft of a long bone

Bone marrow

core of bones, yellow and red bone marrow

Red bone marrow

contains stem cells that can turn into red blood cells, white blood cells or platelets

Yellow bone marrow

stores fat and contains stem cells that can become cartilage, fat or bone cells

spongy bone

second layer, shock absorbing

Compact bone

third layer, for strength, support and protection

Periosteum

shiny white membrane that covers the bone to help in bone growth, repair and attachment

Ligament

connects bone to bone

Tendon

connects bone to muscle

3 types of articulations

fibrous, cartilaginous and synovial

Long bones with example

Length greater than width, femur, tibia

Long bone function

supports weight, facilitates movement

Short bone with example

small and cube shaped, tarsals, carpals

flat bone with example

helps protect internal organs, sternum, ribs

Irregular bones

complex shapes for specialised functions, vertebrae, coccyx

sesamoid bone

patella (kneecap)

sutural bones

flat bones between skull bones

Fibrous joints

thin layers of fibrous tissue connecting edges of bones together

Cartilaginous joints

bones separated by a fibrocartilage disc in between

Synovial joints

common joints with a joint cavity and synovial fluid.

Fibrous joint ROM

NO movement

Cartilaginous joint ROM

LIMITED movement

Synovial joint ROM

BIG RANGE of movement

Bursae

Fluid-filled sacs reducing friction in joints

Meniscus

moon shaped fibrocartilage disc in between bones for stability and cusioning

synovial joint cavity

enclosed space between bones protecting a joint, lined with synovial membrane

articular capsule

encapsulates the whole joint preventing dislocation

synovial membrane

lining of membrane on bone ends containing bursae

articular cartilage

smooth layer that covers articulating surface of bones, reducing friction and absorbing shock

synovial fluid

fluid that lubricates joints and reduces friction

Pivot joint

only allows rotation eg radio-ulnar

Hinge joint

only swinging movement eg knee and elbow

Ball and socket joint

movement in all directions eg shoulder and hip

condyloid joint

forward back and side to side but not all directions eg wrist joint, knuckles and fingers

saddle joint

forwards backwards side side eg thumb

gliding joint

flat surfaces rubbing eg intercarpal joint

Dislocation

displacement of a bone from its joint

Torque

a rotational force

Torque Formula

Force x distance from fulcrum to where force is applied

Mechanical Advantage

measure of how efficient a lever is

First class lever

Fulcrum in the middle, any MA

Second class lever

Load in the middle, MA above 1

third class lever

Effort in the middle, MA below 1

First class lever IRL and in the body

seesaw, neck on spine

Second class lever IRL and in the body

wheelbarrow, plantarflexion

Third class lever IRL and in the body

tongs, bicep curl

Nervous system

electrical signals to maintain homeostasis

Endocrine system

hormonal signals to maintain homeostasis

Nervous system speed

faster but short-term effects

Endocrine system speed

shorter but long-term effects

Two parts of the nervous system

PNS and CNS

CNS consists of

brain and spinal cord

PNS consists of

sensory and motor nerves

motor nerve division

somatic and autonomic systems

somatic nervous system

controls voluntary movement

autonomic nervous system

controls involuntary movement like sympathetic and parasympathetic systems

sympathetic response (eyes, vessels, and breathing)

pupils dilate, vasodilation to muscles, vasoconstriction to inactive areas, breathing increases

parasympathetic response (eyes, vessels, and functions)

pupils enlarge, blood flow normalizes, digestion normalizes

brainstem

passes messages, contains the medulla oblongata

medulla oblongata

controls functions such as heart rate, breathing, blood pressure, and digestion.

Cerebellum

controls balance and coordinates skilled movement

cerebrum

controls voluntary movement, allows awareness and thinking