topic 1

LOCOMOTION AND SUPPORT1)Understanding support & locomotion in human & animals

2) Appreciating a healthy musculoskeletal system

LEARNING OUTCOMES (UNDERSTANDING SUPPORT & LOCOMOTION)

I. Necessity for support/locomotion

II. Problems that could be faced

III. Solution for the problems

IV. Bones (components of axial & appendicular skeletons)

V. Know bones, skeleton muscles & tendons

LEARNING OUTCOMES CONT…

VI. How movement is brought in a limb

VII. Function of cartilage and synovial fluid

VIII. Mechanism of locomotion

IX. Some consequences of impaired musculoskeletal system on support & locomotion

INTRODUCTION

Support/Locomotion

Support/Locomotion in Humans & Animals

Skeleton

Skeletal Muscles & Tendons in movement

The Mechanism of Locomotion

Healthy Musculoskeletal System

FORMS OF LOCOMOTION

INTRODUCTION CONT..

Definition:Locomotion is the whole movement organisms from place to place

Forms of locomotion: walking climbing running swimming crawling flying

NECESSITY FOR SUPPORT & LOCOMOTION IN HUMANS & ANIMALS

The purposes of locomotion are to

search for food search for a mate seek for shelter avoid from predators and other

dangers

PROBLEMS FACED IN SUPPORT & LOCOMOTION

Water- supportive medium

- but it is dense & resists movement

Air - less dense - but a lot of effort and energy is needed to

lift an animal off to fly

Land- provides with surface for support/movement -but most animals need to hold their bodies clear off the ground to minimise friction

SOLUTION FOR THE PROBLEMS

In humans & animals, support & locomotion are provided by the skeleton

Skeleton is a structure that supports the body of a human or an animal

SKELETON

Types of Skeleton

Exoskeleton

crabgrasshopper

Endoskeleton

fishcat

Hydrostatic Skeleton

wormcaterpillar

EXOSKELETON

Outer covering

Made up of rigid & strong materials eg: calcium and chitin

Jointed external skeleton (chitin) provides locomotion & support to insects (Phylum Arthropoda)

For molluscs (eg: snails,oysters) consists of a hard shell of calcium to cover and protect the soft body

ENDOSKELETON

Comprising of many component parts of cartilage or bones

These articulate (move against each other) at the joints

Soft tissues surround the bones, protected by the skin

HYDROSTATIC SKELETON

Pressure in spaces surrounded by muscles exerted by the body fluids

Body fluids do not flow out and is of constant value

Forms an incompressible ‘skeleton’ for the muscles to contract

IMPORTANCE OF SKELETAL SYSTEM

Giving shape and form; without it the whole body collapses

Makes locomotion possible-skeleton works together with muscles

Protects soft tissues and vital organs

Makes breathing possible

Formation of blood cells

Stores calcium and phosphorus within the bones

HUMAN SKELETON

2 main parts Human skeleton

Axial skeleton

Appendicular skeleton

AXIAL SKELETON

Axial skeleton

Skull

Vertebral column (spine)Rib cage

APPENDICULAR SKELETON

Appendicular skeleton

Pectoral girdleUpper limb (Fore limb)

Arm

Upper arm

Forearm

Hand

Pelvic girdle Lower limb (Hind limb)

APPENDICULAR SKELETON

Pectoral girdle (consists of two halves) and each half consists of:

o A scapula (shoulder blade)o A clavicle (collar bone)

Pelvic girdle (hips) Two upper limbs, each limb consists of:

o Arm (upper arm and forearm)o Hand

Two lower limbs, each limb consist of :o Femur ( thigh bone)o Tibiao Fibula (thin bone)o Foot

HUMAN SKELETAL SYSTEM

THE AXIAL SKELETON (SKULL)

Skeleton of the head Consists of :

Cranium Facial skeleton

SKULL (CRANIUM)

Dome-shaped Formed from the fusion of sutures

(immovable joints found only between skull bones) of 8 flat bones soon after birth

Protects the brain Supports organs of special senses (sight,

hearing, smell, and taste) Provides a foundation for structures to take

air, food and water into the body

SKULL (FACIAL SKELETON)

Consists of 14 bones Example:

2 eye sockets (orbits) – which protect the eyeballs

2 nasal bones – which form the bridge of the nose

Upper jaw bone (maxilla) – which is fused to the base of the cranium

Lower jaw bone (mandible) – which is hinged to the cranium

AXIAL SKELETON (VERTEBRAL COLUMN)

Also known as the backbone or the spine Consists of a series of 33 small bones

(vertebrae) Provides protection for the spinal cord which

runs through it Intervertebral cartilage disc:

Separates adjacent vertebrae Acts as a shock-absorbing cushion; reduces

friction and allows movement between adjacent vertebrae

AXIAL SKELETON (VERTEBRAL COLUMN)

33 vertebrae of the vertebral column are made up of: 7 cervical (cervix=neck) vertebrae in the neck

region

12 thoracic vertebrae in the thorax region

5 lumbar vertebrae – supporting the lower back

5 sacral vertebrae – fused to form a single sacrum

4 caudal vertebrae – fused to form a single coccyx

VERTEBRAL COLUMN

VERTEBRAL COLUMN

VERTEBRAL COLUMN (A TYPICAL VERTEBRA)

Common characteristics of a typical vertebra

A centrum- body of the vertebra

A neural arch (vertebral arch)- protects the spinal cord

A neural canal (vertebral canal)- carries the spinal cord

Transverse process- for attachment of muscle

THE TYPICAL VERTEBRA

THE CERVICAL VERTEBRAE

3 types Atlas – first cervical vertebra Axis – second cervical vertebra Typical cervical vertebra

All cervical vertebrae have 1 neural canal – the spinal cord passes through

this hole 2 vertebraterial canals – the vertebral arteries

pass through these holes

THE CERVICAL VERTEBRA (ATLAS)

THE CERVICAL VERTEBRA (ATLAS)

1st cervical vertebra

Supports the head

Do not have these 3 structures Centrum (body) Transverse processes Neural spine

CERVICAL VERTEBRAE (AXIS)

THE CERVICAL VERTEBRA (AXIS)

2nd cervical vertebra

Has centrum and tranverse processes

THE 3RD TO 7TH CERVICAL VERTEBRAE

The smallest and lightest vertebrae

Have thinner centrum and a smaller neural spine

Transverse process has a vertebrarterial canal

THE THORACIC VERTEBRAE

THE THORACIC VERTEBRAE

12 thoracic vertebrae Larger than the cervical vertebrae Increase in size from top to bottom Support the rib cage

A typical thoracic vertebra has A heart shaped centrum (body) A small circular neural canal A long neural spine which point downwards 2 long transverse processes with facets on top fitting

into facets on the bottom of the upper vertebra Neural spine and the transverse processes –for

attachment of ligaments and muscles supporting the head and neck

THE LUMBAR VERTEBRAE

THE LUMBAR VERTEBRAE

5 lumbar vertebrae Kidney shaped

The largest vertebrae found

Provides the only support to the upper body

Triangular spinal canal

Large broad transverse processes

Short broad neural spine

SACRUM AND COCCYX

SACRUM & COCCYX

Sacrum Triangular bone formed by the fusion of 5 sacral

vertebrae 4 transverse lines indicates the fusion of the

vertebrae On both sides of the transverse lines are paired

sacral foramina (openings) Coccyx

Triangular bone formed by the fusion of 4 caudal vertebrae

RIB CAGE (AXIAL SKELETON)

AXIAL SKELETON (RIB CAGE)

12 pairs Articulate with the thoracic vertebrae 7 upper ribs directly join the sternum by

cartilage at the end of the ribs Next 3 ribs (8th,9th,10th) attach to the rib cage

above cartilage The bottom remaining 2 ribs are not

connected to sternum or rib cage (called ‘floating ribs’)

RIB CAGE

Functions:

Protect vital organs (eg: lung, heart)

Attachment of intercostal muscles

Provides the pumping mechanism required for breathing

APPENDICULAR SKELETON

The components are

Pectoral girdle

Pelvic girdle

Upper limb

Lower limb

APPENDICULAR SKELETON (PECTORAL GIRDLE)

Contains 2 bones Clavicle (collar bone) Scapula (shoulder blade)

PECTORAL GIRDLE

Clavicle Long,flat,gently curved bone Articulates with the shoulder at one end and with

the scapula at the other end

Scapula Flat triangular shaped bone with a spine at its

dorsal surface

APPENDICULAR SKELETON (PELVIC GIRDLE)

PELVIC GIRDLE

Strong, bony structure, supporting the upper body (trunk) & transmitting its weight to the legs

Formed by a pair of hips

Each hip bone

Consists of 3 bones ilium pubic ischium

APPENDICULAR SKELETON (UPPER LIMB)

Upper limb (Fore limb)

Arm

Upper arm

Forearm

Hand

APPENDICULAR SKELETON (UPPER LIMB)

UPPER LIMB

2 upper limb Arm

Upper arm Forearm

Hand

Attached to the pectoral girdle Upper one consists 1 bone

Humerus Forearm consist 2 bones

Radius Ulna

UPPER LIMB

Hand consists of: 8 carpals

-Arranged in 2 rows of 4 bones each

5 metacarpals-Form the palm

14 phalanges-Form fingers-2 phalanges in the thumb-3 phalanges in the rest of the four other fingers

APPENDICULAR SKELETON (LOWER LIMB)

LOWER LIMB

Consists of Femur (thigh bone) Tibia and fibula Foot bones

Femur-The longest bone-Femur,tibia and patella together form the knee

joint-Patella (knee cap) covers the front of the lowest

end of the femur

LOWER LIMB

Foot consists of these bones

7 tarsal 5 metatarsals 14 phalanges

MUSCLE

The most abundant tissues in the human body

Specialised to be able to contract to produce movements

3 main types Smooth muscle Cardiac muscle Skeletal muscle

MUSCLE

Smooth muscle Cardiac Muscle

MUSCLE

Skeletal muscle

SMOOTH MUSCLE

Spindle-shaped muscle cells with pointed ends

Each muscle cell has 1 nucleus lying in its centre

Involuntary muscle (no conscious control over them) Eg: the alimentary canal wall

CARDIAC MUSCLE

Found only in the heart Also involuntary muscle

SKELETAL MUSCLE

Also called striated/striped muscle

Because the presence of alternating light and dark bands on the muscle fiber

Voluntary muscle Can be made to contract and relax by conscious

control via nervous system

SKELETAL MUSCLE (STRUCTURE)

Made up of long cylindrical cells called muscle fibres/myofibres

Each muscle fibre Has many nuclei Covered by plasma membrane called

sarcolemma Contains many protein fibers (myofibrils)-

contract

TENDONS & LIGAMENTS

TENDONS & LIGAMENTS

Tendons A cord of dense connective tissue made up of

strong & inelastic collagen fibres Connects muscle tissue to bones or cartilageLigaments Made of collagen fibres containing an elastic

protein Strong and elastic Holding bones together at a joint &

preventing them from being dislocated

COMPARISONS BTW TENDONS & LIGAMENTS

Similarities Connect 2 types of tissues together Made of collagen tissue

Tendons Aspect of Comparison

Ligaments

Muscle to bone Types of tissues connected

Bone to bone

Absent Presence of elastin

Present

Inelastic Elasticity Elastic

CARTILAGE & SYNOVIAL FLUID JOINTS

Joints Found in the skeleton where bones meet

Divided into 3 groups

Immovable (fixed joints) eg: sutures (skull)

Slightly movable eg: joints between adjacent centra of the vertebral column

Freely movable (synovial joints) eg: hip & knee

CARTILAGE & SYNOVIAL FLUID JOINTS

Cartilage In moveable joints, smooth muscle covers

the bone surfaces Reduces the friction between articulating

bone structures

Synovial fluid Secreted by the surrounding synovial

membrane Lubricates the joint & nourishes the

surrounding cartilage

CARTILAGE & SYNOVIAL FLUID JOINTS

Synovial joints Articulating bone ends Surfaces are separated by a fluid-filled space

(synovial joint) Classified according The ball & socket joints (at the shoulders &

the hips ) which allow freedom of movement in any plane

The hinge joints ( at the elbows & the knees) which allow movement only in one plane

HOW MOVEMENT IS BROUGHT ABOUT IN A LIMB (MOVEMENT IN THE UPPER LIMB: ELBOW JOINT)

Flexion = bending of hinge joint Extension = straightening of hinge joint Muscle causes flexion = flexor Muscle cause extension = extensor

In the elbow hinge joint, 2 sets of muscle Biceps muscle Triceps muscle

HOW MOVEMENT IS BROUGHT ABOUT IN A LIMB (MOVEMENT IN THE UPPER LIMB: ELBOW JOINT)

Biceps muscle

Lies in front of the humerus, forms the flexor

Connected to the scapula (point of origin) by 2 tendons at its upper end

Connected to the radius of the forearm (point of insertion) by a single tendon at its lower end

HOW MOVEMENT IS BROUGHT ABOUT IN A LIMB (MOVEMENT IN THE UPPER LIMB: ELBOW JOINT)

Triceps muscle

Lies behind the humerus , forms the extensor

Connected to the scapula & the humerus (points of origin) by 3 tendons at its upper end

Inserted to (olecranon process of)the ulna at its lower end

HOW MOVEMENT IS BROUGHT ABOUT IN A LIMB (MOVEMENT IN THE UPPER LIMB: ELBOW JOINT)

Biseps & triceps muscles form an antogonistic pair

Flexion occurs when biceps muscle contracts & triceps muscle relaxes causing the forearm to bend at the elbow, pulling it towards the scapula

Extension occurs when the triceps muscle contracts and the biceps muscle relaxes causing the extension of the forearm at the elbow

HOW MOVEMENT IS BROUGHT ABOUT IN A LIMB (MOVEMENT IN THE UPPER LIMB: ELBOW JOINT)

HOW MOVEMENT IS BROUGHT ABOUT IN A LIMB (MOVEMENT IN THE LOWER LIMB: KNEE JOINT)

Body moves forward by pushing each foot downwards and backwards against the ground one after another