Download - Topic 1
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LOCOMOTION AND SUPPORT1)Understanding support & locomotion in human & animals
2) Appreciating a healthy musculoskeletal system
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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
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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
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INTRODUCTION
Support/Locomotion
Support/Locomotion in Humans & Animals
Skeleton
Skeletal Muscles & Tendons in movement
The Mechanism of Locomotion
Healthy Musculoskeletal System
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FORMS OF LOCOMOTION
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INTRODUCTION CONT..
Definition:Locomotion is the whole movement organisms from place to place
Forms of locomotion: walking climbing running swimming crawling flying
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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
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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
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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
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SKELETON
Types of Skeleton
Exoskeleton
crabgrasshopper
Endoskeleton
fishcat
Hydrostatic Skeleton
wormcaterpillar
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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
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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
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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
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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
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HUMAN SKELETON
2 main parts Human skeleton
Axial skeleton
Appendicular skeleton
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AXIAL SKELETON
Axial skeleton
Skull
Vertebral column (spine)Rib cage
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APPENDICULAR SKELETON
Appendicular skeleton
Pectoral girdleUpper limb (Fore limb)
Arm
Upper arm
Forearm
Hand
Pelvic girdle Lower limb (Hind limb)
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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
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HUMAN SKELETAL SYSTEM
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THE AXIAL SKELETON (SKULL)
Skeleton of the head Consists of :
Cranium Facial skeleton
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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
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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
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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
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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
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VERTEBRAL COLUMN
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VERTEBRAL COLUMN
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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
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THE TYPICAL VERTEBRA
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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
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THE CERVICAL VERTEBRA (ATLAS)
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THE CERVICAL VERTEBRA (ATLAS)
1st cervical vertebra
Supports the head
Do not have these 3 structures Centrum (body) Transverse processes Neural spine
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CERVICAL VERTEBRAE (AXIS)
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THE CERVICAL VERTEBRA (AXIS)
2nd cervical vertebra
Has centrum and tranverse processes
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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
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THE THORACIC VERTEBRAE
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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
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THE LUMBAR VERTEBRAE
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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
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SACRUM AND COCCYX
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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
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RIB CAGE (AXIAL SKELETON)
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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’)
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RIB CAGE
Functions:
Protect vital organs (eg: lung, heart)
Attachment of intercostal muscles
Provides the pumping mechanism required for breathing
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APPENDICULAR SKELETON
The components are
Pectoral girdle
Pelvic girdle
Upper limb
Lower limb
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APPENDICULAR SKELETON (PECTORAL GIRDLE)
Contains 2 bones Clavicle (collar bone) Scapula (shoulder blade)
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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
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APPENDICULAR SKELETON (PELVIC GIRDLE)
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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
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APPENDICULAR SKELETON (UPPER LIMB)
Upper limb (Fore limb)
Arm
Upper arm
Forearm
Hand
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APPENDICULAR SKELETON (UPPER LIMB)
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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
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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
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APPENDICULAR SKELETON (LOWER LIMB)
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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
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LOWER LIMB
Foot consists of these bones
7 tarsal 5 metatarsals 14 phalanges
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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
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MUSCLE
Smooth muscle Cardiac Muscle
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MUSCLE
Skeletal muscle
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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
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CARDIAC MUSCLE
Found only in the heart Also involuntary muscle
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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
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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
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TENDONS & LIGAMENTS
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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
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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
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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
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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
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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
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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
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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
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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
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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
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HOW MOVEMENT IS BROUGHT ABOUT IN A LIMB (MOVEMENT IN THE UPPER LIMB: ELBOW JOINT)
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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