Locomotion and Support - .Locomotion and Support. 2.1 SUPPORT AND LOCOMOTION IN HUMANS AND ANIMALS

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Transcript of Locomotion and Support - .Locomotion and Support. 2.1 SUPPORT AND LOCOMOTION IN HUMANS AND ANIMALS

  • Chapter 2Locomotion and Support

  • 2.1 SUPPORT AND

    LOCOMOTION IN

    HUMANS AND ANIMALS

  • 2.1 Support and Locomotion in

    Humans and Animals Importance of support and locomotion

    Search for food

    Provide protection by escaping from enemies or avoiding danger

    Search for more conducive living environment

    Find mates for reproduction

    Avoid overcrowding which enables the offspring to move to another place

  • 2.1 Support and Locomotion in

    Humans and Animals (contd)

    Human skeletal system

    Consist of two main part; axial skeleton and appendicular skeleton

    Human

    skeleton

    Parts

    Axial skeleton 1. Skull

    2. Vertebral column

    (the backbone)

    3. Ribcage

    Cranium, bones of the face, jaw

    Cervical vertebrae, thoracic vertebrae,

    lumbar vertebrae, sacrum, coccyx

    Sternum and ribs

    Appendicular

    skeleton

    1. Pectoral girdle

    2. Arm (forelimbs)

    3. Pelvic girdle

    4. Leg (hind limbs)

    Scapula and clavicle

    Humerus, ulna, radius, carpals,

    metacarpals, phalanges

    Ischium, pubis, ischium

    Femur, tibia, fibula, tarsals, metatarsals.

    phalanges

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Skull

    Cranium enclose and protect the brain

    Facial bones and jaw

    Protect the eyes and ears

    Upper jaw is fixed

    Skull is joined to the vertebral column at the base

    of cranium

  • 2.1 Support and Locomotion in

    Humans and Animals (contd)

    Rib

    Twelve pairs of ribs

    Articulate with thoracic cavity

    dorsally, and sternum ventrally

    Sternum is the front part

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Vertebral column

    Consists of 33 vertebrae, joined but separated by discs of cartilage

    Five types of vertebrae

    1. Cervical vertebrae (7)

    2. Thoracic vertebrae (12)

    3. Lumbar vertebrae (5)

    4. Sacral vertebrae (5)

    5. Coccyx

  • 2.1 Support and Locomotion in

    Humans and Animals (contd)

    Centrum

    Gives support

    Neural arch

    Forms neural

    canal

    Neural spine

    Muscle

    attachment

    Neural canal

    Protects spinal

    cord

  • 2.1 Support and Locomotion in

    Humans and Animals (contd)

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Support head and

    neck

    Sentrum is short

    and thick

    Large and thick

    sentrum

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Appendicular skeleton

    Consists of

    1. Pectoral girdles and forelimbs (arms)

    2. Pelvic girdle and hind limbs (legs)

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Arms

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Legs

    Pelvic

    girdle

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Joints

    Place where two bones meet

    Bones are held together by ligaments

    Sinovial joints joints that contains a cavity filled

    with fluid

    End of bones are covered with cartilage.

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Joints

    Various types of joints1. Hinge joint Allow movement in one plane

    2. Ball-and-socket joint Allow movement in all directions

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Movement in a limb

    Skeletal muscles are attached to bones by tendons. Movements of cause by antagonistic movement

    of muscles: One muscles is contracted, another is relaxed

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Structure of a muscle

    Muscle fibre single, long cylindrical cell that contains many nuclei

    Myofibrils smaller units that made up muscle fiber

    Interaction of actin and myosin will cause muscle contraction

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of earthworm

    Earthworms have a hydrostatic skeleton (the force of contraction is applied to a coelum(fluid filled chamber).

    Coelom is surrounded by two antagonistic muscle circular muscles surround the chamber

    longitudinal muscles extend from one end to the other.

    Thinner and longer: When circular muscle contract and the longitudinal muscle relax. (and vice verca)

    The muscles contract rhythmically to produce peristaltic waves which begins at the front and move towards the end of the body.

    Earthworm has chaetae (bristles) which anchor parts of the body to the ground so that other parts can be pulled towards it.

  • 2.1 Support and Locomotion in

    Humans and Animals (contd)

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of grasshopper

    The flexor and extensor (antagonistic) muscles are attached to the internal surface of the exoskeleton.

    Flexor muscles bend a joint.

    Extensor muscles straighten it.

    The rear legs of a grasshopper are long and muscular and is adapted for hopping.

    Sitting position: When the flexor muscle contracts, the lower leg is pulled towards the body. The hind leg is folded in a Z shape and ready for a jump.

    Jump: When the extensor muscle contracts, the leg jerks backwards, propelling the grasshopper forward and upward into the air.

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of grasshopper

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of grasshopper

    The flexor and extensor (antagonistic) muscles are attached to the internal surface of the exoskeleton.

    Flexor muscles bend a joint.

    Extensor muscles straighten it.

    The rear legs of a grasshopper are long and muscular and is adapted for hopping.

    Sitting position: When the flexor muscle contracts, the lower leg is pulled towards the body. The hind leg is folded in a Z shape and ready for a jump.

    Jump: When the extensor muscle contracts, the leg jerks backwards, propelling the grasshopper forward and upward into the air.

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of fish

    Fish has streamlined body shape

    Scales that overlap one another, with free ends pointing backwards to reduce friction

    Fish have W-shaped muscles called myotome

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of fish

    Fish move forward from the

    contraction and

    relaxation

    (antagonistic) of

    myotome on either

    side of the body

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of fish

    Function of fins in fish balance the body

    Pectoral fins for steering

    Pelvic fins for balance, to prevent diving and rolling

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of bird

    Bird can fly either by flapping their wings or gliding

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of bird

    When wings move down Pectoralis major contracts

    Wings are pulled down

    When wings move up Pectoralis minor contracts

  • 2.1 Support and Locomotion in

    Humans and Animals (contd) Locomotion of bird

    During gliding, wings are spread act as

    aerofoil

    Bernoulli principle provide upward

    thrust

  • 2.3 SUPPORT SYSTEM IN PLANTS

  • 2.3 Support Systems in Plants

    Support in plants is necessary to:

    Stay upright

    Obtain sufficient sunlight

    Bear the weight the plant

    Provide strength to withstand wind ressistance

  • 2.3 Support Systems in Plants

    (contd)

    Plants

    Aquatic

    Submerged Floating

    Terrestrial

    Herbaceous Woody

  • 2.3 Support Systems in Plants

    (contd) Submerged plants

    Hydrilla sp.

    Have thin, narrow and flexible leaves provide

    little ressistance

    Air sacs inside the leaves and stems - keep

    the plant floating close

    to the surface to obtain

    maximum sunlight.

  • 2.3 Support Systems in Plants

    (contd)

    Floating plants

    Lotus plant

    Have broad leaves that are firm but flexible enough to resist tearing by wave action.

    Aerenchyma tissues (spongy tissues with large air spaces between the cells) in the stems and

    leaves provide buoyancy so that the plants can

    float on the surface of the water

  • 2.3 Support Systems in Plants

    (contd) Herbaceous plant

    Support provided by the turgidity of the parenchyma and collenchyma cells.

    Turgor pressure of the fluid content in the central vacuole pushes the cell membrane and the cell contents against the cell wall, creating support for the stem, root and leaves.

    The thickening of the cell walls with cellulose and pectin in collenchyma cells provide additional mechanical strength

  • 2.3 Support Systems in Plants

    (contd) Woody plants

    Support provided through tissue modification

    Xylem tissues

    Strenghtened by lignin

    Lignin tough, not elastic and nor permeable

    to water

    Parenchyma tissues

    Store starch, sugars and water

    It become turgid give support

  • 2.3 Support Systems in Plants

    (contd) Woody plants

    Collenchyma tissues

    Thickened with cellulose and pectin

    Sclerechyma tissues

    Thickened with lignin