title Support and movement

14.1 What is support? 14.2 Support in mammals 14.3 Support in plants Support and movement content 14.1 What is support? 14.2 Support in mammals 14.3 Support in plants 14.4 Locomotion in mammals

reduces friction with ground 14.1 What is support? take up particular shapes kept in particular positions allows bodies important for animals SUPPORT SYSTEM important for plants helps movement raises body above ground gives particular shapes (e.g. streamlined shape of fish) helps plants to stand upright to get more sunlight reduces friction with ground

14.2 Support in mammals SUPPORT SYSTEM muscular system skeleton

The skeleton Skeleton consists of : bones cartilage hard made up mainly of minerals found between bones softer reduces friction during movement e.g. calcium phosphate, calcium carbonate

The skeleton Mammalian skeleton is divided into two main parts: skull Mammalian skeleton is divided into two main parts: rib (12pairs) sternum 1 The axial skeleton middle part of the skeleton for support and protection of internal organs consists of vertebral column skull (made up of vertebrae) sternum rib vertebral column

The skeleton Mammalian skeleton is divided into two main parts: pectoral girdle Mammalian skeleton is divided into two main parts: humerus radius 2 The appendicular skeleton pelvic girdle joins limbs to spine developed to allow movement consists of limb bones pectoral girdle and pelvic girdle ulna femur knee cap tibia fibula

Examination of a mammal skeleton Carry out Practical 14.1 Examination of a mammal skeleton

The skeleton What the skeleton does? skull brain eye heart lungs vertebrae spinal cord 3 Movement 2 Protecting internal organs of the body 1 Support

The skeleton What the skeleton does? bone marrow Ca2+ Ca2+ Ca2+ Ca2+ 4 Producing blood cells 5 Storage of minerals such as calcium

The muscular system muscular system many different sets of muscles tendons tough sheets of inelastic fibres allow muscles to control the way bones move the two ends of each muscle are attached to the limb bones through tendons Muscles are attached to bones through tendons

The muscular system Muscles as part of the support system If the forces of the muscles acting on both sides of two adjacent bones are balanced A skeleton falls down if let loose because nothing joins the bones together bones will be kept in the same position

14.3 Support in plants SUPPORT SYSTEM Hardness of thick- walled cells Turgidity of cells

> Turgidity of cells Inside stem of herbaceous plants If adequate water supply, Cells become turgid water potential of living cells water potential of xylem > water move from xylem to living cells in stems Turgid cells press against each other to give support to the plant

< Turgidity of cells Inside stem of herbaceous plants If inadequate water supply, Cells become flaccid water potential of living cells water potential of xylem < Flaccid cells cannot provide support to the plant The plant wilts

mostly xylem cells which contain lignin The hardness of thick-walled cells Plants are also supported by thick-walled cells mostly xylem cells which contain lignin As plant grows, older xylem tissues in stems are pushed inwards and become wood.

Carry out Practical 14.2 Examination of transverse sections of a young herbaceous plant stem and an older woody plant stem with microscope

14.4 Locomotion in mammals joint ligament flexible, elastic fibres the place where two bones meet At the joint, two bones do not directly touch each other ,they are held by ligament cartilage reduces wear synovial fluid reduces friction As ligament is flexible, the joint allow the limb bones to move synovial membrane secretes synovial fluid Structure of a movable joint

How do mammals move? Movement is caused by coordinated contractions and relaxations of antagonistic muscles Body can move from one place to another when limbs push or pull against the ground/other surface LOCOMOTION pair of muscles carry out opposite actions in movement

How do mammals move? Antagonistic muscles flexor extensor bends a joint on contraction straightens a joint on contraction How contraction and relaxation of opposing muscles brings about movement of the lower arm

The lever principle of movement For example: Advantage: x < y indicates a small movement in effort load to a large movement in load load on arm = load on lever joint = fulcrum contraction of the biceps = effort The elbow joint A lever y effort x contraction of biceps joint fulcrum load load

Different degrees of movement Joints movable fixed (e.g. between different bones of skull) Hinge joint Ball and socket joint move in one plane and one direction only move in many directions ball socket hinge

Examination of the movement of knee, elbow, hip and shoulder joints Carry out Practical 14.3 Examination of the movement of knee, elbow, hip and shoulder joints

Please click to continue... Concept diagram Support in plants provided by in animals provided by maintaining a particular position shape action of on attached by tendons to skeleton muscles turgidity of cells thick-walled xylem cells consists of contain lignin axial skeleton appendicular skeleton Please click to continue...

Please click to continue... Concept diagram muscles attached by tendons to axial skeleton appendicular skeleton made up of made up of girdles limb bones skull vertebral column ribs and sternum Please click to continue...

Concept diagram Locomotion in mammals joints limb bones involves between act on joints limb bones skeletal muscles function in pairs involving can be ball and socket joints hinge joints flexor e.g. biceps extensor e.g.triceps