* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download The body in action 1/ Movement 1-What are the 3 main roles of the
Document related concepts
The body in action 1-What are the 3 main roles of the skeleton? 2-Describe the range of movements allowed by a ball and socket joint and by a hinge joint. 3-State the functions of ligaments (2) and cartilage at a joint (2). 4 (C)-Describe the structure of the synovial joint and state the function of its parts 5-What is bone composed of? (2) 6-(C) What is bone formed by 7-How are muscles attached to bones? 8-Why are tendons inelastic? 9-Describe how movement is brought about by muscle contraction. 10-(C) Explain the need for a pair of opposing muscles at a joint. 1/ Movement it provides - a framework for support against the force of gravity and muscle attachment - protection for the heart (ribcage), lungs (ribcage), brain (skull) and spinal cord (vertebrae of the backbone). Ball and socket: e.g. hip and shoulder, movement in all directions Hinge: e.g. knee and elbow; movement in one plane only Ligaments: tough fibrous tissues: hold bones together at a joint and prevent dislocation (ligaments are very slightly elastic) Cartilage: smooth, slippery and rubbery: reduce friction at the end of bones and acts as a shock absorber 1- Capsule: surrounds and protects the joint 2- Cartilage: cushions the joint 3- Synovial sac: secretes synovial fluid 4- Ligament: holds bones together 5- Synovial fluid: liquid that lubricates the joint (reduce friction) Bone is composed of flexible fibres (living cells) and hard minerals (calcium phosphate). Bone is formed by living cells. Muscles are attached to bones by tendons. Tendons are inelastic. To allow fast and precise movement. Needed for the transfer of muscle forces. One end of a muscle is usually attached to a rigid part of the skeleton whereas the other end is attached to a bone which can be moved. When the muscle contracts, it becomes shorter thereby pulling the moveable bone it is attached to. Muscle can contract but they cannot elongate of their own accord. To be pulled back to their original length, they need the contraction of a muscle in the opposite direction (e.g. biceps: flexor muscle/ triceps: extendor muscle). A pair of opposite muscles are also called an antagonistic pair. Body in action 1-State the effects of an imbalance between energy input and energy output. (2) 2-State what sort of gas exchange take place during breathing 3- Describe the internal structure of the lungs. (name and role in breathing) Larynx 2 3 1 3 4 2/ The need for energy 1- Energy input more than energy output: extra energy stored as fat → gain weight 2- Energy input less than energy output: body gets extra energy needed from stored body fat → loose weight Oxygen (needed to release the energy from food during aerobic respiration) is absorbed and carbon dioxide (waste product of aerobic respiration) is released 1- Trachea: the air passes through the larynx and through the trachea (1). 2- Bronchus (plu. bronchi): after the trachea, the air flow is divided within the 2 bronchi which connect to each lung. 3- Bronchioles: bronchi which have divided many times and are smaller in size 4- Air sacs 5- Blood capillaries surrounding the air sac where gas exchange takes place. 5 4-(C) Describe the mechanism of breathing in humans 5- (C) Explain the function of mucus, cilia and cartilage in the trachea and bronchi 6- (C) Describe the features which make the lungs efficient gas structures (4) Air is drawn in when the diaphragm muscles pull the diaphragm downwards + the intercostals muscles contract which lifts the ribcage upwards Air is squeezed out of the lungs when both intercostals and diaphragm muscles relax Mucus: lines the trachea and the bronchi; it is thick and traps germs and dust in the passing air Cilia in the trachea: push mucus upwards towards the throat and the oesophagus. Once in the stomach, germs are destroyed by stomach acids. Cartilage in the trachea and bronchi: prevent the collapsing (and closing…) of the airways during breathing - very large surface area: maximises gas exchange - very thin gas exchange surface (air sacs): allow quick passage of gases - moist gas exchange surface: allows diffusion of gases - many capillaries: excellent blood supply to air sacs 7- (C) Describe gas exchange between the air sacs and the surrounding blood vessels 8- Identify the four chambers of the heart 1 In the capillaries, the blood has low levels of oxygen and high levels of carbon dioxide. In the air sacs, fresh air has a higher concentration of oxygen and lower concentration of carbon dioxide. As result, diffusion takes place so that oxygen passes diffuses from the air to the blood and carbon dioxide from the blood to the air. 1- Right atrium (Plural atria) 2- Right ventricle 3- Left atrium (Plural atria) 4- Left ventricle 3 2 2 4 9- Describe the path of blood flow through the heart and blood vessels connected to it. 6 8 4 5 7 3 1 3 2 4 10- Describe the positions and functions of the heart valves. V2 2 Blood return from organs via the vena cava (5) and enters the right atrium (1). When the right atrium is full, the blood is squeezed into the right ventricle (2). The muscular wall of the right ventricle contracts and pushes the blood through to the pulmonary artery (6) towards the lungs. Blood return from the lungs via the pulmonary vein (7) and enters the left atrium (3). When the left atrium is full, the blood is squeezed into the left ventricle (4). The muscular wall of the left ventricle contracts and pushes the blood through to the aorta (8). When the atria are full, the blood is squeezed into the ventricle and valves (V1) prevent its return to the atria. When the ventricles are full, the blood is squeezed towards the arteries (pulmonary artery and aorta) and valves (V) prevent its return to the ventricles. V1 11- Explain the difference in thickness of the walls of the ventricles The walls of the right ventricle are thinner than that of the left ventricle. This is because the right ventricles only pumps the blood to the lungs which are close to the heart whereas the left ventricle needs to pump blood at higher pressure so that it can reach all places in the body. 12- State where the heart obtain its supply of energy from 13- State the path of blood in the circulatory system 14- State what the pulse indicates 15- Describe the function of red blood cells and plasma in the transport of respiratory gases and food The coronary artery supplies the heart with blood. Blood leaves the heart in arteries. Arteries further divide and become capillaries which are the tiny blood vessels found in organs and tissues. Finally, blood returns to the heart through veins. The pulse indicates that blood is flowing through an artery. This is because every time the heart beats, blood is pushed at high pressure through arteries which causes the artery walls to bulge. Blood= red blood cells + white blood cells + plasma Red blood cells - filled with haemoglobin (carry oxygen) - No nucleus Function: - transport of oxygen from lungs to the tissues Plasma - yellowish coloured liquid Function: - transports cells - carries food (e.g. glucose and amino acids) - carries dissolved carbon dioxide 16- (C) Explain the function of haemoglobin in the transport of oxygen 17- Describe gas exchange between the body cells and the surrounding capillaries 18- (C) Describe the features of a capillary network which allows efficient gas exchange To transport oxygen In lungs: Haemoglobin binds oxygen to become oxyhaemoglobin In tissues: Oxyhaemoglobin separates into haemoglobin and oxygen for cells to use. The cells in tissues have low concentration of oxygen and high concentration of carbon dioxide. The blood entering capillaries has a high concentration of oxygen and a low concentration of carbon dioxide. This creates a concentration gradient for both oxygen and carbon dioxide so that oxygen diffuses from the blood to the cells and carbon dioxide diffuses from the cells to the blood Arteries dividing many times so that tiny capillaries with thin walls (one cell thick) provide a large surface area allowing gas exchange Body in Action 1- Explain the benefit of having two eyes rather than one 2- (C) Explain the relationship between judgement of distance and binocular vision 3- Parts of the eye and their function 3 4 1 2 5 4- Explain the benefit of having two ears rather than one 5- Identify the different parts of the ear and state their function 2 1 4 3 6- (C) Explain how the arrangement of semi-circular canals is related to their function 7- State the name of the three parts that make up the nervous system 3/ Co-ordination Using two eyes (binocular vision) makes the judgement of distances more accurate than using one eye only A slightly different image is formed on the retina of each eye. As a result, two different images are sent to the brain which combines them into one. The brain uses the difference between the two images to estimate the distance of an object 1- Cornea: allows the light to enter and start to focus 2- Iris: control the amount of light entering the eye 3- Lens: focussed the light which has passed through the hole in the middle of the iris (called the pupil) 4- Retina: light-sensitive layer of cells where an image is formed 5- Optic nerve: carries nerve impulse from the retina to the brain. Using two ears makes the judgement of direction of sound more accurate 1- Ear drum: thin membrane which is set to vibrates when sound waves are funnelled in it by the outer ear. 2- Middle ear bones (Hammer, Anvil and Stirrup): transmit and amplify vibration from the ear drum to the cochlea (inner ear). 3- Cochlea: filled with fluid and lined with sound receptor cells with hair-like endings which convert sound to nerve impulse. 4- Semi-circular canals filled with fluid which moves with head movements. Receptors detect movement of liquid. Essential for balance. 5- Auditory nerves: carries nerve impulse from the cochlea to the brain. The 3 semi-circular canals are at right angle to each other ensuring that head movements in all 3 planes will be detected: Nodding head: up and down Shaking head: left to right, right to left Bending head towards shoulder: side to side The brain, the spinal cord and nerves 8- State where nerves carry information to and from. 9- State in general terms the 2 main functions of the Central Nervous System (CNS). 10- Give three examples of reflex actions. Describe how a reflex action works, using the simple model of a reflex arc. 11- Identify the cerebrum, cerebellum and medulla. State their function. Sensory nerves carry information from the senses to the Central Nervous System (CNS= brain + spinal cord). Motor nerves carry information from the Central Nervous System to the muscles. The CNS (Brain + spinal cord) sorts out information from the senses and sends messages to those muscles which make the appropriate response. Some information is analysed by the brain before conscious action is taken (seeing a cake and decide to grab it). Other information (e.g. touching something very hot) require rapid action (reflex action see below) to prevent body damage. Reflex actions are fast, automatic and involuntary actions. They either protect the body from damage (e.g. removing hand from heat, sneeze) or help its normal functioning (e.g. swallowing). Receptors (1) are stimulated (e.g. pain) and send a nerve impulse though the sensory neurone (2). From the sensory neurone, the message has to pass through a synapse (junction, 3) before it reaches the intermediate neurone or relay neurone (4) in the spinal cord. From the intermediate/relay neurone, it crosses another synapse (5) and travels down a motor neurone (6) which stimulates a muscle to contract (7) (e.g. jerking movement of the hand). 1- Cerebrum: the largest part, divided into two halves. Different regions are responsible for memory, conscious thought, reasoning, intelligence, personality. 2- Cerebellum: controls balance and co-ordination. 3- Medulla: controls automatic functions of the body: breathing, heart beat, etc… Watch: the last part of the topic “Changing levels of performance” is missing.