Download The Body in Action - Glasgow Gaelic School

The Body in Action
Standard Grade Biology
The Skeleton
• Supports our weight
• Protects vital organs
• Provides a point of
attachment for
muscles
• Keeps our shape
• The marrow is where
red and white blood
cells are made
The Structure of Bone
• Bones are made of
living tissue
• Made up of flexible
fibres and hard
minerals
• Flexible fibres make
bone bendy
• Hard minerals give it
strength
Synovial Joints
• The meeting point of 2 bones is called a
joint
• Some joints allow very little movement
• Some allow a wide range of movement
• Ball and socket joints (hip, shoulder)
allow movement in 3 directions
• Hinge joints (knee, elbow ) only allow
movement in 1 plane
• Ligaments hold 2 bones together
The Structure of a Joint
Cont.
• The ends of the bones are covered with
a layer of smooth cartilage
• Cartilage acts as a shock absorber
• The joint capsule contains synovial fluid
which helps reduce friction between the
bones
Muscles and Movement
Respiration and Breathing
• The body needs oxygen in order to
release energy from food (respiration)
• Breathing supplies that oxygen and
removes carbon dioxide, the waste
product of respiration
Lung Structure
Gas Exchange in the Alveoli
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Alveoli increase the surface area for gas exchange
They have a rich blood supply
They have thin walls to allow easy diffusion
They have moist surfaces
Oxygen diffuses into the blood
Carbon dioxide diffuses out of the blood into the air
space
• Blood carries oxygen to the cells and brings carbon
dioxide from the cells to the lungs
Gas Exchange
Breathing
Breathing in
• Intercostal muscles
contract
• Ribs move up and out
• Diaphragm contracts
and flattens
• Chest volume increases,
pressure decreases
• Air is drawn into the
lungs
Breathing out
• Intercostal muscles
relax
• Ribs move down and in
• Diaphragm relaxes and
moves up
• Chest volume decreases,
pressure increases
• Air is forced out of the
lungs
Breathing in
Breathing out
Mucus and Cilia
• Air passages are
lined with ciliated
cells and mucus
producing cells
• Mucus traps dust
and germs
• Cilia move the mucus
out of the air
passages to the nose
The heart and circulation in
mammals L.Os
• Describe the flow of blood through the
heart and its associated blood vessels
• Describe the positions and functions of
the heart valves
• Explain the difference in thickness of
the walls of the ventricles
• State that the heart obtains its blood
supplies from coronary arteries
The Heart
Blood Flow
Blood Vessels
• 3 main types
• Arteries carry oxygenated blood away
from the heart, have thick walls to
withstand the high pressure
• Veins carry deoxygenated blood back to
the heart, have thinner walls and valves
to prevent backflow
• Capillaries have walls 1 cell thick to
allow diffusion to take place easily
Gas Exchange at the Capillaries
Valves and Blood Flow
Blood
• Blood is necessary for
the transport of oxygen,
nutrients and waste
products round the body
Part of the
Blood
Red Blood Cells
White Blood
Cells
Platelets
Plasma
Function
Have no nucleus
Contain
haemoglobin
Carry oxygen
Fight disease
and infection
Involved in
clotting
Transports
dissolved
substances
(food, carbon
dioxide etc.)
Co-ordination and the Nervous
System
1. Every action we make is controlled by
the nervous system
2. The sense organs detect information
from the surroundings and send
messages to the brain and spinal cord
3. The brain and spinal cord sort out
these messages and send instructions
to the body
4. The body responds
Learning outcomes
• Structure of the eye:
• Cornea, iris, lens, retina, optic nerve
• How we see
The Eye
The Pupil
The lens
• The lens focuses the light entering the
eye onto the retina.
• If the light is not focused, vision is
blurry
• Wearing glasses or contact lenses can
help focus the light to make vision clear
The retina
• Made up of millions of light sensitive
cells which convert light into nerve
impulses which are carried to the brain
via the optic nerve.
• Rods are sensitive to dim light
• Cones are sensitive to bright light and
colour.
The Ear and Hearing
The Ear and Balance
• The semi-circular canals are three
tubes , each at right angles to each
other
• When the head moves, cells in the
canals pick up the movement of fluid in
the canals and sends a message to the
brain
The Nervous System
• The central nervous system
(CNS) comprises the brain,
spinal cord and nerves
• Sense organs contain
receptors that detect stimuli
(changes in the environment)
• The receptors send
messages, called nerve
impulses, along the nerves to
the brain and spinal cord
• The CNS sends nerve
impulses to muscles to bring
about movement
Nerves
• Nerves are made up of nerve cells or
neurones
• There are 3 types of neurone
• Nerve impulses travel in only 1 direction
• The fatty sheath acts as insulation and
speeds up the impulse
• A relay neurone connects the sensory
and motor neurones
The Reflex Arc
• The flame is the stimulus
• The heat sensor in the skin
sends an impulse along the
sensory neurone to the spinal
cord (red)
• The impulse is passed to the
relay neurone in the spinal
cord (green)
• The impulse passes to the
motor neurone which carries
a message to the muscle
(blue)
• The muscle contracts to
move the hand away from the
heat
• NOW the brain feels the
pain
• Damage to body tissues is
avoided
The Brain
Exercise and Fatigue
• When we run fast the muscles use up a lot of glucose for energy
• If enough oxygen cannot get to the muscles they respire
anaerobically
• Lactic acid is produced instead of carbon dioxide and water
• Lactic acid builds up in the muscle and causes a sore, burning
feeling
• Aerobic respiration
glucose + oxygen →carbon dioxide + water + energy
• Anaerobic respiration
glucose → lactic acid + energy
• After exercise the lactic acid is broken down to carbon dioxide and
water
• The volume of oxygen needed to break down the lactic acidis called
the oxygen debt
The Effects of Training
• During exercise the pulse rate and breathing
rate increase
• The heart beats faster to carry more oxygen
and glucose to the muscles
• After exercise they return to normal, this is
the recovery time
• The recovery time can be used as an
indication of a person’s fitness
• A fit person has a shorter recovery time than
an unfit person