4.5.1
Homeostasis
Describe what the term
‘homeostasis’ means.
Which molecules cannot
function properly if these
conditions are not kept
constant?
Why are these molecules
important?
Unscramble the word to find one condition
that the body controls in homeostasis and
describe what happens if this condition is
not kept constant.
State the two types of control
systems that can occur in the
body to help maintain a constant
internal environment.
EMPTRAUERET -
1.
2.
Fill in the boxes to identify the
parts of the pathways that
control an environmental
condition.
Unscramble the word to find
one condition that the body
controls in homeostasis and
describe what happens if this
condition is not kept constant.
S
TERAW VELEL Unscramble the word to find one condition
that the body controls in homeostasis and
describe what happens if this condition is
not kept constant.
DLBOO CSELOGU VELEL -
R
C
E
R
What is the main coordination
centre in the human body.
4.5.2
Nervous system
Name the five sense organs
1.
2.
3.
4.
5.
For each of the senses you
have named, give an example
of a stimuli that would
generate a nervous response.
1.
2.
Tim stands on a nail. Describe the what happens in his
body to make him move his foot.
(Hint: Receptor, Sensory, Relay, Motor, Effector)
Name the structure
inside of these
sense organs that
detect stimuli.
Use the image below to help
you describe how a nerve is
adapted for its function.
Describe the differences between a
chemical and nervous response in the body.
Speed:
What is involved?
Recovery:
3.
4.
5.
Why are reflex actions
important for the
body?
What is the
effector in this
example?
What is the
receptor in this
example?
Give an
example of a
stimulus that
would cause a
reflex in this
example.
4.5.1
Homeostasis
Describe what the term
‘homeostasis’ means.
Regulation of the internal conditions
of a cell or organism to maintain
optimum conditions for function in
response to internal and external
changes.
Unscramble the word to find
one condition that the body
controls in homeostasis and
describe what happens if this
condition is not kept constant.
Which molecules cannot
function properly if these
conditions are not kept
constant? Enzymes
Unscramble the word to find one condition
that the body controls in homeostasis and
describe what happens if this condition is
not kept constant.
State the two types of control
systems that can occur in the
body to help maintain a constant
internal environment.
EMPTRAUERET –
1. Chemical
TEMPERATURE
2. Nervous
If your temperature is not kept constant
this could impact on the rates of
reactions in your body. It could also
impact on the amount of blood reaching
different parts of your body.
Fill in the boxes to identify the
parts of the pathways that
control an environmental
condition.
STIMULUS
TERAW VELEL –
WATER LEVEL
If your water levels are not
maintained this can affect the
osmotic pressure inside of
cells and they could die.
Why are these molecules
important?
They help to control
reactions in your body.
Unscramble the word to find one condition
that the body controls in homeostasis and
describe what happens if this condition is
not kept constant.
DLBOO CSELOGU VELEL -
RECEPTORS
COORDINATOR
EFFECTOR
BLOOD GLUCOSE LEVELS
If your blood glucose levels are too low,
your cells will not get enough glucose for
respiration to occur and lead to decreased
levels in energy. If they are too high this
could lead to circulatory problems.
RESPONSE
What is the main coordination
centre in the human body.
The brain
a
+
+
1800
=
4.5.2
Nervous system
Name the five sense organs
1. Skin
2. Nose
3. Tongue
4. Ears
5. Eyes
For each of the senses you
have named, give an example
of a stimuli that would
generate a nervous response.
Name the structure
inside of these
sense organs that
detect stimuli.
Receptors
Use the image below to help
you describe how a nerve is
adapted for its function.
1. Someone hugging you would
cause the receptors in the skin
to respond.
Nerve cells are long in shape
to allow nerve impulses
(electrical signals) to travel
throughout the body.
2. Someone spraying
deodorant would cause the
receptors in the nose to
respond. (chemical)
They also contain many
dendrites which connect to
other nerves throughout the
nervous system.
3. Chewing a sour sweet would
cause the receptors in the
nose to respond (chemical)
4. A loud bang would cause the
receptors in the ears to
respond.
5. A flash of light would cause
the receptors in the eye to
respond.
Tim stands on a nail. Describe the what happens in his
body to make him move his foot.
(Hint: Receptor, Sensory, Relay, Motor, Effector)
Receptors in Tim’s skin detect the nail, which then
send an electrical impulse down the sensory neurone.
The electrical signal then travels down the relay
neurone to the motor neurone. The motor neurone then
carries the electrical signal to the effect (muscles in
the leg) which cause the muscles to move which is the
response.
Describe the differences between a
chemical and nervous response in the body.
Speed:
Nerve responses are quick, while chemical
responses are slower.
What is involved?
Nervous responses involves electrical
signals, while a chemical response involves
hormones.
Recovery:
Nervous responses are quicker to recover
than chemical responses.
Why are reflex actions
important for the
body?
Reflex actions are
important in protecting
the body from danger
or harming itself.
Sensory Neurone
Motor Neurone
Spine
What is the
effector in this
example?
Muscle
What is the
receptor in this
example?
Stretch
Receptor
Spine
Receptor
Effector/Muscle
Give an
example of a
stimulus that
would cause a
reflex in this
example.
A hammer
hitting the
knee.