Coordination and Response

- What are the messages called that travel around the body

Impulses are passed through to the rest of the body

- What is a stimulus?

Change in the environment that can be detected by an organism

- Give an example of external stimuli

Noises, smells

- Give an example of internal stimuli

body temperature, carbon dioxide

- What are receptors?

cells that detect the stimuli

- What are effectors?

organs that bring about responses (muscles)

- What does the sensory system do?

detect changes in the environment

- What does the nervous system do?

coordinating response and initiating actions

- How are impulses passed?

From the receptor to the coordinator to the effector

- What is the nervous system?

An organ system that allows humans and other animals to detect stimuli and respond to them.

- How is the brain protected?

by the skull

- How is the spinal cord protected?

vertebral column

- What are the parts of the nervous system?

Brain, Spinal cord , Nerves

- What are the parts of the central nervous system

Brain, Spinal cord

- What are the parts of the peripheral nervous system

Cranial Nerves , Spinal nerves

- What are the cranial nerves?

Nerves that go to every part of your face coming from your brain

- What are Spinal Nerves?

Nerves that go to every part of your body (apart from face) coming from your spinal cord

- What parts of the nervous system are made up of nuerons?

Brain (all parts ), Spinal Cord, Nerves

- What are the 3 parts of nuerons

Dendite, Cell body/axon, Axon

- Function of Dendron

To receive an impulse

- What is simple reflex

automatic response to a stimulus coordinated by a nervous system

- Sequence of impulse

stimulus ⇒receptor⇒coordinator⇒effector⇒response

- Function of Neurons

transmit information in the form of nerve impulses

- Function of Soma

To receive an impulse from the dendron and pass it to the axon

- Function fo axon

To receive an impulse from soma and pass it to the axon terminal

- Function of Mylein Sheath

To wrap the axon which causes electrical insulation which helps in faster transfer of impulse

- What is the difference between chemical and electrical impulse?

Electrical- when an impulse passes through the neuron, Chemical- when an impulse passes between the nueron

- What is a relay neurone

short, passes impulses from the sensory nuerons to the motor neurons inside brain and spinal cord

- How do impulses travel through the neurons in the nervous system

the neurones do not touch each other, but travel through a gap called the synapse, a chemical transmitter neuron is released, diffuses across synapse, triggers impulse in second neuron

- Why do some regions of the brain have less mylein sheath?

The lack of mylein sheath allows for

- What is reflex arc

pathway of impulse along the neurons, only in one direction

- What are presynaptic neurons

Neuron that carries impulse to the synapse

- What is the postsynaptic neuron

neurone that carries the impulse away form the synapse, has large protein molecules at the surface acting as receptor sites for neurotransmitters.

- What is the process of synaptic transmission

When an impulse comes to the synaptic bulb, vesicles containing neurotransmitter to move towards the presynaptic membrane, vesicles fuse with presynaptic membrane, neurotransmitter is released into the synaptic gap where it diffuses accross it and attaches to specific receptor sites on the post synaptic membrane, Receptor sites have a complementary shape to the neurotransmitter, binding of neurotransmitter triggers impulse to postsynaptic neurone, after neurotransmitter is broken down by enzyme in synaptic gap, mitochondria provides energy to reform neurotransmitter

- What are the 5 sensory organs?

tongue- responds to chemical in food and drinks⇒gives sense of taste, ear- respond to sound vibration gives detects movements and position of the body providing info about balance, skin- responds to pressure, pain, temperature⇒gives sense of touch, nose- responds to chemicals in the air⇒gives sense of smell, eye- responds to light rays⇒gives sense of sight

- What is the structure of the eye?

spherical

- What is the pupil?

A gap created by the iris

- Why does the pupil appear black

The lens itself is transparent, but the inside of the eye is dark so it appears black

- What is the function of cileary muscels?

Hold the lens in place

- What is the shape of the lens?

biconvex shape

- What are the 2 types of muscles that form the iris?

circular muscle, Radial muscle

- What happens to the pupil when bright light hits it?

The pupil reduces in size- constricts , circular muscles contract, radial muscles relax

- Why do the pupils increase in size when bright light hits it?

The bright light can damage the retina cells, overstimulation can cause blurred vision.

- What happens to the pupil when dim light hits it?

The pupil increases in size- dilates, Circular muscles relax ,Radial muscles contract

- Why does the pupil increase in size when dim light hits it?

So it can receive any possible stimulus

- What happens to the pupil in normal light?

Both the radial and circular muscles relax

- What is refraction?

Changing of light through a medium

- What happens to the eye when light is near?

Ciliary muscles contract which making the curve more and increase in size, the refraction (bending) of light is more.

- What happens to the eye when light is far?

The ciliary muscles relax making the eye smaller and decrease in size, the refraction (bending) of light is less

- What are the 2 reflex's

pupil reflex, accommodation reflex

- What are the cells of the retina

Rod cells⇒sensitive to low light intensity , Cone cells⇒ sensitive to high light intensity

- Why do cone cells have 3 different types

because it has a high light intensity it has 3 different wavelengths

- What forms the central and what forms the peripheral vision?

The fovea forms the central vision, the retina forms the peripheral vision

- What cells do the fovea have

only cone cells

- What is the hormone

a chemical substance that is secreted by a gland within an organism which affects cells in another part of the organism

- What are glands

organ that makes the hormone

- What are endocrine glands

sends the hormone via blood to the rest of of the body,

- How does the hormone travel through the body without activating another cell

every target cell has a hormone specific receptor that it attaches to and nowhere else

- What is homeostasis

maintaining all body functions⇒temperature, PH of the blood, hormone levels, co2 levels

- What are the 4 main endocrine glands and their location

adrenal⇒one on top of each kidney, pancreas⇒central abdominal cavity, testicles⇒scrotum, ovaries⇒female pelvic region

- What hormone do the 4 main endocrine glands produce

Adrenal gland⇒ adrenaline⇒fight or flight response, Pancreas⇒ Insulin (breaks glucose into glycogen), glucagon (breaks glycogen into glucose), Ovary⇒ oestrogen⇒ building endometrium lining and secondary sexual characteristics, Testis⇒ testosterone⇒ sperm production and secondary sexual characteristics

- What is the excess glucose in the blood called

blood sugar

- How is the blood sugar level decreased

Whatever excess glucose that was in the blood was converted to glycogen in the liver which reduces blood sugar levels

- How is blood sugar level increased

The low blood sugar will make the pancreas produce glucagon which converts glycogen to glucose secreted into the blood raising the blood sugar levels

- What are the target organs of adrenal glands (examples)

heart⇒increasing the pulse rate⇒oxygen and glucose is delivered faster, lungs⇒increasing the breathing rate⇒oxygen supplied faster, liver⇒increase the glucose in the body⇒faster rate of respiration, more energy supply, pupil⇒dilates (increases) so more light can enter the eye⇒broader, clearer vision/ tunnel vision, blood vessels is redirected to the brain and muscles

- What are the structures of the endocrine system

made up of glands and hormones

- What are the structures of the nervous system

spine, brain, neurons

- What are the forms of information for nervous system

electrical and chemical impulses

- What are the forms of information for endocrine

hormones travelling through the blood

- What are the pathways for travel for the nervous system

across the neuron

- What are the pathways for travel for the endocrine system

blood vessel to the target organ

- Speed of information transfer for nervous system

fast

- Speed of information transfer for endocrine system

little longer

- Longevity of response for nervous system

short

- Longevity of response for endocrine system

longer

- Target area for endocrine system

target organ

- Target area for nervous system

dendron of the next nueron

- Responses of nervous system (eg)

contraction of muscles, dilation of pupils

- Responses of endocrine system (eg)

dilation of pupils, starting sperm production, increased heart rate

- What is homeostasis?

Controlled by a mechanism called negative feedback, responsible for increasing levels if something gets too low and decreasing levels if something gets too high.

- What are the functions of the skin

Protecting the body from damage, Stops pathogen from entering, prevents too much water loss⇒ controlled sweat so your body can sweat as much as it wants, Detects changes in temperature⇒ sensory nuerons, Detects pressure and pain⇒sensory nuerones, Loses heat by conduction (heat transfer via direct contact), convection, radiation and evaporation

- What is the hypothalamus

part of the brain that receives impulses from the thermoreceptors (skin and blood vessels) which detects the body temperature. Then the effectors will take effect⇒ sweat glands, blood vessels, muscle cells

- What is vaso constricition?

Prevents heat loss⇒ the blood vessels narrow and contrict the blood flow, this allows very little blood to flow and thus less heat through radiation, Generation of heat⇒ When you feel cold, every cell in the body will do more cellular respiration. The product of cellular respiration is heat and ATP. ATP causes movement of the muscles⇒ shivering.

- What is vaso dilation

Excess heat is lost⇒ the blood vessels get wider and dilate the blood flow, this allows a lot of blood to flow and thus more heat is removed through radiation.

- What is gravitropism?

a response in which parts of a plant grow towards or away from gravity⇒ Roots show positive response to gravitropism growing towards it, shoots show negative response to gravitropism growing away from it.

- What is phototropism?

response in which parts of a plant grows towards or away from light⇒ roots show negative response to phototropism growing away from it, shoots show positive response to phototropism growing towards it.

- What does auxin do?

Auxin as a hormone inhibits cell growth in a root and exhibits cell growth in the shoot. Auxin increases cell growth and causes cell elongation

- How does the auxin move in the shoot and in the root?

The auxin moves to the opposite direction of the sunlight for the shoot, the auxin moves closer to the sunlight in the shoot.