Coordination

Question 1

What are 2 body systems responsible for coordination and response

Answer 1

1. Nervous System

2. Endocrine System

Question 2

What is a stimulus an a response

Answer 2

A stimulus is a change in the environment and the response is a reaction to that change.

Question 3

What is the sequence of events that occur in coordination and response

Answer 3

stimulus —> Receptor —> coordination —> effector —> Response

Question 4

Difference between the nervous and endocrine system

Answer 4

The nervous system is a collection of nerves, the brain, and the spinal cord that allows the body to coordinate and respond to internal or external stimuli in the environment. The endocrine system allows the body to respond to internal or external changes in the environment by a collection of glands around the body that secrete chemicals.

The nervous system transfers nerve impulses faster than the endocrine system that transfers hormones.

The nervous system also causes a shorter lasting effect, while the endocrine system causes a longer-lasting effect.

The nervous system carries the messages through nerve cells and nerves, but the endocrine system carries messages through the bloodstream.

The nervous System targets specific muscles or tissues. The Endocrine system targets a more widespread area

Question 5

How do receptors work

Answer 5

Any receptor converts its own energy into electrical energy for nerve impulses.

Ex: The eye converts light energy into nerve impulses.
The ear converts sound energy into nerve impulses.

Question 6

What is Homeostasis

Answer 6

This is the maintenance of a constant internal environment. Ex: maintaining constant blood glucose levels, maintain body temperature.

Question 7

What are the 3 types of Neurons

Answer 7

1. Sensory Neurons
2. Motor Neurons
3. Relay Neurons

Question 8

What are the roles of the 3 types of neurons

Answer 8

1. Sensory Neurons carry nerve impulses from the receptors to the CNS
2. The relay Neurons carry the nerve impulses around the CNS, between motor and sensory neurons.
3. The motor neurons carry nerve impulses from the CNS and to the effectors.

Question 9

How does the transfer of nerve impulses take place during a reflex?

Answer 9

When the receptor gets stimulated by any kind of stimuli in the environment, it sends an electrical signal through a sensory neurone into the CNS.

Then the signal is carried on inside the CNS and goes to a motor neurone through a relay neurone.

The motor neurone then sends the signal to an effector, which carries out the response.

Question 10

What are some adaptations of Neurons that allows them to transfer electrical signals more efficiently around the body

Answer 10

1. They have a long axon in which signals travel through. This means that the signal spends less time travelling from cell to cell.
2. They also have an insulating mylein sheath, which increases the speed of the nerve impulses.

3, The dendrons branch out further into dendrites, which give the neuron a larger surface area

Question 11

What happens in the synapse

Answer 11

When the electrical impulse is traveling through the axon of the first neuron, it stimulates the production of a chemical called, “neurotransmitters” to form at the nerve ending.

These chemicals then diffuse through the membrane and enter the receptor cells of the second neurone.

This stimulates the second neuron to transmit an electrical impulse down its axon.

The neurotransmitter then gets destroyed by enzymes to prevent any further stimulation of impulses

Question 12

Advantages of reflex actions

Answer 12

1. They are fast
2. They are automatic
3. They are protective

Question 13

Can light escape the eye once it has entered it

Answer 13

No

Question 14

What is the function of the cornea

Answer 14

This is where the light entering the eye gets refracted.

Question 15

What is the function of the pupil?

Answer 15

This lets light enter the eye.

Question 16

What is the function of the lens

Answer 16

This also refracts light but changes size to focus on distant or close objects.

Question 17

What is the function of the Retina

Answer 17

This consists of the Rods and Cones that react to light and convert the light energy into electrical impulses that are sent through the optic nerve and to the brain.

Question 18

What is the function of the ciliary muscles

Answer 18

These contract or relax to change the shape of the lens.

Question 19

What is the function of the suspensory ligaments

Answer 19

These connect the ciliary muscles to the lens. Q

Question 20

What is the function of the sclera

Answer 20

This is the tough outer layer of the eye that is used to protect the eye from being damaged.

Question 21

How does an Image get formed in the eye

Answer 21

As light enters into the eye, the light first gets refracted at the air/cornea boundary. Then the light again gets refracted at the lens. This refraction causes the image formed on the retina of the eye to become inverted. This inverted image is then interpreted by brain in the right way up

Question 22

How does the iris control the amount of light entering into the eye.

Answer 22

When in a dark room, the circular muscles relax and the radial muscles contract to dilate the pupil. This widens the pupil and lets more light enter.

When in a brightly lit room, the circular muscles contract, and the radial muscles relax. This constricts the size of the pupil, which reduces the amount of light entering the pupil

Question 23

What is the purpose of the iris reflex

Answer 23

To make sure that the right amount of light is entering the eye.

Too high of light intensity can damage the rods and cones in the retina

Too low of light intensity may not form a proper image on the retina.

Question 24

Why doesn’t the blindspot of an eye affect vision?

Answer 24

Because the brain takes the image from both eyes and cancels out each blind spot.

Question 25

What is accommodation

Answer 25

These are the changes that happen inside the eye that allow us to focus on distant objects.

Question 26

How does accommodation work

Answer 26

When the ciliary muscles contract and the suspensory ligaments slacken, the lens becomes more rounded.

When the ciliary muscles relax and the suspensory ligaments tighten, the lens becomes thinner.

Question 27

How does a nerve impulse travel inside the CNS

Answer 27

The receptor sends a nerve impulse through the sensory neuron, which enters the Spinal cord through a dorsal root. Then the impulse travels to a short relay neuron through a synapse. This impulse then passes out of the spinal cord through the ventral root and goes to a motor neuron through a synapse. The motor neuron then carries the nerve impulse to the effector/muscle.

Question 28

What are the adaptations of a motor neuron to carry out its function

Answer 28

1. It has an Axon to carry the nerve impulse.
2. It contains a Myelin Sheath that acts as an insulator, which protects it from short circuits from other nerve cell axons.
3. It has dendrites to increase the surface area of contact with the other nerve cell.
4. They are attached to muscle fibers through synapses to transfer nerve impulses.