Homeostasis- Introduction to the Nervous and Endocrine Systems

Question 1

What is the nervous system composed of?

Answer 1

The nervous system is composed of the central nervous system and the peripheral nervous system.

Question 2

what does the central nervous system contain?

Answer 2

the brain and spinal chord

Question 3

what does the peripheral nervous system contain?

Answer 3

sensory neurons, motor neurons, and interneurons

Question 4

what is the PNS pathway?

Answer 4

Sensory neuron transmits to CNS, interneuron transmits in CNS to motor, motor transmits to effector.

Question 5

What is the myelin sheath?

Answer 5

An insulating layer that surrounds axons and allows nerve impulses to travel faster.

Question 6

describe the function and structure of sensory neurons

Answer 6

Sensory neurons function to transmit impulses from receptors to the CNS. Sensory neurons have:
1. Centralised cell body (sticks out in center).
2. Two short axons connected from both sides.
3. Myelin sheath.
4. Long dendrites.

Question 7

describe the structure and function of interneurons

Answer 7

Interneurons function to transmit information from sensory neuron to motor neuron. Interneurons have:
1. Cell body (center or middle)
2. Short dendrites.
3. Short axon.
4. No myelin sheath.

Question 8

describe the structure and function of motor neurons

Answer 8

Motor neurons function to transmit information from CNS to effectors. Motor neurons have:
1. Cell body near dendrites.
2. Myelin sheath.
3. Long axon.
4. Short dendrites.

Question 9

Describe the structure of a nerve pathway from receptor to effector

Answer 9

Dendrites receive information. passed along axon. End of axon has a synapse between the next neurons.
Sensory Receptor → Sensory Neuron → CNS (Interneurons) → Motor Neuron → Effector.

Question 10

Describe the role of synapses and neurotransmitters.

Answer 10

1. Electrical signal reaches axon terminal.
2. Vesicle with neurotransmitter fuses with cell membrane.
3. Neurotransmitter released into synaptic cleft (exocytosis).
4. Neurotransmitter binds (complementarily) to receptor on next neuron.
5. Signal passed along.

Question 11

Describe the role and pathway of reflex responses

Answer 11

Reflex response is:
1. Involuntary.
2. Not under the control of the brain.
3. Allows an organism to respond rapidly to a stimulus.
Sensory Receptor → Sensory neuron → Interneuron → Motor neuron → Effector.

Question 12

What is the function of the endocrine system?

Answer 12

The endocrine system releases hormones that are amino acid derivatives, peptides, proteins, or steroids.

Question 13

What is the function of hormones and how do they travel to target sites?

Answer 13

Hormones travel to target sites via the blood.
Hormones can alter the metabolism of target cells, tissues, or organs.

Question 14

What is the function of the endocrine system?

Answer 14

The substance released by the Endocrine system is hormones.
Endocrine hormones reach target cells in the bloodstream.