The Nervous System

Question 1

components of the nervous system

Answer 1

central nervous system (CNS): brain and spinal cord → main control centers for all body activities.
peripheral nervous system (PNS): nerves derived from brain and spinal cord (12 pairs of cranial nerves and 31 pairs of spinal nerves) → linkage between CNS and body parts.

Question 2

how does the nervous system function?

Answer 2

gathers information
transmits information brain and spine
processes information
sends information to muscles, glands, and organs so they can respond
appropriately

Question 3

types of peripheral nervous system (PNS)

Answer 3

somatic nervous system (SNS): controls voluntary contraction of skeletal muscles.
- sensory nerves (afferent neurons) send signals to the brain from body receptors.
- motor nerves (efferent neurons) send commands to muscles from the brain and SC.

autonomic nervous system (ANS): controls involuntary functions like heartbeat and digestion.
- sympathetic nerves: stimulate activities of effector organs. “fight or flight”
- parasympathetic nerves: inhibit activities of effector organs. calm the body

Question 4

types of cells in nerve tissue

Answer 4

neuron: sends nerve signals and forms the nervous system’s structure.
neuroglia: cells that help neurons but don’t send signals.
- astrocytes
- microglial Cells
- ependymal Cells
- oligodendrocytes

Question 5

what do neurons consist of?

Answer 5

• dendrite: Receives signals and sends them to the cell body.
• cell body: Contains the nucleus.
• axon fiber: Sends signals away from the cell body.
• schwann cells: Make myelin (fat layer) in the PNS.
• myelin sheath: Insulates the axon for faster signal transmission.
• node of ranvier: Gaps in the myelin sheath that help signals move efficiently.

Question 6

types of neurons

Answer 6

sensory: detect
interneurons: process
motor: produceresponse

Question 7

process of nerve impulses

Answer 7

stimulus
excitability
all-of-nothing rule

Question 8

components of the brain

Answer 8

Cerebrum/Telencephalon (right and left hemispheres)
- Frontal lobe: personality characteristics, decision-making and voluntary
movement.
- Parietal lobe: sensory perception and integration including the management of
taste, hearing (e.g., languages), sight, touch, and smell.
- Temporal lobe: processing of auditory information and memory.
- Occipital lobe: processing visual information including color and motion.

● Diencephalon
- Subthalamus: regulates skeletal muscle movements (somatic motor function).
- Thalamus: filters and relays information to brain regions.
- Hypothalamus: responsible for homeostasis.
- Epithalamus: secretes hormones

● Brain Stem
- Midbrain (Misencephalon): motor control, particularly regulating eye
movements, vision and hearing.
- Pons: located between midbrain and medulla oblongata, controls certain
respiratory functions.
- Medulla oblongata: centers that regulate heart and lung functions, swallowing,
coughing, vomiting, sneezing.

● Cerebellum
- Coordinates musculoskeletal movement to maintain posture, balance, and
muscle tone.

Question 9

what does the spinal cord consist of?

Answer 9

24 articulating vertebrae + 7 vertebrae
blood vessels and nerves
posterior roots (transmit sensory info)
anterior roots (transmit motor info)
grey matter
white matter

Question 10

spinal cord structure

Answer 10

Dura mater: outer tough fibrous membrane
Arachnoid mater: middle weblike membrane containing cerebrospinal fluid.
Pia mater: innermost layer containing blood vessels.