Nervous System and Reflex Action Lecture Notes

This set of vocabulary flashcards covers the anatomy of a neuron, the mechanism of nerve impulse transmission, reflex actions and arcs, and the structure and function of the major regions of the human brain.

Axon

The longest path of the neuron that conducts the impulse away from the cell body and arises from the cyton.

Myelin sheet

A protective sheet that covers the axon and consists of constrictions called Node of sanvier.

Node of sanvier

The points of constriction found along the protective Myelin sheet of an axon.

Saynatic-leeminals

The branched nerve endings of the axon.

Synapse

The junction between two adjacent neurons, specifically between the nerve ending of one and the dendrites of another.

Neuromuscular Junctn

The point where the muscle fibre comes in contact with a motor neuron carrying nerve impulses from the central nervous system.

Nerve impulses

Information in the form of chemical electrical signals that are carried by dendrites towards the cell body.

Transmission of Nerve Impulse

A process where information acquired at the dendritic tip sets off a chemical reaction creating an electrical impulse that travels to the axon end, releasing chemicals that start a similar impulse in the next neuron.

Reflex Action

An unconscious, automatic, and involuntary response of effectors (muscles and glands) to a stimulus, monitored through the spinal cord.

Sensory neuron

The neuron that carries the message of sensory impulse from the receptor organs to the spinal cord.

Relay neuron

A neuron in the spinal cord that modulates and transmits the impulse to the motor neuron.

Motor neuron

A neuron that conducts the impulse away from the spinal cord back to the effectors to respond to the stimulus.

Reflex Arc

The nerve pathway in a reflex action that leads from the receptor organ to the spinal cord and then to the effector organ.

Central Nervous System (CNS)

The part of the human nervous system consisting of the brain and the spinal cord.

Cranium

The part of the skeleton that protects the brain.

Vertebral column

The part of the skeleton that protects the spinal cord.

Total spinal nerves

There are $31$ pairs of spinal nerves in the peripheral nervous system.

Fore brain

The largest and main thinking part of the brain, which includes the cerebrum and olfactory lobes.

Occipital lobe

A region in the cerebrum responsible for sight and visual reception.

Temporal lobe

A region in the cerebrum responsible for hearing and auditory reception.

Frontal lobe

A region in the cerebrum for speech, facial muscular activities, and higher mental activities.

Parietal lobe

A region in the cerebrum responsible for taste, smell, touch, and conscious association.

Olfactory lobe

Organs of smell containing olfactory receptors that lie below the cerebrum.

Mid Brain

Connects the fore brain to the hind brain and controls reflex movements of the head, neck, and trunk in response to visual and auditory stimuli.

Hypothalamus

The region lying between the pituitary glands and the inferior side of the cerebrum that determines hunger and controls thirst, sleep, fatigue, sweating, and body temperature.

Pituitary gland

Also called the master gland, it controls the activity of other endocrine glands in the body.

Cerebellum

A region of the hind brain that controls coordination of body movements, posture, orientation, and equilibrium.

Pons

A part of the hind brain lying just above the medulla that takes part in regulating respiration.

Medulla oblongata

The floor of the hind brain that controls involuntary actions like heart beat, blood pressure, peristaltic movements, and regulating centers for swallowing, coughing, cheezing, and vomiting.