Understanding the Human Brain and Nervous System

Thalamus

Regulates communication between several parts of the brain and the endocrine system.

Corpus Callosum

Structure made of nerves that bridges two hemispheres.

Hippocampus

Part of the limbic system, responsible for long-term memory.

Cerebellum

Responsible for motion, balance, and new learning. Exterior grey matter, interior grey matter.

Brainstem

Several regions including medulla oblongata (elongates into the spinal column). Location of several centers of involuntary nervous control.

Hypothalamus

Master gland of the endocrine system, controlling most of its activity.

Two Cerebral Hemispheres

Surfaces known as cerebral cortex and comprised of grey matter. Folder structure made of rounded gyri and recessed sulci divide the lobes.

Spinal Cord

Brings messages back and forth between the brain and the body. Information goes to the brain and motor responses coming from the brain. Capable of rapid, automatic responses known as reflex arcs.

Nerve Impulse

Electrical signal that travels rapidly through a neuron from the dendrites to the axon.

Synaptic Transmission

The signal passes across the synapse to the dendrite in the next cell through chemical messengers called neurotransmitters.

3 Types of Neurons

• Interneurons: Central nervous system. They connect sensory and motor neurons.
• Sensory Neurons: Carry messages from the receptors to the central nervous system.
• Motor Neurons: Carry messages from the central nervous system to the receptors.

Reflex Arcs

Synaptic transmission occurs between sensory neurons and motor neurons. 1- Receive sensory input, nerve impulse moves towards the brain, relaying the message. 2- At the same time, a 'short circuit' within the spinal cord, automatic response helps prevent an injury.

Anatomic Division

1- Central Nervous System: Neurons entirely confined within the brain and spinal cord. 2- Peripheral Nervous System: All neurons at least partially outside the organs of the central nervous system.