Apologia Advanced Biology Module 8

Gray Matter

Collections of neuron cell bodies and their associated neuroglia

White matter

Bundles of parallel axons and their coverings

Decussation

The anatomical crossing over of neurons from left to right

______- as the fibers pass up or down the brainstem and spinal cord they cross over from the left to the right side and vise versa.

Vital functions

Functions of the body necessary for life

Commissures

Connections of neuron axons that allow the two hemispheres of the brain to communicate with one another

Hypoxia

Not enough oxygen in the blood, this can be dangerous for the brain because it kills neurons

Hypoglycemia

Abnormally low blood sugar (glucose) level can cause the brain to not function well because neurons can only use glucose for energy production

Brain stem structures

Midbrain, Pons, Medulla Oblongata

Diencephalon structures

A portion of the embryonic forebrain that includes the thalamus, hypothalamus,

Medulla oblongata

- site of decussation

- contains nuclei which control many vital functions

Pons

relays messages from the cerebrum to the cerebellum ("bridge")

Midbrain

The portion of the brain responsible for visual and auditory startle reflexes.

Hypothalamus

controls the pituitary gland

Thalamus

Performs a crude interpretation of the sensory information and then relays that information to the cerebrum

Gyri

Elevated portions of the cerebral cortex ("hills")

Sulci

Shallow grooves or furrows in the cerebral hemispheres ("valleys")

Cerebellum

Major structure of the brain which is considered the control center for subconscious motor functions

Cerebrum

Area of the brain responsible for all voluntary activities of the body, the largest part of the brain that contains the cerebral cortex, limbic system, and basal ganglia.

Corpus callosum

Nerves that enable communication between the right and left cerebral hemispheres.

Ventricles of the brain

Canals in the interior of the brain that are filled with CSF or cerebral spinal fluid which cushions and protects the brain.

Primary somatic sensory area

receives and localizes sensations from the entire body

Somatic sensory association area

interprets the sensory information and puts it into context with past experiences

Visual association area

recognizes the meaning of visual information by putting it into context with past experiences

Visual cortex

interprets basic visual information like color, shape and size

Wernicke's area

comprehension of speech

Auditory association area

interprets meaning of sound by placing it into context with past experiences

Primary auditory area

interprets basics of sound such as pitch and volume

Broca's area

initiates muscle movement for speech

Taste area

interprets taste

Prefrontal area

Motivation and insight / regulates mood and emotion / inhibits impulsive behavior

Premotor area

Works out sequence of neural signals needed for learned complex motion

Primary motor cortex

initiates basic skeletal muscle movements

Lateral ventricles

produces most of the cerebrospinal fluid

Meninges

the three membranes (the dura mater, arachnoid, and pia mater) that line the skull and vertebral canal and enclose the brain and spinal cord.

Arachnoid granulation

Small projections of the arachnoid membrane through the dura mater into the superior sagittal sinus; CSF flows through them to be reabsorbed into the blood supply.

The three neurons in a reflex arc

- afferent neuron

- association neuron

- efferent neuron

efferent neuron

nerve cell that send messages from brain and spinal cord to other parts of body; also called motor neurons

afferent neuron

nerve cell that sends messages to brain or spinal cord from other parts of the body; also called sensory neurons

association neuron

A neuron that has as its primary function the job of connecting other neurons is called a(n) ________.

reflex arch

allows for a pre-programmed muscle response without a need for a neural message traveling to and from the brain. The neuronal circuit that coordinates a spinal cord reflex response

Converging circuit

allows the effector to be controlled by both the reflex arc and the brain, this allows the signals from the brain and reflex to act as one since the two neurons both synapse with the same effector neuron

Diverging circuit

in the spinal cord, the signal divides which it allows the afferent signal to both initiate the reflex to the muscle and initiate a signal to the brain

Cerebrospinal fluid

Cushions, protects and provides nutrients to the brain