cns lab

What are the two main divisions of the nervous system?

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

What structures make up the Central Nervous System (CNS)?

Brain and spinal cord

What structures make up the Peripheral Nervous System (PNS)?

All nerves outside the brain and spinal cord

What are the two divisions of the Peripheral Nervous System?

Sensory Division and Motor Division

What are the two divisions of the Motor Division?

Somatic Nervous System and Autonomic Nervous System

What are the two divisions of the Autonomic Nervous System?

Sympathetic Division and Parasympathetic Division

What are gyri?

Elevated ridges of the brain

What are sulci?

Shallow grooves that separate gyri

What are fissures?

Deep grooves that separate major regions of the brain

What is gray matter?

Neuronal cell bodies that make up the cortex and internal nuclei

What is white matter?

Myelinated fiber tracts beneath the cortex

What does the longitudinal fissure separate?

The right and left cerebral hemispheres

What does the central sulcus separate?

The frontal lobe from the parietal lobe

What does the lateral sulcus separate?

The temporal lobe from the frontal and parietal lobes

What is the function of the precentral gyrus?

Primary motor cortex; controls voluntary skeletal muscle movement

What is the function of the postcentral gyrus?

Primary somatosensory cortex; receives sensory information

Which brain lobe is responsible for voluntary motor function?

Frontal lobe

Which brain lobe is the primary sensory area?

Parietal lobe

Which brain lobe is responsible for hearing and smell?

Temporal lobe

Which brain lobe is responsible for vision?

Occipital lobe

What is the function of the olfactory bulbs?

Receive smell information

What is the function of the olfactory tract?

Carries smell information to the temporal lobe

What is the function of the optic nerve?

Carries visual information from the retina to the brain

What happens at the optic chiasma?

Optic nerve fibers cross

What is the function of the optic tracts?

Carry visual information to the occipital lobe

What is the infundibulum?

The stalk connecting the pituitary gland to the hypothalamus

Where are the mammillary bodies located?

Inferior to the optic chiasma

What are the cerebral peduncles?

Fiber tracts connecting the brain to the lower CNS

What is the function of the pons?

Contains motor and sensory fiber tracts connecting the brain to the lower CNS

What are the major functions of the medulla oblongata?

Controls heart rate, breathing, and blood pressure

What is the decussation of the pyramids?

The crossing of motor tracts in the medulla

What is the primary function of the cerebellum?

Balance, coordination, equilibrium, and fine motor control

What is the corpora quadrigemina?

Four prominences on the posterior midbrain

Which structures make up the corpora quadrigemina?

Two superior colliculi and two inferior colliculi

What are the superior colliculi responsible for?

Visual reflexes

What are the inferior colliculi responsible for?

Auditory reflexes

Where does the spinal cord begin?

At the medulla oblongata

How many pairs of cranial nerves are there?

12 pairs

Which cranial nerves do not arise from the brainstem?

Olfactory (CN I) and Optic (CN II)

What is the cortex?

The outer layer of the cerebrum

What is the cortex made of?

Gray matter

What lies deep to the cortex?

White matter

What are nuclei in the CNS?

Clusters of neuronal cell bodies

What are association tracts?

Fiber tracts connecting areas within the same hemisphere

What are commissural tracts?

Fiber tracts connecting the left and right hemispheres

What are projection tracts?

Fiber tracts connecting the cortex to lower brain centers and the brainstem

What is the corpus callosum?

The major commissural tract connecting the two cerebral hemispheres

What is the fornix?

A limbic system tract located inferior to the corpus callosum

What is the main function of the thalamus?

Major sensory integration and relay center

Approximately what percentage of the diencephalon is the thalamus?

80%

What connects the two lobes of the thalamus?

The interthalamic adhesion (intermediate mass)

What does the ventral posterior lateral (VPL) nucleus receive?

General somatic sensory information

What is the function of the lateral geniculate nucleus?

Visual relay center

What is the function of the medial geniculate nucleus?

Auditory relay center

What is the main function of the hypothalamus?

Controls temperature, hunger, thirst, sleep, sex drive, water balance, and autonomic functions

Where is the hypothalamus located?

Inferior to the thalamus and superior to the optic chiasm

Which hypothalamic nucleus produces ADH?

Supraoptic nucleus

Which hypothalamic nucleus produces oxytocin?

Paraventricular nucleus

What hormone does the pineal gland secrete?

Melatonin

What is melatonin's primary function?

Regulates the sleep-wake cycle

What are the primary functions of the medulla oblongata?

Respiration, heart rate, and blood pressure regulation

What is the function of the cuneate and gracile nuclei?

Process touch and proprioception

What do the visceral nuclei regulate?

Heart rate, blood pressure, respiration, coughing, and other autonomic functions

What is the function of the olivary nuclei?

Relay sensory information to the cerebellum

What is the main function of the pons?

Relay center between higher and lower brain regions

What do the middle cerebellar peduncles connect?

The pons to the cerebellum

What is the function of the pontine nuclei?

Relay information between the motor cortex and cerebellum

What structures are found in the midbrain?

Cerebral peduncles, corpora quadrigemina, and red nucleus

What is the function of the red nucleus?

Relays motor information in descending pathways

Approximately what percentage of brain mass is the cerebellum?

About 11%

Where is the cerebellum located?

Superior (dorsal) to the pons and inferior (ventral) to the occipital lobe

What is the vermis?

The structure connecting the two cerebellar hemispheres

What is the arbor vitae?

Tree-like pattern of white matter inside the cerebellum