Central Nervous System

What are the four primary regions of the brain?

1. Cerebrum

2. Diencephalon

3. Brain stem

4. Cerebellum

What is white matter in the brain made of?

Myelinated neurons (axons)

What is gray matter in the brain made of?

Short, nonmyelinated neurons (cell bodies and dendrites)

What are the ventricles of the brain?

1. Lateral ventricle

2. Third ventricle

3. Cerebral aqueduct

4. Fourth ventricle

How many hemispheres does the cerebral cortex have, and how are they divided

Two hemispheres (left and right), each divided into 5 lobes

What are gyri In the cerebral cortex

Eelvated ridges on the brains surface

What are sluci in the cerebral cortex

Shallow grooves between the gyri

What are the four motor areas?

1. Primary motor cortex

2. Premotor cortex

3. Broca’s area

4. Frontal eye field

What are the four sensory area?

1. Primary sensory cortex

2. Visual cortex

3. Auditory cortex

4. Olfactory cortex

What are the special senses

• Vision

• Smell

• Taste

• Hearing

• Balance

What is the primary role of the basal nuclei (gang

What structures make up the basal nuclei?

• Caudate nucleus 

• Putamen

• Globus pallidus

What structures help the basal nuclei with movement control?

• Subthalamic nuclei

• Substantia nigra

What neurotr

What is the diecencephalon

The central core of the brain

What are the three paired structures of the diencephalon

1. Thalamus

2. Hypothalamus

3. Epithalamus

What is the thalamus structurally?

Bilateral, egg-shaped nuclei

What is the main function of the thalamus

It acts as a relay station, sorting and sending information to the right area of the cortex.

What is the main role of the hypothalamus

It is vital for body homeostasis

What are some key functions of the hypothalamus

• Controls the autonomic nervous system

• Regulates emotional responses

• Maintains body temperature

• Regulates food intake

• Controls thirst

• Regulates sleep-wake cycles

• Oversees endocrine functions

What structure makes the epithalamus visible?

The pineal gland (pineal body)

What hormone does the epithalamus secrete?

Melatonin

What is the function of melatonin?

Acts as a sleep-inducing signal, vital for regulating the sleep-wake cycle

What are the parts of the brain stem?

• Midbrain

• Pons

• Medulla

What are the superior cerebellar peduncles?

Fiber tracts that connect the cerebellum to the midbrain

What is the function of the superior colliculi?

Visual reflex centers (coordinates head and eye movements)

What is the function of the inferir colliculi?

Auditory reflex centers (startle reflex to loud sounds)

What is the role of the substantia nigra?

Produces dopamine; linked to movement regulation. Degeneration leads to Parkinson’s disease.

What is the role of the red nuclei?

Involved in motor coordination (especially of flexor muscles)

What does the word “pons” mean

“Bridge”

What is the pons mainly composed of?

Fiber tracts

What are the two main types of tracts in the pons?

• Longitudinal tracts

• Transverse/middle cerebellar tracts

Longitudinal tracts

Connect higher brain centers and spinal cord

Transverse/middle cerebellar tracts

Connect the pons to the cerebellum

What is the main role of the medulla oblongata?

It is cruical for autonomic nervous system functions

What are the important nuclei found in the medulla oblongata?

• Cardiac center

• Respiratory center

• Cochlear nuclei

What is the function of the cardiac center

Controls heart rate

What is the function of the respiratory center

Controls breathing rhythm

What is the function of the cochlear nuclei

Relay auditory information

What happens at the medulla’s site of decussation?

Most motor fibers cross over to the opposite side

What is the role of the inferior cerebellar peduncle

Connects the cerebellum to the medulla, carrying sensory information

What is the primary function of the cerebellum?

It provides the precise timing and appropriate patterns of muscle cotractions

Is cerebellar activity conscious or subconscious

Subconscious - It fine tunes movements without conscious effort

Is cerebellar control contralateral or ipsilateral?

Primarily ipsilateral (same side of the body)

What are the three meninges layers from superficial to deep?

1. Dura mater

2. Arachnoid mater

3. Pia mater

What are the functions of the meninges

1. Protect the CNS

2. Protect the blood vessels

3. House cerebrospinal fluid

4. Form partitions in the skull

What are the two layers of the dura mater?

• Periosteal layer (attached to skull)

• Meningeal layer (true covering of brain)

What’s between the layers of the dura mater?

The dural venous sinuses (drain venous blood from brain)

What are the three main dural foldings (partitions)

• Falx cerebri

• Falx cerebelli

• Tentorium cerebelli

What is the falx cerebri

Seperates the two cerebral hemispheres

What is the falx cerebelli

Seperates the two cerebellar hemispheres

What is the tentorium cereblli

Seperates cerebrum from cerebellum

What does the word arachnoid mean, and what is its structure?

“Spider”, fine, elastic connective tissue

Where is the arachnoid mater located

Between the dura mater and pia mater; it bridges over the brains sulci

What does the arachnoid mater contain beneath it?

The subarachnoid space, which contains cerebrospinal fluid and blood vessels

What does the word pia mean, and what is its structure

“Gentle,” a delicate connective tissue layer

What is unique about the pia mater’s location?

It is in direct contact with brain tissue, clinging tightly to every gyrus and sulcus

What are the main functions of cerebrospinal fluid?

• Reduces brain weight by 97% 

• Provides nutrients and removes waste

Where is CSF produced?

In the choroid plexuses of the ventricles

How much CSF is formed daily

About 500 mL

How often is CSF replaced?

About 150 mL is replaced every 8 hours

Where is CSF produced?

In the choroid plexus of each ventricle

After being produced, where does CSF flow next?

Through the ventricles and into the subarachnoid space via the median and lateral apertures

Once in the subarchnoid space, what does CSF do?

It circulates around the brain and spinal cord

How is CSF returned to the blood stream

It is absorbed into the dural venous sinuses via arachnoid granulations

What is hydrocephalus?

A condition called “water on the brain” where CSF builds up due to overproduction or poor drainage

What causes hydrocephalus?

CSF is produced faster than it drains, leading to pressure buildup

What is a common treatment for hydrocephalus?

Inserting a shunt to drain excess CSF and reduce pressure

What is the main function of the limbic system?

Regulates emotions, behavior, motivation, and visceral responses

What structures are part of the limbic system?

1. Amygdala

2. Cingulate gyrus

3. Hypothalamus

4. Hippocampus

Whats the function of amygdala

Processes fear and aggression

Whats the function of cingulate gyrus

Links emotion to behavior

What is the function of the hypothalamus

Regulates autonomic and endocrine responses

What is the function of the hippocampus

Memory formation and learning

Is language processing only left sided in the brain?

Both hemispheres contribute

What are the two critically important regions for language?

• Broca’s area

• Wernicke’s area

What is broca’s area function

Speech production (motor aspect)

What is wernicke’s area function

Language ccomprehension (understanding meaning)