NEUROANA - Unit 1

1. Central Nervous System - brain and spinal cord

2. Peripheral Nervous System - nerves and nerve endings (anything outside the CNS)

the two divisions of the nervous system:

1. Telencephalon → Cerebrum (w/ cerebral cortex and basal nuclei)

2. Diencephalon → Diencephalon (thalamus, hypothalamus, epithalamus)

3. Mesencephalon → Midbrain (part of the brainstem)

4. Metencephalon → Pons (part of the brainstem) and Cerebellum

5. Myelencephalon → Medulla (part of the brainstem)

the five divisions of the brain:

Forebrain

the __ develops into the Telencephalon and the Diencephalon

Midbrain

the __ develops into the Mesencephalon

Hindbrain

the __ develops into the Metencephalon and the Myelencephalon

Cerebrum

MATCHING TYPE: Telencephalon → __

Diencephalon (divisions of the Thalamus)

MATCHING TYPE: Diencephalon → __

Midbrain

MATCHING TYPE: Mesencephalon → __

Pons and Cerebellum

MATCHING TYPE: Metencephalon → __ & __

Medulla

MATCHING TYPE: Myelencephalon → __

Telencephalon

this is the largest portion of the brain

1. Cerebral Cortex (Cerebrum)

2. Limbic System

3. Basal Ganglia

the telencephalon consists of the:

Cerebral Cortex (CEREBRUM)

the largest portion of the telencephalon—it is in charge of higher-order thinking

1. thoughts and consciousness

2. perception

3. communication

4. understanding

5. sensory processing

6. executive function

the cerebrum is associated with:

1. Frontal - contains the Motor Cortex (any higher executive functions)

2. Parietal - contains the Sensory Cortex (general senses)

3. Occipital - contains the Visual Cortex (recognition of features)

4. Temporal - contains the Auditory Cortex (memory and understanding of the environment)

5. Insular (Insula) - no known function

the five major cortices of the cerebrum:

Hippocampus

this is located behind the temporal lobe and is the region for memory

1. Longitudinal Fissure

2. Central Sulcus

3. Lateral Sulcus

4. Parieto-Occipitofrontal Sulcus

the different landmarks of the brain:

Longitudinal Fissure

this separates the left and right hemispheres

Central Sulcus

this divides the frontal lobe from the parietal lobe

Lateral Sulcus (Sylvian Fissure)

this separates the temporal lobe from the frontal and parietal lobes

Parieto-Occipital Sulcus

divides the parietal lobe from the occipital lobe

Homunculus (“little man”)

the more lateral and superior the innervation to the attachment is, the more processing it requires

Interneurons

these allow the brain to communicate—it passes through the white matter tracts in the cortical layer

White Matter

these are heavily myelinated axons, which connect the brain regions to help with learning, attention, and motor control—it peaks in middle age

Myelinated Sheaths

in the white matter, these make the movements of electrical signals faster by attracting and expelling

Gray Matter

these have no myelin sheath and are mostly neuronal cell bodies; they process and transmit information, control movement, memory, and emotion—they retain information for processing and fully develop in your 20s

TRUE

TRUE or FALSE: you talk in white, while you process in gray

TRUE

TRUE or FALSE: in the brain, white is in, while gray is out, but in the spine, white is out, while gray is in

Reflex Arc

this connects to muscles from the spine to send information directly for immediate reactions (acting without thinking)

1. Association Fibers

2. Commissural Fibers

3. Projection Fibers

the three types of white matter:

Association Fibers

these connect regions within the same hemisphere

Commissural Fibers

these connect two hemispheres together

Projection Fibers

these connect the cortex with the subcortical structures, brainstem, or spinal cord

Corpus Callosum

this is a bundle of the largest project fibers that connect the right and the left hemispheres together

Split-Brain Syndrome

when the corpus callosum is bisected or lesioned, the right brain is unaware of what the left brain is processing

Basal Ganglia

this is the motor relay nuclei responsible for producing smooth and precise motor quality—this works in conjunction with the cerebellum to regulate complex motor output

Cerebellum

this acts like a gateway to excite (do) or inhibit (not do) an action

1. Caudate

2. Putamen

3. Globus Pallidus

the three nuclei:

Striatum

this is composed of the putamen and the caudate, which receives input from the cortex

Lenticular Nuclei

this is composed of the globus pallidus and the putamen, which receives and processes information from the cerebellum and relays it back to the cortex

Substantia Nigra

this produces dopamine

TRUE

TRUE or FALSE: dopamine can be both an inhibitory (D1) and an excitatory (D2) neurotransmitter

Basal Nuclei

the GABA neurotransmitter is produced from the __

TRUE

TRUE or FALSE: GABA is solely an inhibitory neurotransmitter

Cortex → Striatum → GPi (Globus pallidus interna) → Thalamus → Cortex

the direct (excitatory) pathway:

GPi (Globus pallidus interna)

this relays D1 to inhibit GABA production in the excitatory pathway

Cortex → Striatum → GPe (Globus pallidus externa) → Subthalamic Nuclei → GPi → Thalamus → Cortex

the indirect (inhibitory) pathway:

GPe (Globus pallidus externa)

this relays D2 to excite GABA production in the inhibitory pathway

Diencephalon

this division of the brain is formed by the thalamus

Thalamus

a large, egg-shaped mass of gray matter that forms the diencephalon

1. Limbic information

2. Sensory information

3. Motor information

the thalamus serves as the relay center of:

1. Thalamus - relay center

2. Epithalamus - sleep-wake cycle (Circadian rhythm)

3. Hypothalamus - hunger and thirst, temperature, sleep, and hormones

4. Metathalamus - hearing and vision

5. Pituitary Gland - master hormone gland (growth, metabolism, and reproduction)

the six structures of the diencephalon:

Brainstem

this connects the cerebrum and cerebellum to the spinal cord, acting as the body's control center for vital involuntary life functions

1. Midbrain

2. Pons

3. Medulla Oblongata

the brainstem has three parts called:

1. Conduit for ascending and descending tracts

2. Reflex center of the body (respiration, cardiovascular system, and consciousness)

3. Contains important nuclei of CN III to CN XII

the three broad functions of the brainstem are:

Peduncles (“little foot”)

this is the connection from the brainstem to the cerebellum

1. Cerebral peduncles (midbrain)

2. Cerebellar peduncles (cerebellum to brainstem)

3. Pontine peduncles (pons)

the three different peduncles are:

1. Superior - from the cerebellum to the cortex

2. Middle - motor plan to the cerebellum from the brainstem

3. Inferior - sensory information to the cerebellum from the skeletal muscles

the three types of cerebellar peduncles:

Medulla Oblongata

connects the spinal cord with the pons and is the site of CN IX-XII—it appears as the superior dilated portion of the spinal cord

FALSE

TRUE or FALSE: anything that goes out of the border of the foramen magnum is the medulla oblongata, and anything above the foramen magnum is the spinal cord

Pyramids

these are two long parallel bridges that contain the axons of the corticospinal tracts

Inferior Olives

these are located lateral of the pyramids and are used for motor control and learning

TRUE

TRUE or FALSE: 90% of decussation (cross-over) occurs in the medulla oblongata

Pons

this is the site of the communication between the medulla oblongata and the cerebrum

1. influences sleep

2. manages pain signals

3. connects to the cerebellum

the key functions of the pons are:

Midbrain

this is located inferiorly (below) the cerebral cortex and superiorly (above) the part of the brainstem—it processes visual and audio signals

CN I and II - directly from the brain

CN III and IV - from the midbrain

CN V, VI, and VII - from the pons

CN VIII - from the pons and the MO

CN IX, X, XI, and X11 - from the MO

origin of the CNs from the different parts of the brainstem: