Diencephalon, Brainstem, Cerebellum, Spinal Cord, & MeningesBrittany Vetter, Andrea Jarrett, & Jessie Qualls

Diencephalon

A subcortical nuclear mass forming the central core of the brain

Consists of two major structures:

- Thalamus

-Hypothalamus.

The third ventricle bisects the bilateral diencephalic nuclei in the midline.

Caudally, the diencephalon is continuous with the midbrain of the brainstem.

Thalamus

Oval nuclear mass, above the hypothalamus in the floor of the lateral ventricles.

Bilateral thalamic nuclei are interconnected by the mass intermedia tissue.

Has a number of specific and non-specific nuclei, and projects to different parts of the brain.

Thalamus

Major functions:

- Relay sensorimotor information to the cortex

-Role in speech, language and auditory functioning (contains the Medial Geniculate Body).

Lesions in the Thalamus result in:

-Impaired contralateral somatic sensation

-Burning sensation

- Low tolerance to pain

Hypothalamus

Consists of nuclei that regulate various autonomic and endocrine functions.

These autonomic and endocrine functions include:

- Temperature

-Water and food intake

-Hormone production

-Emotions

-Reproduction.

Diencephalon

Diencephalon QUIZ 1. The Diencephalon consists of the Thalamus and the

________________.

A. Hippocampus

B. Basal Ganglia

C. Hypothalamus

D. Cerebellum

2. The _____________ is responsible for various autonomic and endocrine functions such as; temperature, water and food intake, hormone production, emotions, and reproductions. A. Hypothalamus

B. PonsC. MedullaD. Autonomic Nervous System

Diencephalon QUIZ 3. The ____________ is responsible for relaying sensory motor

information to the cortex, and also plays an important role in speech, language and auditory processing.

A. Amygdala

B. Hippocampus

C. Tectum

D. Thalamus

4. Lesions in the ___________ usually result in impaired contralateral somatic sensation, burning sensation, and low tolerance to pain.

A. Cerebrum

B. Thalamus

C. Brainstem

D. Cerebellum

Diencephalon QUIZ

5. Bilateral thalamic nuclei are interconnected by the ________________ tissue.

A. Commissure

B. Peduncle

C. Fasciculus

D. Mass Intermedia

Diencephalon QUIZ ANSWERS!

Question 1 C. Hypothalamus

Question 2 A. Hypothalamus

Question 3 D. Thalamus

Question 4 B. Thalamus

Question 5 D. Mass Intermedia

Brainstem

Short extension of the CNS that connects the diencephalon to the spinal chord.

The Brainstem consists of the following 3 structures:

- Midbrain

-Pons

-Medulla

The medulla is continuous with the spinal chord at the level of the foramen magnum.

Ventral View of the Brainstem

Brainstem

The Brainstem is responsible for:

-Monitoring all conscious brain output.

-Possessing automatic control systems that are more

genetically programmed.

Contains 10 of the 12 CN nuclei

-2 from the midbrain (CN 3 & 4)

-4 from the pons (CN 5-8)

-4 from the medulla (CN 9-12).

Brainstem

Internally, the brainstem primarily consists of :

-CN nuclei

- Longitudinal fiber tracts

-The reticular formation

The reticular formation is composed of neuronal circuits that are connected to other nuclei of the brainstem and cortex.

Integrates sensorimotor function with internally generated thoughts, emotions, and cognition.

Brainstem

Also, governs the Reticular Activating System (RAS) that controls consciousness and arousal.

Important to communication, the RAS regulates respiration and swallowing by integrating information of CNs V, VII, IX, X, and XII.

Lateral View of the Brainstem

Brainstem QUIZ 1. _____________ can be defined as short extension of the CNS that

connects the diencephalon to the spinal chord.A. Cerebral Cortex

B. Brainstem

C. Diencephalon

D. Somatic Nervous System

2. The brainstem is composed of the following three structures; midbrain, pons, and ______________.

A. Forebrain

B. Medulla

C. Hindbrain

D. Thalamus

Brainstem QUIZ

3. The _______________ is composed of neuronal circuits that are connected to other nuclei of the brainstem and cortex.

A. Reticular Formation

B. Prosencephalon

C. Rhombencephalon

D. Anterior Commissures

4. The _____________ contains 10 of the 12 cranial nerves. A. Cerebral Cortex

B. Basal Ganglia

C. Brainstem

D. Hypothalamus

Brainstem QUIZ

5. The medulla is continuous with the spinal chord at the level of the ________________.

A. Corpus Callosum

B. Posterior Commissures

C. Arcuate Fasciculus

D. Foramen Magnum

Brainstem QUIZ ANSWERS

Question 1 B. Brainstem

Question 2 B. Medulla

Question 3 A. Reticular Formation

Question 4 C. Brainstem

Question 5 D. Foramen Magnum

Cerebellum

Function: Does not initiate movement, but coordinates motor activity.

Location Part of the

metencephalon Dorsal to pons and

medulla Separated from the

cerebral hemispheres by the meningeal durameter

Separated from the brainstem by the IV ventricle

Cerebellum

Structure: Outer gray matter, inner

white matter

Two Parts: Vermis

Midline Hemisphere

Bilateral Three lobes:

Anterior, posterior, & flocculonodular

Cerebellum

Cytoarchitecture Three layers:

Molecular, Purkinje, and granular Contains a large # of granular; therefore it accounts for

nearly 50% of all the neurons in the body Cerebral dysfunction

Intention Tremors: tremors during movement Dysmetria: over or underestimation of force Dysdiadokinesia- inabiltiy to perform rapid alternating

movements (/p/, /t/, /k/) Cerebellar or ataxic dysarthria: speech that is slower

than normal & at an unsteady rate

Cerebellum

Cerebellum QUIZ

The cerebellum is part of the _______.a. Metencephalonb. Diencephalonc. Mesencephalond. Telencephalon

What are the two parts of the cerebellum?a. Tectum and tegmentumb. Vermis & hemispherec. Tegmentum and basilar ponsd. Tegmentum and RAS

Cerebellum QUIZ

Because of the large number of _______ cells, the cerebellum contains almost 50% of neurons in the brain.a. Granularb. Molecularc. purkinje

What cerebellar dysfunction is characterized by speech that is slower than normal and at an unsteady rate?a. cerebellar or ataxic dysarthriab. Dysmetriac. Dysdiadokinesia

What cerebellar peduncle is responsible for output from the cerebellum?a. Middleb. Inferiorc. superior

Cerebellum QUIZ ANSWERS

Question 1 B. METENCEPHALON

Question 2 B. VERMIS AND HEMISPHERE

Question 3 A. GRANULAR

Question 4 C. CEREBELLAR OR ATAXIC DYSARTHRIA

Question 5 D. SUPERIOR

Spinal Cord

Internally: Grey matter (butterfly

shaped)

Externally: White matter

Spinal Cord

2 Dorsal and 2 Ventral Horns Dorsal horns receive

sensory information through the dorsal root fibers entering posterior laterally.

Ventral horns has motor nuclei that project their axons, anterior laterally, to control skeletal and visceral muscles and glands.

Spinal Cord

Important for speech b/c: Innervates the muscles for respiration and speech

Inspiration: Diaphragm external intercostals Expiration: internal intercostals and abdominal muscles

C3-C5-: diaphragm

T1-T12: internal & external intercostals

T6-T12: abdominal muscles

Spinal Cord QUIZ

1.The spinal cord has _____ matter on the inside.a. White

b. Grey

c. black

2. What shape is the grey matter in the spinal cord?a. Butterfly

b. Circle

c. Square

Spinal Cord QUIZ

3. Dorsal horns receive______ information through the dorsal root fibers entering posterior laterally.

a. motor

b. sensorimotor

c. sensory

4. Ventral horns have ________that project their axons, anterior laterally, to control skeletal and visceral muscles and glands.

a. Motor nuclei

b. Sensory nuclei

c. Sensoimotor nuclei

Spinal Cord QUIZ

5. The spinal cord is relevant to speech in that the diaphragm external intercostals help with _______ and the internal intercostals and abdominal muscles help in ________.

a. expiration, inspiration

b. inspiration, expiration

c. speech, inspiration

Spinal Cord QUIZ ANSWERS

Question 1 B. Grey

Question 2 B. Butterfly

Question 3 C. Sensory

Question 4 A. Motor Nuclei

Question 5 B. Inspiration, Expiration

Meninges

3 concentric, fibrous tissue layers covering the CNS

1.Duramater

2.Arachnoid membrane

3.Piamater

Meninges: Duramater

Duramater is the toughest, outter, gray layer 2 spaces: Epidural – space between the skull and duramater

Subdural – Space between the dura and arachnoid

2 layers: – External periosteal

internal meningeal 3 cavaties:

Falx cerebri – is the largest of the dural extensions, it projects into the longitudinal fissure that separates the two cerebral hemispheres

Tentorium Cerebelli - Separates the cerebellum from the inferior portion of the occipital lobes.

Falx Cerebelli - small triangular extension of the tentorium cerebelli that separates the two cerebellar hemispheres.

Meninges: Duramater

Pathology of Duramater: Subdural hematoma:

Abnormal collection of blood between the dura and the arachnoid, usually as a result of torn veins secondary to head trauma.

Epidural hematoma: A collection of blood between the dura and the inner surface of the skull, and is usually due to arterial bleeding.

Meninges: Arachnoid membrane

Arachnoid membrane is separated from the dura mater by the subdural space. Arachnoid membrane finger-like projections within

this layer are known as the arachnoid villi. The CSF drains back to the ventricular system

through these villi.

The subarachnoid space lies between the arachnoid membrane and the pia mater Is filled with CSF produced by the ventricular

system which enters through the foramina of the fourth ventricle

Covers the whole CNS

Meninges: Pia Mater

Pia mater is the thin, transparent, collagenous, innermost membrane.

It is closely attached to the brain tissue and follows its contours

The brains blood vessels penetrate the pia mater

Meninges of Spinal Cord

All 3 meninges cover the spinal chord

Spinal arachnoid membrane extends all the way to the cauda equina and the subarachnoid space is filled with CSF

Spinal pia mater continues with the filum terminale after the conus medullaris until the sacral level of the vertebrae

There are a few differences: Spinal duramater is single

layered Spinal dura is a relative loose

layer, punctured with the exiting spinal nerves

Meninges QUIZ

1. The ______cavity of the duramater is the largest of the dural extensions, it projects into the longitudinal fissure that separates the two cerebral hemispheres.

a. Falx cerebri

b. Tentorium Cerebelli

c. Falx Cerebelli

2. A ______hematoma is an abnormal collection of blood between the dura and the arachnoid, usually as a result of torn veins secondary to head trauma.

a. Epidural hematoma

b. Subdural hematoma

Meninges Quiz

3. The ________layer contains finger-like projections known as villi, which drain the CSF back to the ventricular system.a. Duramaterb. Arachnoid membrane c. Piamater

4. The _______ space is CSF produced by the ventricular system and lies between the arachnoid membrane and the pia mater.a. Subduralb. Piarachnoidc. Subarachnoid

Meninges Quiz

5. Which meninge(s) also cover the spinal cord?

a. Duramater and Piamater

b. Arachnoid membrane

c. Piamater and Arachnoid membrane

d. Duramater, Arachnoid membrane, and Piamater

Meninges QUIZ ANSWERS

Question 1

Question 2

Question 3

Question 4

Question 5

A. Falx cerebri

B. Subdural Hematoma

B. Arachnoid membrane

C. Subarachnoid

D. Duramater, arachnoid membrane, and piamater

PINKY & THE BRAIN!

http://www.youtube.com/watch?v=Li5nMsXg1Lk