General nervous system anatomy

Session 2

What do you think?

Objectives

• Recognize the surface of the brain from every perspective

• Correctly use the terms for the anatomical breakdown of the central nervous system

• Compare and contrast white and gray matter and recognize terms that distinguish them

• Describe the structure of the spinal cord

• Recognize cross-sections of the brain in each plane

• Describe the locations and functions of supporting systems of the CNS

• Describe the difference between a tract and a pathway

• Visualize a second order sensory neuron

• Discuss the role of major neurotransmitters

Who originally proposed the Cell Theory in 1839?

A. Paul Broca

B. Theodor Schwann

C. Charles Darwin

D. Rene Descartes

Paul B

roca

Theodor Sch

wann

Charles D

arwin

Rene Descart

es

25% 25%25%25%

:30Answer Now

Alzheimer’s and Parkinson’s are both characterized by progressive degeneration of specific neurons in the peripheral nervous system.

A. True

B. False

50%50%

:30Answer Now

Developmental vs anatomical breakdown

• Development based terms (left)

• Visible structure based terms (right and middle)

• Cellular level based terms (for later on)• Nuclei, internal

structures, etc.

Rostral

Caudal

Cerebrum

Midbrain

Medulla

Pons

White matter vs gray matter

• White:• Tract, capsule, commissure,

lemniscus, fasciculus, column, peduncle, funiculus, crus

• Gray:• Ganglia, nuclei, cortex, specialized

names (like thalamus)

Spinal region

• Gray matter• Horns (anatomical)

• Laminae (functional)

• White matter• Funiculi (anatomical)

• Tracts, columns, lemnisci, etc. (functional)

• Surface Features• Fissures, Meninges,

Arteries

lemnisci contain synapses

A. True

B. False

True

False

50%50%

:30Answer

Now

brainstem

cerebellum

• Crus = Peduncle

• Lined with gray matter just like cerebral cortex

• Word cerebellum is a diminutive of cerebrum (mini-brain)

Cerebellum – arbor vitae

Subcortical structures

• Diencephalon

• Basal Ganglia• Lenticular Nuclei

• Corpus Striatum

• Parts of Limbic System

Cerebral cortex

• https://www.youtube.com/watch?v=6M0XbFa6QnY

• Watch a zebrafish think! (kind of)

Where is the tectum located?

A. Midbrain

B. Pons

C. Medulla

D. Diencephalon

Midbra

inPons

Medulla

Diencephalo

n

25% 25%25%25%

:30Answer

Now

Cerebral cortex

• Gray matter cortex – gyri and sulci to increase area

• Increased cortex area = increased processing space*

• White matter – connects cortex with other processing structures

• Increased white matter = increased processing power or speed*

*Professor Burnell’s unresearched hypotheses

Cerebral cortex microscope slide (stained)

Cerebrum vs cerebellum

• Brain vs. mini-brain• Gray cortex, white tracts, deep

nuclei

• Arbor vitae = capsules and commissures

• Peduncles

• Cerebellum function:

• Coordination, balance, subconscious motor control, unknown

• Cerebrum function:

• Sensation, conscious motor control, language, planning, etc., mostly known

identify the surfaces

Which views allow you to see the 4th ventricle?

A. Anterior view of brainstem

B. Posterior view of brainstem with cerebellum removed

C. Posterior view of brainstem with cerebellum intact

D. Midsagittal section

E. Lateral view of brainstem

Anterio

r view of b

rainste

m

Posterio

r view of b

rainst..

Posterio

r view of b

rains...

Midsa

gittal s

ection

Latera

l view of b

rainste

m

20% 20% 20%20%20%

:30Answer

Now

Cross sections

• Sagittal (midsagittal)

• Coronal/Frontal

• Horizontal/Transverse/Axial

Cross Sections - midsagittal

• Cerebral cortex, diencephalon, brainstem

Cross sections - coronal

• Cerebral cortex and subcortical structures

Cross sections - axial

• Cerebral cortex, subcortical structures, brainstem, cerebellum, spinal cord

The lateral ventricles appear in two places (4 total) in which cross section?

A. Coronal

B. Axial

C. Midsagittal

Coronal

Axial

Midsa

gittal

33% 33%33%

:30Answer

Now

What term best describes these structures?

A. Lentiform nuclei

B. Basal ganglia

C. Limbic system

Lentifo

rm nucle

i

Basal g

anglia

Limbic

system

33% 33%33%

:30Answer

Now

What is the name of this structure?

A. Tectum

B. Basis Pontis

C. Mammillary body

D. Crus Cerebri

Tectum

Basis Pontis

Mammilla

ry body

Crus C

erebri

25% 25%25%25%

:30Answer Now

Support Systems

• Arteries• Vertebral -> Basilar -> Circle of

Willis

• Internal Carotid -> Circle of Willis

• Veins, Sinuses• Superior Sagittal Sinus

• CSF – Ventricles, aqueducts, canals• Lateral ventricles ->

(interventricular foramen) -> 3rd ventricle -> (cerebral aqueduct) -> 4th ventricle -> SAS

• Meninges• Pia, SAS, Arachnoid, SDS, Dura

After flowing through the lateral ventricles, where does the CSF travel next?

A. 4th ventricle

B. 3rd ventricle

C. SAS

D. Cerebral aqueduct

E. Interventricular foramen

4th ve

ntricle

3rd ventri

cle SAS

Cerebral aqueduct

Interventri

cular f

oramen

20% 20% 20%20%20%

:30Answer Now

Tracts vs pathways

• Pathway is the whole road trip, including stops

• Tract is one road

• Decussations

Sensory vs motor pathways

• Sensory pathways tend to have 3 neurons (primary, secondary, tertiary)

• Motor pathways tend to have 2 neurons (upper and lower)

First, Second, Third Order Sensory Neurons

• 1st (primary)

• 2nd (secondary)• Tract

• 3rd (tertiary)• Soma in

thalamus

• Ends in cortex

Upper vs Lower Motor Neurons

• Upper Motor Neurons• Soma in Cortex

• Synapses in spinal cord, after decussating

• Interneurons – processing

• Lower Motor Neurons• Starts in spinal cord, exits

through anterior root

Lower Motor neurons cross midline.

A. True

B. False

True

False

50%50%

:30Answer

Now

Neurotransmitters• Glutamate (+)

• GABA (-)

• Dopamine – reward system, mostly noticed when absent (parkinson’s, schizophrenia, ADHD, restless leg syndrome)

• Serotonin – enteric NS, mood, sleep, learning, memory, etc.

• CCK (cholecystokinin) – enteric NS

• Acetylcholine – PNS

• Epinephrine

• Norepinephrine

• Substance P – pain perception

• Enkephalin – pain regulation

Objectives

• Recognize the surface of the brain from every perspective

• Correctly use the terms for the anatomical breakdown of the central nervous system

• Compare and contrast white and gray matter and recognize terms that distinguish them

• Describe the structure of the spinal cord

• Recognize cross-sections of the brain in each plane

• Describe the locations and functions of supporting systems of the CNS

• Describe the difference between a tract and a pathway

• Visualize a second order sensory neuron

• Discuss the role of major neurotransmitters

conclusion

• Questions on general anatomy?

• Study Guide will be posted this afternoon

• Read for next class:• Bear Ch. 7

• L-E Ch. 5

• Pdf attachment of Haines Ch. 8