Activity 7:Nervous System Histology, Brain, &

Cranial Nerves

Chapters 14 & 15 – McKinley et al., Human Anatomy, 4e.

Objectives:• Histology: Identify structures indicated on three different slides or

images of nervous system tissue. Some of these are also visible on the classroom model of a neuron.

• Human brain: Identify listed structures of the human brain on classroom models, the cranial meninges, and structures involved in cerebrospinal fluid circulation.

• Human brain: Identify the 12 pairs of cranial nerves by name and number on a model and on the sheep brain.

• Dissect a sheep brain and identify structures listed.

1Compilation: Mohammad Tomaraei & Cristin Fail

Nervous System Tissues: Spinal Cord Smear (Histology)

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Nervous System Tissues: Cross Section of a Nerve (Illustration)

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Nervous System Tissues: Cross Section of a Nerve (Histology)

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Nervous System Tissues: Cross Section of a Nerve (Histology)

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Nervous System Tissues: Teased Myelinated Nerve Fibers (Histology)

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Nervous System Tissues: Multipolar Neuron Model

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Nervous System Tissues: Multipolar Neuron Illustration

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Brain Anatomy – Adult Human Brain

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Brain Anatomy – Sheep Brain

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Brain Anatomy – Adult Human Brain

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Brain Anatomy – Sheep Brain

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Brain Anatomy – Sheep Brain

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Brain Anatomy – Cerebrum

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Brain Anatomy – Cerebrum

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• Cerebral hemispheres are divided by the longitudinal fissure into left

and right sides

• Central sulcus divides the frontal lobe from parietal lobes

Brain Anatomy – Lobes of the Brain

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Brain Anatomy – White Matter of Cerebrum

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Brain Anatomy – Cerebral Hemispheres

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Brain Anatomy – Hemispheric Lateralization

Brain Anatomy – Lobes of the Brain

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Brain Anatomy – Lobes of the Brain & their Functions

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Frontal Lobe Parietal Lobe Occipital Lobe

Temporal Lobe

Brain Stem Cerebellum

• Primary Motor Cortex (Precentral Gyrus)

• Voluntary motor functions

• Concentration• Verbal

communication• Decision making• Planning• Personality

• Primary Somatosensory Cortex (Postcentral Gyrus)

• Sensory functions (Pain, heat and other sensations)

• Comprehension of language

• Primary Visual Cortex

• Processing visual information

• Storing visual memories

• Understanding Speech

• Interpretation and storage of auditory and olfactory sensations

• Breathing• Swallowing • Heart rate

Includes Midbrain, Pons, and Medulla Oblongata

• Coordination • Balance• Stores

memories of previously learned movement patterns

Brain Anatomy – Primary Somatosensory Cortex

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The amount of cortex devoted to any given body region is proportional to how richly innervated that region is.

Brain Anatomy – Homunculus Model

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Which model is more realistic?

Brain Anatomy – Cross-section Brain Model

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1. Corpus Callosum 2. Corpora Quadrigemina

(Tectal Plate)• Superior Colliculus (pl.

colliculi)• Inferior Colliculus

3. Cerebellum (Arbor Vitae)4. 4th Ventricle5. Central canal of spinal cord6. Medulla Oblongata7. Pons8. Pituitary gland9. Optic Chiasm10. Hypothalamus11. Thalamus12. Septum Pellucidum13. Fornix14. Pineal Gland

Brain Anatomy – Corpus Callosum

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• Carries messages between the left and right hemispheres

• Its under surface forms the roof of the body of the lateral ventricle.

Brain Anatomy - Diencephalon

• Sits on top of the brain stem• Enclosed by the cerebral

hemispheres• Made of three parts

• Thalamus• Hypothalamus• Epithalamus

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Brain Anatomy - Diencephalon

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Brain Anatomy – Epithalamus & Pineal Gland

• Pineal gland is an endocrine gland that secretes the hormone Melatonin.

• Melatonin helps regulate day-night cycles known as the body’s Circadian Rhythm.

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Brain Anatomy – Thalamus & the Interthalamic Adhesion

• The Interthalamic

Adhesion is

located midsagitally

and connects the

left and right

thalamic bodies

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Brain Anatomy – Hypothalamus

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Includes:• Mammillary

Body• Infundibulum• Pituitary Gland

• Optic Chiasm• Optic Tracts• 3rd Ventricle

Brain Anatomy – Functions of Hypothalamus

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• Master control of the autonomic nervous system• Heart rate, blood pressure, digestive activities and respiration

• Master control of the endocrine system• Metabolism, growth, stress responses and reproduction

• Regulation of body temperature• Body’s “thermostat”, detects altered blood temperatures, heat or cool the body:

shivering/sweating

• Control of emotional behavior• Emotional responses: pleasure, aggression, fear, rage, contentment and sex drive

• Control of food intake• Monitors levels of glucose and amino acids in the blood and produces sensations

of hunger

• Control of water intake• Monitors blood solute concentration

• Regulation of sleep-wake rhythms• The Suprachiasmatic Nucleus directs the Pineal gland to secrete melatonin,

regulating circadian rhythms.

Brain Anatomy – Brain Stem

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Includes:• Midbrain

(mesencephalon)• Pons• Medulla Oblongata

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Brain Anatomy – Overview of Brain Stem Functions

Brain Anatomy – Midbrain

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Includes:• Corpora Quadrigemina

(tectal plate)• Superior Colliculus:

Visual reflex center (turns eyes and head in response to visual stimulus)

• Inferior Colliculus:Auditory reflex center (turns eyes and head in the direction of a sound)

• Cerebral Peduncles

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Brain Anatomy – Pons

Functions:• Bridge between the

cerebellum and cerebrum

• Houses cranial nerves• Trigeminal (CN V)• Abducens (CN VI)• Facial (CN VII)• Some of the nuclei for

Vestibulocochlear (CN VIII)

• Helps regulate skeletal muscles of breathing

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Brain Anatomy – Medulla Oblongata

Functions:• Regulates heart rate

and strength of

contraction• Controls blood pressure• Regulates respiratory

rate• Involved in coughing,

sneezing, salivating,

swallowing, gagging

and vomiting

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Brain Anatomy – Medulla Oblongata & Pons

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Brain Anatomy – Medulla Oblongata & Pons

Brain Anatomy – Cerebellum

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Functions:• Processes sensory input• Coordinates movement

output• Balance

Includes:• Vermis

• Separates right and left hemispheres

• Arbor Vitae (“tree of life”)

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Brain Anatomy – Cerebellum

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Brain Anatomy – Cerebellum

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Brain Anatomy – Meninges and Spaces

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Brain Anatomy – Cranial Dural Septa

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Brain Anatomy – Dural Venous Sinuses

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Brain Anatomy – Ventricles

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Brain Anatomy – Ventricles

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Brain Anatomy – Circulation of Cerebrospinal Fluid

Brain Anatomy – Cranial Nerves

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1. Olfactory nerve (I)

2. Optic nerve (II)3. Oculomotor nerve (III)4. Trochlear nerve (IV)

5. Trigeminal nerve (V)6. Abducens nerve (VI)

7. Facial nerve (VII)8. Vestibulocochlear nerve

(VIII)9. Glossopharyngeal nerve

(IX)

10. Vagus Nerve (X)11. Accessory Nerve (XI)

12. Hypoglossal nerve (XII)

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Brain Anatomy – Cranial Nerves

Brain Anatomy – Cranial Nerves

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Sensory, Motor or Both1. Some2. Say3. Marry4. Money5. But6. My7. Brother8. Says9. Big10.Brains11.Matter12.Most

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Brain Anatomy – Origins of Cranial Nerves

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Brain Anatomy – Sheep Brain

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Brain Anatomy – Sheep Brain

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Brain Anatomy – Trigeminal Nerve

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Brain Anatomy – Facial Nerve

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Brain Anatomy – Vestibulocochlear Nerve

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Brain Anatomy – Glossopharyngeal Nerve

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Brain Anatomy – Vagus Nerve

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Brain Anatomy – Accessory & Hypoglossal Nerve

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Brain Anatomy – Cerebral Nuclei

Includes:• Caudate Nucleus• Lentiform Nucleus

• Putamen• Globus Pallidus

• Claustrum• Amygdaloid body

Brain Anatomy – Cerebral Nuclei

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Brain Anatomy – Functions of Cerebral Nuclei

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• Caudate• Spatial processing

• Posture and directed movements

• Putamen• Controls muscular movements at the subconscious level

• Globus Pallidus• Excites and inhibits the activities of the thalamus to control muscle tone

• Amygdaloid body

• Expression of emotions , control of behavioral activities, development of

moods

• Claustrum• Processes visual information at a subconscious level

Brain Anatomy – Lobes & Structures of the Brain

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B. A.

C.

D. E.

F.

G.

http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

Brain Anatomy – Lobes & Structures of the Brain

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B.

A. (groove)

C. (groove)

D. E.

F.

G.

B. Frontal Lobe

G. Parietal Lobe

F. Occipital Lobe

D. Temporal Lobe

A. Central Sulcus

(groove)

E. Transverse Fissure

C. Lateral Fissure

http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif