rhombencephalon mesencephalon metancephalon myelencephalon

Rhombencephalon

Mesencephalon

MetancephalonMyelencephalon

Prosencephalon

Fore brain

TelencephalonDiencephalon

Neuron Classification ?I ) Function : * Sensory Receptor Cells * Sensory Neurons ( Afferent N.) * Interneurons (Association) * Motor Neurons ( Efferent N.) * Neurosecretory cells

II) Shape : * Monopolar / Unipolar Neurons * Bipolar Neurons * Multipolar Neurons

III) Size : * Long Axon ( Golgi Type I ) * Short Axon ( Golgi Type II)

Ectoderm

Neural Plate

Neural Folds

Neural groove

Neural tube

Spinal Nerves :

*Cervical – 8 pairs*Thoracic – 12 pairs*Lumbar – 5 pairs*Sacral – 5 pairs*Coccygeal – 1 pairs

Meninges :

1) Piamater2) Arachnoid3) Dura mater

PachymeningeLeptomeninge

Denticulate lig. (21)

Segment Vertebra

C1 C1

C8 C6

T6 T4

T12 T9

L5 T11

Anteromedian Fissure

Posteromedian Sulcus

Anterolateral Sulcus

Posterolateral Sulcus

Posterior IntermediateSulcus

Gray Matter ( H Shape ) : Ant. Horn Post. Horn Lat. Horn ( S 2- 4 and Thoracic seg. ) Intermediate Gray MatterWhite Matter ( Funiculi) : Ant. Funiculus Lat. Funiculus Post. Funiculus ( Gracilis , Cuneatus )

Ant. Gray CommissurePost. Gray Commissure

Dorsal And Ventral RootsDoral Root GanglionSpinal Nerve-Dorsal ramus-Venteral ramusCervical Plexus :C1- C4Brachial Plexus: C5 – T1Intercostal Nerve: T1 – T12Lumbar Plexus : L1- L4Sacral Plexus : L4 – S3

1) Pain and Temperature

Lat. Spinothalamic Tract

2) Light touchAnt. Spinothalamic

Tract

Spinothalamic Tract

Proprioceptive (Conscious )

Fine TouchDiscriminative

Receptors :Muscle spindle , Golgi tendon organs , and Joint

Proprioception ( non conscious )

Spinocerebellar TractDorsal Ventral

Receptors :muscle spindle , Golgi tendon organs , and Joint

Motor System(Efferent)

Pyramidal (Direct or Voluntary) Extra pyramidal (Indirect or Involuntary)

Pyramidal

Upper Motor Neuron ( U.M.N )

Lower Motor Neuron ( L.M.N )

alpha and gamma motor neurons bulbar nucleus

Babinski reflex

+_

Tendon Reflexes

Biceps C5-6Triceps C6-7Patellar L3-4Achilles S1-2

Extra pyramidal (Indirect or Involuntary)

Regulating posture and reflexesAid in voluntary movement

1)Rubro spinal Tract

Rubro spinal Tract

* Cervical segment

* Facilitations of flexor musculature ( alfa and gamma)

2) Tecto spinal Tract

Vestibulo spinal Tract

Lat. Vestibular N. ( Deiter’s N.)

* Reflex of equilibrum

Facilitating reflex activity and extensor muscle tone

Arterial supply1) Vertebral a. Ant. Spinal a. Post. Spinal a.

2) branchesVertebral , ascending , deep cervical , posterior intercostal , lumbar , and lateral sacral a. a) radicular a. Dorsal ,ventral roots , covering meninges

b) Great ant. Segmental medullary artery ( Medullary artery of adamkiewicz ) left side lumbar enlargement

NEUROANATOMY

Brain Stem Medulla Oblongata Pons Mid brain

Pontomedullary sulcus

Pontopeduncular sulcus

Medulla Oblongata Anterior :

-Anteromedian fissureDecussation of the pyramid

- PyramidCorticospainal fibers

-Anterolateral sulcusHypoglossal nerve (XII)

PonsAnterior :

-Basilar SulcusBasilar a.

-Trigeminal nerve ( V )Motor and sensory roots

- Foramen Cecum

-Pontomedullary sulcusAbducent n. (VI )Fascial n. (VII ) Motor and sensory ( NervusIntermedius )roots Sensory include Parasympathetic

Vestibulocochlear ( VIII )

Fourth Ventricle

Roof:

-Upper partSup. Cerebellar PeduncleSup. Medullary Velum ( Ependym + Nerve Fibers)

-Lower partInf. Cerebellar PeduncleInf. Medullary Velum ( No nerve fibers)ObexForamen of MagendieForamen of LuschkaChoroid Plexus

Fourth VentricleFloor:-Median Sulcus

-Medial EminanceFacial Colliculus ( Genu of FacialNerve + Abducens nucleus )Hypoglossal Triangle

-Sulcus LimitansSup. Fovea (Locus Coeruleus )Inf. Fovea (Vagal Triangle)area posterma

-Lateral EminenceVestibular area

-Stria medullaris

Brain Stem Nucleus

1) Motor

2) Sensory

3) Parasympathetic

4) Other

Motor Nucleus

Med. Coulmen:(GSE)

3 , 4 , 6 , 12

3

4

6

12

Hypoglossal Nucleus

-Receives corticobulbar

(corticonuclear) fibers , Mainly the contralateral hemispher

Abducent Nucleus

Floor of the 4 ventricle (Facial Colliculus)

Motor Nucleus

Lat. Coulmen:(SVE)

- Ambigus N. (motor 9,10 and 11 cranial nerve)

-Motor N. of the Facial nerve

- Motor N. of the Trigeminal nerve

5

7

91011

Ambigus N.

(motor 9,10 and 11 cranial nerve)

GlossopharyngealVagusAccessory

91011

Ambigus N.

motor 9,10 and 11 cranial nerve

Ambigus N.

In situated deep in medulla

Ambigus N.

- Connected with corticonuclear tracts of both fibers

Lesion of Ambigus N.

Motor N. of the Facial nerve

Motor N. of the Facial nerve

- contralateral corticonuclear fibers end in the part of the nucleus innervating the muscles of the lower part of the face

Motor N. of the Trigeminal nerve

-Receives fibers from both corticonuclear tracts

Solitarius nucleus

gastatory nucleus

7 , 9 , 10

Vestibular and Cochlear nucleus

- SVA

- Vestibular nuclei Superior Pons Inferior Medial Lateral Medulla ( Deiter’s nucleus) -Cochlear nuclei Ventral Dorsal

Sensory nucleus of trigeminal nerve

- GSA

- C3 – Midbrain

1) Spinal nucleus

2) Proper or Pontine nucleus

3) Mesencephalic nucleus

Sensory nucleus of trigeminal nerve

Trigeminal lemniscus

Talamus

Cornea Reflex

Parasympathetic

-GVE

- Dorsal vagal nucleus- Inf. Salivatory nucleus- Sup. Salivatory nucleus- Nasolacrimal nucleus

Inf. Salivatory nucleus

Sup. Salivatory nucleus

Nasolacrimal nucleus

Mid brain(Mesencephalon)

Ant:-Pontopeduncular groove-Crus cerebri-Interpeduncular fossa-Posterior perforating substance-Oculomotor nerve

Mid brain(Mesencephalon)

Post:

-Corpura quadrigemina-Superior Colliculus Pineal gland-Inferior Colliculus Frenulum Veli

Mid brain(Mesencephalon)

Post:

-Superior ColliculusSup. or ant. BrachiumLat. Geniculate body of talamus

-Inferior ColliculusInf. or post. BrachiumMed. Geniculate body of talamus

Mid brain

-Cerebral aqueduct(aqueduct of sylvius)

Cerebral peduncleTectum

Mid brain

-Cerebral aqueduct(aqueduct of sylvius)Periaqueductal greymatter

Cerebral peduncle-Substantia nigra 1)Crus cerebri 2)Tegmentum

Tectum-Colliculus

Substantia nigra

-Pars reticula-Pars compactaدوپامين

Parkinsonism

Cerebellum-Vermis-sup. surface

Cerebellum-Inf. SurfaceValleculaPostero lateral fissureFlocculonodular lobe

Cortex :

Nucleus :-Fastigial-Globus-Emboliform-Dentate or olive