Brain Flashcards
1
Q
What are the pars of the Brain?
A
A. Hindbrain:
1. RHOMBENCEPHALON (4th ventricle)
= Myelencephalon (MO) and
= Metencephalon (Pons+Cerebellum)
B. Midbrain
2. MESENCEPHALON
C. Forebrain
3. PROENCEPHALON
= DIENCEPHALON (3rd ventricle) and
= TELENCEPHALON
Other divisions: CEREBRUM CEREBELLUM BRAIN STEM = Medulla oblungata + bulb \+ Pons \+ Midbrain
2
Q
Function of the BRAIN
A
Controll of organs
Regulation,
Co-ordination and
Integration of rest of nervous system
3
Q
The position of the Brain?
A
Enclosed in the Cranial cavity
- rostral cavity (larger) -> CEREBRUM
tentorium Cerebelli
- Caudal cavity (smaller) -> CEREBELLUM
4
Q
MENINGES of the BRAIN
A
Meninges = Soft tissue membranes enclosing CNS It has 3 layers(superf-deep) 1. DURA MATER (thick and fibrous) - Dura Mater ENCEPHALI - Dura Mater SPINALIS
- ARACHINOIDEA
- Cavum SUBARACHINOIDEA
- CISTERNA - PIA MATER
5
Q
MENINGES of the BRAIN
DURA MATER
A
Thick and fibrous
Devided into:
- Dura Mater SPINALIS !!
- lining ENDORACHIS = vertebral canal from CAVUM EPIDURALIS
- Encloses Spinal roots
- At caudal end:
Blind ending sac
Fusion with other Meninges layers
FILUM TERMINALE DURA MATIS
BLOODSUPPLY: SPINAL ARTERIES - Dura Mater ENCEPHALI !!
- fused with inner PERIOSTEUM of skull
It has 3 portions:
I: FALX CEREBRI from:
CRISTA Galli ->
INT. OCCIPITAL PROTUBERANTIA
II: TRANSVERSE TENTORIUM CEREBELLI
Btw CEREBRUM and CEREBELLUM
III: DIAPHRAGMA SELLAE
Separates HYPOTHALAMUS from Brain, in FOSSA HYPOPHYSEALIS
6
Q
MENINGES of the BRAIN
ARACHINOIDEA
A
ARACHINOIDEA with CAVUM SUBARACHINOIDEA!
= Nerwork of TRaBECULaE + FILAMENT + CEReBRAL FLUID
CISTERNA:
- CEREBROMEDULLARIS
- VALLECULAE LATERALIS CEREBRI
- CHiASMATIS
- INTER PEDUNCULARIS
7
Q
MENINGES of the BRAIN
PIA MATER
A
ENCEPHALI and SpINALIS
- Direct contact with GLIAL LIMITING membrane of Neural Tissue!
- Richly innervated by BS ++
- Bilaterally thickened Along lateral surface of Spinal chord = DENTICULATE LIG.
8
Q
STRUCTURES of Medulla Spinalis
A
From inside out:
1. GREY MATTER = Neural bodies + Glial cells + Neuron processes A. CANALIS CENTRALIS B. CORNU - Ventralis (EFFERENT MOTOR) - Lateralis - Dorsalis (AFFERENT SENSORY)
- WHiTE MATTER
= Myelinated axons + descending nerve fibers
A. FUNiCULUS
- Ventralis
- Lateralis
- Dorsalis
( FUNICULUS CUNEATUS and FUNICULUS GRACILIS) - SULCUS
- Medianus dorsalis
- Intermedius Dorsalis
- Lateralis Dorsalis - FISSURA Medianus Ventralis
- SEPTUM Medianus
- Radix Dorsalis
- Radix Ventralis
9
Q
The reflex arch?
A
SENSORY:
AFFERENT from the muscle through FOR. iNTERVERTEBRAle to the Ggl SPINALiS to the Dorsal CORNU!
AFF MUSCLE - Ggl SPINALiS - Cornu dorsalis
MOTOR Cornu Ventralis - For. iNTeRVERtEBrAle - Muscle
10
Q
SPINAL SEGMENT and formation of SPINAL NERVES
A
Spinal segment: Has 4 parts: 1. Pars Cervicalis - Cervical Spinal Nerves - INTERMENSCENTIA CERVICALIS - Plexus Brachialis
- Pars Thoracica
- Thoracic Spinal Nerves - Pars Lumbalis et Sacralis
- INTERMENSCENTIA LUMBALIS
- PLEXUS Lumbalis et Sacralis - Pars Coccygea
- conus terminalis
- Cauda EQUINA
11
Q
Spinal segment
PARS CERViCALis
D: Dorsalis
V: ventralis
A
DORSAL
N. suboccipitalis (C1)
N.Occipitalis Major (C2)
R. dorsalis (C3-C5)
R.dorsalis rami medialis er lateralis (C6-C8)
R. dorsalis rami medialis et lateralis (Th1-2)
VENTRAL
N. Auricularis Magnus (C2)
N. transversus colli (C2)
C1+C2: ANSA CERVICALIS = connection
Head and NECK!
Nn. SUPRAClAVICULARIS —> N. PHRENICUS // Respi —> NECK!
TH1-2: PLEXUS BRACHiALIS With: RADIX Plexus NN. spinalis
12
Q
Formation of the N.Spinalis
A
RADIX dorsalis with Ggl spinalis
RADIX Ventralis
- Through For. intervertebrale
=> N. Spinalis
13
Q
Nn CERVICALIS
A
RADIX Dorsalis
RADIX Ventralis
Branches:
- n. Medialis
- N. Cutaleus medialis
- N. Lateralis
- N. Dorsalis -> Apiaxial muscles of trunk
- N. Ventralis -> Hypaxial muscles of trunk + FL + HL + Skin
- N. Cutaneus lateralis
- N. Cutaneus Ventralis
14
Q
RHOMBENCEPHALON
In general
A
- MYENCEPHALON = Medulla oblubgata (CAUDAL part)
- METENCEPHALON =
Pons + Cerebellum (ROSTRAL Part)
- Includes the: VENTRICULUS QUARTUS (4th ventricle)
15
Q
RHOMBENCEPHALON
- MYELENCEPHALON
Borders
A
= MEDULLA OBLUBGATA
Borders:
- From 1st pair of Nervi Cervicales—> PONS
- Encloses Caudal Part of 4th VENTRICLE
+ VELUM MEDULAE CAUDALE
16
Q
RHOMBENCEPHALON
- MYELENCEPHALON
Location Nuclei
A
= MEDULLA OBLUNGATA
FOSSA MEDULLARE OBLUNGATA, DORSAL to Basi Occipital
NUCLEI of Cranial Nerves VI - XII
+ corresponding PARASYMPATHETIC NUCLEI
+ caudal part of LARGE nucleus of TRIGEMINAL NERVE
17
Q
RHOMBENCEPHALON
- MYELENCEPHALON
Function
A
- Controll of RESPiRATION & CIRCULATION
- Reflex for:
- Protection of the EYE
= Palpebral reflex and lacrimal secretion
- Upper RESPIRATORY TRACT
= Sneezing, Couching - Food intake
= SUCLING and SWALLOWING
NB!!
- LEISON of MO = defekt of Cranial Nerves
—> DEATH
18
Q
RHOMBENCEPHALON
- MYELENCEPHALON
Structures found on the Ventral AsPect
A
- Fissura mediana
- Sulcus medianus
- Pyramis/ Tractus Pyramidalis
- Deccussatio Pyramidum
- OLIVIA
- Sulcus lateralis Ventralis
- Nn. hypoglossus & abducens - Funiculus lateralis
- Cranial Nerves VI-XII IX, X and XI - in Ca leaving through For. Jugulare - in Eq: For. lacerum XII - Foramen N. hypoglossi
19
Q
RHOMBENCEPHALON
- MYELENCEPHALON
Structures found on the DORSAL AsPect
A
Corpus restiforme (lat) —> Afferent fibers \+ Corpus Juxtarestiforme (med) —> Tractus vestibulocerebellaris & Tractus Cerebelloveestibularis
= Pedunculus Cerebellaris Caudalis
—> Connection of MO to Cerebellum
- TUBERCULUM Nuclei Cuneati
= Prominence - FACICULUS cuneatus = Bundach’s tract
—> Sensory fibers —> FL - TUBERCULUM Nuclei OPTICUS
- FACICULUS Gracilis = Goll’s tract
—> Sensory fibers —> HL - Sulcus Intermedius dorsalis
- Sulcus lateralis dorsalis
- Sulcus Medianus dorsalis
20
Q
RHOMBENCEPHALON
- MYELENCEPHALON
Structures found on the Transverse Section
A
Faciculus cuneatus (Burdach) Faciculus Gracilis (Goll) Sulcus MEDIANUS dorsalis Sulcus intermedius dorsalis Sulcus lateralis dorsalis Sulcus lateralis Ventralis Fissura MEDIANUS
21
Q
RHOMBENCEPHALON
- METENCEPHALON
A
PARTS
- PONS
- CEREBELLUM
- TEGMENTUM METENCEPHALI
- VELUM MEDULARE ROSTRALE
22
Q
RHOMBENCEPHALON
- METENCEPHALON
PONS
A
Pons = Bridge btw MO and MESENCEPHALON
- DORSAL part = TEGMENTUM Pontis (=ROOF of the 4th ventricle)
- VENTRAL part
23
Q
RHOMBENCEPHALON
- METENCEPHALON
PONS
Main features
A
TRIGEMINAL nerve (V) (lat)
+ its motor nucleus
+ other motor Nuclei
- Nuclei + Nervefibers of Formatio Reticularis = 1/2 PONS
- Ascending + Descending Tracts
Pedunculus cerebellaris medius—> CEREBELLUM - Fossa RHOMBOIDEA —> 4th ventricle
24
Q
RHOMBENCEPHALON
- METENCEPHALON
CEREBELLUM
Location
A
Above ventricle IV / DORSAL to FOSSA RHOMBOIDEA
25
RHOMBENCEPHALON
- METENCEPHALON
CEREBELLUM
Composed of:
```
BULK of GREY MATTER
= CORTEX CEREBELLI
+
WHITE MATTER (Enclosed in Cortex)
= CORPUS MEDULLARE
—> Forms a «tree of Life»
= ARBOR VITAE
```
PARTS:
- Median Saggital Ridge = VERMIS
- Lat. Hemispheres = Hemisphera Cerebellaris
```
VERMIS:
- Rostral Lobe = ARCHICEREBELLUM
- Caudal Lobe = NEOCEREBELLUM
- Flocculonodular Lobe = PALEOCERREBELLUM (caudoventr)
+ HEMISPHERA CEREBELLI
```
26
RHOMBENCEPHALON
- METENCEPHALON
CEREBELLUM
FUNCTION
1. Balance
2. Coordination of skelletal muscles// Posture and locomotion
—> Caudal Lobe : MOTOR function
—> Rostral Lobe : PROPRIPCEPTIVE information
27
RHOMBENCEPHALON
- METENCEPHALON
CEREBELLUM
Connection to BRAINSTEM
Rostral Cerebellar Peduncles
—> Velum MEDULLARE rostrale
Caudal Cerebellar Peduncles
—> Velum MEDULLARE caudale
Middle Cerebellar Peduncles
—> PONS
28
RHOMBENCEPHALON
- METENCEPHALON
4th VENTRICLE
VELA MEDULLARE & FOSSA RHOMBOIDEA
= 4th ventricle
```
Velum MEDULLARE rostrale et caudale
- Btw FOSSA RHOMBOIDEA - Cerebellum
- like a TENT
// Velum MEDULLARE Caudale
—>TELA CHOROIDEA
```
Velum MEDULLARE + Cerebellum
= ROOF of 4th ventricle
Fossa RHOMBOIDEA
= FLOOR of 4th ventricle
- WALL marked by bilateral EMINENCES
= AREA ACCUSTICA
- EMINENTIA Medialis: Btw Sulcus mediastinus —> LIMITANS
- Nuclei of Cranial Nerves IX, X, XII
OBEX = Caudal end of Sulcus MEDIANUS
29
RHOMBENCEPHALON
| - Nuclei MO (MESENCEPHALON)
Ca:
1. Nucl Parasympatheticus vagi
2. Nucl Intercalatus
- reflex connection to nucleus motorius N.HYPOGLOSSi
3. Nucl Tractus Solitarii
(Tractus solitarius=
GUSTATORY fibers of nn VII & IX
+ Sensory fibers of nn. IX & X
4. Nucl Ambiguus(Nucl motorius nn vagi et glossopharyngeus)
5. TEGMENTUM RHOMBENCEPHALI
—> To canalis centralis & 4th ventricle
30
RHOMBENCEPHALON
| - Nuclei PONS (METENCEPHALON)
1. Nucleus ceruleus?
2. Nucl. Sensibilis pontinus n. Trigemini
3. Nucl. Motorius n. Trigemini
4. Nucl. Motorius n. Abducentis
5. Nucl. VESTIBULARIS med et lat
6. Nucl. Cochlearis dors et ventr
7. Nucl. Motorius n. Facialis
8. Nucl dorsalis corporis trapezoidei + ventr
9. Trat. Spinalis n. Trigemini + Nucl
31
MESENCEPHALON, DIENCEPHALON
MESENCEPHALON = Midbrain
Dorsal—>Ventral
1- Tectum mesencephali
(Lamina tecti, lamina Quadrigemina)
2+ TEGMENTUM mesencephali
3+ cerebral Peduncles / Crura Cerebri, Pedunculi Cerebri
```
DIENCEPHALON = Forebrain
=
1. EPIthalamus
2. Thalamus
3. Metathalamus
4. Hypothalamus
```
32
Midbrain
| Function
Function of MESENCEPHALON
```
// Nuclei of III & IV Cranial Nerves
—> Coordination of voluntary Muscle functions
```
```
// Red nucleus
—> Muscle Tone, Body posture, LOcOmOtIoN
```
```
// Substantia Nigra
—> Intitia phase of FAST movement
```
Aquaductus mesencephali: Btw III and IV ventricles
33
MESENCEPHALON
| - Tectum mesencephali
TECTUM mesencephali (Lamina tecti, Lam quadrigemina)
= ROOF of Midbrain
—> Covers Aquaductus Mesencephali
```
= Coliculus rostrale + Coliculus caudale
- Colliculi = Reflex centers for HEARING&VISION
- Coliculus rostrale = VISION PATHWAY
Corpus geniculatum laterale
- Coliculus caudale = AUDITORY PATHWAY
Corpus geniculatum mediale
```
34
MESENCEPHALON
| - TEGMENTUM mesencephali
= cone of Midbrain
Formed mostly by reticular formation!
1. Nucleus Motorius m. OCULOMOTORIUS III
2. Nucleus Parasympatheticus N. OCULOMOTORIUS IIi
3. Nucleus Ruber = red nucleus
4. Nucleus TRochlearis IV
5. Nucleus motorius N. Trigemini V
Substantia Nigra = Underly TEGMENTUM and Red nucleus
35
MESENCEPHALON
| - CRURA CEREBRI
Visible on Ventral aspect
Caudal to optic tract!
Bound:
Laterally —> by Piriform lobes
Caudally —> by the PONS
```
Contains:
Decending tracts —> to TELENCEPHALON
- Fossa Interpedubcularis: contain:
1. mammillary body
2. hypophyseal INFUNDIBULUM
3. Pituitary gland
```
36
DIENCEPHALON
= Forebrain
= Part of the PROENCEPHALON!
3rd ventricle
```
Rostrally:
ventriculus lateralis L/R
Foramen interventriculare
Lamina terminalis
Commisura rostralis
Optic Chiasma
```
```
Caudally:
Plexus choroideus
Epithalamus w/ Glandula Pinealis
Habenula
Lamina terminalis grisea
Commissura caud
Aquaductus mesencephali
```
```
Ventrally:
Pedunculus Cerebri
Corpus mammilae
Hypothalamus
Cavity of hypophysis
```
37
DIENCEPHALON
| Function
1. Pineal Gland
—> Regulates SEXUAL AVTIVITY and its seasonal changes
Involved in Sleep-wake cycle!
2. Thalamus:
—> Sensory tract -> cerebral Cortex
(exept olefactory)
```
3. Hypothalamus:
—> Controlls HYPOPHYSIS —> Endocrine syst
- Eating and Drining behavoir
- temperature regulation
- Autonomic nervous system regulation
```
38
DIENCEPHALON
| - EPITHALAMUS
- Glandula Pinealis
+ Habenula & Assosiated tracts
```
GLANDULA PINEALIS
= Endocrine gland
Function:
—> Secrets MELATONIN + others
- affects sexual activity
- Ovarian activity
```
```
HABENULA
= Habenular Nuclei
—> Recieve fibers from TELENCEPHALON
—> Send fibers to MESENCEPHALON
Function:
—> IMPoRTaInt part of OLEFACTORY Pathway
```
39
DIENCEPHALON
| - THALAMUS
= lateral wall of 3rd ventricle
= largest part of DIENCEPHALON
```
DORSAL THALAMUS
- a lot of Nuclei —> cerebral Cortex = Integration centers to the brain stem (bs)
- Afferent tracts:
GUSTATORY
OPTIC
ACOUSTIC
VESTIBULAR organ (not olefaction)
```
SUBTHALAMUS
= Rostral continuation of
TEGMENTUM MESENCEPHALI
- Contains Subthalmic Nuclei =
relay for EXTRAPYRAMIDAL MOTOR PATHWAY
- L+R THALAMUS = Connected by
ADHESIONS INTERTHALAMICA = Enclosed by 3rd ventricle!
40
DIENCEPHALON
| - METATHALAMUS
= Caudolateral part of THALAMUS
| - Comprises medial & lateral geniculate bodies/ Corpora Geniculata
41
DIENCEPHALON
| - HYPOTHALAMUS
```
= Floor of 3rd ventricle
Rostral —> Caudal
- Optic Chiasma
- Tuber cineneum/ grey tuber of 3rd ventricle
- Corpus Mammilae/ mammillary body
```
INFUNDIBULUM with Hypophysis= pituitary Gl
HYPOPHYSIS = Neurophysis Intermediate part
+ ADENOPHYSIS
42
TELENCEPHALON
```
= Paired hemispheres
- separated by:
Longitudinal Fissures
- connected by:
Commisural Fissures
—> Corpus callosum
- on the surface of the Hemispheres
Elevated bands: GYRI CEREBRI
Separated by: SULCI CEREBRI
```
- Composition of Hemispheres:
Surface GREY Matter = Cerebral Cortex or PHALLIUM
Cerebral WHITE Matter + deep accumulation of grey matter = BASAL NUCLEI
43
TELENCEPHALON
| Function
Olefactory area - Rhinencephalon
Visual area
Auditory area
Motor area —> controll of voluntary posture and movement
44
TELENCEPHALON
| Cortex or PALLIUM
= PALEO+ARCHI+NEOPALLIUM
PALEOPALLIUM —> OLFACTION
ARCHIPALLIUM —> short term memory
NEOPALLIUM! 4 lobes
Ventral —> medial —> dorsolateral
= Enveloping the brainstem
45
TELENCEPHALON
| PALEOPALIUM
```
OLEFACTION
= Oldest part phylogenetically
Ventral part of each HEMISPHERES
- Part of RHINENCEPHALON
- between sulcus rhinalis lateralis & sulcus endorhinalis
ROSTRAL to it: Bulbus Olefactorius
LATERAL: includes Lobus Piriformis
MEDIAL: commisura terminalis rostralis (Rostral wall of IV ventricle)
```
46
TELENCEPHALON
| - ARCHIPALLIUM
= Short term memory
Next oldest
- MEDIAL Part of each HEMISPHERES
= HYPOCAMPUS + associated structures
47
TELENCEPHALON
| - NEOPHALLIUM
= youngest
Predominant part
Dorsolateral
4 LOBES, named by the overlying bone:
1. FRONTAL
Motor areas + origin of pyramidal tracts + concentration
```
2. PARIETTAL
Sensory area (Pain, touch, pressure)
```
```
3. TEMPORAL
Auditory area (+langage)
+ LIMBIC system in it!!
- Hypocapus, short term memory
- Amygdala, emotions
```
4. OCCIPITAL
Visual Area
Separated from RHINENCEPHALON by sulcus rhinalis
48
TELENCEPHALON
| - NEOPALLIUM and CEREBRAL HEMISPHERES
```
Fissura LONGITUDINALIS Cerebri
- Separates L+R HEMISPHERES
- Flanked by:
Sulcus MARGINALIS
Sulcus CRUCIATUS
```
Picture:
- Sulcus suprasylvius
- Sulcus ectosylvius (rostral/caudal)
- Olefactory bulb
- Sulcus rhinalis lateralis
- pars rostralis et caudalis
- Lobus piriformis
- Fissura transversa Cerebri
- FISSURA Sylvia
49
TELENCEPHALON
GYRi and Sulcuses
DORSAL view
```
DORSAL VIEW
GYRi:
- Frontal
- Prorean
- Precruciate
- Postcruciate
- Endomarginal
- Marginal
- Ectomarginal
- Suprasylvian (rostral et caudal)
- Ectosylvian
```
SULCI: fissura LONGITUDINALIS most DORSAL
- Prorean
- Presylvian
- Cruciate
- Postcruciate
- Coronal
- Ansate
- Endomarginal
- Marginal
- Ectomarginal
- Suprasylvian (rostr/caud)
50
TELENCEPHALON
GYRi and Sulcus
Lateral view
```
LATERAL VIEW
GYRi:
- Frontal
- Prorean
- Precruciate
- Postcruciate
- ROSTRAL COMPOSITE
- Marginal
- Ectomarginal
- Suprasylvian (ROSTRAL, MIDLE, CAUDAL)
- Ectosylvian (ROSTRAL, MIDLE, CAUDAL)
- Sylvian (rostral and caudal)
```
SULCI:
- Prorean
- Presylvian
- Cruciate
- Coronal
- Ansate
- Marginal
- Ectomarginal
- Suprasylvian (rostral, middle and caudal)
- Ectosylvian (rostral, middle and caudal)
- Pseudosylvian fissure
- Lateral Rhinal sulcus (caudal)
OLFACToRY BULB:
- lateral rhinal sulcus (rostral)
- Piriform Lobe
51
TELENCEPHALON
GYRi and sulcus
Ventral view
LATERAL VIEW
GYRi:
- ROSTRAL and caudal COMPOSITE
- Prorean
(OLFACToRY bulb, lat OLFACToRY tract+tubercle and Piriform Lobe)
- Frontal
- Diagonal
- PARAHYPOCAMPAL
- SPLEENIAL
- OCCIPiTAL
SULCI:
- Presylvian lateral
- Rhinal sulcus (lateral and caudal limb)
- Pseudosylvian fissure
- supra splenial
- SPLENIAL
- Hippocampal
OLFACToRY BULB:
- lateral rhinal sulcus (caudal)
- OLFACToRY Peduncles
- endorhinal sulcus
- Piriform Lobe
52
TELENCEPHALON
GYRi and sulcus
Median view
GYRI
- Frontal
- GENUAL
- STRAiGHT
- septal region
- OLFACToRY bulb
- PARAOLFACTORY
- PARATERMINAL
- GENICULI
- SUPRA CALLOSAL
- INDUCIUM GRISEUM
- GYRUS FASCIOLARIS
- CALLOSAL
- DENTATE GyRUs TUBERCLE
- Occipital
- splenial
- parahippicampal
- CINGULATE
CORPUS CALLOSUM
Internal capskledde (transected)
Rostral commisura
SULCI:
- Median Rhinal
- Ectogenual
- GENUAL
- Cruciate
- CALLOSAL
- OLFACToRY bulb
- PARAOLFACTORY
- Supra splenial
- splenial
- hippocampal
- Piriform Lobe
```
CORPUS CALLOSUM
Internal capsule (transected)
Rostral commisura
OLFACToRY Tubercle
OLFACToRY Peduncles
OLFACToRY bulb
```
53
TELENCEPHALON
| CORPUS STRIATUM
(Basal ggl)( INTERNAL organ of the HEMISPHEREs)
= Nucleus Caudatus
+ Putamen
+ Claustrum
+ Corpus amygdaloideum
FUNCTION:
Reaponsible for producing appropriate direction and magnitude
```
NUCLEUS CAUDATUS
= rostral part of FLOOR of lateral ventricle
—> Capsula interna
PUTAMEN
= Lateroventral to Nucl Caudatus
—> Capsula Externa
CLAUSTRUM
= lateral to Putamen,
// Visual and LIMBIC System
```
54
TELENCEPHALON
| CORPUS CALIOSUM
= Cohesion btw 2 HEMISPHEREs
- Truncus Corpori callosi
= elongated region
—> Splenium = Caudal rounded end
—> Genu Corporis callosi = rostral end
- Septum Pallucideum
= Thin membrane btw the 2 lateral ventricles
55
Organ of OLEFACTION
In the nose!
Olefactory mucosa covering :
- lateral wall of CONCHA
+ caudal part of nasal cavity
1. Organum Olefactorius
—> Regio Olefactoria Tunica mucosae Nasi
= Olefactory mucosa on caudal portions of CONCHA ETHMOIDALIS & Septum Nasi
—> Glandulae Olefactoriae
= Moistens, wash away previous odorants
= Olfactory glands = serous glands
- in olfactory epithelium
2. Organum Vomeronasale
—> Ductus Vomeronasalis
= caudally blind-ending tube of olefactory mucosa.
- Associated with OLFACTORY glands
3. OLFACTORY NERVES
- Bipolar
- From mucosa —> Lamina Cribrosa -> BO
56
OLFACTORY PATHWAY
= Cranial Nerve nr 1!
N. OLEFACTORIUS I
- Sensory
- Numerous
NON-MYELINATED AXONS Bodies in OLFACTORY epithelium
AXONS —> Cribriform plate —> BO: Synapses
- Nervous terminalis: VOMERONASAL organ
—> RHINENCEPHALON
```
PATHWAY:
Fila olefactoria —> lamina cribrosa —> BO —> Pedunculus Olefactorius —> Tractus Olefactorius
—> Lat —> Lobus piriformis
—> INT —> Trigonum Olefactorius
—> med —> Gyrus Subcallosus
```
57
RHINENCEPHALON
= OLFACTORY Brain!
= Basal TELENCEPHALON + HIPPOCAMUS + Associated structures paleus + Auchi Pallium
```
1. Pars BASALIS
= Paleopallum
—> Olfactory
—> Conscious Perception of smell
(//Frontal Lobe)
```
- Fila olefactoria ***
= nervebundles —> N.OLEFACTORIUS
- Bulbus Olefactorius ***
- Pedunculus Olefactorius ***
Joins BO to HEMISPHEREs
- Tractus Olefactorius (lat+med) ***
- Trigonum Olefactorium ***
Lobus piriformis -> caud to ped. Olf!
Tuberculum olf
2. Pars Septalis
—> Medial aspect of Hemispheres
```
- Septum Telencephali (pelucidum) ***
—> Connects corpus callosum & Fonnix
—> Separates Ventriculi laterales
- Gyrus paraterminalis
- Gyrus diagonalis
- Gyrus Subcallosus ***
(area subcallosa)
```
3. Pars Limbica
—> NON-olefactory
—> EMOTIONAL response - ARCHIPALLIUM
- HIPPOCAMPUS ***
- Gyrus Supracollosus
- Gyrus geniculi
- Tuberculum Hyppocampus
- FORNIX ***
= accurate fibers
Hyppocampus —> Corpus Mammilae
- Pars Precommissuralis
*** = mentioned by ferenc
58
RHINENCEPHALON
| Pars BASILARIS
PALEOPALLIUM
—> separated from NEOPALLIUM by sulcus RHINALIS
- FILA OLFACTORIA
Olfactory Nerves —> lamina cribrosa —> BO
- BULBUS OLEFACTORIUS = most rostral part
In FOSSA ETHMOIDALIS
Contains mitral cells ++
- PEDUNCULUS OLEFACTORIUS = caud part
—> from BO to TRACTUS OLEFACTORIUS
LATERATIS —> Lobus Piriformis
MEDIALIS —> Commisura rostralis g. Subcallosus
- Trigonum Olefactorium +
- Substentia Perforata Rostralis
= OLFACTORY AREA
59
RHOMBENCEPHALON
| - Pars LIMBICA/ LIMBIC SYSTEM
= Structures involved in EMOTIONAL BEHAVIOUR
1. Cortical Part: Gyrus Angulus / Cingulum
+ Lobus Piriformis
+ Hippocampus
```
2. Subcortical Part:
Habenula + Hypothalamus + Thalamus (Diencephalon)
Interpendecular & Tegmental Nuclei
(Mesencephalon)
+ Corpus Amygdaloideum
```
FUNCTION:
- Olfactory Input from PIRIFORM LOBE
= Visceral motor activities
- Emotional Behaviours
(fear, agression, pleasure)
- Input // Thirst, Hunger, Sexual behaviour
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Pathways of the Brain
ASCENDING - AFFERENT (Sensory)
1. SOMATIC AFFERENT PATHWAY
Skin
Touch, pressure, vibratory sensation —> Brain
Deeper Somatic tissue
Thermal sens, pain, kinaestetic sens -> Brain
- LEMINISCUS System
Conciousness
A. TRIGEMINAL pathway
B. SPINAL pathway
- EXTRA LEMINISCUS system
Sense organs
A. VISUAL pathway
B. VESTIBULAR/AUDITORY pathway
61
LEMINISCUS SYSTEM
LEMINISCUS SYSTEM=
Most importaint Ascending tract//Conciousness
```
TRIGEMINAL LEMINISCUS
- Sensory fibers FROM head!
Nucl. sensibilis pontinus n. Trigeminus
Nucl. Tractus Spinalis n. Trigeminus
Deccusatio of Leminiscus
```
```
SPINAL LEMINISCUS
Medial = Fascicus gracilis (Goll’s Column)
Lat= Fasciculus cuneatus
Nucleus cuneatus
Nucleus gracilis
```
Facies CUNEATUS
- Plexus brachialis & Cranial trunk
- Plexus lumbosacralis & caudal trunk
62
EXTRALEMINISCAL system
- Spinothalmic tract
- Proprioceptive info from tendons
I neurons — to neurons of DORSAL horns
Close to Spinal roots, synapses with interneurons.
II neurons — to white matter ventrolat funiculi, synapses in THALAMUS
III neurons — thalamus —> Cortex
—> Afferent pathway from SENSE ORGANS
63
EXTRA LEMINISCAL system
| VISUAL pathway
Visual info = light
Retina R
Optic nerve
Optic Chiasma
Tractus opticus
(Mesoenceph)
- Lateral geniculate
- optic thalamus
- Coliculus roatralis (nuclei of reticular formation, caudate nucleus)—> Reflex
```
Optic radiation (internal capsule)
Visual Caleb (occipital Kobe)
—> conscious
```
64
Vestibular/ Auditory pathway
Vestibular nerves -> majority terminate in vestibular nuclei
- Nucl. Vestibularis lat (Deiters)
- Nucl. Vestibularis rostralis (Bechtenew)
- Nucl. Vestibularis med (Swalbe)
= PONS and MO
- Nucl. Vestibularis caud (Roller)
= Cerebellum
COCHLEAR Nerves: synapses in cochlear Nuclei
- Nucl. Cochlearis dorsalis
- Nucl. Cochlearis Ventralis
= lateral to MO
65
ASCENDING Pathway
ASCENDING —> CNS
*3 neurons
1. light, tactile sensation. GOLL-BURDACH
2. Motor Afferent
SC
-fasciculus
+ gracilis cuneatus = Goll burdacu
66
EFFERENT - DECEnDINg pathway
SOMATIC EFF pathways: Regulated at 2 levels with CNS
1. Lower motor neurons (LMN)
Located within
—> Ventral column of grey matter of sp.chord
—> Motor Nuclei of Cranial Nerves
2. uPPer motor neurons (UMN)
Located in NEOPHALLIUM
+ red Nucleus of MESENCEPHALON
+ reticular formation
Do not project directly to
—> controll activity of LMN
- connection btw LMN & UMN
- 2 descending patways in close collaberation
- Controlled by CEREBELLUM
67
PYRAMIDAL SYSTEM
```
Corticospinal tract —> concious
- Finelly adjusted movements
- interspecial diff way importaint
Primates: dup ++
- Damages = PARALYSIS
MO lesion —> spinolat side paralysis
Cortex lesion —> Centrolat side paralysis
```
Origin of pyramidal FIBeRs:
Neophallum(TELENCEPHALON)
—> basal Nuclei —> Tractus pyramidalis
= 75% deccussatio pyramideum = corticospinal lateral tract —> HL and FL
= 25% NON—crossing fibers = corticospinal Ventral tract —> Trunk
3 types of fibers:
1. corticospinal fibers
2. corticobulbar fibers : term in nuclei of cranial nerves
3. Corticopontine fibers: nuclei in pen
68
Motor pathways
PYRAMiDAL
EXTRAPYRAMIDAL
Visceral eff pathways
- controlled by hypothalamus
SYMPATHETIC
- caudal part of hypothalamus
UP: BP- heart rate- respiratory rate - dilated pupils
DOWN: gut motility - intestinal gland activity
PARASYMPATHETIC
- roatral part of hypothalamus
DOWN: heart rate - resp.rate - pupils constrict
UP: gut motility, intestinal secretion, defecation and urination
69
Fluid environment
Periosteum
Dura mater
Arachnoidea
Pia Matter
Cavum EPIDURALE
Cavum SUBDURALE
Cavum SUBARACHINOIDALE
70
Cavum EPIDURALE
Btw 2 layers of DURA MATTER
But only SPINAL CORD
-> brain: fusion btw periosteum
71
CAVUM SUBDURALE
Btw dura matter & archinoidea
72
CAVUM SUBARACHINOIDALE
Btw arachnoidea & Pia matter
Enlarged cisterna *4
1. C. Cerebromedullaris: Btw Cerebellum - MO
2. c. Vallecula lay. Cerebri: in vallecula lat cerebri
3. c. Chiasmatis: around chiasma opticus
4. C. Interpesuncularis: in fossa interpesuncularis
73
CEREBRO SPiNaL FLUID (CSF)
Clear, colorless fluid
```
FORMATION:
- in plexus choroideus
- from blood plasma
-by ultrafiltration
Through blood cerebrospinal fluid barrier (BBB)
- Produced continuously 30mL/h (ca)
```
```
COMPOSITION:
HIGH: [cu2+] [K+]
LOW: [Na+][Cl-][Mg2+]
Deficiency in GLUCOSE
Little proteins //BBB
```
```
FUNCTION
- Mechanical protection of Brain&spinal chord
- Chemical buffering capacity
—> stabile Mileu
- transport of:
—> Nutrients
—> Waste products
—> Neuroendocrine subst
—> Neurotransmitters
```
74
CIrCUlATION of cerebrospinal fluid (CSF)
1. Circulates through ventricular system (in brain)
—> onwards by
- filtration pressure
- Ciliary activity of ependymal lining
2. Escapes from interior of brain
- by 2 aperture lateralis of IVth ventricle
- + apertura Medianus (eq, ca)
3. Bathes brain and spinal chord
4. Returns to blood
-> through arachnoid granules that pierse dura matter
—> enters dorsal saggital venous system
+ smaller part of fluid —> to meningeal cuffs around origin of cran & spinal non.
—> absorbed by perineal lymph
75
VENTRICULAR SYSTEM
- CSF secretion in V. II (lat), III, IV —> appertura lat of IV
```
VENTRICULUS *4
I: Recess of olfactory bulb
II= lat. TELENCEPHALON
III DIENCEPHALON
IV RHOMBENCEPHALON
```
76
PLEXUS CHOROIDEUS
= onfolding og blood vessels of PIA MaTTER
- covered by epidymal cells —> CSF produces
* 2 in lateral ventriculus
* 1 in III ventricle
* 1 in IV ventricle
Supported by TELA CHOROIDEA = ROOF of IV ventricle!
Extends int appertura Lateralis (IV v)
