Gross anatomy of human brain

slides about basic anatomy of brain with cranial nerves for undergraduates.

1. DEPT OF NEUROSURGERY, CMCH,
LUDHIANA

2. The Human
Brain
Master Watermark Image: http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

3. Students will be able to describe the general
structure of the Cerebrum and Cerebral Cortex.
• Students will be able to identify the Cerebrum, the Lobes of
the Brain, the Cerebral Cortex, and its major regions/divisions.
• Students will be able to describe the primary functions of
the Lobes and the Cortical Regions of the Brain.

8. Cerebrum -The largest division of the brain. It is
divided into two hemispheres, each of which is
divided into four lobes.
Cerebrum
Cerebrum
Cerebellum
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

9. Cerebral Cortex
Cerebral Cortex
Cerebral Cortex - The outermost layer of gray
matter making up the superficial aspect of the
cerebrum.
http://www.bioon.com/book/biology/whole/image/1/1-6.tif.jpg

10. Cerebral Features:
• Sulci – Small grooves dividing the gyri
– Central Sulcus – Divides the Frontal Lobe from the Parietal
Lobe
• Fissures – Deep grooves, generally dividing large
regions/lobes of the brain
– Longitudinal Fissure – Divides the two Cerebral Hemispheres
– Transverse Fissure – Separates the Cerebrum from the
Cerebellum
– Sylvian/Lateral Fissure – Divides the Temporal Lobe from the
Frontal and Parietal Lobes
• Gyri – Elevated ridges “winding” around the brain.

11. Gyri (ridge)
Fissure
(deep groove)
Sulci
(groove)
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

14. Longitudinal Fissure
Transverse Fissure
Sylvian/Lateral
Fissure
Central Sulcus
http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg http://www.dalbsoutss.eq.edu.au/Sheepbrains_Me/human_brain.gif
Specific Sulci/Fissures:

15. Frontal
Parietal
Occipital
Temporal
* Note: Occasionally, the Insula is considered the fifth lobe. It is located
deep to the Temporal Lobe.
http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

16. The Frontal Lobe of the brain is located deep to
the Frontal Bone of the skull.
(Investigation: Phineas Gage)
• It plays an integral role in the following functions/actions:
- Memory Formation
- Emotions
- Decision Making/Reasoning
- Personality
Investigation (Phineas Gage)
Modified from:
http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

17. Orbitofrontal Cortex – Site of Frontal Lobotomies
• Primary Motor Cortex (Precentral Gyrus) – Cortical site involved with controlling
movements of the body.
• Broca’s Area – Controls facial neurons, speech, and language comprehension. Located
on Left Frontal Lobe.
– Broca’s Aphasia – Results in the ability to comprehend speech, but
the decreased motor ability (or inability) to speak and form words.
• Olfactory Bulb - Cranial Nerve I, Responsible for sensation of Smell
* Desired Effects:
- Diminished Rage
- Decreased Aggression
- Poor Emotional
Responses
* Possible Side Effects:
- Epilepsy
- Poor Emotional Responses
- Perseveration (Uncontrolled,
repetitive actions, gestures, or words)

18. Primary Motor
Cortex/ Precentral
Gyrus
Broca’s Area
Orbitofrontal
Cortex
Olfactory Bulb
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg
Regions
Investigation (Phineas Gage)

19. The Parietal Lobe of the brain is located deep
to the Parietal Bone of the skull.
• It plays a major role in the following functions/actions:
- Senses and integrates sensation(s)
- Spatial awareness and perception
(Proprioception - Awareness of
body/ body parts in space and
in relation to each other)
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

20. Primary Somatosensory Cortex (Postcentral
Gyrus) – Site involved with processing of tactile
and proprioceptive information.
• Somatosensory Association Cortex - Assists with the
integration and interpretation of sensations relative to body position
and orientation in space. May assist with visuo-motor coordination.
• Primary Gustatory Cortex – Primary site involved with the
interpretation of the sensation of Taste.

21. Primary Somatosensory
Cortex/ Postcentral
Gyrus
Primary Gustatory Cortex
Somatosensory Association
Cortex
Regions
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

22. The Occipital Lobe of the
Brain is located deep to the
Occipital Bone of the Skull.
•
Its primary function is the
processing, integration,
interpretation, etc. of VISION and
visual stimuli.
Modified from:
http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

23. Primary Visual Cortex – This is the primary
area of the brain responsible for sight
-recognition of size, color, light, motion,
dimensions, etc.
• Visual Association Area – Interprets
information acquired through the primary visual
cortex.

24. Primary Visual Cortex
Visual Association Area
Regions
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

25. The Temporal Lobes are located on the sides of
the brain, deep to the Temporal Bones of the
skull.
•
They play an integral role
in the following functions:
- Hearing
-
Organization/Comprehension of
language
- Information Retrieval
(Memory and Memory Formation)
Modified from:
http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

26. Primary Auditory Cortex – Responsible for hearing
•
Primary Olfactory Cortex – Interprets the sense of
smell once it reaches the cortex via the olfactory
bulbs. (Not visible on the superficial cortex)
• Wernicke’s Area – Language comprehension.
Located on the Left Temporal Lobe.
- Wernicke’s Aphasia – Language comprehension is
inhibited. Words and sentences are not clearly
understood, and sentence formation may be inhibited or
non-sensical.

27. Primary Auditory
Cortex
Wernike’s Area
Primary Olfactory Cortex
(Deep)
Conducted from Olfactory Bulb
RegionsModified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

28. • Arcuate Fasciculus - A white matter tract that connects Broca’s Area and
Wernicke’s Area through the Temporal, Parietal and Frontal Lobes. Allows
for coordinated, comprehensible speech. Damage may result in:
- C o nd u c tio n A p ha s ia - Where auditory comprehension
and speech articulation are preserved, but people find it difficult to
repeat heard speech.
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

29. Click the Region to see its Name
Korbinian Broadmann - Learn about the man who divided the Cerebral Cortex into 52 distinct regions:
http://en.wikipedia.org/wiki/Korbinian_Brodmann
Modified from: http://www.bioon.com/book/biology/whole/image/1/1-8.tif.jpg

30. Lobes and Structures of the Brain
B.
A.
C.
D.
E.
F.
G.
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

31. Lobes and Structures of the Brain
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. Sylvian/Lateral Fissure
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

32. Cortical Regions
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

33. Cortical Regions
A.
B.
C.
D.
E. F.
G.
H.
I.
J.
K.
A. Primary Motor Cortex/ Precentral Gyrus
B. Broca’s Area
C. Orbitofrontal Cortex
K. Primary Somatosensory
Cortex/ Postcentral Gyrus
I. Primary Gustatory Cortex
J. Somatosensory
Association Cortex
G. Primary Visual Cortex
H. Visual Association
Area
E. Primary Auditory Cortex
F. Wernike’s Area
D. Primary Olfactory Cortex (Deep)
http://williamcalvin.com/BrainForAllSeasons/img/bonoboLH-humanLH-viaTWD.gif

34. A: Primary Motor Cortex
* This graphic representation of the regions of the Primary Motor Cortex and
Primary Sensory Cortex is one example of a HOMUNCULUS:
Homunculus

49. Q: Assuming this comical situation was factually
accurate, what Cortical Region of the brain would
these doctors be stimulating?
Copyright: Gary Larson

50. 
Ⅰ
Olfactory nerve

Ⅱ
Optic nerve

Ⅲ
Oculomotor nerve

Ⅳ
Trochlear nerve

Ⅴ
Trigeminal nerve

Ⅵ
Abducent nerve

Ⅶ
Facial nerve

Ⅷ
Vestibulocochlear nerve

Ⅸ
Glossopharyngeal nerve

Ⅹ
Vagus nerve

Ⅺ
Accessory nerve

Ⅻ
Hypoglossal nerve

51. Sensory cranial nerves: contain only afferent (sensory) fibers
ⅠOlfactory nerve
ⅡOptic nerve

Ⅷ
Vestibulocochlear nerve
Motor cranial nerves: contain only efferent (motor) fibers

Ⅲ
Oculomotor nerve

Ⅳ
Trochlear nerve
ⅥAbducent nerve

Ⅺ
Accessory nerv

Ⅻ
Hypoglossal nerve
Mixed nerves: contain both sensory and motor fibers---
ⅤTrigeminal nerve,

Ⅶ
Facial nerve,
ⅨGlossopharyngeal nerve
ⅩVagus nerve

52. N.Location of cell
body and axon
categories
Cranial
exit
Terminal
nuclei
Main
action
ⅠOlfactory cells
(SVA)
Cribrifom
foramina
Olfactory
bulb
Smell
ⅡGanglion cells
(SSA)
Optic
canal
Lateral
geniculate
body
Vision
ⅧVestibular
ganglion(SSA)
Internal
acoustic
meatus
Vestibular
nuclei
Equilibri
um
Cochlear
ganglion (SSA)
Cochlear
nuclei
Hearing

53. Olfactory mucosa (SVA)→ Cribriform foramina → Olfactory
bulb

54. Ganglion cell (SSA) → Optic canal → Lateral geniculate body

55. Vestibular ganglion(SSA) ↘ ↗ Vestibular nuclei
Internal acoustic meatus
Cochlear ganglion (SSA) ↗ ↘ Cochlear nuclei

56. N. Nucleus of origin and
axon categories
Cranial exit Main action
ⅢNucleus of oculomotor
(GSE)
Superior orbital
fissure
Motot to superior, inferior
and medial recti; inferior
obliquus; levator
palpebrae superioris
Accessory nucleus of
oculomotor (GVE)
Parasympathetic to
sphincter pupillea and
ciliary muscl
ⅣNucleus of trochlear
nerve (GSE)
Superior orbital
fissure
Motor to superior obliquus
ⅥNucleus of abducent
nerve (GSE)
Superior orbital
fissure
Motor to lateral rectus
ⅪNucleus of accessory
nerve (SVE)
Jugular foramen Motor to
sternocleidomastoid and
trapezius
ⅫNucleus of hypoglossal
nerve( GSE)
Hypoglossal canalMotot to muscles of
tongue

58. Components
General somatic efferent fibers (GSE)
General visceral efferent fibers (GVE)
Main action－supplies
Superior, inferior and medial recti; inferior obliquus; levator palpebrae
superioris
Sphincter pupillea and ciliary muscle
Ciliary ganglion: lies between optic nerve and lateral rectus
Oculomotor nerve

59. Abducent nerve
Accessory nerve

60. Hypoglossal nerve

61. Oculamotor paralysis
Abducent nerve injury

63. Components of fibers
SVE fibers: originate from motor nucleus of
trigeminal nerve, and supply masticatory
muscles
GSA fibers: transmit facial sensation to
sensory nuclei of trigeminal nerve, the GSA
fibers have their cell bodies in trigeminal
ganglion, which lies on the apex of petrous part
of temporal bone

65. Branches
Ophthalmic nerve
( 1, sensory) leave
Ⅴ
the skull through the
superior orbital fissure,
to enter orbital cavity
Branches
Frontal nerve:
Supratrochlear nerve
Supraorbital nerve
Lacrimal nerve

Nasociliary nerve

66. Distribution:
Sensation from
cerebral dura mater
Visual organ
Mucosa of nose
Skin above the eye
and back of nose

67. Maxillary nerve ( 2,
Ⅴ
sensory)
Leave skull through
foramen rotundum
Branches
Infraorbital nerve
Zygomatic nerve
颧
Superior alveolar
nerve
Pterygopalatine
nerve

68. Distribution:
Sensation from cerebral
dura mater
Maxillary teeth
Mucosa of nose and
mouth
Skin between eye and
mouth

69. Mandibular nerve ( 3,
Ⅴ
mixed)
Leave the skull through the
foramen ovale to enter the
infratemporal fossa
Branches
Auriculotemporal nerve
耳颞
Buccal nerve
Lingual nerve
Inferior alveolar nerve
Nerve of masticatory muscles

71. Distribution:
Sensation from cerebral
dura mater
Teeth and gum of lower
jaw
Mucosa of floor of mouth
Anterior 2/3 of tongue
Skin of auricular and
temporal regions and
below the mouth
Motor to masticatory
muscles, mylohyoid, and
anterior belly of digastric

72. Components of fibers
SVE fibers originate from nucleus of facial nerve, and supply
facial muscles
GVE fibers derived from superior salivatory nucleus and
relayed in pterygopalatine ganglion and submandibular
ganglion. The postganglionic fibers supply lacrimal,
submandibular and sublingual glands
SVA fiber from taste buds of anterior two-thirds of tongue
which cell bodies are in the geniculate ganglion of the facial
nerve and end by synapsing with cells of nucleus of solitary
tract
GSA fibers from skin of external ear

74. Course: leaves skull
through internal
acoustic meatus, facial
canal and stylomastoid
foramen, it then enters
parotid gland where it
divides into five
branches which supply
facial muscles

75. Branches within the facial canal
Chorda tympani : joins lingual branch of mandibular nerve
To taste buds on anterior two-thirds of tongue
Relayed in submandibular ganglion, the postganglionic fibers supply
submandibular and sublingual glands

76. Greater petrosal nerve: GVE fibers pass to pterygopalatine ganglion
翼腭神经节 and there relayed through the zygomatic and lacrimal
nerves to lacrimal gland
Stapedial nerve : to stapedius

77. Branches outside of facial canal
Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical

78. Pterygopalatine ganglion : lies in pterygopalatine
fossa under maxillary nerve
Submandibular ganglion : lies between lingual
nerve and submandibular gland

79. Injury to the facial nerve

80. Components of fibers
SVE fibers: originate from nucleus ambiguus, and supply
stylopharygeus
GVE fibers: arise from inferior salivatory nucleus and
ralyed in otic ganglion, the postganglionic fibers supply
parotid gland
SVA fibers: arise from the cells of inferior ganglion, the
central processes of these cells terminate in nucleus of
solitary tract, the peripheral processes supply the taste
buds on posterior third of tongue
GVA fibers: visceral sensation from mucosa of posterior
third of tongue, pharynx, auditory tube and tympanic
cavity, carotid sinus and glomus, and end by synapsing
with cells of nucleus of solitary tract
GSA fibers: sensation from skin of posterior surface of
auricle and

82. Course: leaves the skull via jugular foramen
Branches
Lingual branches : to taste buds and mucosa of posterior third of
tongue
Pharyngeal branches : take part in forming the pharyngeal plexus
Tympanic nerve : GVE fibers via tympanic and lesser petrosal
nerves to otic ganglion, with postganglionic fibers via
auriculotemporal ( 3) to parotid gland
Ⅴ
Carotid sinus branch : innervations to both carotid sinus and glomus
Others: tonsillar and stylophayngeal branches
Otic ganglion : situated just below foramen ovale

84. components of fibers
GVE fibers: originate from dorsal nucleus of
vagus nerve, synapse in parasympathetic
ganglion, short postganglionic fibers innervate
cardiac muscles, smooth muscles and glands of
viscera
SVE fibers: originate from ambiguus, to
muscles of pharynx and larynx
GVA fibers: carry impulse from viscera in neck,
thoracic and abdominal cavity to nucleus of
solitary tract
GSA fiber: sensation from auricle, external
acoustic meatus and cerebral dura mater

86. Course
Exits the skull from jugular foramen
Descends in the neck in carotid sheath between
internal (or common) carotid artery and internal
jugular vein
Right vagus nerve
Enter thoracic inlet on right side of trachea
Travels downward posterior to right
brachiocephalic vein and superior vena cava
Passes posterior to right lung root
Forms posterior esophageal plexus
Forms posterior vagal trunk at esophageal hiatus
where it leaves thorax and passes into abdominal
cavity, then divides into posterior gastric and celiac
branches

87. Left vagus nerve
Enter thoracic inlet between left common
carotid and left subclavian arteries, posterior
to left brachiocephalic vein
Crosses aortic arch where left recurrent
laryngeal nerve branches off
Passes posterior to left lung root
Forms anterior esophageal plexus
Forms anterior vagal trunk at esophageal
hiatus where it leaves thorax and passes into
abdominal cavity , then divides into anterior
gastric and hepatic branches

88. Branches in neck
Superior laryngeal nerve: passes down side
of pharynx and given rise to
Internal branch, which pierces thyrohyoid
membrane to innervates mucous membrane of
larynx above fissure of glottis
External branch, which innervates cricothyroid
Cervical cardiac branches : descending to
terminate in cardiac plexus
Others: auricular, pharyngeal and
meningeal branches

89. Superior laryngeal nerve
External branch
Internal branch

90. Branches in thorax
Recurrent laryngeal nerves
Right one hooks around right
subclavian artery, left one hooks aortic
arch
Both ascend in tracheo-esophageal
groove
Nerves enter larynx posterior to
cricothyroid joint, the nerve is now
called inferior laryngeal nerve
Innervations: laryngeal mucosa below
fissure of glottis , all laryngeal
laryngeal muscles except cricothyroid
Bronchial and esophageal branches

91. Branches in abdomen
Anterior and posterior gastric
branches
Run close to lesser curvature
and innervate anterior and
posterior surfaces of stomach
As far as pyloric antrum to fan
out into branches in a way like
the digits of a crow’s foot to
supply pyloric part
Hepatic branches: join hepatic
plexus and then supply liver
and gallbladder
Celiac branches: send
branches to celiac plexus to be
distributed with sympathetic
fibers to liver, pancreas,
spleen, kidneys, intestine as
far as left colic flexure

99. "Men ought to know that from
nothing else but the brain come
joys, delights, laughter and
sports, and sorrows, griefs,
despondency, and lamentations.
Hippocrates (460 BC – ca. 370 BC)