Cranial Anatomy Revision

8/6/2019 Cranial Anatomy Revision

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Second Year Semester One Revision

Cranial Bones

Frontal bone

Parietal bone (*2) Occipital bone

Temporal bone (*2)

Sphenoid bone

Ethmoid bone

Facial Bones

Nasal

Maxillae

Lacrimals

Zygomatics

Palantines

Middle Nasal Conchae

Inferior Nasal Conchae

Nasal Septum

Mandible

The Scalp

There are 5 layers spelling out the word SCALP

1. Skin

2. Connective tissue (blood vessels travel through this tissue)

3. Aponeurosis

4. Loose connective tissue (allows fluid/bacteria to pass from back of head into

eyelids)

5. Periosteum

NB. The veins of the scalp drain into the superior saggital sinus and then to the

confluency of sinuses. They have no valves and therefore can be a source of infection

in the brain.

Sutures

Coronal

Lamboidal

Saggital

Squamosal

Pterion

Sphenoid

Parietal

Temporal


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The Meninges

The surface of the brain is made up of 3 layers:

1. Dura Mater toughest and thickest forms venous sinuses and subdivides brain

with: Falx Cerebri down centre of brain, separating two hemispheres.

Tentorium Cerebelli separating cerebellum from the rest of the

brain.

2. Arachnoid Mater spider-like appearance. Thin, transparent, fibrous.

3. Pia Mater attached to brain.

Between the arachnoid and pia mater layers lies the subarachnoid space. This contains

CSF which is continuously being produced by ependyma cell in the ventricles. CSF is

removed by arachnoid granulations, allowing CSF to enter the venous sinuses.

The Circle of Willis


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Sinuses

Superior Sagittal Sinus Straight Sinus

Right Transverse Sinus Left Transverse Sinus

Communication at the

Internal Occipital Protuberance

(confluency of sinuses)

Sigmoid Sinus

Internal Jugular Vein

Air Sinuses in the Head

Frontal

Ethmoid

Sphenoid

Maxillary

Mastoid

The Cranial Nerves

There are 12 pairs of cranial nerves:

Nerve Exit from Skull Function

1. Olfactory Cruciform Plate Smell

2. Optic Nerve Optic Canal Vision

3. Occulomotor Sup. Orbital

Fissure

Innervates Eye Muscles except SO.

Innervates Sphincter Pupillae for pupil

constriction.

4. Trochlear Sup. Orbital

Fissure

Innervates Superior Oblique Muscle

(moves eye down and out).

5. Trigeminal

Olfactory (V1)

Maxillary (V2)

Mandibular (V3)

Sup. Orbital

Fissure

Foramen

Rotundum

Sensory from: Eyes, Conjuctivia, orbital

contents, nasal cavity, frontal sinus,

Ethmoid sinus, upper eyelid, dorsum of

nose, ant. part of scalp.

Dura, nasopharynx, palate, nasal cavity,

upper teeth, maxillary sinus, skin

covering nose, lower eyelid, cheek,

upper lip.

Skin of lower face, cheek, lower lip, ear,external acoustic meatus, temporal fossa,


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Foramen Ovale

ant. 2/3 of tongue, lower teeth,

mandible, dura in mid cran fossa.

Innervates temporalis, masseter, ant.

belly of digastric, mylohyoid muscles.

6. Abducens Sup. Orbital

Fissure

Innervates lateral rectus muscle.

7. Facial

Temporal

Zygomatic

Buccal

Mandibular

Cervical

Internal Acoustic

Meatus

8. Auditory (Vestibulo-

cochlear)

Internal Acoustic

Meatus

Vestibular Balance

Cochlear Hearing

9. Glossopharyngeal Jugular Foramen

10. Vagus Jugular Foramen11. Accessory Jugular Foramen Innervates sternocleidomastoid and

trapezius muscles.

12. Hypoglossal Hypoglossal Canal Innervates hypoglossus, genioglossus,

and styloglossus mucles and intrinsic

muscles of tongue.

Osteology of the Skull

Foramina:

Foramen Nerve Content

Cribiform Plate Olfactory (I)

Optic Canal Optic (II)

Ovale Mandibular (V3)

Rotundum Maxillary (V2)

Spinosum

Superior Orbital Fissure Occulomotor (III)

Trochlear (IV)

Ophthalmic (VI)

Abducens (VI)

Internal Acoustic Meatus Facial (VII)Vestibulocochlear (VIII)

Stylomastoid Mid Meningeal Artery

Jugular Glossopharyngeal (IX)

Vagus (X)

Accessory (XI)

Hypoglossal Hypoglossal (XII)

Magnum Medulla Oblongata

Meninges

Carotid Canal Internal Carotid Artery


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The Muscles of Facial Expression

The Muscles of Mastication

Blood Vessels of the Face

Facial Artery:

1. Occipitofrontalis

2. Corrugator supercilii

3. Procerus

4. Palpebral ligament

5. Orbicularis oculi

6. Levator labii superioris alaeque nasi

7. Nasalis

8. Levator anguli oris

9. Levator labii superioris

10. Zygomaticus minor

11. Zygomaticus major

12. Risorius

13. Depressor anguli oris

14. Depressor labii inferiorisi

15. Orbicular oris

16. Mentalis

17. Buccinator

18. Platysma

19. Temporoparlis

20. Temporali

21. Masseter

22. Lateral pterygoid

23. Medial pterygoid


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Branch of External Carotid

Crosses border of jaw at ant. border of jaw

Runs up to medial angle of jaw.

Transverse Facial appears at ant border of parotid gland.

Facial Vein:

Commences at medial angle of eye

Runs to angle of jaw

Joins Internal Jugular Vein.

The Facial Nerve

Motor nerve for all muscles of facial expression

Leaves skull at stylomastoind foramen.

Runs to parotid gland and forms nerve plexus.

The 5 nerves are:

1. Temporal2. Zygomatic

3. Buccal

4. Mandibular

5. Cervical

Glands

Submandibular

Parotid

Sub Mental

The Muscles of the Neck


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The Brachial Plexus:


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Sagittal Section of the Brain:

Corpus

Callosum

Septum

PellucidumFornix

Cerebellum

Genu

Medulla

Oblongata

Pineal Bod


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Lumbar Nerves

PonsThalamus


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Horizontal Section of Normal Brain

Gastrointestinal Revision

Two layers of superficial fascia

1. Campers Fascia (fatty layer)

2. Scarpas Fascia (membranous layer)

Then comes:

External Oblique

Internal Oblique

o Neurovascular plane supplying

abdominal wall.

Transersus Abdominus

Rectus Abdominuso Contains tendonous intersections

o Superior and Inferior Epigastric Arteries

Rectus Sheath

Near the pubic tubercle is a triangular slit in the

external oblique aponeurosis called the SUPERFICIAL

INGUINAL RING. This contains the:

Round ligament in females

Spermatic cord in males

Ilioinguinal nerve in both.


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The posterior section of the rectus sheath is only in the

upper 2/3.

The lower border = the ARCUATE line

Below the level of the Arcuate line = transveralis fascia

Then comes peritoneum.

NB. External Oblique hands in front pockets (anteriorly and inferiorly)

Internal Oblique hands in back pockets (anteriorly and superiorly)

Inguinal ligament

formed by curving

inward of the lower

border of the external

oblique aponeurosis.

Superficial Inguinal

Ring in external

oblique

Deep Inguinal Ring in

transversalis fascia

Coverings of spermatic

cord derived from

layers of anteriorabdominal wall

Tunica Vaginalis

from peritoneum. Lets

testis descend.

The Liver

Bare Area

(right lobe)

Falciform

Ligament

Cornary

Ligament


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Posterior View of the Liver

Ligamentum

Teres (obliterated

umbilical vein)

contained withinfalciform ligament

Gall Bladder

Portal Vein

Hepatic

Artery

Caudate

Lobe

Quadrate

Lobe Inferior

Vena Cava

Cystic Duct

(runs to gall bladder

Common

Bile Duct in porta hepatis

Porta Hepatis

Gall Bladder

The stomach Pyloric Region, Fundus, Body, Pyloric

Sphincter

Duodenum

NB. LOOK AT STOMACH ARTERIES

DIAGRAHM

Space which lies deep to the stomach = the

LESSER SAC

Epiploic Foramen = opening to lesser sac

Neck

Body

Fundus


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NB. Arteries: R+L gastro-epiploic vessels

L+R gastric arteries, gastro-duodenal artery, superior pancreaticoduodenal artery,

anterior and posterior vagus nerves.

The colon

1. Transverse colon

2. Splenic Flexure

3. Descending colon

4. Sigmoid colon

5. Rectum

6. Caecum

7. Ascending colon

8. Hepatic Flexure

NB. The transverse colon has APPENDICES EPIPLOIC, teniae coli and haustrations

Ascending colon is fixed to the posterior abdominal wall (retroperitoneal)

Teniae coli bands of muscle fibre in colon

Haustrations polysac appearance of colon due to teniae coli.

Jejunum and Ileum

Note Appendix

Caecum

Jejunum has fewer vasa recta

than ileum

Ileum has many more vasa recta

than jejunum

NB. The ileum attaches to the caecum andthe jejunum to the duodenum

The sigmoid colon has its own mesentery.

Retroperitoneal and Mesentery Organs

Mesentery Retroperitoneal

Transverse colon

Sigmoid colon

Ileum

Jejunum

Ascending colon

Descending colon

Rectum

Ileocaecal

junction


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The mnemonic SAD PUCKERis commonly used to remember the retroperitoneal

viscera:

Suprarenal glands

Aorta and IVCDuodenum

Pancreas

Ureter

Colon (ascending and descending)

Kidneys

Eosophagus

Rectum

Mesentery Viscera

1. Mesentery (proper) jejunum and ileu

2. Mesocolon surrounds parts of colon

Meso-appendix

Transverse mesocolon

Sigmoid mesocolon

Broad ligament of uterus, uterine tubes, ovaries

The Duodenum 4 parts

NB. Inside the

duodenum are

ridges called

papillae.

The Ampulla of

Vater is the union

between common

bile duct andpancreatic duct.

Know opening

of Hepato-

pancreatic duct

(little opening

inside)

Superior

Part

Descending

Part

Inferior

Part

AscendingPart


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The Pancreas 4 parts

Head

Neck

Body

Tail

Abdominal Vessels - Arteries

TailBody

Neck

Head


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Abdominal Vessels Veins

Biliary System

NB. R+L heptic

ducts join to form

the common hepatic

duct.

The common

hepatic duct

combines with the

cystic duct to make

the common bile

duct.

The common bile

duct combines with

the pancreatic duct

at the Ampulla of

Vater.


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Lymphatic Drainage

The Superior Mesenteric Artery

The Celiac Trunk

L. Gastric Artery

Splenic Artery

Commonhepatic Artery

Superior Mesenteric Artery. Lies over

horizontal section of duodenum


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The celiac trunk has 3 branches:

1. Common Hepatic Art. 2. L. Gastric Art. 3. Splenic Art.

Lumbar Plexus Above

Inferior Mesenteric Artery

The Abdominal Aorta


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Muscles of the Posterior Abdominal Wall

External Iliac

Artery

Internal Iliac Artery

Cranial Anatomy Revision

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