General AnatomyPractical Revision (1): Skeletal System

Dr. Ashraf RamzyProfessor of Anatomy & Embryology

ash-ramzy@hotmail.com

I. Skull

5 Unpaired bones

1. Frontal

2. Occipital

3. Ethmoid

4. Sphenoid

5. Vomer

1

2

3

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Dr Ashraf Ramzy

8 Paired bones1. Parietal

2. Temporal

3. Maxillary

4. Zygomatic

5. Nasal

6. Lacrimal

7. Palatine

8. Inferior concha

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4

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Dr Ashraf Ramzy

Frontal Bone

Parietal Bone

Occipital Bone

Lambdoid Suture

Sagittal Suture

Coronal Suture

Bregma

Lambda

* It presents 3 sutures:

1. coronal suture:

2. The sagittal suture:

3. The lambdoid suture:

Dr Ashraf Ramzy

* It presents 2 meeting points:

1. The bregma: is the meeting of coronal and sagittal sutures.

2. The lambda: is the meeting of the lambdoidand sagittal sutures.

Dr Ashraf Ramzy

Parietal Bone

Temporal Bone(Squamous part)

Occipital Bone

Temporal Bone(Tympanic part)

Temporal Bone(Styloid process)

Zygomatic Arch

Coronal Suture

Lambdoid Suture

Temporal Bone(Mastoid process)

Sphenoid Bone(Greater Wing)

Zygomatic Arch

Coronal Suture

Lambdoid Suture

Pterion

Asterion

Superior Temporal Line

Inferior Temporal Line

External Auditory Meatus

*It is formed of: frontal, parietal, occipital, temporal, greater wing of sphenoid bone, maxilla and zygomatic bones.

*The superior temporal line: extends from zygomatic bone and passes backwards.

*The inferior temporal line: with the temporal fossa lies below it.

F P

OS T

M

Z

Dr Ashraf Ramzy

* The zygomatic arch (Z): * The external auditory meatus (E):* The mastoid process (M): * The Styloid process (↑):* Pterion (P).* Asterion (↓).

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Z

P

ME

Frontal Bone

Temporal Bone

Zygomatic Bone

Maxillary Bone

Nasal Bone

Inferior Nasal Choncha

Mandible

Frontal Bone

Supraorbital Foramen (Notch)

Infraorbital Foramen

Mental ForamenMandible

Maxillary Bone

2. The 2 nasal bones:

3. Zygomatic bone:

4. The maxillary bone:

Is has a body which contains

the maxillary air sinus.

It is pierced by the infra-

orbital foramen (which gives

passage to infra-orbital nerve

& vessels).

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Dr Ashraf Ramzy

External Occipital Protuberance

External Occipital Crest

Superior Nuchal Line

Inferior Nuchal Line

Dr Ashraf Ramzy

* The occipital bone presents:

1. External occipital protuberance:

2. External occipital crest:

3. The superior nuchal lines:

extends laterally from the

protuberance.

4. The inferior nuchal lines:

extends laterally from the crest & run

parallel to and below the superior

nuchal lines.

External Occipital Protuberance

External Occipital Crest

Inferior Nuchal Line

Superior Nuchal Line

Posterior Nasal Openings (Choanae)

Vomer

Hard Palate:

- Palatine Bone

- Maxillary BoneAlveolar Arch

Greater Palatine Foramen

Foramen Ovale

Foramen Spinosum

Foramen Lacerum

Jugular Foramen

Stylomastoid Foramen

Posterior Condylar Foramen

Carotid Canal

Foramen Magnum

Incisive Fossa

Hard Palate:

- Palatine Bone

- Maxillary Bone

Greater Palatine Foramen

Maxillary Tuberosity

Foramen Ovale

Foramen Spinosum

Jugular Foramen

Foramen Magnum

Incisive Fossa

Foramen Ovale

Foramen Spinosum

Foramen Lacerum

Jugular Foramen

Internal Auditory Meatus

Foramen Magnum

Ethmoid Bone(Crista Galli) Rotundum Foramen

Hard Palate:

- Palatine Bone

- Maxillary Bone

Vomer

Occipital Bone(Basilar part)

- Lateral Pterygoid Plate

- Medial Pterygoid Plate

- Pterygoid Fossa

Pterygoid Process:

Sphenoid (Body)

Sphenoid (Greater wing )

Temporal Bone(Petrous part)

Temporal Bone(Mastoid process)

Temporal Bone(Tympanic Part)

Occipital Condyle

* The greater palatine foramen (↓) lies in the posterior part of the hard palate. It gives passage to greater palatine nerve & vessels.

* The lesser palatine foramina, usually two, lie behind the greater palatine foramen. They give passage to lesser palatine nerve & vessels.

* The maxillary tuberosity (→) is present at the posterior end of the alveolar arch.

* The incisive fossa (↑) lies posterior to the central incisor teeth. It contains foramina which serve as a connection between palate & nose.

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↓→

B. Middle part:

* In the middle, it shows:

1. Vomer.

2. Body of sphenoid.

3. Basilar part of occipital bone.

* Laterally, it shows:

4. Pterygoid process.

5. Greater wing of sphenoid.

6. Petrous part of temporal bone.

7. tympanic parts of temporal bone.

8. Mastoid process.

* It contains: Posterior nasal openings (9) (choanae) which are separated by vomer (part of nasal septum).

1

2

3

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** The pterygoid process of the sphenoid bone:

* It is formed of lateral pterygoid plate (L) and medial pterygoid plate (M) with the pterygoid fossa (F) in between.

ML F

Dr Ashraf Ramzy

** The greater wing of sphenoid bone shows:

1. Foramen ovale (↓):

* Gives passage to:

a. Mandibular nerve.

b. Lesser petrosal nerve.

c. Accessory meningeal artery.

2. Foramen spinosum (↑):

* Gives passage to:

a. Nervus spinosus.

b. Middle meningeal artery.

↓

↓

Dr Ashraf Ramzy

C. Posterior part:

** The basilar part of occipital bone (B) articulates anteriorly with the body of the sphenoid bone.

** Foramen lacerum (↓) lies between petrous part of temporal bone, basilar part of occipital and the pterygoid process. In life it is closed by cartilage plate.

** The carotid canal (↑): lies posterolateral to foramen lacerum. Gives passage to internal carotid artery.

↓

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Dr Ashraf Ramzy

B

** Notice the following:

1. The jugular foramen: lies lateral to the occipital condyle. Gives passage to internal jugular vein.

2. The stylomastoid foramen: lies between styloid and mastoid processes. Gives passage to facial nerve.

3. The occipital condyles: articulate with the atlas to form atlanto-occipital joint.

4. The anterior condylar (hypoglossal) foramen. Gives passage to hypoglossal nerve.

5. The posterior condylar foramen.

6. The foramen magnum: communicates the cranial cavity with the vertebral canal. Gives passage to brain stem which continues as spinal cord.

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Dr Ashraf Ramzy

Frontal Bone(Frontal Crest)

Ethmoid Bone(Crista Galli)

Sphenoid Bone(lesser Wing)

Sphenoid Bone

Foramen Caecum

Ethmoid Bone(Cribriform Plate)

Frontal Bone(Orbital Plate)

Sphenoid Bone(Body)

Sphenoid Bone (Greater Wing)

Temporal Bone(Petrous Part)

Occipital Bone

Anterior Condylar Foramen(Hypoglossal)

Rotundum Foramen

Transverse Sulcus

Sigmoid Sulcus

Jugular Foramen

Internal Auditory Meatus

Internal Occipital Crest

Internal Occipital Protuberance

Clivus

* It is formed by the following bones:

* In the midline:

1- Frontal bone.

2- Ethmoid.

3- Sphenoid.

* On each side:

a. Frontal bone.

b. Sphenoid (lesser wing).

1

2

3

a

b

Ant. Cranial Fossa

Dr Ashraf Ramzy

* Midline structures of the anterior cranial fossa:

1. Frontal crest.

2. Foramen caecum.

3. Crista galli.

4. Cribriform plate of ethmoid (gives passage to olfactory nerve).

Dr Ashraf Ramzy

* Formed by the following bones:

* In the midline:

Sphenoid (body).

* On each side:

1- Sphenoid (greater wing).

2- Temporal bone:

a. Petrous part.

b. Squamous part.

3- Parietal bone.

Middle Cranial Fossa

3 2-b 1 Body

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Dr Ashraf Ramzy

* Middle cranial fossa shows:

Greater wing of sphenoid which contains:

1. Sup. Orbital Fissure → gives passage to nerves & vessels of orbit.

2. F. Rotundum → gives passage to maxillary nerve

3. F. Ovale.

4. F. Spinosum.

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←←

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Dr Ashraf Ramzy

* Formed by the following bones:

* In the midline:

Occipital bone.

* Laterally-placed:

1- Petrous part of temporal bone.

2- Parietal bone.

3- Occipital bone.

Post. Cranial Fossa

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Dr Ashraf Ramzy

* Midline structures in the posterior cranial fossa :

1. Clivus (formed by: body of sphenoid + basilar part of occipital bone).

2. Foramen magnum.

3. Internal occipital crest.

4. Internal occipital protuberance.

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* Two sulci & 3 foramina:

1. Transverse sulcus (contains transverse sinus).2.Sigmoid sulcus (contains sigmoid sinus).3. Hypoglossal canal (gives passage to hypoglossal nerve).4. Jugular foramen (gives passage to internal jugular vein).5. internal auditory meatus → gives passage to 7th & 8th

cranial nerves).

* Laterally-placed structures in the post. cranial fossa:

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2

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4

→

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Dr Ashraf Ramzy

You have to know & revise

The structures passing through the different

foramina mentioned in the lectures.

II. Mandible

A. The body

* External surface:* The mental foramen lies midway between upper & lower borders, below 2nd

premolar tooth.

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↑

* Internal surface :•It shows the mylohyoid line (↑).•Below this line is the submandibular fossa (SM), while above this line is the sublingual fossa (SL).

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SL↑ SM

B. Ramus of mandible

* It has two surfaces.

1. The medial surface: shows the mandibular foramen which leads to mandibular canal.

• Projecting over the foramen is the lingula .

• The mylohyoid groove starts at the lower border of the foramen.

2. The lateral surface: is flat

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** Upper border:

• Shows two process coronoid anteriorly and condylar process posteriorly and in between the mandibular notch.

• The condylar process is expanded to form the head of the mandible.

• The constricted area below the head is the neck.

• Angle of the mandible is the area of meeting of body and the ramus .

Dr Ashraf Ramzy

III. Cervical Vertebrae

Transverse ProcessForamen Transversarium

Atlas (C1)

Vertebral foramen

Foramen Transversarium

Odontoid Process (Dens)

Spinous Process

Axis (C2)

Vertebral foramen

Transverse Process

Foramen Transversarium

Atlas (C1)

Odontoid Process (Dens)

Spinous Process

Axis (C2)

Vertebral foramen

Vertebral foramen

Transverse Process

Foramen TransversariumVertebral foramen

Typical Cervical Vertebra

Spinous Process(Bifid)

Body

7th Cervical Vertebra

Spine is long & not bifid

IV. Thoracic Vertebrae

Body

Pedicle

Transverse process

Lamina

Spinous Process

Vertebral foramen

Articular facet Body

Articular Process

Body

Pedicle

Transverse process

Lamina

Spinous ProcessVertebral foramen

Body

Spinous Process

Dr. Ashraf Ramzy

The Thoracic Vertebrae

* 12 in number

* Each is formed of :

•Body

•Pedicle

• Transverse process

• Lamina

• Spine

•Vertebral foramen

•Articular facets

V. Lumbar Vertebrae& Sacrum

Sacrum

Coccyx

1

4

2

3

5

Lumber Vertebra

Body

Transverse process

Spine

Pedicle

Transverse process

Lamina

Spinous Process

Vertebral foramen

Body

Spinous Process

Transverse process

Pedicle

Spinous Process

Lumber Vertebra

VI. Typical Ribs

Dr. Ashraf Ramzy

Parts of a typical rib

•Vertebral end →

head, neck & tubercle•Shaft •Sternal end →groove for attachment of costal cartilage.

VII. Sternum

Sternal Angle(Angle of Louis)

Xiphisternal Joint

Manubrium

Body

Xiphoid Process

1

2

8

3

4

7

5

6

9

10

Costal Cartilage

Jugular NotchClavicular Notch

VIII. Bones of Upper Limb

Medial end (Sternal End)

Lateral End (Acromial End)

Medial 2/3 (Concave posteriorly)

Lateral 1/3(Concave Anteriorly)

Upper Surface (smooth)

Right Clavicle

Medial end (Sternal End)

Lateral End (Acromial End)

Upper Surface (smooth)

Right Clavicle

Medial end (Sternal End)

Lateral End (Acromial End)

Lower Surface (Rough)

Suparaspinous Fossa

Infraspinous Fossa

Spine of scapula

Acromion Process

Inferior Angle

Superior Angle

Lateral Angle

Glenoid Cavity

Coracoid Process

Subscapular Fossa

Suparaspinous Fossa

Infraspinous Fossa

Spine of scapula

Acromion Process

Inferior Angle

Superior Angle

Lateral Angle

Glenoid Cavity

Coracoid Process

Subscapular Fossa

Inferior Angle

Superior Angle

Infraspinous Fossa

Spine of scapula

Acromion Process

Glenoid Cavity

Coracoid Process

Subscapular Fossa

Inferior Angle

Head

Anatomical Neck

Surgical Neck

Greater Tuberosity

Olecranon Fossa

Lateral Epicondyle

Medial Epicondyle

Body (Shaft)

Head

Anatomical Neck

Surgical Neck

Greater Tuberosity

Coronoid Fossa

Lateral EpicondyleMedial Epicondyle

Lesser Tuberosity

CapitulumTrochlea

Radial Fossa

Body (Shaft)

Head

Anatomical Neck

Surgical Neck

Greater Tuberosity

Olecranon Fossa

Lateral EpicondyleMedial Epicondyle

Body (Shaft)

Greater Tuberosity

Lateral Epicondyle

Coronoid Fossa

CapitulumTrochlea

Radial Fossa

Lesser Tuberosity

UlnaRadius

HeadStyloid Process

Olecranon Process

Coronoid Process

Radial Notch

Trochlear Notch

Radial Notch

Coronoid Process

Olecranon Process

Head

Neck

Radial Tuberosity

Styloid Process

Ulnar Notch

Radius Ulna

Styloid Process

Coronoid Process

Radial Notch

Trochlear NotchOlecranon Process

Head

Neck

Radial Tuberosity

Radius Ulna

Scaphoid

Lunate Triquetrum

PisiformTrapezium

TrapezoidCapitate

Hamate

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2 3 4 5

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Metacarpal bones:

- Body (Shaft)

- Head (Distal)

- Base (Proximal)

Phalanges:

- Base

- Body

- Head

ScaphoidLunate

Triquetrum

Trapezium

Trapezoid

Capitate

Hamate

IX. Bones of Lower Limb

Acetabulum

Obturator Foramen

Iliac Crest

Gluteal Surface

Anterior Superior Iliac Spine (ASIS)

Anterior Inferior Iliac Spine (AIIS)

Posterior Superior Iliac Spine (PSIS)

Posterior Inferior Iliac Spine (PIIS)

Pubis:

- Body of pubis

- Superior pubic Ramus

- Inferior pubic Ramus

Greater Sciatic Notch

Ischial Spine

Ischial tuberosity

Ischial Ramus

Lesser Sciatic Notch

Acetabulum

Obturator Foramen

Iliac Crest

Iliac Fossa

Anterior Superior Iliac Spine (ASIS)

Anterior Inferior Iliac Spine (AIIS)

Pubis:

- Body of pubis

- Superior pubic Ramus

- Inferior pubic Ramus

Ischial Ramus

Ischial tuberosity

Pubic Symphysis

Head

Neck

Greater Trochanter

Lesser Trochanter

Intertrochanteric LineIntertrochanteric Crest

Medial Condyles Lateral Condyle

Medial Epicondyles

Lateral Epicondyle

Intercondylar Fossa(Notch)

Patella(Anterior Surface)

Patella(Posterior Surface)

Base

Apex

Base

Apex

Articular Facets

Medial Condyle

Lateral CondyleArticulation Facet

for Fibula

Tibial tuberosity

Medial MalleolusFibular Notch

TibiaFibula

Head of Fibula

Lateral Malleolus

Medial Condyle

Lateral Condyle Articulation Facet for Fibula

Tibial tuberosity

Medial Malleolus

Fibular Notch

Talus

Calcaneus

Navicular

Cuboid

Medial Cuneiform

Lateral Cuneiform

Intermediate Cuneiform

TibiaFibula

Lateral Malleolus

Tarsal Bones

12

3

Big Toe

4

5- Base (Proximal)

- Shaft

- Head (Distal)

Metatarsal Bones:

Phalanges:- Base

- Shaft

- Head