Cranium AnatomyCranium Anatomy

What’s in your head?What’s in your head?

ANATOMY OF THE SKULL ANATOMY OF THE SKULL & BRAIN& BRAIN

A. The “SCALP”A. The “SCALP”S – Skin- of the scalp is more dense S – Skin- of the scalp is more dense

than anywhere else on the bodythan anywhere else on the bodyC – Connective tissue- dense; binds C – Connective tissue- dense; binds

skin to apneurosis. Bleeds severely skin to apneurosis. Bleeds severely when cut. Painful region when when cut. Painful region when injured, but little swelling.injured, but little swelling.

A - Apneurosis- is tissue that becomes A - Apneurosis- is tissue that becomes MM when over the frontal & MM when over the frontal & occipital areas. Helps absorb occipital areas. Helps absorb trauma to the skull, especially trauma to the skull, especially glancing blowsglancing blows

L – Loose Connective Tissue- Forms a L – Loose Connective Tissue- Forms a potential space in which large potential space in which large quantities of blood& pus quantities of blood& pus accumulate around the entire skull accumulate around the entire skull

P – Periosteum- Deepest layer is loosely P – Periosteum- Deepest layer is loosely attached to skull except at suture attached to skull except at suture LinesLines

Bones of the SkullBones of the Skull 1. The Skull: 1. The Skull:

a) Frontal a) Frontal b) Parietalb) Parietalc) Occipital c) Occipital

Occipital Protuberance- Occipital Protuberance- d) Temporal d) Temporal

Zygomatic Arch-Zygomatic Arch-Mastoid Process-Mastoid Process-Styloid ProcessStyloid Process

e) Sphenoide) Sphenoidf.) Ethmoidf.) Ethmoid

Facial BonesFacial Bones

AA Lacrimal Lacrimal BB Nasal Nasal CC MaxillaMaxillaDD Zygomatic Zygomatic EE MandibleMandible

BodyBodyAngleAngleRamusRamus

The DuraThe Dura

1. Dura – The outer most layer of the meninges(membrane 1. Dura – The outer most layer of the meninges(membrane surr.brain& sp. cord) that consists of three distinct layers:surr.brain& sp. cord) that consists of three distinct layers:

a) Dura Mater- is the outer most layer of the meninges & is a) Dura Mater- is the outer most layer of the meninges & is made of strong white Fibrous tissuemade of strong white Fibrous tissueb) Arachnoid membrane- delicate & weblike layer, is the b) Arachnoid membrane- delicate & weblike layer, is the innermost layerinnermost layerc) Pia mater- transparent adheres to the outer surface of c) Pia mater- transparent adheres to the outer surface of the brain & contains blood vesselsthe brain & contains blood vessels

2. Dural Spaces- Spaces among the dura2. Dural Spaces- Spaces among the dura Epidural spaceEpidural space Subdural spaceSubdural space Subarachnoid space Subarachnoid space

THE BRAINTHE BRAIN1. Four Major Areas: 1. Four Major Areas: a) Cerebral Hemisphere- major portion of a) Cerebral Hemisphere- major portion of

the brain (83%)the brain (83%)1) 1) DivisionsDivisions::

LEFTLEFT RIGHTRIGHT

2) 2) SUD DIVISIONS: “LOBES”SUD DIVISIONS: “LOBES” FrontalFrontal Parietal Parietal OccipitalOccipital TemporalTemporal

The BrainThe Brainb. Diencephelon: sits on the uppermost b. Diencephelon: sits on the uppermost

region of the brain stem and region of the brain stem and has 3 Major Divisions:has 3 Major Divisions:

1. Thalamus1. Thalamus2. Hypothalamus2. Hypothalamus3. Epithalmus3. Epithalmus

c) Brain Stem: the control center of the c) Brain Stem: the control center of the brain. Consists of the Medulla Oblongata, brain. Consists of the Medulla Oblongata, Pons, and Mid-BrainPons, and Mid-Brain

d) Cerebellum – beneath the occipital lobed) Cerebellum – beneath the occipital lobe

The Anatomy and Function The Anatomy and Function of the Brainstemof the Brainstem

Medulla OblongataMedulla Oblongata Ascending and descending tractsAscending and descending tracts Connect spinal cord with the brainConnect spinal cord with the brain Some tracts cross over in medullaSome tracts cross over in medulla Reticular formation - controls Reticular formation - controls

consciousnessconsciousness Reflex centersReflex centers

Pons MidbrainPons Midbrain Connects spinal Connects spinal

cord with braincord with brain Helps control Helps control

breathingbreathing

reflex centerreflex center Controls movement Controls movement

of head and of head and eyeball (visual eyeball (visual stimuli)stimuli)

Controls movement Controls movement of head and trunk of head and trunk (auditory stimuli)(auditory stimuli)

The Anatomy and Functions of The Anatomy and Functions of the Diencephalonthe Diencephalon

ThalamusThalamus relay station for sensory impulsesrelay station for sensory impulses interpretation center for pain, interpretation center for pain,

temperature and touchtemperature and touch Hypothalamus - homeostasisHypothalamus - homeostasis

The Cerebrum: Structure The Cerebrum: Structure FunctionFunction

The Cerebrum: Structure The Cerebrum: Structure FunctionFunction

Cerebral cortex - gray matter surfaceCerebral cortex - gray matter surface Longitudinal fissure separates two Longitudinal fissure separates two

hemisphereshemispheres Gyri - foldsGyri - folds Sulci - groovesSulci - grooves Corpus callosum - bridge connecting Corpus callosum - bridge connecting

two hemispherestwo hemispheres

Cerebral HemispheresCerebral Hemispheres Frontal lobe - muscle movement, Frontal lobe - muscle movement,

moods, aggression, smell, motivationmoods, aggression, smell, motivation Parietal lobe - touch, pain, balance, Parietal lobe - touch, pain, balance,

taste, temperaturetaste, temperature Temporal lobe - hearing, smell, Temporal lobe - hearing, smell,

memory, abstract thought, judgmentmemory, abstract thought, judgment Occipital lobe - visionOccipital lobe - vision

The Cerebellum: Structure and The Cerebellum: Structure and FunctionFunction

Butterfly-shapedButterfly-shaped Two partially separated hemispheres Two partially separated hemispheres

connected by vermisconnected by vermis FunctionsFunctions

coordinating muscular movementscoordinating muscular movements maintaining posturemaintaining posture maintaining balancemaintaining balance