2 SKULL & ORBIT see handouts ORBITAL REGIONFronto-Zygomatic suture – over outer canthus, palpate w/finger tipsSuperior Orbital Notch – located in sup. orbital rim, (highest point of curve.Supercilliary Ridge – palpated the most medial aspect of the orbit.Glabella – located on frontal bone. Flattened midline area between (2) ridges, differs from one subject to another.Nasion – ½” below glabellaNasolacrimal Canal – inner cantus of eye, located by pressing lightly when eye is closed.Anterior Nasal Spine – “False acanthion,.Zygomatic Arch – palpate don lateral aspect of head.
3 SKULL SKULL & ORBIT SKULL REGION Mastoid Process – push auricle of ear forward and palpate.Pre-auricular point – on root of Zygomatic arch, verified by feeling faint pulse of the superficial temporal artery over that bone.Head of mandible – palpate by pushing tragus up w/ moving jaw from side to side.
5 SKULL SKULL & ORBIT LINES AND POINTS OML (radiographic) IOML (Reids) EAMGMLAuricular line rt. angles to IOML through EAMInterpupilary LineAMLGALInion – (EOP) unmistakably foundLambda – 3”in. above inion (meeting of lamboid and Sagittal suture)Inner cantusOuter cantus
6 SKULL SKULL & ORBIT VESSELS: 1. Common carotid artery – behind anterior border of sternomastoid muscle. Runs from SC.jt to level of upper border of thyroid cartilage. (c-4) it divides into internal and external carotids.
7 SKULL SKULL & ORBIT VESSELS: 2. External carotid artery – after divides into maxillary and superficial temporal arteries.
9 SKULLSKULL & ORBITVESSELS:4. Superficial temporal – feeds the scalp. (ant. & post. brain
10 SKULLSKULL & ORBITVESSELS:5.Internal carotid artery – runs upward entering skull through carotid canal in temporal bone. Supplies the ant. 2/3 of the brain with blood. It eventually unites w/the opposite int. car. & vertebral art. via the Circle of Willis & basilar the base of the brain.
11 SKULLThe circle of Willis (also called the cerebral arterial circle or arterial circle of Willis) is a circle of arteries that supply blood to the brain. It is named after Thomas Willis ( ), an English physician.
13 SKULL6. Vertebral artery – runs up back of neck through the vertebral foramina in the transverse processes. (C-1 – C-6)
14 SKULLVenous Sinuses of the skull: are channels between the two layers of the dura matter (outer)Dura MatterVenous Sinuses
15 SKULL Venous Sinuses: Blood Drains,→ 1. SSS (Superior Sagittal Sinus) runs from glabella to inion. →2. Transverse Sinus inion it travels lat. to a pt. opp. the base of the mastoid process.→3. Jugular foramen – where blood leaves skull and transverse sinus becomes internal jugular vein►►►► empties into subclavian vein….
16 SKULL FIVE LOBES OF THE BRAIN 1. Frontal – ant. above orbits & nasal cavities, lower border is ½” above fronto-zygomatic suture.
17 SKULL FIVE LOBES OF THE BRAIN 2. Temporal – lower border corresponds approx. to the upper border of Zygoma.
18 SKULL FIVE LOBES OF THE BRAIN 3. Occipital – continuation of temporal lobe runs above Zygomatic arch down to the EOP.
19 SKULL FIVE LOBES OF THE BRAIN 4. Parietal – lies in posterior cranial fossa below level of inion.
20 SKULL FIVE LOBES OF THE BRAIN 5. Insula – lies behind occipital bone “5th Lobe”
22 MAJOR FISSURES OF THE BRAIN Fissures divide the lobes of the brain SKULLMAJOR FISSURES OF THE BRAINFissures divide the lobes of the brain1. Longitudinal Fissure – divide the cerebrum into (2) hemispheres. Separation is complete ant/post., however, the hemispheres are connected by a band of white fibers in the center called the Corpus Callousum. The long. Fissure also contains Falx Cerebri which is an extension of the dura matter.Corpus CallousumFalx CerebriLongitudinal Fissure
23 MAJOR FISSURES OF THE BRAIN Fissures divide the lobes of the brain SKULLMAJOR FISSURES OF THE BRAINFissures divide the lobes of the brain2. Transverse Fissure – separates the cerebrum from the cerebellum
24 MAJOR FISSURES OF THE BRAIN Fissures divide the lobes of the brain SKULLMAJOR FISSURES OF THE BRAINFissures divide the lobes of the brain3. Central Fissure *Rolando Fissure – separates frontal & parietal lobes.
25 MAJOR FISSURES OF THE BRAIN Fissures divide the lobes of the brain SKULLMAJOR FISSURES OF THE BRAINFissures divide the lobes of the brain4. Lateral Fissure *Sylvian Fissure – separates frontal & parietal lobes above & temporal below
26 MAJOR FISSURES OF THE BRAIN Fissures divide the lobes of the brain SKULLMAJOR FISSURES OF THE BRAINFissures divide the lobes of the brain5. Parietal/Occipital Fissure– separates parietal lobes & occipital lobe
53 SKULL ANATOMY Cerebrum: * largest and most prominent part of the human brain* governs all higher mental processes* stimulates sensation, controls motor activities.* center for reason, intellect, memory, language, and consciousness.* Has (2) hemispheres and is separated by a longitudinal fissure.
54 SKULL ANATOMY Midbrain/Mesencephalon: * smallest aspect of brainstem * extends from the Pons to the diencephalon* rests on sphenoid bone* involved in hearing and visual reflexes
55 SKULL ANATOMY Diencephalon: * located between the cerebrum & mesencephalon* consists of several structures and is near the 3rd ventricle.* houses the thalamus and hypothalamus glands
56 SKULL ANATOMY Layers of material before the brain: Skull Periostem Dura materSubdural spaceArachnoidSubarachniod (vessels lie here)Pia materThe brain
57 SKULL ANATOMY Gray Matter: Groups of cell bodies and their dendrites on surface of brain called – Cortexdeep within the brain – Nuclei
58 SKULL ANATOMY White Matter: Bundles of axons and their myelin sheaths sheetsForms the conduction pathways of nerve tracts which propagate messages from one area of gray mater to the next
59 SKULL ANATOMY Meningies: Covering of the brain into (3) layers, A. pia matter- inner – (attached to brain)B. arachnoid – middleC. duramater – outer – (spinal cord)
60 SKULLANATOMYMeningies:pia matter- inner – (attached to brain)
64 SKULL Brainstem: Medulla Oblongata ANATOMY Most inferior portion of the brain stemContinuous w/spinal cordContains vital centers that regulate;Heartbeat, respiration and blood pressure
65 SKULL ANATOMY Brainstem: Pons Bridge Lies just above medulla and is cont. with itConnective link for various aspects of the brainRelays info. Between cerebrum and cerebellum
66 SKULL ANATOMY Brainstem: Midbrain -smallest aspect of brainstem -extends from the Pons to the diencephalon-rests on sphenoid bone- involved in hearing and visual reflexes
67 SKULL ANATOMY Ventricles: Fluid filled cavities within the brain where CSF flows.CSF flows from the lateral ventricle to the 3rd ventricle, through the cerebral aqueduct to the 4th ventricle then into the subarachnoid space.
68 Ventricles: Various Imaging Modalities SKULLVentricles: Various Imaging Modalities
69 CSF (Cerebral Spinal Fluid) SKULLCSF (Cerebral Spinal Fluid)-Baths the brain and spinal cord-Provides a protective cushion-Formed in the Choroid Plexus-Contains H2O,electrocytes, and proteins
70 SKULL Choroid Plexus Specialized structure in the ventricles Produces CSFStart as tiny blood ves. within the 3rd vent. & lat. vent.’s
71 SKULL Cerebellum Second largest aspect of the brain Responsible for smooth coordinated movementThe cerebellum (Latin: "little brain") is a region of the brain that plays an important role in the integration of sensory perception and motor control.
92 SKULL THIRD VENTRICLE - Lies in middle of forebrain - Superior to the Sella Turcica
93 SKULL Fourth Ventricle Lies in the hindbrain The fourth ventricle has a characteristic diamond shape in cross-sections of the human brain. It is located within the pons or in the upper part of the medulla.
94 SKULL Lateral Ventricle’s One in each hemisphere of the cerebrum separated by the corpus callosumCommunicate with each otherThe lateral ventricles are part of the ventricular system of the brain. Classified as part of the telencephalon, they are the largest of the ventricles.corpus callosum
95 Lateral Ventricle Communications (4) SKULLLateral Ventricle Communications (4)1. Foramen of Monro (Interventricular) – connects lateral ventricle to upper part of third ventricle.SEE HANDOUT…
96 Lateral Ventricle Communications (4) SKULLLateral Ventricle Communications (4)2. Foramen of MAGENDIE – extends from midline of roof of the 4th ventricle to the subarachnoid space.The median aperture of the brain (or foramen of Magendie) is an opening in the hollow nerve tube, connecting the fourth ventricle of the brain with the subarachnoid space.SEE HANDOUT…
97 Lateral Ventricle Communications (4) SKULLLateral Ventricle Communications (4)3. Foramen of LUSCHKA – extends from the roof of the lateral recesses of the 4th ventricle to the subarachnoid space.SEE HANDOUT…
98 Lateral Ventricle Communications (4) SKULLLateral Ventricle Communications (4)4. Aqueduct of Sylvius (cerebral) – connects posterior portion of 3rd ventricle to the 4th ventricle.SEE HANDOUT…
99 SKULLOld CSFIs disposed of through osmosis through the arachnoid villi on the top of the brain and filters into the bloodstream.Osmosis is the spontaneous net movement of water across a semipermeable membrane from a region of low solute concentration to a solution with a high solute concentration, down a solute concentration gradient.
100 SKULLFalx CerebriThe falx cerebri, so named from its sickle-like form, is a strong, arched fold of dura mater which descends vertically in the longitudinal fissure between the cerebral hemispheres. It is also attached to the occipital bone.
101 SKULL GLANDS The pituitary gland, or hypophysis, Located in st. Endocrine glandMaster gland, secretions stimulateother endocrine glandsStimulates growthThe pituitary gland, or hypophysis,
102 SKULLGLANDSEndocrine glands are glands that secrete their product (hormones) directly into the blood rather than through a duct. This group contains the glands of the Endocrine system. The main Endocrine glands include the pituitary gland, the pancreas, the gonads, the thyroid gland and the adrenal glands. Other organs which are not so well known for their endocrine activity include the stomach, which produces such hormones as ghrelin.
103 SKULL GLANDS 2. Thalmus -Influences mood -Between cerebrum and midbrain-Rely stationThe Thalamus The thalamus is the way-station of the brain's networks. It has three circuits running through its walnut sized core.
104 SKULL GLANDS 3. Pineal Gland -Endocrine gland that influences the onset of puberty-Calcifies over later in life-Located in body of thalamus
105 SKULL STRUCTURES Caudate Nucleus -located in the center of all white matterCenter of cerebrumIsland of gray matterBasal-ganglia (posture)The basal ganglia (or basal nuclei) are a group of nuclei in the brain interconnected with the cerebral cortex, thalamus and brainstem. Mammalian basal ganglia are associated with a variety of functions: motor control, cognition, emotions and learning.
106 SKULL STRUCTURES Corpus Callosum -vast nerve tracts Allow communication between the (2) hemispheresThe corpus callosum is a structure of the mammalian brain in the longitudinal fissure that connects the left and right cerebral hemispheres. It is the largest white matter structure in the brain, consisting of million contralateral axonal projections. It is a wide, flat bundle of axons beneath the cortex. Much of the inter-hemispheric communication in the brain is conducted across the corpus callosum.
107 SKULL STRUCTURES Peduncles -white matter that allows communication between different aspects of the brain.In anatomy, a cerebral peduncle is a band of neurons, resembling a stalk, which connect varied parts of the brain
143 SKULL ANATOMY Cranium (8) Bones Occipital (1) -Forms inferiorposterior portion of the cranium-Foramen magnum-Prominent bump, EOP, Inion
144 SKULL ANATOMY Temporal (2) -Contain many complex structures -Forms both sides of the base of the cranium.-Ant.- Zygomatic Arches,-Petrous pyramids-TMJ, EAM, IAM-Hearing, balance, equilibrium-Jugular foramina & Carotid canals
145 SKULL ANATOMY Sphenoid (1) -Butterfly shaped bone -(3) Major parts; a. body, b. lesser wings, c. greater wings-Body contains the ST, houses the pituitary gland(hypophysis)
146 SKULL ANATOMY Ethmoid (1) -Smallest of cranial fossa bones -Cube shaped, divides into (4) parts; 1. Horizontal portion (cribriform plate)(horizontal plate) contains olfactory nerves, Crista galli which anchors the brain to the anterior cranial fossa Vertical portion (perpendicular plate) – forms bony nasal septum 3&4. two lateral masses (labyrinths), thin walls containing Ethmoid air cells. Also contain middle and superior nasal conchae (turbinate's)
151 SKULL ANATOMY FACIAL BONES (14) Nasal (2) The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face, and form, by their junction, "the bridge" of the nose.
152 SKULL ANATOMY FACIAL BONES (14) Lacrimal (2) The lacrimal bone, the smallest and most fragile bone of the face, is situated at the front part of the medial wall of the orbit. It has two surfaces and four borders.
153 SKULL ANATOMY FACIAL BONES (14) Maxilla (2) The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible, which is also a fusion of two halves at the mental symphysis
154 SKULL ANATOMY FACIAL BONES (14) Zygoma (2) The zygomatic bone (malar bone) is a paired bone of the human skull. It articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. It forms part of the orbit and is commonly referred to as the cheekbone
155 SKULL ANATOMY FACIAL BONES (14) Palantine (2) The palatine bone is a bone in the palate (Latin palatum; unrelated to palatium 'palace', from which other senses of palatine derive
156 SKULL ANATOMY FACIAL BONES (14) Inferior nasal conchae (2) The inferior nasal concha (Inferior Turbinated Bone) is one of the turbinates in the nose. It extends horizontally along the lateral wall of the nasal cavity [Fig. 1] and consists of a lamina of spongy bone, curled upon itself like a scroll.
157 SKULL ANATOMY FACIAL BONES (14) Volmer (1) The Vomer (from Latin vomer, -ĕris, "ploughshare") is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and touches the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones
158 SKULL ANATOMY FACIAL BONES (14) Mandible (1) The mandible (from Latin mandibūla, "jawbone") or inferior maxillary bone is, together with the maxilla, the largest and strongest bone of the face . It forms the lower jaw and holds the lower teeth in place.
159 SKULL ANATOMY ORBITS (2) In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated.It can also mean the skin which surrounds the eye of a bird.In the adult human, the volume of the orbit is 30 ml, of which the eye occupies 6.5 ml. 
160 SKULLANATOMYORBITS-Cone shaped structure-Surrounds and protects the eyeball (Oculus Bulbous)-Created by the junction of the sphenoid, frontal and Ethmoid bone of the cranium-Also created by the junction of the Lacrimal, palatine, maxillary and Zygoma bones of the face.
161 SKULL ANATOMY ORBITS (3) OPENINGS Superior Orbital Fissure Inferior Orbital FissureOptic Canal
162 SKULLSUTURESSquamous Suture- on the side of the cranium, joins temporal and parietal bone.Coronal Suture – runs transversely across the top of the cranium and is the articulation between thefrontal and parietal bones.
163 SKULLSUTURES3. Sagittal Suture – articulation between parietal bone and MSP.4. Lambdoidal Suture – posterior in cranium and joins the occipital and parietal bones.
164 CEREBRAL VASCULAR SYSTEM SKULLCEREBRAL VASCULAR SYSTEM-Thin and weak, have no valves.Allows blood to flow in either direction, this is a problem because it may create a route for blood-borne-pathogens to pass from the body to the brain and the brain to the body….The blood-brain barrier (BBB) is a membranic structure that acts primarily to protect the brain from chemicals in the blood, while still allowing essential metabolic function. It is composed of endothelial cells, which are packed very tightly in brain capillaries. This higher density restricts passage of substances from the bloodstream much more than endothelial cells in capillaries elsewhere in the body. Astrocyte cell projections called astrocytic feet (also known as "glial limitans") surround the endothelial cells of the BBB, providing biochemical support to those cells. The BBB is distinct from the similar blood-cerebrospinal fluid barrier, a function of the choroidal cells of the choroid plexus.
165 VENOUS DRAINAGE (3) SEGEMENTS (Sinuses) SKULLVENOUS DRAINAGE (3) SEGEMENTS (Sinuses)Cerebral – drains superficial and deep inner-lying veins (drains into the dural).Dural – receives blood from the cerebral veins. (drains into the internal jugular segment).Internal Jugular Segment- begins with the sigmoid sinus. (drains out into jugular foramen).
201 12 Cranial Nerves MR FACE CORONAL Numbered from anterior to posterior, according to their attachment to the brain…All have specific functions; touch, smell, sight, hearing, etc…..Cranial nerves are nerves that emerge directly from the brain in contrast to spinal nerves which emerge from segments of the spinal cord. Although thirteen cranial nerves in humans fit this description, twelve are conventionally recognized. The nerves from the third onward arise from the brain stem.
202 Olfactory Nerve (CN1) – “Smell” (18-20) small nerve bundles. Optic Nerve (CN2) – “Sight” arise from optic retina.Oculomotor Nerve (CN3) – “moves eye” emerges from midbrain.Trochlear Nerve (CN4) – “muscle” controls sup. orbital muscle.Trigeminal Nerve (CN5) – “sensory” (3) divisions, ophthalmic, maxillary and mandibular.Abducens Nerve (CN6) – “motor impulses” lat. movement of eye.Facial Nerve (CN7) – “taste” facial nerves and 2/3 of the tongue.Vestibulocochlear Nerve (CN8) – “sound” picks up sounds & interrupts.Glossopharyngeal Nerve (CN9) – “motor” impulses, monitors blood.VagusNerve (CN10) – “stimulates” pharynx, larynx, thoracic & abdomen viscera.Accessory Nerve (CN11) - “stimulates” pharynx, palatine & larynx.Hypoglossal Nerve (CN12) -“muscle” muscle of tongue.