midterm 1

saggital plane
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Terms in this set (257)
saggital plane
divides the body into a right and left side (vertical plane)
coronal (frontal) plane
anterior (ventral) and posterior (dorsal)
transverse plane
superior and inferior
hollow structure that encloses cavity filled with fluid
globe (whole eye)
3 coats (tunics) of the globe
1. outer fibrous layer
2. vascular layer (uvea)
3. inner neural layer
outer fibrous layer
sclera and cornea
sclera
white of eye
85% fibrous portion
protection - KEY POINT
maintains shape of globe
what covers sclera
tenon's capsule
tenon's capsule
connective tissue layer that's clear and covers sclera
what covers tenon's capsule
transparent conjuctiva
corneatransparent layer allows light rays to enter eye refraction occurs here (bring light rays to focus on retina)vascular layer (uvea) consists ofiris, ciliary body , choroidirismost anterior layer of uvea gives eye color hole in center (pupil) two muscles that help control light entering pupil - iris dilator and iris sphinctertwo muscles in iris that help control light entering pupildilator and iris sphincteriris dilator vs iris sphincterdilator: contraction dilates pupil sphincter: contraction constricts pupilciliary bodymiddle layer of uvea continous with iris ciliary muscle and ciliary process controls power of lens in eyezonules in cilairy muscleattach ciliary body to crysilline lens (suspensory ligament of lens)ciliary muscle contracts and relaxes controlling shape ofcrystilline lensciliary proccessesfibers that connect to lens produce and secrete aqueous humor - clear fluid that provide nutrition to structure of eyechoroidposterior layer of uvea continous with ciliary body netweork blood vessels (nutriotion outer 1/3 of retina)retina (inner neural layer)neural tissue converts light energy -> electrical signal which can be sent to brain via optic nerve (most anterior portion of optic nerve is optic disc)maculahelp see most detailed vision small area of retina responsible for central visionfoveapart of macula specifically responseible for detailed vision and is in center of maculaanterior chambercavity filled with fluid located between cornea and iris/lensposterior chambercavity filled with flid located between ciliary body and lensaqueous humorproduce ciliary body clear fluid that provides nourishment for surrounding structurevitreous chamberlargest chamber between lens and retina contains vitreous humorvitreous humorclear, gel-like substance that maintains shape of eyelocation where cornea transitions to sclera/tenon's capsule/conjuctiva islimbussuturesseam-like immovable junction (exception: movable TMJ)body of sphenoidhouses the pituitary gland in sella turcicalesser wings sphenoidprojects from anterior aspect of bodygreater wings sphenoidprojects from lateral aspect of body4 parts ethmoid bonevertical (perpindicular) plate- nasal septum horizontal (cribriform) plate - olfactory nerves pass through plate labryinths x2 - house ethmodial sinusesshape of orbitshaped like 4-sided pyrmid with apex posterior and base anterior - orbital apex most posterior portion of orbit and located slightly nasal7 bones of orbitfrontal, palatine, lacrimal, zygomatic, maxillary, sphenoid, ethnoidroof formed byfrontal and sphenoid (lesser wing)floor formed bypalatine, maxillary, zygomatic bonesfloor strengthweakest wall in orbit (air filled sinus beneath floor)medial wallmaxilla, lacrimal, ethmoid, sphenoidmedial wall propertythinnest wall in orbitlateral wallzygomatic and sphenoid boneslateral wall strengthstrongest area of orbit, exposed most to possible injurywhat passes through optic canal and annulus of zinn? (2 things)opthalmic artery and optic nerve (CNII)what passes THROUGH superior orbital fissure and through annulus of zinnoculomoter nerve (CNIII) nasociliary nerve (CN V1) abducens nerve (CN V1)what passes through superior orbital fissure and ABOVE annulus of zinnsuperior opthalmic vein, trochlear nerve (CN IV), lacrimal nerve (CN V2), frontal nerve (CN V1)what passes through inferior orbital fissureinferior opthalmic vein, zygomatic nerve (CN V2), infraorbital neve (CN V2), artery, veinsupraorbital foramen/ notch what passes throughsupraorbital neve (CN V1), artery and veinsuperior trochlear (supratrochlear) foramen/notch what passes throughsupratrochlear neve (CNV1), artery and veininferior orbital (infraorbital) foramen what passes throughinfraorbital nerve (CNV2), artery and veinforamenhole or opening in bonefissurelong narrow opening in bonefossashallow depression in bonecommon tendinous ring (annulus of zinn) lies _____ to optic foramenanteriorwhat is the common tendinous ring (annulus of zinn)band of connective tissue origin of 4 of the EOMs (extraoccular muscles)where does the common tendinous ring (annulus of zinn) like in relation to superior orbital fissurelies anterior to the inferior portion of the superior orbital fissurenasolacrimal canala canal in the maxillary bone extends from fossa to open into nasal cavity nasolacrimal duct also located in nasolacrimal canalhow is nasolacrimal canal separated from orbitby orbital septum (dense sheet of connective tissue)two parts of the skullthe cranium facebones of craniumfrontal, parietal, occipital, temporal, sphenoid, ethmoidbones of the facefrontal, palatine bone (x2), lacrimal (x2), nasal (x2), inferior conchae, vomer, zygomatic bone (x2), maxillary bone (x2), mandiblepurpose of the paranasal sinusespurpose to reduce weight of skull and filter the air we breaththe largest paranasal sinusmaxillaryparanasal sinus top to bottomfrontal -> ethmoid -> sphenoidal -> maxillarytenon's capsule (bulbar fascia) tissue type what does it cover rolesheet of dense connective tissue covering the sclera + also covers EOMs as insert into sclera separates globe from contents of orbit to prevent from orbital infections from entering the globetenon's capsule ANTERIORLY merges withsclera/conjunctiva at the limbustenon's capsule POSTERIORLY merges withdural sheath of the optic nerveconjuctiva vs tenon's capsule - how do they cover the globe?conjuctiva (anteriorly) --- covers tenon's capsule tenon's capsule (anteriorly and posteriorly)orbital septum (palpebral fascia) where on the eyesheet of dense connective extending from entire rim of orbit to TARSAL plate *continuous with periosteum at superior and inferior orbital rim (creating scaffolding for nerves or other tissues to attach to it)orbital septum (palpebral fascia) primary and secondary functionprimary role: barrier to facial/eyelid/nasolacrimal system infections from entering orbit secondary role: keeps orbital fat in placePeriorbita (Orbital fascia, Periosteum) locationSheet of dense connective tissue that covers the bones of the orbit *anteriorly: continuous with: periosteum of facial bones and orbital septum *posteriorly continuous with: dural sheath of optic nerve and forms common tendinous ringPeriorbita (Orbital fascia, Periosteum) roleattachment sites for muscles, tendons, ligaments as well as support structure for vascular supply to orbital bonesWhitnall's ligament / superior transverse ligamenttransverse dense connectve tissue located in superior orbit role: support and maintains spatial relationship between anatomic structures in superior orbitwhitnall's ligament formed bylevator musclelockwood's ligament (suspensory ligament)transverse dense connective tissue in INFERIOR orbit provides support and maintains spatial relationships between anatomic structures in inferior orbitlockwood's ligament (suspensory ligament) contributes to formation ofcapsulopalpebral fasciamedial check ligament- transverse dense connective tissue that is an expansion of the sheath of the medial rectus - attaches to lacrimal bone - prevents overaction of medial rectuslateral check ligament- transverse dense connective tissue that is an expansion of the sheath of the lateral rectus - attaches to zygomatic bone - prevents overaction of lateral rectuswhitnall's ligament ____ lid, lockwood's ligament ____ lidwhitnall's ligament upper lid, lockwood's ligament lower lid_________, __________, and ____________ form supporting hammock-like formation for the globewhitnall's ligament, lockwood's ligament and check ligaments form supporting hammock-like formation for the globeorbital septumweb of interconnecting connective tissue septa organizes orbital space surrounding the globe - anchors and supports EOMs, nerves, and blood vesselslist the orbital nervesII optic nerve III oculomotor nerve IV trochlear nerve V1 opthalmic V2 maxillary VI abducensbranches off ICA and is main blood source to eyeophthalmic arterycontrol movement of the globe - what type of musclesextraocular musclestwo types of extraocular musclesrecti muscles (medial, lateral, superior, inferior) oblique muscles (superior (SO), inferior (IO))what are the eyelid retractors (control movement of the eyelid)levator palpebrae superior and inferior tarsal muscles (superior tarsal = muller's muscle) capsulopalpebral fascia (NOT ACTUAL A MUSCLE, ON LOWER LID)space not filled with orbital structures is filled with:adipose tissuehow many fat pads are anterior to the levator aponeurosis (anterior orbit)preaponeurotic afat pads (nasal and central) held in place by orbital septumhow many fat pads are posterior to orbital septum and anterior to capsulopalpebral fasciathree! nasal, central, temporal held in place by orbital septumeyebrows are located between the ______________ and ___________eyebrows are located between the superior orbital rim (inferior origin) and superior nuchal line (superior origin)4 layers of the eyebrow (similar to scalp)skin dense connective tissue muscle loose connective tissue periosteum (NOT A TRUE LAYER)role of skin on the eyelidsbarrier to prevent microbes from causing infection in underlying tissueskin three layersepidermis, dermis, hypodermis4 types of cells in epidermis (outermost layer)keratinocytes melanocytes langerhans cells merkel cellskeratinocytes how much % make up epidermis produce what protein vascular or avascular90% of cells produce protein: keratin a-vascualr : relies on dermis for blood supplykeratinprovides structure and water-resistant properties4 layers of keratinocytes (inner to outer)stratum basale -> stratum spinosum -> stratum granulosum -> stratum corneum (Outer )stratum basalecells that undergo mitosis and then will migrate to other layers deepest layer of keratinocytesstratum granulosumcells lose nucleus, become more flattenedstratum corneumdead, flattened cells with keratin cells shed every few weeks in process known as desquamationmelanocytesproduce pigment (melanin) that filters UV light (protects UV damage)langerhan cellstype of WBC in epidermis; immune system responsemerkel cellsattach to nerve endings (sensory neurons) to form "light touch" responsekeratinocytes attached to basement membrane which connects epithelial cells to underlying dermis. serves as partial barrier, allowing only ______________ and ___________ to pass into dermissmall molecules and waterdermis composed ofconnective tissue (fibroblasts, collagenous fibers, elastic fibers, adhesive proteins, ground substance), wbcs, adnexal structurerole of fibroblasts in dermismake collagen and elastincollagena protein that provides structure and tensile strength (snap back)elastina protein provides elasticity enabling movementground substance (dermis)transparent gel composed of water, glycosaminoglycans, and proteoglycans ALL OTHER CONNECTIVE TISSUE EMBEDDED IN IT SUBSTANCFE TRAVEL THROUGH IT IN SHORT, ITS THE H2O SURROUNDING CELLSadnexal structure (dermis)hair follices, sebaceous gland (oil gland), sweat glandwhat hair first to produce in embryologic developmenteyebrowhypodermis (subcutaneous tissue)mainly composed of adipose and lose connective tissuedense connective tissue (eyebrows) what made of rolewhat made of : fibroblasts, collagenous fibers, elastic fibers, adhesive proteins, ground substance role: connects skin to underlying muscle; contains the arteries, veins and nerve supplying eyebrows4 muscles influencing eyebrowsfrontalis corrugator procerus orbicularis oculifrontalis muscle (eyebrow )vertical fibers high on scalp and insert near supraorbital margin role: elevate brows, look of surprisethe muscles of the eyebrows are all innervated byCN III (occulomotor nerve)corrugator muscle (eyebrow)oblique fibers towards medial aspects of eyebrows depresses medial brows forming ventrical wrinkles in glabella - trouble/confusion or concentrationprocerus (eyebrow)between eyebrow ventrical fibers depresses the medial brow forming horizontal ridges along bridge of nose - look of menace or aggressionorbicularis oculi (eyebrow muscle)run all way around eye originate from medial orbital rim (maxillary and lacrimal bones) to encircle the eye and insert into lateral palpebral ligament 1) depress brows 2) protracts (closes) eyelidsloose connective tissue of eyebrowconnects three layers of of skin to underlying periosteum danger zone: ps and blood can spread easily in layer and infections can pass into cranial cavity through veinsperiosteumcomposed of dense, irregular connective tissue (fibroblasts, collagenous fibers, ground substanes), osteogenic cells, osteoblasts covers boneosteogenic cellsstem cells that divide and differentiate into osteoblastsosteoblastsform bone matrixfunction of eyebrowsshield from persperation, bright light plays role in aging facial expressoinmuscle atrophywhen eyebrows and eyelids can droopupper eyelids extend from ______________ to _____________upper eyelids extend from conjunctiva fronix to the superior orbital rim (superior orbital margin)lower eyelids from __________ to ___________lower eyelids extend from conjunctiva fronix to the nasojugal and palpebromalar sulciopening between the upper and lower eyelids is thepalpebral fissurehorizontal palpebral fissure what is normal30 mm is normal distance between medial + lateral canthusvertically palpebral fissure what is normal10 mm is normal distance between upper and lower lidvertically palpebral fissure formulaMRD-1 + MRD-2MRD-1 what is it normal nubmersdistance between corneal reflex and UL margin 4-4.5 mm normalMRD-2 what is it normal numbersdistance between corneal reflex and LL margin > 5 mm is normalstructures that make up eyelidsskin, tarsal plate, orbital septum, orbicularis oculi muscle, leavator palpebrae muscle, muller's muscle, capsulopalpebral fascia, palpebral conjunctivamedial canthus makesthe lacrimal lake where tears sit before drain into lacrimal sac sits lower than lateral canthusupper and lower eyelids meet atcanthuslateral canthys is ______ mm medial to lateral orbital rim and lies directly on the globe5-7 mmmedial canthus is at the medial orbital rim and is separated from the globe by thelacrimal lake (where tears sit before drain into lacrimal sac)skin eyelids rolebarrier to prevent microbes causing infection in underlying tissue folds easily, very flexible - rapid movements during blinking thinnest skin in body < 1 mm thickness -(attenuated (thinned) dermis and minimal hypodermal tissue)eyelid skin is composed of epidermis, dermis, and hypodermis (similar to eyebrow) but how is it different?eyelid's dermis is LESS attenduated (thinner), dermis less adnexal structures (hair follicles, hair, sebaceous glands, sweat glands) in eyelid, minimal hypodermis in oribtal region and absent in tarsal region of eyelidin eyelid where is there minimal hypodermis and where is there none?minimal in orbital region and absent in tarsal regionduring eyelid reconstruction surgery, ideal skin choice iscontralateral eye note: due to having less connective tissue in eye, tissue is subject to less scaringtarsal plate (tarsus) made out of: how thick: how long: what does it do:made out of: dense connective tissue (fibroblasts, collagenous, elastic, adhesive proteins, ground substance) -> gives lids STRUCTURE + RIGIDITY how thick: 1-1.5 mm thick how long: extends horizontal length of the eyelid: 30 mm (just like horizontal palpebral fissure) what does it do: conform to the countour of the anterior globewhat spans the same length as the horizontal palpebral fissuretarsal platecentral vertical height superior tarsus9-11 mmcentral vertical height inferior tarsus4-5 mmsuperior tarsus boundaries (of eyelid)eyelid margin to superior palpebral sulcusinferior tarsus boundaries (of eyelid)eyelid margin to inferior palpebral sulcusinferior tarsus boundary ________ laterally and mediallytaperswhat glands are in the tarsal plate? what are their properties?meibomian glands more glands in UL than LL extend VERTICLE length of tarsal plate open onto eyelid margin modified sebaceous glandstarsal plate attachmentslaterally: attached to medial and lateral palpebral ligaments (aka canthal tendons) upper edge: attached to levator aponeurosis and superior tarsal muscle (muller's muscle) lower edge: inferior tarsus attached to capsulopalpebral fascia and inferior tarsal muscleoribtal septum in upper lidbecomes THICKENING of periosteum at superior orbital rim *distal fibers merge with levator aponeurosis 3-5 mm above tarsal plateorbital septum lower lidbecomes THICKENING of periosteum at inferior orbital rim - distal fibers merge with capsulopalpebral fascia several mm below tarsal plateorbital septum acts as anterior barrier of the orbit because it separates ____________ and _________ from the orbit , prevents facial/eyelid/nasolacrimal system infections from entering the oribit, keeps orbital fat in placeorbital septum acts as anterior barrier of the orbit because it separates EYELIDS and LACRIMAL SAC from the orbit , prevents facial/eyelid/nasolacrimal system infections from entering the oribit, keeps orbital fat in placeskeletal muscle think _______ and cranial nerve ____ innervatesskeletal muscle think VOLUNTARY and cranial nerve 7 innervatesorbicularis oculi function (eyelid)close eye or protract eyelid depress eyebrow -> secondary functiontwo regions of orbicularis oculiorbital region, palpebral regionconcentric fibers extend from orbital rim to forehead, temple cheek contraction closes eyelids tightly and dpresses the broworbital regionsuperior and inferior SEMILUNAR fibers extend from lateral palpebral ligament across the eyelid to medial palpebral ligament contraction closes eyelids gently (sleep, winking, blinking)palpebral regionpalpebral region separated intopreseptal and pretarsalpreseptal region locationin FRONT of orbital septumpretarsal region location rolein FRONT of tarsal plate contains specialized muscle fiberspretarsal's region contains what fibersriolan's muscle (near lid margin) * maintains the lid margin close to globe horner's muscle (medial fibers) * aids in lacrimal pump mechanismriolan's muscle(near lid margin) * maintains the lid margin close to globehorner's muscle(medial fibers) * aids in lacrimal pump mechanismantagonists to orbicularis oculilevator palpebrae and frontaliswhat skeletal muscle functions as MAIN retractor (opens eyelid) of UIslevator palpebrae musclelevator palpebral muscle innervated by cranial nerve3 (oculomotor)levator aponeurosis how fuses superiorly, medially, laterallysuperiorly: orbital septum medially: medial palpebral ligament (canthal tendon) laterally: lateral palpebral limit (canthral) --> divides lacrimal gland into orbital and palpebral loveslevator aponeurosis anteriorattaches to anterior surface tarsal plate, muscle fibers of orbicularis oculi, eyelid skinlevator aponeurosis attachment to skin formssuperior palpebral sulcussuperior palpebral sulcusfold/groove 8-12 mm above UL margin divides eyelid into tarsal region and septal region may be absent if levator aponeurosis attaches to skin more inferiorly *aging changes, certain ethnicitiesantagonist to levator palpebrae muscleorbicularis oculismooth muscleinvoluntary muscle, autonomic system support muscletarsal muscle (muller's muscle)smooth muscle functions as ACCESSORY (not primary) retractor of ULs and LLs *contraction opens eyes involuntary, autonomic, innervated by sympathetic (fight or flight)tarsal muscle upper lid originates from: inserts at:originates from: levator muscle inserts at: superior border of tarsustarsal muscle lower lid originates from: inserts at:originates from: capsulopalpebral fascia inserts at: lower border of tarsuscapsulopalpebral fasciaconnective tissue sheet that functions as MAIN retractor of the LLs NOTE NOT A MUSCLEcapsulopalpebral fascia fibers arise from _____________ and the sheaths of _______ and ________capsulopalpebral fascia fibers arise from LOCKWOOD'S LIGAMENT and the sheaths of IR (INFERIOR RECTUS) and IO (INFERIOR OBLIQUE)capsulopalpebral fascia attaches to lower border of tarsus, muscle fibers of obicularis oculi, and skin attachment to skin forms theinferior palpebral sulcusinferior palpebral sulcusdivides eyelid into tarsal region and sepatal region less marked than suoperior sulcus 5 mm below lL marginpalpebral conjuctivathin, transparent mucous membrane that lines the underside of the lidspalpebral conjuctiva contains what type of cellgoblet cells which are a type of epithelial cell that secretes mucingoblet cellstype of epithelial cell that secretes mucin (a component of tear film) -> keeps eye lubricated, eyelids move over cornea when blink, and aids in eye movementwhat accessory lacrimal glands are in palpebral conjuctivakrause and wolfring *glands that secrete the AQUEOUS portion of tear film (help produce watery structure)anterior lamella (outer layer of eyelid)skin - anterior to orbicularis occuli, mainly keratinocytes orbicularis ocluli - inncervated by cranial neve 7, shut/protracts eyelid (elongates eyelid)middle lamella (eyelid)not present in area of tarsal plate, hard to see contains: -orbital septum (note: starts where tarsal plate ends) -retractor musclesposterior lamella (eyelid)tarsal plate (not present in superior portion of UL or inferior portion of LL) palpebral conjuctiva - lines inside of lidgray linedivides anterior and posterior lamellae posterior: meibomian glands anterior: hair this is a surgical landmark for the anterior border of riolan's musclethis is a surgical landmark for the anterior border of riolan's musclegray lineepiphoraabnormal overflow of tears, dry eye not tight rional musclewhat things are present in the margin of eyelideyelashes, lacrimal papilla/puncta, mucocutaneous junction, lid wiper region, and meiobomian glad orifices are present here5/6 of eyelid margin has _____________, 1/6 of eyelid margin has ____________5/6 of eyelid margin has EYELASHES, 1/6 of eyelid margin has LACRIMAL PAPILLA/PUNCTAeyelashes functionprotect eye with blink response; has many nerves which make them very sensitive to slightest toughglands within eyelashes of marginglands of zeis glands of mollglands of zeisholocrine, sebaceous gland - secrete sebum into hair follicle -coat eyelash shaft to keep from becoming brittle -keep eyelid margin lubricatedglands of mollapocrine, sweat glands into hair follicle or directly on lid margin function is unknown (maybe immune response)area where no lashes has thelacrimal portion (lacrimal papilla/puncta)lacrimal papillaslight elevation of tissue present at medial portion of UL and LLhole in center of lacrimal papilla calledpunctum (pl: puncta)punctumbeginning of nasolacrimal drainage systemholocrine secretion what is it what example of thiswhole cell + product release example: zies gland (release sebum)apocrine secretion what is it what example of itapex + product ie: glands of moll (release sweat)mucocutaneous junction (line of marx)-Present in the ciliary and lacrimal portion of the eyelid margin -Transition zone between the palpebral conjunctiva and skin where inside and outside eyelid meetlid wiper region-Present in the ciliary and lacrimal portion of the eyelid margin -Elevated strip of palpebral conjunctiva just posterior to the mucocutaneous junction -Comes into contact with the globe during blinkingmeibomian gland orifices-Present in the CILIARY portion of the eyelid margin -Located in a row along the eyelid margin -Secretes oils (lipids) onto the skin just in front of the mucocutaneous junctionstimulation of __________ nerves leads to contraction of the orbicularis oculi. upon eyelid closure, globe _________ 1.5 mm into orbit.sensory nerves, 1.5 mmeyelid FORCED closureuses orbicularis oculi voluntary closer of eyelids either tightly or gentlyreflexive closure of eyelids (occurs rapidly in response to three types of stimuli)tactile: touching the cornea, conjuctiva, eyelash, eyelid skin, eyebrow (CN5 - TRIGEMINAL) optical: viewing bright lights (dazzle) or unexpected/threatening objects (menace) - CN2 (optic nerve) auditory (+ balance): hearing/unexpected threatening sounds (menace) - CN8 vestibulocochlear nervespontaneous closure of eyelidevery 3-8 seconds helps ocular surface from drying out - initiates cycle of tear secretion, dispersal, drainage removes debris from ocular surfaceglands/cells that secrete tear filmmeibomian glands goblet cells lacrimal gland lacrimal accessory glands of krause and wolfringwhat eyelid closure vs eyelid opening does to tear filmeyelid closure: secretion of tear film components (aqueous, mucin, meibum) + pushes tears to punctum eyelid opening: dispersal of tear film components (aqueous, mucin, meibum) across ocular surface (conjuctiva + cornea)tears are pushed to the puncta via what type of movementcapillary action (movement of water without external forces) and the action of the horner's musclesensory innervation of the eyelids via what nervetrigeminal nerve (CN V)trigeminal nerve splits into what three nervesopthalmic nerve (V1) maxillary nerve (V2) mandibular nerve (V3)ophthalmic nerve (V1) separated intonasociliary - splits into: infratrochlear nerve (UL, LL) frontal nerve - splits into: supratrochlear nerve (UL), supraorbital nerve UL) lacrimal nerveV2 maxillary nerveinfraorbital nerve (LL)motor innervation of orbicularis oculi muscle by what nerveCN VII (facial nerve)what branches of CN VII innervate orbicularis occulitemporal and zygomatic branchesmotor innervation of the levator muscle byCN III (oculomotor nerve) , keeps eyelid open superior division innervates the levator musclemotor innervation of superior and inferior tarsal muscle bysympathetic fibers smooth muscle = involuntary = autonomic = sympathetic4 main components of bloodplasma, red blood cells, white blood cells, plateletsliquid component of blood (91% water, 7% protein, 2% other solutes)plasmared blood cells-most abundant cell in our body -do NOT have nucleus (allows to change shape to fit through blood vessels) , limits cell life (120 days) -contain special protein hemoglobincarries oxygen from lungs to rest of the body return carbon dioxide from body to the lungs so it can be exhaledhemoglobinhematocritpercentage of blood volume occupied by red blood cellsnot actually cells but smaller fragments of cellsplateletsplatelets functionhelp blood clotting or coagulationblood functions-transport nutrients and oxygen to cells -remove waste products from cell to deliver to kidneys and liver -transport hormones -protect body from infection and foreign body -form blood clots -regulate body temp and pHhow blood flowsarteries, arterioles, capillaries, venules, veinstransport oxygenated blood away from the heart deliver to tissues in the bodyarteriescapillarieslocation fro exchange of gases, fluid and nuetirents between blood and tissues cells recieve oxygen, fluid, and nutrients from blood in capillaries cells deposite waste and carbon dioxide to the blood in capillariesreturn deoxygenated blood to the heartveinslargest artery in the body isthe aortacarriest oxygen rich blood from heart to other parts of the bodyaorta4 sections of heartascending orta aortic arch descending aorta abdominal aortaascending aortagives rise to coronary arteries that supply the heartaortic archcurves over the heart, giving rise to branches that bring blood to the head, neck, and arms.aortic arch splits intoleft common carotid artery left subclavian artery brachiocephalic artery (divides into right common carotid and right subclavian arteries)descending aortatravels down through chest small branches supply the ribs and some chest structuresabdominal aortabegins at the diaphragm splits to become paired iliac arteries in the lower abdomen to supply the legs and most of the organscommon carotid artery is in neck and branches intoexternal and internal carotid arteriesexternal carotid arteriesgives off 6 branches, divides into two terminating branches to supply blood to face and neck6 branches of external carotid arteryS: superior thyroid artery. A: ascending pharyngeal artery. L: lingual artery. F: facial artery. O: occipital artery. P: posterior auricular artery. S: superficial temporal artery. M: maxillary artery.facial arteryangular branch supplies medial portion of LL and nasolacrimal apparatus anastomeses with the dorsonal artery (branch of the opthalmic artery)maxillary artery (terminal branch)infraorbital branch supplies the lL and nasolacrimal apparatussupplies blood to most of the anterior portion of cerebruminternal carotid arteryinternal carotid artery sectionscervical petrous carvernous cerebralhow internal carotid artery travelscervical (runs upward in neck) -> petrous (enters skull through carotid canal goes through it and curves anteriorly and medially) -> cavernous (enters cavernous sinus, courses forward along medial wall beside sphenoid and exits roof of sinus between CN II and CN III) -> cerebral (gives off its terminal branches (10 branches))opthalmic artery a branch of internal carotid artery rolesupplies globe and adnexaopthalmic artery coursefirst major branch of the cerebral portion of the internal carotid artery -> courses anteriorly to enter the orbit through optic canal within dural sheath of ON -> after entering orbit, emerges from dural sheath of the ON -> courses inferolateral to the ON for a short distance and then crosses either below or above it -> courses medially and then anteriorly between MR and SO to give off terminal branchesopthalmic artery give off 9 branches (what two need to know as fo now)lacrimal artery medial palpebral arteries (2, superior and inferior)lacrimal artery coursebranches from opthalmic artery after enters orbit -> courses anteriorly, along upper boarder of lateral rectus -> supplies the lacrimal gland -> pierces through orbital septum to enter UL and LL as lateral paplpebral arteries (2, superior and inferior) which anastomose with medial palpebral arteries to form palpebral arcades)palpebral arcadessupply eyelids and palpebral and forniceal conjuctivamedial palpebral arteries coursebranch from opthalmic artery after enter orbit -> piece orbital septum to enter UL and LL -> anastomose with lateral palpebral arteries to form palpebral arcades (marginal and peripheral)marginal palpebral arcade (aka marginal arterial arcade)anterior to tarsal plate supplied UL and LL near eyelid margin supplies cornea when eyelids protractedperipheral palpebral arcade (aka peripheral arterial arcade)anterior to tarsal (muller's muscle) supplies UL and LL near peripheral edge of tarsal plate