1. Head and NeckCognitive ObjectivesUpon completion of this lesson, the student should be able to: 1. Identify the bones of the head. (see picture on pg. 204). Abnormal findings: enlarged skull may signify hydrocephalus or Paget’s disease of bone. Tenderness or step-offs are common after trauma • Frontal bone • Parietal bone • Occipital bone • Temporal bone • Mastoid portion of temporal bone: behind the ears • Maxilla bone • Mandible bone • Zygomatic bone • Nasal bone 2. Identify the anatomical structures of the eye. (starting on pg. 205)
2. 3. Describe the function of each part of the eye.- Eyelid: covers and protects the eyes- Sclera: outer layer of the eye containing collagen and elastic fiber also known as the white of the eye. Maintains the shape of the globe, offering resistance to internal and external forces, and provides an attachment for the extraocular muscle insertions.- Conjunctiva: helps lubricate the eye by producing mucus and tears. It also contributes to immune surveillance and helps to prevent the entrance of microbes into the eye.- Iris: responsible for controlling the diameter and size of the pupils and the amount of light reaching the pupil.- Pupil: allows light to enter the retina.
3. - Cornea: the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, accounting for approximately two-thirds of the eyes total optical power- Eyelashes: protect the eye from debris; are sensitive to being touched, thus providing a warning that an object (such as an insect or dust mite) is near the eye (which is then closed reflexively).- Tarsal plate: elongated plates of dense connective tissue, about 2.5 cm. in length; one is found in each eyelid, and contributes to its form and support.- Levator palpebrae: muscle in the orbit that elevates the superior (upper) eyelid.- Bulbar conjunctiva: the conjunctiva covering the eyeball.- Palpebral conjunctiva: lines the inside of the eyelids.- Lacrimal gland: produces tears.- Lacrimal sac: connects the lacrimal canaliculi, which drain tears from the eyes surface, and the nasolacrimal duct, which conveys this fluid into the nasal cavity.- Puncta: collect tears produced by the lacrimal glands- Nasolacrimal duct: carries tears from the lacrimal sac into the nasal cavity.- Ciliary body: has three functions: 1) accommodation (Accomommodation essentially means that when the ciliary muscle contracts, the lens becomes more convex, generally improving the focus for closer objects. When it relaxes,it flattens the lens, generally improving the focus for farther objects); 2) aqueous humor production (responsible for providing most of the nutrients for the lens and the cornea and involved in waste management of these areas), 3) anchors lens in place.- Lens: transmits and refracts light, converging or diverging the beam.- Canal of Schlemm: circular channel in the eye that collects aqueous humor from the anterior chamber and delivers it into the bloodstream via the anterior ciliary veins.- Vitreous body: in contact with the retina and helps to keep it in place by pressing it against the choroid, it does not adhere to the retina, except in three places: around the anterior border of the retina; in the macula and at the optic nerve disc.- Choroid: vascular layer containing connective tissue, of the eye lying between the retina and the sclera. Provides oxygen and nourishment to the outer layers of the retina- Retina: is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Contains rods and cones.- Fovea: responsible for sharp central vision- Extraocular muscle: six muscles that control the movements of the eye.
4. - Central retinal artery: supplies all the nerve fibers that form the optic nerve that carries the visual information to the occipital lobe cerebral cortex, including those that reach over the fovea.- Central retinal vein: runs through the optic nerve and drains blood from the capillaries of the retina into the larger veins outside the eye.- Optic nerve: also called cranial nerve II, transmits visual information from the retina to the brain.- Optic disc: location where ganglion cell axons exit the eye to form the optic nerve.4. Explain the causes of visual field defects. (pg. 254)Horizontal Defect Occlusion of a branch of the central retinal artery and ischemia of theoptic nerve may cause a horizontal (altitudinal) defect.Blind Right Eye (right optic nerve) A lesion of the optic nerve, and of course of the eyeitself, produces unilateral blindness.Bitemporal Hemianopsia (optic chiasm) A lesion at the optic chiasm may involve onlyfibers crossing over to the opposite side. Since these fibers originate in the nasal half of eachretina, visual loss involves the temporal half of each field.Left Homonymous Hemianopsia (right optic tract) A lesion of the optic tract interruptsfibers originating on the same side of both eyes. Visual loss in the eyes is therefore similar(homonymous) and involves half of each field (hemianopsia).Homonymous Left Superior Quadrantic Defect (right optic radiation, partial) A partiallesion of the optic radiation in the temporal lobe may involve only a portion of the nervefibers, producing, for example, a homonymous quadrantic defect.
5. Left Homonymous Hemianopsia (right optic radiation) A complete interruption of fibers inthe optic radiation produces a visual defect similar to that produced by a lesion of the optictract.5. Explain the causes of an abnormal extra ocular movement exam (EOMs).If one of these muscles is paralyzed, the eye will deviate from its normal position in thatdirection of gaze and the eyes will no longer appear conjugate, or parallel.
6. Developmental dysconjugate gaze is caused by an imbalance in ocular muscle tone. Thisimbalance has many causes, may be hereditary, and usually appears in early childhood. Thesegaze deviations are classified according to direction: exotropia esotropiaDisorders of cranial nerves: New onset of dysconjugate gaze in adult life is usually theresult of cranial nerve injuries, lesions, or abnormalities from such causes as trauma,multiple sclerosis, syphilis, and others. Ex: • Left cranial nerve VI paralysis: o Looking to the right: eyes are conjugate. o Looking straight ahead: estropia appears o Looking to the left: esotroia is maximum • Left cranial nerve IV paralysis: o Left eye cannot looking down when turned inward. • Left cranial nerve III paralysis: o Eye is pulled outward by action of the 6th nerve. Upward, downward and inward movements are lost. Ptosis and pulpillary dilation may be associated.
7. 6. Discuss the difference between papillary reaction to light by direct and consensual reaction. Direct reaction: papillary constriction in the same eye. Consentual reaction: papillary constriction in the opposite eye. 7. Discuss the importance of the cover / uncover test. A cover-uncover test may reveal a slight or latent muscle imbalance not otherwise seen with just inspection. 8. Define ptosis: is lid lag, when the lid does not overlap the iris when eyes move up and down. In hyperthyroidism: a rim of sclera is visible above the iris w/ downward gaze called protosis. 9. Describe and identify corneal arcus. Corneal Arcus. A thin grayish white arc or circle not quite at the edge of the cornea. Accompanies normal aging but also seen in younger people, especially African-Americans. In young people, suggests possible hyperlipoproteinemia. Usually benign. 10. Describe normal findings on insufflation of the tympanic membrane with a pneumatic otoscope.This normal right eardrum (tympanic membrane) is pinkish gray. Note the malleus lying behindthe upper part of the drum. Above the short process lies the pars flaccida. The remainder of thedrum is the pars tensa. From the umbo, the bright cone of light fans anteriorly and downward.Posterior to the malleus, part of the incus is visible behind the drum. The small blood vesselsalong the handle of the malleus are normal.
8. 11. Identify the anatomical parts of the outer, middle, and inner ear.
9. 12. Identify the anatomical structures of the nose and sinuses.
10. 13. Identify anatomical structures of the mouth and pharynx.
11. 14. Identify lymph nodes in the head and neck. (p. 238) (Ch. 18 p.773 Child) 1. Preauricular 2. Postterior auricular 3. Occipital 4. Tonsillar 5. Submandibular 6. Submental 7. Superficial cervical 8. Posterior cervical 9. Deep cervical chain 10. Supraclavicular
12. Note: Tonsillar, Submandibular, Submental nodes: drain portions of mouth, throat, and face.15. Discuss function of lymph nodes and sites of drainage. (p. 239) a. Preauricular – in front of ear. b. Posterior auricular – superficial to maistoid process c. Occipital – base of skull posteriorly d. Tonsillar – angle of mandible • Small, hard, tender, high deep btwn mandible & sternomastoid is probably the styloid process. • If it pulsates, it is really the Carotid artery. e. Submandibular – midway btwn angle & tip of mandible. Smaller and smoother than the lobulated submandibular gland against which they lie. f. Submental – midline a few cm behind tip of mandible. g. Superficial cervical – superficial to sternomastoid. h. Posterior cervical – along anterior edge of trapezius i. Deep cervical chain – deep to sternomastoid. Hook thumb and fingers around either side of sternomastoid muscle to find them. j. Supraclavicular – deep in angle formed by clavicle and sternomastoid.
13. • Enlarged: especially on the Left: possible metastasis from a thoracic / abdominal malignancy. Note: Tender Nodes: suggests Inflammation. Enlarge or Tender Nodes: If unexplained 1. Reexamine of regions they drain. 2. Assess lymph nodes elsewhere to distinguish btwn regional and generalized lymphadenopathy. (Diffuse Lymphadenopathy raises suspicion of HIV / AIDS) Hard/Fixed Nodes: suggests Malignancy.16. Identify anatomical landmarks of the neck. (p. 236 - 236) a. Anterior triangle: Mandible above, Sternomastoid laterally, & Midline of neck medially forms the anterior angle of neck. b. Posterior triangle: Sternomastoid, Trapezius, & Clavicle form the posterior angle. Omohyoid muscle crosses lower portion of this triangle . c. Great Vessels: Carotid artery & Internal jugular vein locate deep to the sternomastoids. External jugular vein passes diagonally over the sternomastoid (helpful when trying to identify JVP). d. Midline Structures & Thyroid Gland: 1. Hyoid bone: below mandible 2. Thyroid cartilage: identified by notch on superior edge. 3. Cricoid cartilage 4. Tracheal rings 5. Thyroid gland
14. Clinical Objectives 1. Obtain a relevant history for complaints relating to the head, eyes, ears, nose, mouth. throat, and neck, to include the history of present illness (HPI), relevant past medical history (PMH) , social history (SH) and family history (FH) and review of system(s) (ROS) as outlined in Bickley and H&P Plus Booklet. 2. The student will demonstrate a complete and systematic examination of the head and neck by completion of the following objectives: a. Describe and document appropriate examination of the head, including scalp and hair.
15. b. Obtain relevant history for complaints related to the eye, ear, nose, mouth, and neck.c. Demonstrate and document appropriate examination of the eye, including the cover/uncover test and screening of visual fields by confrontation.d. Describe the steps to use an ophthalmoscope.e. Demonstrate skill in the use of the ophthalmoscope.f. Discuss and demonstrate the functional assessment of hearing.g. Describe and demonstrate the Weber and Rinne tests.h. Describe a normal tympanic membrane and common abnormalities of the tympanic membrane (TM).i. Demonstrate a complete ear examination using the otoscope.j. Demonstrate ability to document a complete ear examination (objective).k. Demonstrate an appropriate examination of the nose, frontal, and maxillary sinuses.l. Demonstrate a complete oral examination and document findings.m. Identify cranial nerves that innervate the eye, ear, face, tongue, soft palate, and neck (also covered in Neurology).n. Demonstrate proper lymph node examination techniques.o. Demonstrate and document an appropriate examination of the neck to include lymph nodes and thyroid gland.p. Accurately record history and physical exam findings related to the HEENT systems using appropriate terminology