L29 Organ of Special Senses

• State 4 special senses with it organ and nerves

  -olfaction -nose -olfactory

  -vision -eye -optic

  -auditory -ear -auditory

  -gustatory -tongue -facial, glossopharyngeal, vagus
• state 4 bones that contribute to the framework of each orbit

  -zygomatic

  -maxilla

  -lacrimal

  -frontal
• describe orbit as socket of eyeball

  -conical cavities

  -eyes situated in it

  -intended to protect eye grom mechanical injury
• state 2 for each fascias and extrarocular muslces

  -orbital -inferior oblique

  -bulbar -inferior rectus
• differentiate two groups within orbit

  extrinsic muscle - raising upper eyelids

  intrinsic muscle - control size pupil
• classify nerve supply for each oculomotor muscle

  superior oblique - trochlear

  lateral rectus - abducens

  inferior, medial, superior rectus & inferior oblique - oculomotor
• name impairment that causes drooping of upper eyelid (ptosis)

  3rd nerve palsy
• what is ophthalmoplegia

  paralysis of muscles of eyeball
• state 3 layers of eyeball

  -inner

  -vascular

  -fibrous
• differentiate fibrous outer coat of sclera and cornea

  sclera - opaque

  cornea - transparent
• state 2 functions of sclera

  -maintain shape of eyeball

  -ensure only light enters through pupil
• why corneal grafting is possible ?

  -absence of blood vessels

  -absence of antigen presenting cells
• which component provides attachment for lens ? what is the significance of it ?

  -ciliary body

  -controls thickness of the lens due to contraction or relaxation
• what is iris ?

  -an adjustable diaphragm

  -lies between cornea and lens
• describe two functional parts in retina

  -optic part which sensitive to visual light rays

  -non visual part which have blind sot with no photoreceptor
• differentiate photoreceptors in retina

  functions - rods vs cones

  sensitivity to light - low vs high

  dark adaptation - later vs early

  colour vision - black/white vs colour
• describe nose

  -part of respiratory tract

  -superior to hard palate

  -contains external nose and nasal cavities
• state areas involve in nasal cavity

  -olfactory

  -respiratory
• state 4 fuuntions of nose

  -olfaction

  -respiration

  -filtration

  -humidification
• state 4 part that made the external nose

  -nasal septum

  -apex

  -naris

  -root
• what is nasal cavity and nasal septum ?

  nasal cavity : extends from naris to choana and divided into right and left cavities by nasal septum

  nasal septum : partly bony, cartilaginous and cuticular, dividing nasal cavity into two cavities
• function of turbinate in lateral wall

  -increase surface area of nasal cavity

  -provides effective air conditioning function
• draw and label nasal septum

  Draw first then label

  A) Nasal spine frontal bone

  B) Nasal bone

  C) Septal cartilage

  D) Incisor crest

  E) Nasal crest maxilla

  F) Palatine bone

  G) Vomer

  H) Pitituary fossa

  I) Spenoidal sinus

  J) Perpendicular plate of ethmoid bone

  
• draw and label lateral wall of nasal cavity

  draw first then label

  A) Superior

  B) Middle

  C) Inferior

  D) Concha

  E) Soft Palate

  F) Nasopharynx

  G) Opening of pharyngotympanic tube

  
• name area where epistaxis usually arise in little's area

  Kiesselbach's area
• state 4 arteries that supply the nose

  -superior labial artery

  -anterior ethmoid artery

  -greater palatine artery

  -sphenopalatine artery
• describe paranasal air sinuses (PNS)

  -air filled spaces covered internally by mucus membrane

  -present bilaterally around nasal cavity
• draw and label PNS

  draw first then label

  A) Frontal

  B) Ethmoid

  C) Maxillary

  D) Sphenoid

  
• state 2 functions of PNS

  -lighten the skull

  -help in dentition
• describe drainage of nose

  -drains into middle meatus of nose through ostium

  -ostium lies on base of sinus close to its roof

  -location of ostium is a drawback for drainage of maxillary air sinus
• state components of lacrimal apparatus

  -lacrimal gland

  -lacrimal sac
• state 3 parts of the ear and its component

  -external -auricle

  -middle -tympanic cavity

  -internal -labyrinth
• state function of each part of ear

  -external -collect sound

  -middle -transmit sound

  -internal -convert vibration into electric signal
• name the germ layers which tympanic membrane developed from

  -ectoderm

  -mesoderm

  -endoderm
• state 4 contents of tympanic cavity

  -ossicle

  -muscle tensor

  -vessels

  -nerves
• state 3 auditory ossicles

  -malleus

  -incus

  -sttapes
• whyy middle ear infection (otitis media) common in children ?

  -children's auditory tube are half shorter, horizontally placed, and wider in diameter

  -cause easy transmission of infection from nasopharynx to middle ear cavity

  -cause otitis media;
• draw external ear and label

  draw first then label

  A) Helix

  B) Antihelix

  C) Lobule

  D) Antitragus

  E) Tragus

  F) Concha

  
• Describe tongue

  -mobile muscular organ

  -can assume variety shapes and positions

  -partly oral cavity and oropharynx
• functions of tongue

  -mastication

  -taste

  -deglutition