Chalter 19: Senses Flashcards
Olfactory receptors
Detect odour
Supporting / sustentacular cells
- Support, nourish, and insulate the receptor cells
- odour binding proteins
Basal cells
- replace worn-out olfactory receptor cells
Olfactory (Bowman’s ) gland
- mucous producing glands that moisten the epithelial surface and dissolve the odourant molecules
Olfactory pathway
-olfactory receptor
- olfactory nerves (CNI)
- olfactory bulbs
- olfactory tract
-cerebral cortex
- temporal lobe
What lobe of the brain is responsiabke for smell
Temporal lobe
What is the nerve that carry’s smell
Olfactory nerves (CNI)
Sweet
Sugars
Salty
-Na
-Cl
Sour
Acids (H)
Bitter
Alkaloids
Umami
Amino acids
Where are taste buds found
- soft palate
- epiglottis
- pharynx
- elevations of the tongue called papillae
What are papillae
Elevations on the tongue whee taste buds are found
Filiform papillae
- contain tactile receptors but no taste buds
- increase friction between the tongue and the food making it easier for the tongue to move food to the oral cavity
Fungiform papillae
5 taste buds
- mushroom shaped elevations scatted over the surface of the tongue
Vallate (circular) papillae
100-300 Taste buds
- form an inverted v-shaped row at the back of the tongue
Foliate papillae
-most of the taste buds degenerate in early childhood
What three types of papillae contain tastes buds
- fungiform
- vallate (circular)
- foliate (degenerate in early childhood)
Gustatory pathway
- taste buds
- gustatory receptor
- CNVII, CNIX, CNX
-gustatory nucleus
-thalamus - insula
What nerves are responsible for taste
-CNVII facial
-CNX vagus
- CNIX glossopharyngeal
What is the part of the brain that detects taste
Insula
What is the other name for eyelids
-palpebrae
Levator palpebrae muscle is responsiable for
A week twitch
What is the palpebral fissure
- space between eyelids (palpebrae)
Lacrimal caruncle contains
Sebaceous and sudoriferous glands
What does the tarsal plate do
Supports the eyelids
Function of tarsal (meibomian) gland
- located in the tarsal plate
- are sebaceous glands within eyelids;secretion prevents the overflow of tears from sticking together
Chalazion
-a tumour or cyst in the tarsal glands
Conjunctiva
- the lining over the anterior surface of the eye
Palpebral conjunctiva
A thin protective mucous membrane
Eyebrows
- thick, short hairs along the superior orbital ridge that prevents sweat from dripping into the eye
Eyelashes
- hairs on the margins within the eyelids that prevent large foreign objects from contacting eyes
What are the medial and lateral palpebral commissures
Are the corners of the eyes
What is the lacrimal caruncle
-is a medial pink bump containing ciliary glands that produce gritty secretion
Fibrous tunic / layer contains
- scelera
- cornea
- sclera venous sinus
Sclera
- support, protects, and maintains the shape of the eye and muscle attachments
Cornea
- a vascular collangous tissue
Sclera venous sinus
Waste removal
Vasucular tunic / layer contains
-choroid
- ciliary body/process
- iris
-pupil
- lens
Choroid
-vascular, melanocytes
Ciliary body / process
-melanocytes, aqueous humour
Iris
Coloured portion of the eye, consists of two smooth muscles
Pupil
Opening in the iris, regulates light entrance
Where is aqueous humour produces
Ciliary process and released into the posterior chamber
Where is aqueous humour stored
Moves through the pupil to the anterior chamber
Excess aqueous humour is absorbed by…
The sclera venous sinus
Pigmented Layer of the Retina
- melanin helps absorb stray light rays
Photoreceptor cells
- outermost layer
- compromised of rods (dim light) and cones (precise and colour vision)
Bipolar cells
- synapse with photoreceptors and ganglion cells
Horizontal cells
- in between photoreceptors and bipolar cells
Amacrine cells
- in between bipolar cells and ganglion cells
Ganglion cells
- innermost layer
- axons leave the retina the form the optic nerve
Optic discs functions
- “Blind spot”
- located where ganglion cell axons exit the retina to form the optic nerve, and where blood vessels enter and exist the retina
Fovea centralis
- depression in the retina contain a large portion of cones (no rods)
- area of sharpest vision
- located in the macula lutea
Visual pathway
- bipolar cells
- optic nerve (II)
- optic chaism
- optic tract
- lateral Venice,ate nucleus: thalamus
- occipital lobe
What nerve Carrys vision to the brain
Optic (II) nerve
What part of the brain does visual information go to
Occipital lobe
Function of the external ear
- collects sound waves
Function of the middle ear
- transmits sound waves to the oval window
What is the function of the internal ear
- receptors for hearing and equilibrium
The external ear consists of
- auricle (pinna)
- external auditory canal
- cerumious glands
-tympanic membrane (eardrum) - umbo
- malleus
What is the middle ear
- is a small, air-filled cavity in the temporal bone that is lined by epithlium
What does the middle ear consists of:
- ossicles (malleus, incus, stapes)
- tensor tympani muscle
- stapedius muscle
- auditory tube (pharyngotympanic tube) also know as the Eustachian tube
What is the internal ear also called
Labyrinth
What are the three main areas on the bony labyrinth
- semicircular canals: circular motion
- vestibule: utricle/saccule: linear motion
-cochlea: organ of corgi- hearing
Bony labyrinth
Perilymph
Membranous labyrinth
- epithelial sac portion
- endolymph and receptors for hearing and equilibrium
Hair cells
Receptors for hearing
Where does the auditory pathway lead to
Temporal lobe
Static/linear equilibrium
- maintain the position of the body realize to the force of gravity
- receptor are located in the utricle and saccule: maculae
Dynamic / rotation equilibrium
- maintain the body position in relation to sudden movements (acceleration / deceleration)
- located in the semicircular canal: crista
Vestibular apparatus
- saccule
- utricle
- semicircular ducts
Macula
- sense organs of the utricle and saccule
