Bio 11 Anatomy - Senses

Free Nerve Endings

touch, pain, pressure

Root Hair Plexuses

hair movement

Tactile Discs

light touch

End Bulbs

light pressure, low vibration (in mucus membranes)

Lamellated Corpuscles

course touch, deep pressure, high vibration; Inner core of neurolemmocytes

Bulbous Corpuscles

skin distortion, deep pressure

Tacticle Corpuscle

textures, shapes

Vallate Papillae

Largest but least common. “V” shape in posterior. Most taste buds

Palpebra

Eyelid

Foliate Papillae

Extend as ridges on lateral tongue; few tastebuds in infancy + childhood

Filiform Papillae

No tastebuds, detects texture, mechanically moves food during mastication.

Fungiform Papillae

On tip and sides of tongue, few taste receptors

Basal Cells

neural stem cells that replace gustatory cells every 7-9 days

Cranial Nerve IX

Glossopharyngeal - responsible for taste sensations at the posterior region of the tongue, initiates swallowing, and carries afferent sensory and efferent motor information

CN VII

Facial - responsible for taste sensations at the anterior regions of the tongue

Where are parasympathetic pre-ganglionic neurons?

brainstem nuclei, craniosacral, and CN III, VII, IX, and X

where are sympathetic pre-ganglionic neurons?

lateral horns, thoracolumbar

Submucosal Plexus

part of enteric nervous system; controls secretion, absorption, mucosal folding. 

Myenteric Plexus

part of enteric nervous system; controls GI tract smooth muscle activity

Plasma Proteins

60% albuminum, 36% globulins 4%fibrogen

Lamina Propria

deep to the epithelium; contains mucin-secreting olfactory glands

Pigmented Layer

provides vitamin A for photoreceptor cells

Emmetropia

normal vision; parallel rays of light focused on retina

Hyperopia

farsightedness, caused by short eye. corrected with convex lens.

Myopia

nearsightedness, caused by long eye. corrected with concave lens. 

Presbyopia

changing from far to near; caused by age, lens cannot change shape

Astigmatism

blurry vision, caused by unequal curves of cornea or lens

Neural Layer

contains photoreceptor cells, bipolar cells, and ganglion cells; 

responsible for converting light → nerve impulses

Tarsal Glands

Sebaceous glands that produce a secretion to prevent tear overflow, prevents eye from sticking together

Lacrimal Caruncle

Houses ciliary glands, modified sweat glands that causes gritty morning eyes.

lacrimal fluid is transferred here

Lysozome

antibiotic-like enzyme produced by lacrimal apparatus

Limbus

structural continuity between cornea and sclera

Lens shape for far-away things

lens flattened, suspensory ligaments taut

Lens shape for up-close things

lens thickened, suspensory ligaments relaxed

Suspensory Ligaments

holds lens in place

Utricle

detects horizontal movement via movement otolithic membrane

Saccule

detects vertical movement via movement of otolithic membrane

Kinocilia

apex of hair cells in sensory epithelium

Stereocilia

converts mechanical energy to electrical energy; communicates to CNVIII

Cochlear Duct

endolymph, 

Scala Tympani

Scala Vestibuli

Otoliths

calcium carbonate (CaCo₃) crystals

Olfactory Glomeruli

spherical structures in olfactory bulbs that detect and differentiate smells

Dilator Pupillae

(radial) sympathetic ANS

Sphincter Pupillae

(circular) parasympathetic ANS

Ciliary Body

relaxation / contraction change tension on suspensory ligaments;

epithelium secretes aqueous humor

Ora Serrata

transitional layer between neural retina and ciliary body