Lab 7: Nerve Pathways and Senses

Trace the 6 Nerves presented, find and describe functions of the eye, tongue, and nose.

Retina

The ___ is the origin for the Optic Nerve, which can be seen on the anterior view of the brain stem at the highest point below the diencephalon.

Thalamus and Visual Cortex (occipital lobe)

The Optic nerve innervates the __ ___ __ __ on its pathway.

Optic Canal in Sphenoid Bone

What foramen does the optic nerve pass through?

Medulla Oblongata

Where does the Vagus Nerve originate from brain?

Jugular Foramen

What foramen does the Vagus nerve pass through?

C3-C5

Which spinal nerves make up the Phrenic Nerve

Cervical Plexus

The Phrenic Nerve belongs in the __ __, which provides somatic motor and sensory innervation to vital respiratory muscles.

Diaphragm

What muscles does the phrenic nerve innervate?

Thorax

Where does the Phrenic nerve have to pass to innervate the diaphragm?

C8 and T1

Which spinal nerves make up ulnar nerve?

Brachial Plexus

The Ulnar nerve is part of the __ ___, which gives rise to almost all nerves that supply the upper limb.

Ulnar

The cutaneous regions for the ___ nerve include the skin of dorsolateral surface of han, most of triceps, and down the medial section of forearm.

Muscle Groups of Ulnar

The flexor Carpi ulnaris, 3 hypothenar muscles, 7 interossei, and adductor policis are the __ __ __ __ nerve.

Respiratory Arrest

What would happen if phrenic nerve were to be cut, knowing it innervates C3-C5 in cervical area of neck?

L2-L4

Which spinal nerves make up obturator nerve?

Obturator Foramen

The Obturator Nerve has to pass through the __ ___ in the coxa bones to enter Medial compartment.

Lumbar Plexus

The Obturator nerve is part of the __ ___, which has it innervates the adductor muscle group of Medial thigh.

L4, L5, S1-S3

Which spinal nerves make up the Tibial Nerve?

Sacral Plexus

The Tibial nerve is part of the __ ___, where it supplies the posterior region of lower limb with sensory information like on the Skin of the sole.

Posterior Thigh and Leg

What muscle groups does Tibial nerve innervate?

Sole skin on foot, plantar nerves

What cutaneous regions does the Tibial nerve innervate?

Fungiform Papillae

Small projections of tongue mucosa, located on anterior tongue surface that house tastebuds for detecting flavors.

Vallate Papillae

Large Projections in V shape at back of tongue to detect flavors and increase surface area.

Foliate Papillae

Projections on posterolateral tongue surface with taste buds in side walls; detect flavors and house tastebuds.

Olfactory Sensory Neurons

Pseudostratified Columnar Epithelium that contains millions of bipolar neurons

Supporting Epithelial Cells

The __ __ __ surround the olfactory sensory neurons in the nose.

Olfactory Cilia

Receptive structures for smell by binding odor molecules; mostly immotile.

Olfactory Bulb

Origin of branching and synapse for olfactory nerve axons; mitral cells synapse here.

Olfactory Tract

Where mitral cells transmit impulses to the limbic region and primary olfactory cortex.

Filaments of Olfactory nerve

Axons gather from sensory neurons to enter CT of Lamina Propria and go into cribriform plate of ethmoid bone.

Nasal Cavity

Where is the origin of Olfactory Nerve I?

Olfactory Tract

The __ __ is different from Olfactory Nerve because the tract extends from the Olfactory Bulb.

Eyebrow

Block Sunlight and Sweat from reaching eye

Eyelids (palpebrae)

Protect eye from light and debris, spread lubricating tears

Eyelashes

richly innervated; trigger reflexive blinking

Tarsal Glands

Release lipid-base substance to lubricate the eye with tears

Conjunctiva

Protective mucous membrane that covers the white of eye

Lacrimal Apparatus

Keep Surface of eye moist with lacrimal fluid; contain ducts for draining fluid into nasal cavity

Lacrimal Gland

Produces Lacrimal fluid (tears)

Lacrimal Punctum

Tiny opening where Lacrimal fluid drains into nasolacrimal duct

Lateral Rectus Muscle

Turns eye laterally

Abducens VI

Lateral Rectus Muscle is controlled by __ __ Cranial nerve.

Medial Rectus Muscle

Turns eye medially

Oculomotor III

Medial Rectus muscle is controlled by ___ __ Cranial nerve.

Superior Rectus Muscle

Elevates eye and turns medially

Oculomotor III

Superior Rectus Muscle is controlled by ___ __ Cranial nerve.

Inferior Rectus Muscle

Depresses eye and turns medially

Superior Oblique Muscle

Depresses eye and turns laterally

Trochlear IV

Superior Oblique muscle is controlled by __ __ Cranial nerve.

Inferior Oblique Muscle

Elevates the eye and turns laterally

Oculomotor III

Inferior Oblique muscle is controlled by__ __ Cranial nerve.

Light Order of Eye

1) Fibrous Layer

2) Vascular Layer

3) Inner Layer

Sclera

Protect eyeball and provides shape and sturdy anchoring for eye muscles. “White of Eye” and outermost layer

Cornea

Thick layer of dense CT between epithelium, allows light to enter the eye

Choroid

Highly vascular darkly pigmented membrane forming around posterior 5/6 of vascular layer.

Ciliary Body

Thickened ring of tissue that encircles lens that contain muscles and processes for shaping lens.

Ciliary Muscle

Smooth muscle in ciliary body that act to focus the lens.

Iris

Contains sphincter and allow light to enter inner eye.

Pupil

Opening of iris that allows light to enter the eye

Retina

Light sensitive layer of tissue located at back of eye; sandwiched between Sclera and Choroid in back of eye. Contains the photorecptors

Fovea

At center of macula lutea in posterior part of retina; ONLY possess cones and provides maximal visual acuity

Vitreous Humor

Jellylike substance containing fine fibrils of collagen and bind tremendous amounts of water; maintain intraocular pressure in eyes when muscles activate.

Optic Chiasma

Crossover of optic nerves; seen on inferior view of brain

Optic Nerve

Axons from ganglion cells exiting eye in posterior part of eye.

Optic Tract

Optic Chiasma splits medially to each half of eye

Optic Disc

elevation in posterior eye where axons of ganglion cells converge and form a blind spot as they leave through optic nerve.