Anatomy and Physiology Lab Exam 4

Choroid

2nd tunic; contains capillaries and pigments that reduce the scattering of light; aka vascular layer

Midbrain

A small part of the brain above the pons that integrates sensory information and relays it upward.

Pharyngotympanic Tube

Aka auditory tube Equalizes pressure on both sides of the tympanic membrane Normally closed

Fourth Ventricle

Between pons and cerebellum; connected to third ventricle by cerebral aqueduct (small passageway through the midbrain)

V - Trigeminal

Both sensory AND motor Sensory Function: detects facial sensation, including stimuli from the oral and nasal cavities Ophthalmic Nerve- its somatic sensory axons supply the skin over much of the scalp, the forehead, around the eyes, and around the nose; they also supply the nasal mucosa and structures of the eye Maxillary Nerve- its somatic sensory axons supply the skin over the middle of the face Mandibular Nerve- the sensory axons of the inferior mandibular nerve supply the skin of the chin and the lateral part of the face Motor Function: Ophthalmic Nerve- no motor function Maxillary Nerve- no motor function Mandibular Nerve- its motor axons supply the masseter and temporalis muscles, which elevate the mandible during chewing and swallowing

X - Vagus Nerve

Both sensory AND motor Sensory Function: somatic sensory neurons serce the skin around the ear. The special sensory neurons convey taste sensation from the pharynx, and the visceral sensory neurons whose chemoreceptors detect the blood CO2 concentration. Motor Function: somatic motor fibers supply the muscles surrounding the pharynx and larynx that contract during speaking and swallowing.

IX - Glossopharyngeal Nerve

Both sensory AND motor Sensory Function: the sensory portion of this nerve detects sensation as follows: the chemoreceptors of the posterior one-third of the tongue are associated with special sensory axons of this nerve. The cell bodies of these neurons are in the inferior ganglion. A small branch of this nerve contains somatic sensory neurons that innervate the external ear alongside the facial nerve. It also contains visceral sensory neurons that provide sensation for the posterior pharynx and surrounding structures In addition, certain visceral neurons detect changes in blood pressure via receptors in the carotid artery of the neck. Motor Function: The motor branches of this nerve supply a muscle around the pharynx that is responsible for swallowing movements. Also, parasympathetic neurons trigger salivation from the salivary gland called the parotid gland.

VII - Facial Nerve

Both sensory AND motor Sensory Function: the sensory root provides taste sensation from chemoreceptors in specialized receptor cells in the mucosa of the anterior two-thirds of the tongue and somatic sensation from the external ear, palate, and nasal cavity Motor Function: the somatic motor neurons of the five branches of the motor root supply the muscles of facial expression and other facial muscles. In addition, the parasympathetic neurons trigger secretion from certain salivary glands in the mouth, the tear glands over the eye, and the nasal mucous glands

Fornix

C-shaped ring of white matter; main output tract

Lateral Ventricle

Cavity that is continuous with central canal of spinal cord Lined with ependymal cells Filled with cerebrospinal fluid

Hypothalamus

Collection of nuclei anterior and inferior to larger thalamus; Regulates the autonomic nervous system, sleep/wake cycle, thirst and hunger, and body temperature

Precentral Gyrus

Contains primary motor cortex

Postcentral Gyrus

Contains the primary somatosensory cortex

Pineal Gland

Endocrine organ that resembles a pine cone Secretes melatonin

Sympathetic Nervous System

Fight or flight division Raises heart rate and blood pressure Causes dialation of bronchioles and pupils Construction of blood vessels Salivation decreases Sweat glands turn on

VIII - Vestibulocochlear Nerve

Function: Vestibular Nerve- its neurons depolarize in response to body position and so are concerned with balance and equillibrium. Cochlear Nerve- its neurons depolarize in response to sound waves and are responsible for audition, or the sound of hearing. Sensory or Motor: Sensory

II - Optic Nerve

Function: nerve for vision; It transmits visual stimuli in the form of action potentials triggered when light hits the eye's photoreceptors. These stimuli are processed in the brain by the primary visual cortex. Sensory or Motor: Sensory

I - Olfactory Nerve

Function: sense of smell; nerve endings contain chemoreceptors that depolarize in response to chemicals in the air that we breathe. Theses stimuli are interpreted in the brain by the primary olfactory cortex. Sensory or Motor: Sensory

IV - Trochlear Nerve

Function: somatic motor neurons innervate the superior oblique muscle, as it is cranial nerve, which moves the eye medially and inferiorly Sensory or Motor: Motor

XI - Accessory Nerve

Function: the cranial component of the accessory nerve innervates certain muscles of speech, whereas the spinal component innervates muscles that move the head and shoulder. Sensory or Motor: Motor

VI - Abducens Nerve

Function: the somatic motor neurons innervate the lateral rectus muscle. Its name comes from the fact that this muscle abducts the gaze when it turns the eye laterally. Sensory or Motor: Motor

XII - Hypoglossal Nerve

Function: this is a motor nerve that innervates the muscles of the tongue - it plays no role in taste sensation. Sensory or Motor: Motor

III - Oculomotor Nerve

Functions: Moving eyeball, opening the eye, constricting the pupil, changing the lens shape Sensory or Motor: Motor

Auricle (pinna)

Funnels sound waves into the ear Elastic cartilage covered in skin

Pons

Inferior to midbrain Regulates movement, breathing, reflexes, and complex Functions associated with sleep and arousal

Left and Right Parietal Lobes

Just posterior to frontal lobes Responsible for processing and integrating sensory information and function in attention

Corpus Callosum

Largest commissural fibers that connects the right and left hemispheres

Round Window

Made up of membranous labyrinth Detects angular or rotational movements

Thalamus

Main entry route of sensory data into cerebral cortex; Relay station that receives input, integrate information, them send information to specific motor or sensory areas in cerebral cortex

Left and Right Occipital Lobes

Make up posterior aspect of each cerebral hemisphere Separated from parietal lobe by parieto-occipital sulcus Neurons in these lobes process all information related to vision

Left and Right Frontal Lobes

Most anterior lobes Responsible for planning and executing movement and complex mental functions such as behavior, conscience, and personality

medulla oblongata

Most inferior structure of brainstem; Continuous with spinal cord at foramen magnum

Parasympathetic Nervous System

Rest and digest division Decreases heart rate and blood pressure Constriction of bronchioles and pupils Digestion increases Relaxation of urinary sphincters No effect on sweat glands Increases salivation

Vestibule of Ear

Separates the middle and inner ear Found in the cochlea

Malleus

Shaped like a hammer Set into motion by the tympanic membrane

Stapes

Shaped like a stirrup Set into motion by the incus

Incus

Shaped like an anvil Set into motion by the stapes

External Auditory Canal

Slightly curved canal tunneled through the temporal bone that ends at the tympanic membrane

Cochlea

Spiral shaped portion of the bony labyrinth Energy from sound waves are transmitted into neural impulses

Diencephalon

Thalamus, hypothalamus, pineal gland

Outer Ear

The part of the ear that collects sound waves; consists of the pinna, the ear canal, and the eardrum.

Tympanic Membrane

Thin sheet of epithelium and connective tissue that is cone shaped Converts sound waves into mechanical waves

VI

What number is the Abducens Nerve?

XI

What number is the Accessory Nerve?

VII

What number is the Facial Nerve?

IX

What number is the Glossopharyngeal Nerve?

XII

What number is the Hypoglossal Nerve?

III

What number is the Oculomotor Nerve?

I

What number is the Olfactory Nerve?

II

What number is the Optic Nerve?

V

What number is the Trigeminal Nerve?

IV

What number is the Trochlear Nerve?

X

What number is the Vagus Nerve?

VIII

What number is the Vestibulocochlear Nerve?

Tensor Tympani Muscle

a middle-ear muscle that is attached to the malleus. This muscle contracts in response to intense sound and to tactile stimulation of the force. Pulls the tympanic membrane medially

cerebral aqueduct

a narrow tube interconnecting the third and fourth ventricles of the brain, located in the center of the mesencephalon

Iris

colored portion of the eye; determines how much light can pass through the pupil

Suspensory Ligaments of Eye

connects the ciliary body to the lens; aids in changing the shape of the lens

Ciliary Body

contains a ring of smooth muscle that surrounds the lens; changes the shape of the lens

Lobule

earlobe

Fovea Centralis

in the center of macula lutea; cones are packed tightly together' high concentration of photoreceptors allows for ectremely detailed vision

Vascular Layer of Eye

iris, ciliary body, choroid

Longitudinal Fissure

long, deep groove that separates left and right cerebral hemispheres

Cerebellum

makes up posterior and inferior portion of brain; functionally connected with cerebral cortex, basal nuclei, brainstem, and spinal cord; interactions between these regions together coordinate movement

Auditory Ossicles

malleus, incus, stapes

Brainstem

midbrain, pons, medulla oblongata

Retina

neural layer of the eyeball; innermost layer of the eyeball; contains photoreceptors cells

Sclera

outermost layer of the eye; white part of the eye; has collagen fibers that help keep the eye's shape

Cingulate Gyrus

plays role in expressing emotions via gestures and resolves mental conflict

Optic Disc

portion of the retina where the axons of the optic nerve gather and exit the posterior of the eye; aka blind spot

Neural Layer of Eye

retina

Fibrous Layer of Eye

sclera and cornea (outermost layer)

parieto-occipital sulcus

separates the parietal lobe from the occipital lobe

Central Sulcus

shallow groove that is the posterior border of the frontal lobe

Central Artery and Vein of Retina

supply retina with nutrients, only area in body where blood vessels can be directly observed

Middle Ear

the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window

Inner Ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs

Ora Serrata

the serrated boundary between the ciliary muscle and the retina

Cornea

the transparent outer covering of the eye plays an important role in admitting light into the eye and focusing it

Semicircular Canals

three fluid-filled canals in the inner ear responsible for our sense of balance detect rotational movement of the head in any plane

Macula Lutea

yellowish area of the retina