AP: PNS, CNS, & Special Senses

Cochlea contains receptors for hearing. Cochlear duct winds through cochlea and separates into upper and lower cavities: upper cavity contains ova window (holds stirrup), lower cavity is bounded by round window. Cochlear duct filled with endolymph (supports spiral organ of Corti; contains receptors for hearing and nerve endings of vestibulocochlear nerve VIII)

Describe the pathway of sound waves that result in the sensation of hearing.

Role: lens changes shape to refract light Disease: Cataracts; with age, the lens hardens and becomes "fuzzy;" causes vision to become distorted, not clear, and possible double vision; eventually leads to blindness

Describe the role of the lens in vision. Name and explain the disease caused by the hardening of the lens.

Semicircular canals

Dynamic equilibrium receptors that detect information about angular or rotational movements of the head are housed in the _____.

Optic chiasma

Fibers from the denial side of each eye cross over to the opposite side of the brain at the _____.

Somatic sensory

Fibers that carry info from the skin, joints, and skeletal muscles to the CNS are _____.

Sensory (afferent) division

Functional NS division that carries info from the CNS toward effectors

Motor (efferent) division

Functional NS subdivision that carries info toward the CNS from receptors

Cell bodies

Ganglia are collections of what?

12

How many pairs of cranial nerves branch from the surface of the brain?

White & gray

Myelinated fibers (tracts) form _____ matter while unmyelinated fibers form _____ matter.

Multipolar

Neurons with several processes branching off the cell body, such as motor neurons and interneurons (association neurons), are structurally classified as _____.

Brain stem

Pons, midbrain, and medulla oblongata

Sympathetic NS

Preparing the body for the "fight or flight" response during threatening situations is the role of the _____.

Cerebrum

Primary motor area

Broca's area

Sally has a brain injury; she knows what she wants to say but can't vocalize the words. The part of her brain that deals with the ability to speak is the _____.

PNS

Structural NS subdivision that consists of spinal nerves and cranial nerves

CNS

Structural NS subdivision that consists of the brain and spinal cord

Neuroglia

Support cells in the CNS are collectively called _____.

False

T/F: Cerebrospinal fluid circulates within the ventricles of the brain and also in the subarachnoid space outside the brain.

True

T/F: Complex networks of spinal nerves are termed nerve plexuses

False

T/F: Cones are photoreceptor cells that allow us to see gray tones in dim light.

False

T/F: Cranial nerve X is the vestibulocochlear nerve, it's fibers carry sensations of hearing and equilibrium to the brain

False

T/F: Difficulty in breathing may reflect damage to respiratory centers located in the cerebellum.

True

T/F: In order to hear sound, vibrations pass from the eardrum to the ossicles, and on to the oval window

True

T/F: One of the major functions of the pons is to produce releasing factors that control the function of the anterior pituitary

True

T/F: The ciliary body is a smooth muscle structure to which the lens is attached

True

T/F: The collection of spinal nerves at the inferior end of the spinal cord is called the cauda equina

False

T/F: The primary motor area allows us to consciously move our skeletal muscles

False

T/F: The thalamus plays a role in regulation of body temp, metabolism, and water balance.

True

T/F: a sensory neuron carries stimuli from the CNS to the effector

True

T/F: the CNS includes the spinal nerves and cranial nerves

Diencephalon

Thalamus, hypothalamus, and epithalamus

Central & peripheral

The NS is structurally subdivided into two systems: the _____ NS & the _____ NS

Parasympathetic

The _____ division of the autonomic NS is often called the "rest and digest" division.

Lacrimal

The _____ gland is located above the lateral end of each eye and releases tears.

Perineurium

The _____ is a connective tissue wrapping around fascicles of neuron fibers.

Outer cartilage of the ear

The auricle (pinna) is located where in the ear?

Lens

The biconvex structure that focuses light in the retina is the _____.

Meninges

The brain and spinal cord are protected and cushioned by three connective tissue membranes that are collectively called _____.

Conch shaped structure attached below the semicircular canals

The cochlea is located where in the ear?

Temporal lobe

The cochlear nerve transmits impulses to the auditory cortex located in the _____.

Malleus, incus, stapes

The correct pathway of vibrations as they travel from the tympanic membrane to the ossicles.

Dura mater, arachnoid mater, pia mater

The correct sequence from outermost to innermost layers if the meninges?

Receptor, sensory neuron, integration center, motor neuron, effector

The correct sequence in a typical reflex arc

Epineurium, perineurium, endoneurium

The correct sequence in connective tissue sheaths, going from outermost to innermost layer

Cervical spinal nerves, thoracic spinal nerves, lumbar spinal nerves, sacral spinal nerves

The correct sequence of nerves that exit the spinal cord, from superior to inferior.

Pia

The delicate innermost membrane, or meningeal layer, that clings to the surface of the brain and spinal cord is known as the _____ mater.

No - Symptoms of brain injuries occur on the opposite side of the body; if his right side is impaired, the left side of his brain was damaged. The sensory area info is also incorrect; should be his motor area.

The family of Mr. Sanchez has learned that his cerebrovascular accident (CVA, or stroke) impaired his ability to move the right side of his body. They were told the CVA involved the primary somatic sensory area in the right cerebral hemisphere. Is this info correct?

Sclera; cornea

The fibrous covering of the eye consists of the white outer layer, known as the _____, and a transparent portion known as the _____.

Longitudinal fissure

The fissure in the brain that separates the two cerebral hemispheres is called the _____.

Retina

The innermost sensory layer of the eye that contains bipolar cells and ganglion cells is the _____.

Corpus callosum

The large fiber tract that allows communication between the two cerebral hemispheres is called the _____.

Sacral

The largest nerve in the body, the sciatic nerve, belongs to the _____ nerve plexus.

Connect motor and sensory neurons in their pathways

The major role of the interneuron (association neuron) is to _____.

Conjunctiva

The membrane that covers the outer surface of the eye and lines the eyelids is the _____.

Brain stem

The midbrain, pons, and medulla oblongata are housed in the _____.

Axon

The part of the neuron that typically conducts nerve impulses away from the cell body is the _____.

Iris

The pigmented portion of the eye that had a rounded opening through which light passes is the _____.

Thalamus

The portion of the diencephalon that acts as a relay station for sensory impulses traveling to the sensory cortex is the _____.

Parietal

The primary somatic sensory cortex is located in the _____ love of the cerebrum.

Optic disc (blind spot)

The region of the optic nerve lacking photoreceptor cells is known as the _____.

Circular canals in innermost ear; above stirrup 'outside' ear canal

The semicircular canals are located where in the ear?

Papillae

The small, peg-like projection of the tongue's surface are called _____.

L3

The spinal cord terminates around vertebra _____.

Stirrup shaped, bone in innermost ear; below semicircular canals 'inside' ear canal

The stapes (stirrup) is located where in the ear?

Tympanic membrane (ear drum)

The structure that divides the outer ear from the middle ear is a membrane j own as the_____.

Brain and spinal cord

The term CNS refers to:

Dicephalon (interbrain)

The thalamus, hypothalamus, and epithalamus collectively constitute the _____.

Fan-like structure separating outside particles from inside ear canal

The tympanic membrane is located where in the ear?

Olfactory receptor

The type of chemoreceptor responsible for our sense of smell is called a(n) _____.

Plexus

The ventral rami of the spinal nerves form complex networks of nerves known as _____.

Medulla oblongata

The vital centers for the control of visceral activities such as heart rate, breathing, blood pressure, swallowing, and vomiting are located in the _____.

12 & 31

There are _____ pairs of cranial nerves, and _____ pairs of spinal nerves in the PNS.

Otoliths

Tiny stones made of calcium salts that roll in response to changes in gravitational pull are called _____.

Color blindess

What is a sex-linked condition that more often affects males?

Oligodendrocytes

What neuroglial cells forms the myelin sheath in the CNS?

Corpora quadrigemina

What part of the. Rain stem houses reflex centers for vision and hearing?

Lens

What structure of the eye focuses on light?

Corpus callosum

Where does cerebrospinal fluid NOT flow?

Vagus

Which cranial nerve descends into the thoracic and abdominal cavities to regulate heart rate and promote digestive activity?

Vestibulocochlear nerve (VIII)

Which cranial nerve transmits hearing and equilibrium info to the brain?

Autonomic

_____ reflexes include secretion of saliva, changes in the size of pupils, and digestion involve the activities of smooth muscles.

Frontal lobe

A stroke in the primary motor area has caused Don to lose control over his skeletal muscles on the right side of his body. What lobe of his brain was damaged?

Sympathetic; other symptoms include: sweating, increased heart rate, increased breathing (panting), etc.

An 18-wheeler just nearly missed hitting Sam head on while driving. Exasperated, he pulls over to the side of the road with his heart pounding. Which division of the autonomic NS is taking control right now? What other symptoms would he be experiencing?

Tracts & neeves

Bundles of nerve fibers (neuron processes) running through the CNS are called _____; whereas, in the PNS, they are called _____.

Choroid plexuses

Cerebrospinal fluid is formed from blood by clusters of capillaries in the brain known as _____.

Hypothalamus

Control of temp., endocrine activity, metabolism, and thirst are functions associated with the _____.

Cerebellum

Controls balance and equilibrium

Oculomotor

Cranial nerve III is known as the _____ nerve.

Lens of the eye focuses light on the retina. The lens contains rods and cones (photoreceptors). Begin events from photoreceptors to bipolar cells, then to ganglion cells. Once stimulated, ganglion cells generate nerve impulses that are transmitted to the optic cortex of brain. Thus, vision.

Describe the pathway of light through the eyeball