Exam 4 Multiple Choice(Lectures 15-18)

What are the divisions of the PNS?

• Afferent division

• Efferent division

What is the function of the afferent division?

Carries sensory information towards the CNS

What is the function of the efferent division?

Carries motor information from the CNS to the peripheral tissues

What are the divisions of the efferent division?

• Somatic Nervous System

• Autonomic Nervous System

What does the somatic nervous system control? What type of control is it under?

• Controls skeletal muscles

• Conscious control

What does the autonomic nervous system control? What type of control is it under?

• Controls cardiac muscle, smooth muscle, and various glands

• involuntary

What are the components of the spinal nerve? Define each component.

• Dorsal Root: sensory nerve entry point

• Dorsal Root Ganglion: collection of sensory neuron cell bodies

• Ventral Root: motor nerve exit point

• Spinal Nerve: formed by the union of the ventral and dorsal roots

What are mixed nerve trunks?

Bundle of fascicles

Define nerve plexus

Merging network of spinal nerve trunks leading to and from specific body regions

What does the cervical plexus innervate? What major nerve does it contain?

• Innervates the neck, jaw, upper back, & diaphragm

• Includes the phrenic nerve

What does the brachial plexus innervate? What major nerves does it contain?

• Innervates the shoulder, arm, & hand

• Includes radial, median, ulnar & axillary nerves

What does the lumbar plexus innervate? What major nerve does it contain?

• Innervates the lower back, lower abdominal wall, thigh, & genitalia

• Includes the femoral nerve

What does the sacral plexus innervate? What major nerve does it contain?

• Innervates the hip region, posterior thigh, calf, & foot

• Included the sciatic nerve

What Is the type of control of the somatic nervous system?

voluntary

What is the type of control of the autonomic nervous system?

Involuntary

Where are preganglionic neurons found? Where do they synapse?

• Cell bodies found in the CNS 

• Synapse on the postganglionic neurons

Where are postganglionic neurons found? Where do they synapse?

• Cell bodies outside the CNS

• Synapse on the peripheral tissue and organs

What are the divisions of the autonomic nervous system? For each division, state if it’s excitatory or inhibitory, and its type of response.

• Sympathetic

Excitatory

“Fight or flight” response

• Parasympathetic

Inhibitory

“Rest & digest” response

Define dual motor innervation. What type of effects do the sympathetic and parasympathetic fibers have when compared to one another?

• Every effector is supplied with one sympathetic & one parasympathetic fiber

• Antagonistic effects

State the effect of the following CNS components on the ANS: hypothalamus, medulla oblongata, cerebral cortex.

• Hypothalamus: controls thermoregulation, hunger & shirts

• Medulla Oblongata: controls HR, BP, respiratory rate, digestion

• Cerebral Cortex: can influence the hypothalamus, indirectly influencing the ANS

What are the accessory structures of the eye? What is the function of each structure?

• Extrinsic skeletal muscles; controls eye movement?

• Lacrimal glands; excrete lacrimal fluid(tears) 

• Conjunctiva; lubricate & moistens the eye/detection of foreign objects

What are the photoreceptors of the retina? What does each photoreceptor detect?

• Rods; detect low levels of light

• Cones; detect “higher” wavelengths of light

What are the segments of the eye? What forms the boundaries of the segments? What fills each segment?

• Anterior Segment; anterior to the lens & posterior to the cornea

Filled with Aqueous humor

• Posterior Segment; posterior to the lens & anterior to the retina 

Filled with vitreous humor

What are the chambers of the anterior segment? What forms the boundaries for each chamber

• Anterior chamber of the anterior segment; between the cornea & iris

• Posterior chamber of the anterior segment; between the iris & iris

What is the function of the aqueous humor? Vitreous humor?

• Aqueous humor; maintains the shape of the cornea

• Vitreous humor; support the retina

What are the functions of the ear?

Hearing & equilibrium

What are the regions of the ear? What are the components of each region?

• External ear; auricle & external auditory meatus

• Middle ear; ear ossicles & auditory tubes

• Inner ear; vestibular complex & cochlea

What is the function of the auricle?

Gathers and funnels sound waves

What lines the external auditory meatus? What is the function of cerumen?

• Lined with skin that contains hair & ceruminous glands

• Function of the cerumen: trap dust & other airborne particles

What does the tympanic membrane separate?

Separates the external ear from the middle ear

What is the function of the tympanic membrane?

• Transfers sound waves to structures of the middle ear

What is the function of the ear ossicles?

Transmit & amplify sound waves to the inner ear

For each ear ossicle, state its function.

• Malleus; transmits vibrations from the tympanic membrane to the incus

• Incus; transmit vibrations from the malleus to the stapes

• Stapes; transmits vibrations from the incus to the oval window

What does the eustachian tube connect? What is the function of the eustachian tube?

• Middle ear to the nasopharynx. It equalizes air pressure in the ear

What is the function of the vestibular complex?

• Sends sensory information regarding balance & equilibrium to the CNS

What are the regions of the vestibular complex? What is the function of each region?

• Vestibule; contains receptors to detect gravity & linear acceleration

• Semicircular Canals; contains receptors responding to rotation of the head

What is the function of organ of corti?

Converts sound waves into electrical impulses