Animal Physiology Last 4 SS#_____________

March 26, 2001

1. Draw a graph of the graded potential changes in a post-synaptic cell if the following stimulations are to the pre-synaptic cell that is electrically attached. Label the graph axes. (6 pts)

___

! !

___ ! !

Stimulation ____! !_____! !______ ___________

!_____!

2. Draw and label a myoneural junction with at least _7_ structures. (14 pts)

Possible structures are:

Schwann cell
axon
vescicles
active sites
synapse
muscle
troughs
site of receptor
site of AchE

3. Draw the graded potential of cell E. Note the drawing of the connections. Cells A and B are stimulatory. Cell C is inhibitory and cell D produces presynaptic inhibition. Be very clear. (16 pts)

A___!!!!!!________________________!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

B_________!!!!!!_____________________!!!!!!_____________!!!!!!_______________

C_______________!!!!!!_____________________!!!!!!_________________________

D____________________!!!!!!_______________________!!!!!!!!!!!!!!!!!!!!___________

E________________________________________________________________________

Time --->

4. List all of the sensations that "hair cells" can detect. (10 pts)

2 pts each up top 10 pts

sound

lateral line, pressure waves in water

gravity

acceleration

electrical receptors in lateral line

5. Describe the anatomy and arrangement of the ear so that you can trace the energy of sound waves through all of the structures until you explain how it stimulates the hair cells. (14 pts) - 7 items

Sound waves vibrate the tympanic membrane

The membrane vibrates the inner ear bones (don't count each separate bone)

The stapes vibrates the oval window

The oval window vibrates the fluid inside

The fluid causes part of the basilar membrane to vibrate that is most susceptible to that frequency

Hair cells are anchored on the basilar membrane they go up and down

The stereocilia of the hair cells are stuck in the tectorial membrane

Movement puts shear force on the stereocilia

The hair cells depolarize and hyperpolarize with the stimulation

6. Match the following Brain parts and the major functions or these parts. Use answers more than once or not at all.(13 pts)

_O__ Secrete cerebro-spinal fluid A. Thalamus

_E__ A cavity in the brain B. Hypothalamus

_D_ Coordinates sensory & motor movement, C. Cerebral Hemispheres

smooths movement

_G_ Respiratory & circulatory control D. Cerebellum

__B "Pleasure" & "Rage" center E. Ventricle

_J__ Middle one of the meninges F. Corpus callosum

_A_ All sensory rerouting area G. Pons

_F_ Fibers connecting left & right cerebral H. Pia mater

hemispheres

_L__ All motor nerve leaving spinal cord I. Dura mater

_M Area processing left visual field J. Arachnoid

_B__ Thirst is started here. K. Dorsal root

_A__ & _C__ Areas that might be L. Ventral root

center of consciousness

M. Right cerebral cortex

N. Left cerebral cortex

O. Choroid Plexus

7. Characterize each of the following: (18 pts)

Rods (2 pts)

Night, dim light, no color, no action potential

Cones )2 pts)

Stronger light, color, no action potential

Horizontal Cells (2 pts)

no action potential, lateral inhibition

Bipolar Cells (2 pts)

Amacrine Cells (2 pts)

Action potentail,

Ganglion Cells (2 pts)

On-center off-surround or off-center on-surround

Thalamic Cells of Vision (2 pts)

Same pattern as ganglion cell

Simple Cells ( 4 pts)

Narrow line of light or dark, small field of vision, angle of line,

Complex Cells (2 pts)

Like simple cells, but broad field of vision

8. Draw and list, in order, the events that happen in the myotactic reflex (gamma efferent) after the brain sends a message down the spinal cord to lift the forearm. (14 pts)

Gamma efferent fires

Contracts ends of intrafusal fiber

Stretches sensory portion of intrafusal fiber

excites sensory nerve

stimulates alpha motor

contracts muscle

relief of stretch on sensory portion of intrafusal fiber

etc.