Straighterline Anatomy and physiology 1 & 2

Lab 8 The Nervous System BIO201L
Student Name:
Access Code (located on the lid of your lab kit):
Pre-Lab Questions:
”1. What is the primary function of the nervous system?”
The primary function of the nervous system is to maintain the homeostasis, sensory
perception, brain function, control muscular movement, endocrine function, and
process information.
”2. Why does the cerebral cortex contain so many folds? ”
The cerebral cortex contains so many folds it increase the surface area.
”3. What is a nerve impulse? ”
A nerve impulse is a signal sent from the axon terminal down nerve fibers from one
neuron to another.
”4. What are Schwann cells and what do they form? ”
Schwann cells are glial cells that insulate and protect axons with myelin sheath.
”5. What is an all-or-none response? ”
An all-or-none response is the principle that the strength by which a nerve or muscle
fiber responds to a stimulus is not dependent on the strength of the stimulus. If the
stimulus is any strength above threshold, the nerve or muscle fiber will either give a
complete response or no response at all..
”6. What two effects might neurotransmitters have? ”
Neurotransmitters excite or inhibit nerve cells.
Experiment 1: Microscopic Anatomy of the Nervous System
Post-Lab Questions
”1. Label the arrows in the slide images below based on your observations from the
experiment. ”
A- axon
B- cell bodies
C- myelinated axons
D- myelin sheaths
Lab 8 The Nervous System BIO201L

Lab 8 The Nervous System BIO201L
”2. What is the major function of the neuron? ”
Neurons are excitable cells that transmit electric impulses and receive stimuli which are
passed to other neurons or effector organs.
”3. Are the nodes of Ranvier spaced equally along the axon? Why is this significant? ”
Yes, the nodes of Ranvier are spaced equally along the axon. This is significant
because the distance in between signals affects the action potential.
”4. Define depolarization. ”
Depolarization is the difference in charge in the plasma membrane due to a change in
permeability and movement of sodium ions to the interior.
”5. Describe how Schwann cells form the myelin sheath and the neurilemma. ”
Schwann cells cover axons with myelin sheath, which is packed tightly in spiral casings
with the cytoplasm squeezed between the layers of cell membranes. Myelin sheath is
the core of the plasma membrane and the exposed part is neurilemma.
”6. What determines whether a neuron is unipolar, bipolar, or multipolar? ”
The amount of signals being processed from the cell body is what determines if a
neuron is unipolar, bipolar, or multipolar. Unipolar neurons have one process that has
two branches, one extends to the CNS and the other extends to the periphery and
acts as a sensory receptor. Bipolar neurons have two processes-one is the dendrite,
the other is the axon. Multipolar neurons have multiple dendrites and one axon.
Experiment 2: Virtual Model – The Nervous System
Post-Lab Questions
”1. Which feature is more superior, the sciatic nerve or the tibial nerve? ”
Sciatic nerve is more superior.
”2. What appendages is the radial nerve located in? ”
The radial nerve is located in both arms and forearms.
”3. Where is the subcostal nerve located? ”
The subcostal nerve is located along the lower portion of the 12th rib.
”4. Is the brachial plexus anterior or superior to the lumbar plexus? ”
The brachial plexus is superior to the lumbar plexus.

Experiment 3: Virtual Model – The Nervous System Coloring Activity
”Upload image for each activity below: ”
”Brain (Side View): ”
Lab 8 The Nervous System BIO201L
”Brain (Aerial View): ”
Lab 8 The Nervous System BIO201L
”Thorax: ”
Lab 8 The Nervous System BIO201L
”Pelvic Region: ”
Lab 8 The Nervous System BIO201L
Experiment 4: Cow Eye Dissection
Post-Lab Questions
”1. How does the eye work? ”
Light rays come to a sharp focusing point on the retina, which receives the image that
the cornea focuses through the eye’s internal lens and transforms this image into
electrical impulses that are carried by the optic nerve to the brain.
”2. What is the hole in the center of the iris? What is its function? ”
The hole in the center of the iris is our pupil, which controls the amount of light
entering the eye.
”3. What are the material properties of the lens? ”
Crystalline, transparent, flexible tissue make up the lens.
”4. What is the blind spot of the retina? ”
The blind spot is the area of the eye which corresponds with the optical disk where an
image cannot be detected due to the absence of rods and cones.
”5. What is the purpose of the reflective material in the choroid coat? What is it
called? ”
Lab 8 The Nervous System BIO201L
The reflective material is called the tapetum lucidum, which allows the cow to see in
the dark and reflects light.
”6. How did the image appear when you looked through the lens? ”
The image on the other side appeared upside down and backwards.
”Image of dissected eye with the lens removed with your name and access code clearly
visible in the background: ”
Experiment 5: Brain Mapping
Post-Lab Questions
”1. Describe the function of three areas of the brain (you choose which areas you wish
to discuss. ”
The hippocampus is linked to memory. The thalamus relays messages between the
cerebral cortex and lower brain centers. The hypothalamus regulated endocrine
function and maintains homeostasis.
”Insert photos of labeled swim cap: ”

Lab 8 The Nervous System BIO201L
Experiment 6: Sheep Brain Dissection
Post-Lab Questions
”1. How does the sheep brain compare to the human brain? Name at least two
differences. ”
The sheep’s brain is smaller, more elongated, and lighter. The frontal lobe of humans
is larger than the sheep brain.
”2. What two lobes does the central sulcus separate? ”
The central sulcus separates the parietal lobe from the frontal lobe.
”3. How does the size of the olfactory bulb in sheep relate to the size in humans?
What might this tell you about the sense of smell in the sheep’s survival, in particular
about how it acquires food? ”
The sheep’s olfactory bulb, which gives the sense of smell, is larger than that of a
human, which means it’s greater sense of smell helps it better perceive food and
predators from a distance.
”4. What circulates through the ventricles? What is the function? ”
Cerebrospinal fluid circulates through the ventricles and its function is to provide
nutrients for the brain, absorb shock, stabilize the environment, and remove waste.
”5. Describe the function of each region of the cerebral cortex. ”
Frontal lobe is the area of reasoning, speech, movement, problem solving and
emotions. The parietal lobe controls movement, orientation, and perception/
recognition of stimuli. The occipital lobe controls visual perception. The temporal
Lab 8 The Nervous System BIO201L
lobe is associated with memory, speech/auditory stimulus, and perception/
recognition.
”Insert photo of the dissected sheep brain with your name clearly visible in the
background: ”
Experiment 7: Reflexes
Post-Lab Questions
”1. What is the papillary response of the right eye when a light was shone into the
pupil? ”
The pupil contracted to decrease the amount of light allowed into the eye.
”2. What is the consensual response (The response of the left eye)? ”
The pupil of left eye also contracted to a lesser degree than the right eye.
”3. What branch of the nervous system controls this response? ”
The autonomic nervous system (ANS).
”4. Can this response be inhibited? ”
This response cannot be inhibited because it is an automatic reflex.
Experiment 8: Reflexes (Part II)
Table 2: Reflex Data
Reflex Trial 1: Distance Caught
(cm)
Trial 2: Distance Caught
(cm)
Trial 2: Distance Caught
(cm)
Lab 8 The Nervous System BIO201L
Post-Lab Questions
”1. Define what a reflex is. ”
A reflex is an action performed by an unconscious thought in response to stimuli.
”2. Name five essential components of a reflex arc. ”
Receptor, sensory neuron, interneuron, motor neuron, and effector are five essential
components of a reflex arc.
”3. What does your data tell you about visual, verbal, and tactile responses? ”
Tactile seems to be the fastest, probably because visual and verbal take longer to be
processed in the brain whereas tactile is a faster moving stimulus.
Experiment 9: Fetal Pig Dissection- Nervous System
Post-Lab Questions
”1. Did you notice a covering on the spinal cord? What is it? ”
The spinal cord is covered by the meninges, which is a layer of tissue that protects it
from injury.
”2. Describe the properties of the vertebral column. Why are these important? ”
Cervical column
Thoracic column
Lumber column
Sacrum
Coccyx
They are important because they protect the spinal cord, nerve roots and several of
the body’s internal organs; provide structural support and balance to maintain an
upright posture; and enable flexible motion.
”3. What is the difference between white and gray matter? ”
Grey matter, myelinated, contains neuron cell bodies and white matter,
unmyelinated, works with axons down the spinal column.
”4. Research multiple sclerosis. What is the effect of this disease on the nervous
system? ”
Multiple sclerosis (MS) is a condition characterized by inflammation and degeneration
of myelin sheaths in the spinal cord and brain. It is an autoimmune disease, but the
triggering pathogens or other stimuli appear to vary.
Visual 9 6 7
Verbal 5 6 3
Tactile 1 2 5
Lab 8 The Nervous System BIO201L
”Insert photo of pig with exposed spinal cord with your name clearly visible in the
background: ”