Lab_4_Neuroanatomy (1)
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Neuroanatomy
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BIO 446L
Human Microscopic & Gross Anatomy
Laboratory Manual
Spring 2023
Visible Body Team
Soroosh Sadeh, M.S.
Gonie Altman, B.S.
Supplies and Equipment:
All students must wear long pants
and closed toe shoes
in lab. Please do NOT bring FOOD OR DRINK
into lab.
Neuroanatomy
1
Lab 4: Neuroanatomy
Objectives:
1. Know the major bones of the human skull and be able to identify them.
2. Be able to palpate the major landmarks of the skull.
3. Understand the foramina of the skull, its importance, and structures passing through the foramen magnum.
4. Be able to identify the different parts of the human brain and know their function.
5. Be familiar with the connective tissue covering of the human brain.
6. Be familiar with the sinuses of the skull.
Neuroanatomy
2
Section: The Human Skull
Resources to use:
●
Visible Body Human Anatomy Atlas App.
Activity 1: The Skull
●
Your main resource during this lab will be the Human Anatomy Atlas Application, please keep this open
while you work through the activities. ●
Looking at the top of the screen, click the Skeletal System Views and select View 2. Of the skull and locate the following bones and bone markings. After identifying each bone with its landmark, locate them on the skull model on your table. Can you palpate any of them on your head? ●
The skull is composed of two parts: the cranium and the facial bones. The cranium is responsible for protecting the brain, while the facial bones form the framework of the face and support the special senses
(sight, smell, and taste). Label the image below with the structures you just learned about in the previous activity (please note that sphenoid is part of the cranium).
1.
Cranial bones
a.
Select the frontal bone, which is located in the forehead region on the anterior and superior part of the skull. Use the landmark icon in the content box to the right of the page and locate the following bone markings:
o
Supraorbital notch
o
Supraorbital margin
o
Glabella
o
Zygomatic process
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b.
Rotate the skull to see the lateral side and select the right or left parietal bone
located on the lateral
and superior part of the skull.
c.
Select the right or left temporal bone
, which is located immediately inferior to the parietal bone.
d.
Use the landmark icon in the content box on the right side of the page to locate the following bone markings and label the image below:
Processes:
Foramen:
Meatus:
Fossa:
Others:
Zygomatic
Styloid
Mastoid
*
note the zygomatic process of the temporal bone is different from the process of the frontal bone
Jugular
Lacerum
*Both are on the temporal surface
External Auditory
Internal Auditory
*Both are part of the acoustics of the ear
Mandibular
Jugular
Petrous part
Carotid Canal
e.
Where does the lower jaw attach to the skull?
f.
Where do sound waves enter the ear? g.
Continue to rotate the skull and select the occipital bone
, located on the posterior side of the skull.
h.
Use the landmark icon in the content box on the right side of the page to locate the following bone markings and label the image below:
o
Foramen magnum
o
Hypoglossal canal
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o
Occipital condyle
o
Condyloid foramen
o
External occipital protuberance
o
Inferior nuchal line
o
Superior nuchal line
o
Jugular foramen (occipital surface)
o
Foramen lacerum (occipital surface)
i.
What structure passes through the foramen magnum?
j.
What structure is responsible for articulating with the vertebral column?
k.
Rotate the skull to look at the superior (top) surface. Select and hide the frontal bone and the two parietal bones and choose the sphenoid bone
shaped like a butterfly (or a bat!).
l.
Use the landmark icon in the content box on the right side of the page to locate the following bone markings and label the image below:
o
Greater wing
o
Lesser wing
o
Sella turcica
o
Optic foramen
o
Superior orbital fissure
o
Inferior orbital fissure (sphenoid surface)
o
Foramen rotundum
o
Foramen ovale
o
Foramen spinosum
o
Foramen lacerum (sphenoidal surface)
o
Medial pterygoid plate
o
Lateral pterygoid plate
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m.
The pituitary gland is nicknamed the “master gland” of the body because it secretes many hormones that have widespread effects in the body. Which part of the sphenoid bone houses it?
n.
Select the ethmoid bone
, which is located anterior to the sphenoid bone between the orbits of the eyes.
o.
Use the landmark icon in the content box on the right side of the page to locate the following bone markings and label the image to the right:
o
Crista galli
o
Cribriform plate
o
Ethmoid sinus o
Labyrinth
o
Perpendicular plate
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Neuroanatomy
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2.
Facial Bones
a.
Rotate the skull so you’re looking at the anterior (face) side again. Zoom into the nose area and select one of the inferior nasal conchae bones, which stick out toward the inside of the nose.
b.
Select the vomer, which is located medial to the two inferior nasal conchae in the nose.
c.
Select one of the maxillae bones, which form the upper jaw.
d.
Use the landmark icon in the content box on the right of the page to locate the following bone markings and label the image below:
o
Alveolar canal
o
Alveolar process
o
Zygomatic process (note how this is different from the zygomatic processes of the frontal and temporal bones, but all point toward the zygomatic bone)
o
Frontal process
o
Hard palate
o
Inferior orbital fissure (maxillary surface)
o
Infraorbital canal and foramen
o
Maxillary sinus
e. What structures insert into the alveolar canal?
f. What structure forms the roof of the mouth?
g. Select the mandible
, which forms the lower jaw
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h. Use the landmark icon in the content box on the right of the page to locate the following bone markings and label the image below:
o
Ramus
o
Body
o
Angle
o
Sublingual fossa
o
Coronoid process
o
Condyle
o
Dental alveoli
o
Mandibular foramen
o
Mental foramen
i. Which part of the mandible attaches to the cranium? Where does it articulate?
j. Select one of the zygomatic
bones, which form part of the cheekbones of the face. The zygomatic bones are shaped roughly like triangles, with each vertex pointing toward a different bone: the temporal bone, maxilla, or frontal bone. Use the landmark icon in the content box on the right of the page to locate
the following bone markings and label the image to the right:
o
Temporal process
o
Maxillary border
o
Frontal process
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k. Locate the small nasal bones
on the bridge of the nose.
l. Locate the lacrimal bones
next to the frontal processes of the maxillae.
m. Locate the palatine bones, which are posterior to the hard palate of the maxillae.
3. Hyoid
o
Rotate the skull to look at the inferior side and find the hyoid bone, which is attached by only ligaments. To better view the hyoid in relation to its function, go back to the Systems menu, scroll down to the Respiratory System Views, and select view 4 of the pharynx and larynx. Although the hyoid does not articulate with any other bones, notice how many muscles and ligaments attach to the hyoid.
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Neuroanatomy
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Section: Cavities of the Skull
Resources to use:
●
Visible Body Human Anatomy Atlas App
Activity 1: Cavities of the Skull
●
Which bones compose the orbit? _________________________________________________
●
Which bones and cartilages compose the nasal septum? ____________________________________
●
Which bones compose the oral cavity
? ____________________________
●
Which bones compose the nasal cavity? ______________________________________________
Check the answers to the previous questions with your groupmates and TAs. In the labeling activities, you learned the cranial and facial bones and the hyoid bone with their landmarks.
In this lab you need to be able to find these bones on the skull model and identify their bony landmarks.
Section: Surface Anatomy Practice
Resources to use:
●
Skeleton models available to you in the lab and your body.
Activity 1: Surface Anatomy
Now see if you can identify the bones and bony landmarks of the skull listed below by palpating your own or your lab partner’s head. o
Frontal Bone
o
Temporal Bone
o
Occipital Bone
o
Parietal Bone
o
Mastoid Process
o
Zygomatic arch
o
Supraorbital margin
o
Mental protuberance
o
Angle of mandible
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o
Hyoid bone
o
External occipital protuberance
Activity 2: Using the Skull Model
Open the model skull and look inside at the basal part (floor) of the cranial cavity. What do you think is the function of the large foramen (the foramen magnum)
and the smaller holes?
Name at least three structures that pass through the foramen magnum.
See if you can locate the sella turcica
[Turkish saddle], the bony recess that cradles the pituitary gland. It lies midway between the foramen magnum and the frontal bone.
The two openings just anterior and lateral to the sella turcica are the optic canals
. Look into the orbits from the outside of the skull and see if you can find the other end of the optic canals. What two structures pass through the optic canal?
The ethmoid bone
lies along the midline just behind the frontal bone. You can find it most easily by the protruding ridge of bone that runs down its center. Note the numerous perforations in floor of the ethmoid bone. These olfactory foramina
provide passage for the olfactory nerves
(cranial nerve I that we cover in the future labs).
Find the frontal bone and find the following landmarks: o
Supraorbital notch
o
Supraorbital margin
o
Glabella
o
Zygomatic process
On the left or right temporal bone, find the followings:
o
Zygomatic process o
Mandibular fossa
o
External auditory (acoustic) meatus
o
Internal auditory (acoustic) meatus (turn the model around to the medial side of the bone to find this)
o
Styloid process
o
Mastoid process
o
Carotid canal
o
Jugular fossa
o
Jugular foramen (temporal surface)
o
Foramen lacerum (temporal surface)
On the occipital bone, find the followings:
o
Foramen magnum
o
Occipital condyle
o
External occipital protuberance
o
Jugular foramen (occipital surface)
o
Foramen lacerum (occipital surface)
On the mandible, find the followings:
o
Ramus
o
Angle
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o
Sublingual fossa
o
Coronoid process
o
Condyle
o
Dental alveoli
o
Mandibular foramen
o
Mental foramen
On one of the zygomatic bones, find the followings:
o
Temporal process
o
Maxillary border
o
Frontal process
Section: Human Brain
Activity 1: Introduction to Human Brain
As before, check them off as you find them. Use the View 2 of the brain to answer the following questions.
You are responsible for the identification of all bold terms and the answers to all questions. You should be able to locate all the structures discussed below. Throughout this activity, use the brain models in the lab to identify the structures you find in the app.
1.
The Cerebrum
a.
Use the Dissect tool to hide the skull bones, exposing the brain. Rotate the view to examine the exterior portion of the left side of the brain. By far, the largest part of the brain is the cerebrum, which is covered by convoluted folds. The folds appear dark because they are composed of gray
matter
which consists mainly of cell bodies and unmyelinated fibers.
o
Select any of the folds. What are these folds called? b.
Zoom in and select any of the grooves between the folds. What are they called? Sulci are important landmarks of the cerebrum. Find the following sulci in your brain model: o
Precentral sulcus o
Central sulcus o
Postcentral sulcus
o
Lateral sulcus
c.
The cerebrum is divided into functional regions called lobes
. Select any of the gyri
above the eyes, and then use the arrow in the content box to choose the frontal lobe
from the selected structure list, highlighting it in the view (see the image below). Rotate the view to locate the sulcus immediately behind the frontal lobe and the two gyri that flank it.
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o
Which sulcus defines the posterior boundary of the frontal lobe? d.
Which gyri are located on either side of this sulcus? e.
Select the postcentral gyrus
, and then use the arrow in the content box to choose the parietal lobe
from the selected structure list, highlighting it in the view. Rotate the view to locate the sulci that separate the parietal lobe from the other cerebral lobes.
o
Which sulcus defines the posterior border of the parietal lobe? o
Which lobe is located posterior to this sulcus? o
Which sulcus defines the lateral border of the parietal lobe? o
Which lobe is located below this sulcus?
2.
The Cerebellum
o
In the Human Atlas App, use the view 2 of the brain to answer the following questions about the cerebellum.
a.
Rotate the view to examine the posterior portion of the brain and use the Dissect tool to hide the cerebrum. Examine the cerebellum
and rotate the view as needed to identify its key structures.
o
The two posterior lobes are separated by the
_____
.
o
In front of the posterior lobes are two _____
.
o
Between the posterior lobes and the medulla oblongata are the paired _____.
b.
Use the Dissect tool to remove the right posterior lobe from the view and examine the patterns of
gray and white matter in the cut section of the cerebellum. Select the cut surface and use the book icon to read the definition.
o
The interior of the cerebellum is made up of a central stem of _____
with a central gray mass
called the _____.
o
The branching tree-like network is called the _____
.
3.
The Thalamus
In the Human Atlas App, use the view 2 of the brain to answer the following questions about the thalamus.
a.
Locate the right lateral ventricle
and rotate the view to examine the third ventricle, found between the two cerebral hemispheres (only one is visible). Use the book icon to read a description of the ventricles.
o
The fourth ventricle is continuous with the _____, which carries cerebrospinal fluid
down into the hindbrain
and the spinal cord
.
b.
Select the right thalamus
in the center of the view and use the book icon to read its definition.
Neuroanatomy
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1.
What are the main functions of the thalamus?
Activity 2: Review of the Brain Functions
For each of the following large structures, select any part of the structure and use the arrow in the content
box to choose the entire structure. Use the book icon to read its definition, and then list its main functions below.
o
Cerebrum: o
Cerebellum: o
Midbrain (mesencephalon): o
Pons: o
Medulla Oblongata:
Select any part of the cerebrum, and then use the arrow in the content box to choose Forebrain
from the selected structures list. Use the book icon to read its definition, and then list its structures below. * Forebrain includes ___________.
Select the medulla oblongata, and then use the arrow in the content box to choose Hindbrain
from
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the selected structures list. Use the book icon to read its definition, and then list its structures below. * Hindbrain includes ___________.
Select the pons and use the book icon to read its definition. Which structures make up the
brainstem
?
Select the third ventricle and use the Dissect tool to remove it from the view. Select the exposed hypothalamus
and use the book icon to read its definition.
o
What is the function of the hypothalamus?
Find the corpus callosum
, which is located beside the left lateral ventricle and below the left cingulate gyrus (limbic lobe).
o
What is the function of the corpus callosum? o
What is the corpus callosum composed of?
Activity 3: Brain Review Questions
1.
Responsible for conscious thought, the largest structure of the brain is the
_____
. It has right and left _____
.
2.
The _____
is responsible for balance and fine-tuning movement.
3.
The brainstem connects the _____ to the _____
. It is responsible for the most primitive and basic brain functions.
4.
Cerebrospinal fluid is found in large chambers called _____.
5. Different parts of the brain communicate via tracts of _____.
Review your answers with your group mates and your TAs.
Section: Sinuses of the Skull
The bones of the face and nasal passages are honeycombed with hollow cavities called the nasal sinuses. These sinuses are lined with a ciliated epithelium and produce a mucous secretion that helps flush foreign material from the nasal passages.
1. The two frontal sinuses
lie in the frontal bone on either side of the midline. They are just above the medial edge of the orbit at about the level of the eyebrows. You can see a frontal sinus on the split skull model. In some people, one or both frontal sinuses are reduced in size or absent.
2. The two maxillary sinuses lie inside the maxillary bone on either side of the nose. The floors of these
sinuses lie just above the upper teeth, one reason that a maxillary sinus infection sometimes manifests itself as an ache in the upper teeth.
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3. The sphenoid sinus
and ethmoid sinuses lie more in the interior of the skull, just above the oral cavity. The ethmoid sinuses lie between the lateral walls of the nasal cavity and the medial walls of the orbits, just under the ethmoid bone. The sphenoid sinus lies medially, just below the sella turcica.
What purpose(s) do you think the sinuses serve? (other than just bothering people with allergies). List at least two reasons.
Section: Relationship Between the Skull and the Brain
The brain and spinal cord of the CNS are protected by specialized membranes called the meninges
, three layers of membranes that anchor the brain and spinal cord securely in place in the cranium and spinal column, respectively. The meninges include the following layers: 1) the dura mater
, 2) the arachnoid
(or arachnoid mater), and 3) the pia mater
. 1. Just under the bone of the skull, a double layer of white fibrous tissue that is attached to the bone exist that is called the dura mater
(search this term in VB Atlas to see). The outer layer of the dura mater is the internal equivalent of the periosteum of bone that covers the internal surface of the cranial bones.
Over much of the brain, venous sinuses
, which are cavities where blood collects after leaving the brain, separate the two layers of the dura mater. The venous blood will then pass through veins in the skull that are valve-less and then to the heart. All veins that drain the brain and the spinal cord are valve-less. o
What problem might this cause and how? 2. A web of connective tissue called the arachnoid membrane
lies beneath the dura.
The subdural space
lies between the inner layer of the dura and the arachnoid membrane. Sometimes a blow
to the head will cause a tear in a vessel in this area and bleeding into the subdural space and result in a subdural hematoma. A hematoma is a collection of blood outside the vascular system that creates a swollen area. Would a subdural hematoma
be the result of an arterial bleed or a venous bleed?
TA talking point.
3. A single membrane called the pia mater
covers and adheres to the surface of the brain. (Notice that the term membrane here is being used to refer to layers of connective tissue, not a phospholipid bilayer.) The pia mater is penetrated by numerous small blood vessels.
The subarachnoid space
lies between the arachnoid membrane and the pia mater.
o
Would a subarachnoid hematoma be caused by an arterial break or a venous break?
o
TA talking point.
o
Why do you think that bleeding into the subdural or subarachnoid space is dangerous?
The suffix for "inflammation" is -itis. What would an inflammation of the meninges be called?
Activity 1: Being a Neurosurgeon
You are a neurosurgeon about to make the incisions necessary to repair an aneurysm in an artery in the parietal brain lobe of your patient.
The skull is covered by the skin of the scalp. The scalp has 5 layers (named external to internal) that can be remembered with the following acronym SCALP. S
kin, C
onnective tissue, A
poneurosis, L
oose connective tissue, P
eriostium. (Aponeurosis is a very dense layer of connective tissue.)
o
Place in correct sequence the tissues in the list below that you will cut through to reach the nervous tissue of the parietal lobe.
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16
____ Arachnoid mater
____ Aponeurosis Layers of dense regular connective tissue. Some smaller muscles of the
face arise from this layer.
____ Connective tissue that contains numerous blood vessels, more than other regions
of skin. For this reason, scalp wounds bleed profusely.
____ Dura mater
____ Loose connective tissue. This layer allows the surface layers to slide over the underlying
skull (try sliding your scalp around on your skull). This is also the layer that rips most
easily and is how people are "scalped" when hair is caught in machinery. It is also the
layer that surgeons cut through when making skin flaps prior to brain surgery.
____ Parietal bone
____ Periosteum. The periosteum is a fibrous membrane that covers the outside of bones
except where the ends of long bones are covered by cartilage or where tendons and ligaments insert.
____ Pia mater
____ Skin. The surface layer that contains hair follicles, sebaceous glands that secrete oily secretions into the lumen of the hair follicles and sweat glands. Review your answers with your group mates and your TAs.
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17
Group Activity: Sheep Brain Dissection
Background Information:
The sheep brain is remarkably similar to the human brain. One major difference, however, is in proportion.
For example, the sheep brain has a proportionately smaller cerebrum. Another difference is in the orientation
of the spinal cord. The sheep spinal cord is orientated anterior to posterior, as in any four-legged animal. The
human spinal cord is orientated superior to inferior. This orientation difference has a major effect on the
location of the brain stem. The sheep brain stem is located more towards the rear (posteriorly). In order to
compensate for this, the sheep skull has the foramen magnum located more towards the rear of the skull. In
humans, since we walk upright (bipedalism), the spinal cord is in a more vertical plane. Thus the foramen
magnum is located centrally on the bottom of the skull (inferiorly). By observing the movement of this major
skull feature from the rear (as in very early human ancestors) to the current location (modern humans),
scientists have been able to determine when the human species began to walk upright on two legs.
Dissection Instructions:
1.For each group of five, obtain the following materials:
Sheep Brain
Dissecting pan
Large knife
Blunt probe
Gloves
Safety goggles
2. The sheep brain is enclosed in a tough outer covering called the dura mater. You can still see some
structures on the brain before you remove the dura mater. Take special note of the pituitary gland and the optic
chiasm. These two structures will likely be pulled off when you remove the dura mater.
Figure 1.
Brain with Dura Mater Intact
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Figure 2.
Removal of the Dura Mater
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19
3.
This image shows the ventral surface of the sheep's brain with most of the dura mater removed. The pituitary gland and the optic chiasma are still intact. (A = pituitary gland, B = optic chiasma, C = olfactory bulb)
Figure 3
. A = pituitary gland, B = optic chiasma, C = olfactory bulb
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20
4. In this image, the dura mater has been completely removed, you can still see the optic chiasm, but the
pituitary gland is missing. The infundibulum (pituitary stalk) is now visible in the center. Careful dissection
also reveals two other large nerves: the oculomotor nerves (C.2). Often these two nerves are removed with the
dura mater, but in this image, they are still intact.
Figure 4
. Ventral view of the brain with dura mater removed
These two figures show the fissures located on the surface of the brain. Longitudinal fissure and Transverse fissure
Figure 5
. These two figures show the fissures located on the surface of the brain, with the longitudinal fissure on the left and the transverse fissure on the right
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5. If you flip the brain over to the other side, you can see the cerebellum
; it will be loosely attached to the
cerebrum in most cases. If you did not carefully remove the dura mater, you might have accidentally pulled
the entire cerebellum away from the brain. The lobes of the brain are visible, as well as the transverse fissure
,
which separates the cerebrum from the cerebellum. The convolutions of the brain are also visible as bumps
(
gyri
) and grooves (
sulci
).
Figure 6. Dorsal View of the Sheep Brain
6.
The gap between the cerebrum and the cerebellum at the transverse fissure can reveal some internal parts of
the brain. In this image, a student is bending the cerebellum down to show the superior and inferior
colliculi
. Just behind the colliculi, the pineal gland is just barely visible.
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Figure 7.
The superior and inferior colliculi
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7.
Use your large knife try to make clean cuts in one swipe rather than sawing back and forth. *You will find
it easier to make the cut if you put the brain on paper towels. Always leave the specimen in the dissecting tray
when cutting it, do NOT hold it in your hand!
First, cut off the spinal cord at the posterior end of the brain. You may have to include a little of the lower medulla with it. Put it aside and cover it with damp paper towels to keep it from drying out. Make a midsagittal section by cutting slightly to one side of the midline.
Don't worry about the brain drying out. Some structures are easier to see as it dries.
If you are very careful, you will cleanly cut the brain into two halves and see the internal structures, the most
visible being the corpus callosum
, which divides the left and right hemispheres. The cerebrum will still be
visible as a wrinkled structure, and you can even locate the "bumps" of the superior and inferior colliculi
.
Remember, you located those structures by pulling down the cerebellum.
The cerebellum, when cut will have a very distinct tree-like white area within it. This is called the arbor vitae
,
or the tree of life.
Figure 8
. The cut cerebellum exposing the arbor vitae
8.
In the image below, a probe indicates the location of the lateral ventricle
.
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Figure 9
. The probe indicates the location of the lateral ventricle
.
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9.
Once the brain is cut this way, the colliculi can also be seen from the inside, and the pineal gland is revealed only if you make a very careful incision.
Figure 10
. In this image, the pineal is pinned in yellow, and the pin continues on to where the colliculi have been bisected.
10.Other major structures are visible; here, the probe indicates the arbor vitae (tree of life) found within the
cerebellum. The fissure between the cerebrum and the cerebellum is called the transverse fissure
. The
cerebellum only loosely connects to the rest of the brain when the dura is removed.
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Figure 11
. The probe indicates the arbor vitae
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11. This brain is pinned to show the pineal gland (blue pin), thalamus (red pin), and lateral ventricle (green pin).
Figure 12
. The pineal gland (blue pin), thalamus (red pin) and lateral ventricle
(green pin)
12. The image below shows a cleanly separated brain with the major internal structures visible and labeled. Did you find all of them?
Figure 13
. The major internal structures visible and labeled
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13. Finally, a section of the brain is cut to examine the difference between white matter and gray matter.
Figure 14
. Cut to show the difference between white and grey matter
14.
Once you have made the cut like in the above diagram, you should be able to see the difference between the white and gray matter, just like the diagram below.
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Figure 15
. Showing the difference between the white and gray matter.
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15. The diagram below will help you understand the difference between the gyri and the sulcus.
Figure 16
. Showing the difference between the gyri and the sulcus
Spinal Cord
Note:
This part can be done if your brain specimen initially has spinal cord attached to it.
The spinal cord extends down from the medulla oblongata of the brain and is about 18 inches long. Identify the following structures:
o
Gray matter consists primarily of neuron cell bodies. The gray matter is divided into anterior (ventral), lateral, and posterior (dorsal) horns.
o
White matter gets its color from the myelin sheath that wraps around the axons of the neurons. White matter of the spinal cord is divided into columns that consist of axons running up and down the length of the spinal cord.
Posterior/dorsal
and anterior/ventral roots
(nerves) consist of axons of peripheral division neurons. You can distinguish the dorsal and ventral roots by the bulbous swelling on the posterior
root. o
The posterior/dorsal root ganglion
consists of the cell bodies of sensory neurons. Sensory neurons enter the spinal cord through the dorsal root and synapse with CNS interneurons whose cell bodies are in the posterior horn.
o
Somatic motor and autonomic neurons exit the spinal cord through the anterior/ventral roots. Their cell bodies are in the anterior horn of the gray matter.
Spinal nerves are formed by the union of the posterior and anterior roots
16. Now, return to the section of the spinal cord you cut from your sheep brain. Identify the following: o
Gray matter, white matter, posterior horn, anterior horn, and central canal
You are now finished with the sheep brain. Place the tissue in the plastic disposal bag near the sink. Throw away the trash. Wash your dissecting pan and tools and spread them out to dry on paper towels.
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More resources at: https://www.biologycorner.com/anatomy/chap9.html
Review your answers with your group
mates and your TAs!
End of Lab 3, Great Job 😊
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