The nervous system is made up of the central nervous system (brain and spinal cord) and peripheral nervous system (nerves). The central nervous system acts as the body's control center and coordinates activities. Impulses travel through neurons to reach the brain. The peripheral nervous system connects the central nervous system to the rest of the body. Together they allow the body to rapidly respond to stimuli. The brain is divided into the forebrain, midbrain, and hindbrain. The forebrain includes the cerebrum and controls higher functions. The midbrain connects the forebrain to the hindbrain. The hindbrain assists in regulating automatic functions and sensory information relay. Within the brain, structures such as the cerebellum,

1. Nervous System

2. Nervous System
The nervous system is a complex collection of nerves and specialized
cells known as neurons that transmit signals between different parts
of the body. It is essentially the body's electrical wiring.
Central Nervous System
• Made up of brain and spinal cord
• Acts as body’s control center, coordinates body’s activities
• Impulses travel through the neurons in your body to reach the
brain
Peripheral Nervous System
• Made up of all the nerves that carry messages to and from the
central nervous system.
• Like telephone wires that connect all our houses in the
community
• Central Nervous System and Peripheral Nervous System work
together to make rapid changes in your body in response to stimuli.

3. •Parts of nervous system:
• Brain
• Spinal cord
• Nerves
•Functions of nervous system:
The nervous system has 3 main functions: sensory, integration, and
motor.
• Sensory. The sensory function of the nervous system involves
collecting information from sensory receptors that monitor the
body’s internal and external conditions.
• Integration. The process of integration is the processing of the
many sensory signals that are passed into the CNS at any given
time.
• Motor. Once the networks of interneurons in the CNS evaluate
sensory information and decide on an action, they stimulate
efferent neurons.

4. • Forebrain: The forebrain is by far the largest brain division. It
includes the cerebrum which counts for about two-thirds of the
brain's mass and covers most other brain structures.
• midbrain: The midbrain is the area of the brain that connects the
forebrain to the hindbrain. The midbrain and hindbrain together
compose the brainstem
• Hindbrain: Several cranial nerves are located in this brain region.
The fourth cerebral ventricle also extends through this region of
the brain. The hindbrain assists in the regulation of autonomic
functions, maintaining balance and equilibrium, movement
coordination, and the relay of sensory information.
• Spinal cord: the spinal cord is a nerve column that extends the
brain into the vertebral canal. The spinal cord is the center for
spinal reflexes.

6. Major parts of the brain
• Gyri (singular-gyrus): many ridges or convolutions separated by
grooves, mark the cerebrum’s surface.
• Sulcus: a shallow to somewhat deep groove is called a sulcus.
• Fissure: very deep groove is called fissure. For example, a
longitudinal fissure separates the right and left cerebral
hemispheres.
• Dura matter: the dura matter is the outermost layer. It is
primarily composed of tough, white, dense connective tissue
and contains many blood vessels and nerves.
• Hemispheres: the cerebrum consists of two right and left
cerebral hemispheres. They provide higher brain functions like
reasoning, memory storage, etc.
• Longitudinal fissure: the fissure which separates two right and
left cerebral hemispheres

7. • Cerebrum: the cerebrum consists of two cerebral
hemispheres connected by corpus collusum. The cerebrum
provides functions like interpretation of sensory impulses,
control of voluntary muscles, etc.
• Cerebellum: the cerebellum consists of two hemispheres
connected by the vermis. It functions primarily as a reflex
center and maintaining equilibrium.
• Arbor vitae: The arbor vitae is the cerebellar white matter so
called for its branched, tree-like appearance. In some ways it
more resembles a fern and is present in both cerebellar
hemispheres. It brings sensory and motor information to and
from the cerebellum.
• Frontal lobe: the frontal lobe forms the anterior portion of
each cerebral hemispheres. Primary motor region lie in this
region.

8. • Parietal: the parietal lobe is posterior to the frontal lobe.
Functions in interpretation of sensory impulses.
• Occipital: the occipital lobe forms the posterior portion of
each cerebral hemisphere. Helps in sensory functions.
• temporal lobes: lies inferior to the frontal and parietal lobes.
Functions in sensory interpretations.
• Olfactory lobes: The olfactory lobes are a small pair of lobes
at the front of the cerebrum. They regulate the sense of
smell.
• Optic nerve: nerve fibers coming from optic cranial nerve.
• Optic chiasma: A X shaped structure formed by some the
optic nerve fibers crossing over.
• Brain stem: the brain stem connects the brain to the spinal
cord. It consists of the midbrain, pons, and medulla
oblongata.

9. • Pons: the pons appears as a bulge on the underside of the brainstem
where it separates the midbrain from the medulla oblongata, which
relay information between the medulla oblongata and the cerebrum.
• Medulla oblongata: the medulla oblongata is an enlarged continuation
of the spinal cord, extending from the level of the foramen magnum to
the pons. This section of the brain helps transfer messages to the spinal
cord and the thalamus, which is in the brain, from the body.
• Corpora quadrigemina (superior and inferior colliculi): Corpora
quadrigemina is the Latin terminology for the quadruple bodies, also
known as the colliculi. These round eminences are located on the
posterior surface of the midbrain, just below the thalamus. There are
two superior and two inferior colliculi, with one of each sitting on either
side of the midline. The entire region, consisting of the four colliculi, is
known as the tectum, or tecta plate. The superior colliculi play an
important role in the visual pathway, while the inferior colliculi are
important in the auditory pathway.

10. • Pineal gland: This small endocrine gland produces the hormone
melatonin. Melatonin production is vital to the regulation of sleep-
wake cycles.
• Thalamus: A structure that connects areas of the cerebral cortex that
are involved in sensory perception and movement with other parts of
the brain and spinal cord. The thalamus also plays a role in the control
of sleep and wake cycles.
• Hypothalamus: Acts as the control center for many autonomic
functions including respiration, blood pressure, and body temperature
regulation. This endocrine structure secretes hormones that act on
the pituitary gland to regulate biological processes including
metabolism, growth,
• Corpus collusum: The corpus callosum is a thick band of nerve fibers
that divides the cerebral cortex lobes into left and right hemispheres
allowing for communication between both hemispheres. The corpus
callosum transfers motor, sensory, and cognitive information between
the brain hemispheres.

11. Sheep brain dissection

15. Eye dissection
• What are the parts of eye?

16. Cornea: transparent
membrane that covers iris and
pupil. Focuses light on the
retina.
Pupil- hole passes different
amounts of light
Iris- colored part of the eye
that controls the size of the
pupil
Sclera- “whites” of the eye
that forms outer covering

17. Anterior view
Posterior view

18. Aqueous Humor- nutritious
fluid between the iris and the
cornea. As we age, it breaks
down and we begin to see
“floaters”
• Retina: The retina is a thin
layer of tissue that lines the
back of the eye on the inside.
It is located near the optic
nerve. The purpose of the
retina is to receive light that
the lens has focused, convert
the light into neural signals,
and send these signals on to
the brain for visual
recognition
• Vitreous Humor- transparent
jelly-like fluid that fills the eye
and refracts light

19. Ciliary Muscles- produces aqueous
humor and controls lens shape
Lens- Bends light rays to the back of
the eye –retina. Elastic so change
in shape allows for focus on
objects close or far away
• Optic Nerve- sends messages
picked up by retina to the brain

20. Choroid Layer- lies between the sclera and the retina it
provides the blood supply to the eye.
Tapetum fibrosum: iridescent film under the retina that
provides animals with “night vision”