2. Sheep brain-dissected and shown
olfactory bulb and optic nerve.
The olfactory bulb is a structure of the vertebrate forebrain involved
in olfaction, the perception of odors
The optic nerve, also known as cranial nerve 2, transmits visual
information from the retina to the brain.
3. Sheep brain-dissected optic
chiasm and pons
The optic chiasm or optic chiasma (Greek χίασμα, "crossing", from the
Greek χιάζω 'to mark with an X', after the Greek letter 'Χ', chi) is the part of
the brain where the optic nerves (CN II) partially cross. The optic chiasm is
located at the bottom of the brain immediately below the hypothalamus.
The pons (pronounced /ˈpɔnz/) is a structure located on the brain stem
It iscranial to the medulla oblongata, caudal to the midbrain, and ventral to
the cerebellum.
4. Sheep Brain-dissected medulla
oblongata
The medulla oblongata is the lower half of the brainstem. The medulla
contains the cardiac, respiratory, vomiting and vasomotor centers and deals
with autonomic, involuntary functions, such as breathing, heart rate and
blood pressure.
5. Sheep Brain-dissected
longitudinal fissure
The great longitudinal fissure (or longitudinal cerebral fissure,
or longitudinal fissure, or interhemispheric fissure) is the deep groove that
separates the two hemispheres of the vertebrate brain.
6. Sheep brain-dissected frontal
lobe
The frontal lobe is an area in the brain of mammals, located at the front of
each cerebral hemisphere and positioned anterior to (in front of) the parietal
lobe and superior and anterior to the temporal lobes. It is separated from the
parietal lobe by a space between tissues called the central sulcus, and from the
temporal lobe by a deep fold called the lateral (Sylvian) sulcus. The precentral
gyrus, forming the posterior border of the frontal lobe, contains the primary
motor cortex, which controls voluntary movements of specific body parts.
The frontal lobe contains most of the dopamine-sensitive neurons in the cerebral
cortex. The dopamine system is associated with reward, attention, short-term
memory tasks, planning, and motivation. Dopamine tends to limit and select
sensory information arriving from the thalamus to the fore-brain. A report from
the National Institute of Mental Health says a gene variant that reduces
dopamine activity in the prefrontal cortex is related to poorer performance and
inefficient functioning of that brain region during working memory tasks, and to
slightly increased risk for schizophrenia.
8. Sheep brain-dissected parietal
and temporal lobe.
The parietal lobe is a part of the brain positioned above (superior to)
the occipital lobe and behind (posterior to) the frontal lobe.
The parietal lobe integrates sensory information from different modalities,
particularly determining spatial sense and navigation.
The temporal lobe is a region of the cerebral cortex that is located beneath
the lateral fissure on both cerebral hemispheres of the mammalian brain.[3]
The temporal lobes are involved in the retention of visual memories,
processing sensory input, comprehending language, storing new memories,
emotion, and deriving meaning.[
9. Sheep brain-dissected occipital
lobe.
The occipital lobe is the visual processing center of
the mammalian brain containing most of the anatomical region of the visual
cortex.[
11. Sheep brain-dissected corpus
callosum
The corpus callosum (Latin: tough body), also known as the
colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in
the eutherian brain at the longitudinal fissure. It connects the left and
right cerebral hemispheres and facilitates interhemispheric communication. It is
the largest white matter structure in the brain, consisting of 200–250
million contralateral axonal projections.
12. Sheep brain-dissected cerebrum
The cerebrum, or telencephalon, together with the diencephalon,
constitutes the prosencephalon during embryonic development.
With the assistance of the cerebellum, the cerebrum controls all voluntary
actions in the body.
13. Sheep brain-dissection of the Pia
Mater.
Pia mater (pron.: /ˈpaɪ.ə ˈmeɪtər/ or pron.: /ˈpiˈ.ə ˈmɑˈtər/[1])
often referred to as simply the pia, is the delicate innermost layer of
the meninges, the membranes surrounding the brain and spinal cord.
14. Sheep Brain-dissection of the
Thalamus and hypothalamus.
The thalamus (from Greek θάλαμος, "inner chamber")[1] is a midline symmetrical
structure within the brains of vertebrates including humans, situated between
the cerebral cortex and midbrain. Its function includes relaying sensory and motor
signals to the cerebral cortex,[2][3] along with the regulation of consciousness, sleep,
and alertness.
The hypothalamus (from Greek ὑπό = under and θάλαμος = room, chamber) is a
portion of the brain that contains a number of small nuclei with a variety of functions.
One of the most important functions of the hypothalamus is to link the nervous
system to the endocrine system via the pituitary gland (hypophysis).
15. Sheep brain-dissected arbor vitae
The arbor vitae /ˈɑrbɔr ˈvaɪtiˈ/ (Latin for "Tree of Life") 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.[1] It brings sensory and motor information to and from
the cerebellum. The arbor vitae is located deep in the cerebellum. Situated
within the arbor vitae are the deep cerebellar and the fastigial nuclei. It also
contains the emboliform-globose and dentate nuclei. These four different
structures lead to the efferent projections of the cerebellum.[
16. Sheep brain-dissected septum
pellucidum
The septum pellucidum (also called the septum lucidum), and not to be
confused with the medial septum, is a thin, triangular, vertical membrane
separating the anterior horns of the left and rightlateral ventricles of the
brain. It runs as a sheet from the corpus callosum down to the fornix.
17. Sheep brain
The brain is the center of the nervous system in all vertebrate and
most invertebrate animals—only a few invertebrates such as sponges, jellyfish,
adult sea squirts and starfish do not have one, even if diffuse neural tissue is
present. It is located in the head, usually close to the primary sensory organs
for such senses as vision, hearing, balance, taste, and smell. The brain of a
vertebrate is the most complex organ of its body. In a typical human
the cerebral cortex (the largest part) is estimated to contain 15–33
billion neurons,[1] each connected by synapses to several thousand other
neurons. These neurons communicate with one another by means of
long protoplasmic fibers called axons, which carry trains of signal pulses
called action potentials to distant parts of the brain or body targeting specific
recipient cells.
Physiologically, the function of the brain is to exert centralized control over the
other organs of the body. The brain acts on the rest of the body both by
generating patterns of muscle activity and by driving secretion of chemicals
called hormones. This centralized control allows rapid and coordinated
responses to changes in the environment. Some basic types of responsiveness
such as reflexes can be mediated by the spinal cord or peripheral ganglia, but
sophisticated purposeful control of behavior based on complex sensory input
requires the information-integrating capabilities of a centralized brain.
