Sheep brain dissection and label

1. Sheep brain-dissection and label By Leslie Young Section 63

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   χί ασμα, "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  /ˈ pɔnz / ) is a structure located on the  brain stem It is cranial  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 .

7. Sheep brain-dissected cerebellum The  cerebellum  (Latin for  little brain ) is a region of the  brain  that plays an important role in  motor control .

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 . [

10. Sheep brain-dissected infundibulum An  infundibulum  (Latin for  funnel ; plural,  infundibula ) is a  funnel -shaped cavity or  organ .

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.: /ˈ paɪ.ə ˈ meɪtər / or pron.: /ˈ piː.ə ˈ mɑːtər /[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   θάλ αμος , "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  θάλ αμος  =  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   / ˌ ɑrbɔr   ˈ vaɪti ː /  ( 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 right lateral 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.