Chapter 7 Flashcards
What are the planes of section? What would be revealed best by various planes of section? -What about
different views of the brain – what would be visible on the dorsal surface, ventral surface, lateral surface?
What are gyri and sulci?
-The direction pointing toward the rat’s nose is known as anterior or rostral
-The direction pointing toward the rat’s tail is known as posterior caudal
-The direction pointing up is known as dorsal
-The direction pointing down is known as ventral
-The invisible line running down the middle of the nervous system is called the midline. Structures closer to the midline are medial such as the nose is medial to the eyes
-Structures away from the midline are lateral
-Structures on the same side are called ipsilateral (right eye to right ear)
- Structures on the opposite side are contralateral (right ear to left ear)
-Splitting the brain into equal right and left halves is called midsagittal plane
-Sections parallel to the midsagittal are in the sagittal plane.
-The horizontal plane is parallel to the ground. It splits the brain into dorsal and ventral parts (could pass through the eyes and the ears)
-The coronal plane is perpendicular to the gorund and the sagittal plane. Coronal plane splits brain into anterior and posterior (could pass through both eyes or both ears)
-The side (lateral ) view of the brain shows the cerebrum, cerebellum, brain stem, and spinal cord.
-The top (dorsal) view of the brain shows the sagittal fissure (line in the middle separating the right cerebral hemisphere to the left cerebral hemisphere), cerebellum, brain stem, and spinal cord
-The midsagittal view shows the brain stem
-Dorsal to the lateral ventricles, at the surface of the brain, lies the cortex. Ventral and lateral to the lateral ventricles lies the basal telencephalon. The lateral ventricles are continuous with the third ventricle of the di- encephalon. Surrounding this ventricle are the thalamus and the hypo- thalamus. The third ventricle is continuous with the cerebral aqueduct. Dorsal to the aqueduct is the tectum. Ventral to the aqueduct is the mid- brain tegmentum. The aqueduct connects with the fourth ventricle that lies at the core of the hindbrain. Dorsal to the fourth ventricle sprouts the cerebellum. Ventral to the fourth ventricle lie the pons and the medulla.
-The grooves in the surface of the cerebrum are called sulci and the bumps are called gyri.
-How do we identify cortical areas from a neuroanatomical standpoint?
-Medial to the lateral ventricle is a piece of cortex that is folded onto itself in a peculiar shape. This structure is called the hippocampus, which, despite its bends, has only a single cell layer.
-Connected to the hippocampus ventrally and later- ally is another type of cortex that has only two cell layers. It is called the olfactory cortex because it is continuous with the olfactory bulb, which sits further anterior
-The olfactory cortex is separated by a sulcus, called the rhinal fissure, from another more elaborate type of cortex that has many cell layers. This remaining cortex is called neocortex. Unlike the hippocampus and olfactory cortex, neocortex is found only in mammals.
What functions are controlled by midbrain, medulla, cerebellum, thalamus, cortex?
-The cerebellum is a movement control center. The left side of the cerebellum is concerned with movements of the left side of the body and the right side of the cerebellum is concerned with movements on the right side of the body.
-The brainstem is a complex of nexus fibers and cells that serve to relay information from the cerebrum to the spinal cord and cerebellum and vice versa. The brain stem regulates breathing, consciousness, and body temperature.
-The midbrain contains neurons that contribute to sensory systems such as consciousness, mood, pleasure, and pain, the control of movement, and several other functions (superior colliculus (eye movement) and (inferior colliculus control of ear), substantia nigra and the red nucleus (control of voluntary movement)
-Neurons of the hindbrain contribute to the processing sensory information, the control of voluntary movement, and regulation of autonomic nervous system. Cerebellum is the movement control center.
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What are the three primary brain vesicles, and what structures develop from each of them?
-The rostral-most vesicle is called the prosencephalon which is the forebrain.
-Behind the prosencephalon lies another vesicle called the mesencephalon (midbrain)
-Caudal to this is the third primary vesicle, the rhombencephalon (hindbrain). The rhombencephalon connects with the caudal neural tube which gives rise to the spinal cord
-The central structure that remains after the secondary vesicles have sprouted off is called the diencephalon (between brain). At this stage forebrain is consist of two optic vesicles, the two telencephalic vesicles, and the diencephalon
-The telencephalic vesicles together form the telencephalon, or “endbrain,” consisting of the two cerebral hemispheres.
-another pair of vesicles sprout off the ventral surfaces of the cerebral hemispheres, giving rise to the olfactory bulbs and related structures that participate in the sense of smell
Compare and contrast neuroanatomy of the human and rat
What are the neural plate, neural tube, neural crest, and what do they differentiate into? What
developmental problems might arise regarding the neural tube?
-The nervous system and the skin derive from the ectoderm that gives rise to the neural plate.
-The first important step in the development of the nervous system is the formation of the neural groove. The walls of the groove are called neural folds fuse together forming a neural tube
-The bits of neural ectoderm that are pinched off when the tube rolls up are called the neural crest from which the PNS will develop
-Failure of the neural tube to close correctly is a common birth defect
What are the ventricles? What moves through them? What is the origin? What is a pathology involving them?
-the fluid-filled space within the cerebral hemisphere is called the lateral ventricle (telencephalon)
-Telencephalon consists of cerebral cortex and basal telencephalon
-the space at the center of the diencephalon is called the third ventricle
-the diencephalon is consist of the thalamus and the hypothalamus
What are the fiber bundles connecting the sides of brain?
Corpus callosum connects the sides of the brain
What are the meninges? Compare and contrast them.
-the skull is protected by three membranes collectively called the meninges.
-The outermost covering is the dura mater which forms a tough, inelastic bag that surrounds the brain and the spinal cord.
-Just under the dura lies the arachnoid membrane which has an appearance and consistency resembling a spider web.
-There is no space between the dura and the arachnoid but if the blood vessels passing through the dura are ruptured blood can collect and form subdural hematoma.
-The buildup of fluid in this subdural space can disrupt brain function by compressing parts of the CNS. This is treated by drilling a hole in the skull.
-The pia mater is a thin membrane close to the surface of the brain. The pia is separated from the arachnoid by a fluid-filled space.
-subarachnoid space is filled with a salty clear liquid called cerebrospinal fluid (the brain floats inside the head in this thin layer of CSF.
What are the various types of brain imaging? What are the strengths and weaknesses of them?
-X-ray-sensitive film works well for the bones of the skull, but not for the brain
-Computed tomography (CT scan) revealed organization of gray and white matter and the position of ventricles in the brain but uses X-irradiation
-Magnetic Resonance imaging (MRI) shows more detailed map of the brain and it does not require X-irradiation and images of the brain can be taken in any plane desired
-CT and MRI are used to look at a swollen muscle
- Positron Emission Tomography (PET scan) and Functional MRI (fMRI) detect changes in regional blood flow and metabolism within the brain. Active neurons demand more glucose and oxygen, more blood to active regions, techniques detect changes in blood flow
- you can see activity in the brain but uses radiation.
What are spinal nerves?
-The dorsal root contains axons bringing information into the spinal cord
-The ventral root contains axons carrying information away from the spinal cord
-The cell bodies of neurons lie outside the spinal cord in clusters called dorsal root ganglia
-somatic motor axons are PNS. motor neuron cell bodies lie within the CNS but axons are mostly PNS
-Visceral sensory axons bring information about visceral function to the CNS, such as pressure and oxygen contend of the blood in arteries.
-Cranial nerves are associated with CNS. Cranial nerves emerge from brainstem
