Exam 6 (CH. 7)

Question 1

What are the planes of section? What would be revealed best by various planes of section?

Answer 1

• midsagittal plane: the plane of section resulting from splitting the brain into equal right and left halves. Sections parallel to the midsagittal planes are in the sagittal plane.
• horizontal plane: parallel to the ground. A single section in this plane could pass through both the eyes and ears. Thus, the horizontal section splits the brain into dorsal and ventral parts.
  - right and left cerebral hemispheres
• The coronal plane: is perpendicular to the ground and to the sagittal plane. A single section in this plane could pass through both eyes or both ears but not through all four at the same time. Thus, the coronal plane spilts the brain into anterior and posterior parts.

Question 2

What about different views of the brain- what would be visible on the dorsal surface, ventral surface, lateral surface?

Answer 2

• dorsal: right and left cerebral hemisphere
• ventral: pons, medulla, and cerebellar hemispheres
• lateral: cerebrum, cerebellum, brain stem, and spinal cord.

Question 3

What are gyri and sulci?

Answer 3

-Gyri: a bump or bulge lying between the sulci of the cerebrum.
- Sulci: a groove in the surface of the cerebrum running between neighboring gyri.

Question 4

How do we identify cortical area from a neuroanatomical standpoint?

Answer 4

by cytoarchitecture: layer thickness, molecular distinctions
by connections: afferent and efferent connections, thalamus
by functions: electrophysiology, behavioral contributions

Question 5

What functions are controlled by midbrain, medulla, cerebellum, thalamus, and cortex?

Answer 5

• midbrain: vision and hearing
• medulla: both critical to survival: respiration, muscle tone, and heart rhythms.
• cerebellum: movement control
• thalamus: gateway of the cortex. axons from thalamus to cortex pass through the internal capsule. carry information from contralateral side of the body.
• cerebral cortex: analyze sensory input and command motor output

Question 6

What are the 3 primary brain vesicles, and what structures develop from each of them?

Answer 6

1. Prosencephalon (forebrain): consists of telencephalic vesicles, diencephalon (thalamus), and optic vesicles.
   - include: lateral ventricle, third ventricle, cerebral cortex, olfactory bulb, hypothalamus and thalamus
2. mesencephalon (midbrain): cerebral aqueduct, tectum (inferior and superior colliculus) and tegmentum
3. rhombencephalon (hindbrain): cerebellum, pons, medulla, cochlear nuclei, decussation, and commissure

Question 7

Compare and contrast neuroanatomy of the human and rat

Answer 7

• humans have a tremendous amount of the forebrain, mainly the frontal cortex
• both: same proportion of cerebellum relative to size.

Question 8

What are the neural plate, neural tube, neural crest, and what do they differentiate into? What developmental problems might arise regarding the neural tube?

Answer 8

• neural tube: the primitive embryonic central nervous system consisting of a tube of neural ectoderm.
  - neural plate becomes neural tube
• neural crest: the primitive PNS consisting of neural ectoderm that pinches off laterally as the neural tube forms.
• Problems: posterior neural tube: spina bifida failure of formation of posterior spinal cord.
  anterior neural tube: anencephaly: degradation of the forebrain and skull. always fatal.

Question 9

What are the ventricles? What moves through them? What is the origin? What is a pathology involving them?

Question 10

What are the fiber bundles connecting the sides of brain?

Answer 10

corpus callosum

Question 11

What are the meninges? Compare and contrast them.

Answer 11

1. Dura mater: outermost covering, leather-like consistency. the dura forms a tough inelastic bag that surrounds the brain and spinal cord.
2. Arachnoid membrane: has an appearance and consistency resembling a spider web. If blood vessels rupture in between the dura and arachnoid it is called a subdural hematoma.
3. Pia mater: “gentle mother”. A thin membrane that adheres closely to the surface of the brain. Wraps around blood vessels. the pura is separated by the arachnoid by the space that contains cerebrospinal fluid (CSF).

Question 12

What are the various types of brain imaging? What are the strengths and weaknesses of them?

Answer 12

• computed tomography (CT)- S: noninvasive, has good resolution W: radiation
• (PET) Positron emission tomography: S: can see what regions are active W: infusing something radioactive into someone and the resolution isn’t good.
• MRI: S- More detail, does not require X-irradiation, brain slice image in any angle. W: powerful magnetic field.