CNS chapter 12

Question 1

Fornix

Answer 1

• Is an arching, fibrous band of nerve fibers that extend from the hippocampus to the mamillary body of the hypothalamus
• An archlike anatomical structure or fold, such as the arched band of white matter located beneath the corpus callosum of the brain.

Question 2

Septum Pellucidum

Answer 2

A thin membrane of nervous tissue that forms the medial wall of the lateral ventricles in the brain

Question 3

Development of the the neural tube from embryonic ectoderm

Answer 3

1) The neural plate forms from surface ectoderm.
2) the Neural plate invaginates, forming the neural groove flanked by neural folds.
3) Neural fold cells migrate, form the nural crest, will form much of the PNS and other surfaces.
4) the Neural groove becomes the neural tube, which will form CNS structures.

Question 4

Gray matter

Answer 4

Neuron cell body clusters

Question 5

White matter

Answer 5

Nerve fibers = (myelinated axons)

Question 6

Basal Nuclei (def. location, function)

Answer 6

• Are densely packed locations of cell bodies (somas) in the subcortical area (beneath the cortex) of the brain. Gray matter
• Nuclear bodies are in the CNS.
• Important in starting, stopping, and monitoring the intensity of movements executed by the cortex

Question 7

Basal Ganglia (def. location)

Answer 7

• Are the cluster of neuron cell bodies and dentrites.
• Located in the PNS. Ex. the dorsal root ganglions that exit each vertabrae at the intervertebral foramen

Question 8

Brain function

Answer 8

Sensory — Integration —– Motor

Question 9

4 Major parts of the brain

Answer 9

1. Brain stem (medulla oblongata, pons, midbrain)
2. Diencephalon (thalamus, hypothalamus)
3. Cerebrum (83% of brain mass)
4. Cerebellum (little brain)

Question 10

Major lobes of cerbrum

Answer 10

1. Frontal lobe (1)
2. Parietal lobes (2)
3. Temporal Lobes (2)
4. Occipital lobe (1)
5. Insula

Question 11

Gustatory cortex (taste) location

Answer 11

In Insula

Question 12

Specific sulci / fissures

Answer 12

1. Central sulcus
2. Lateral / Sylvian sulcus
3. Transverse fissure
4. Longitudinal fissure

Question 13

Extensions of Dura Matter

Answer 13

1. Tentorium cerebelli (separartes occipital lobe from cerebellum)
2. Falx cerbelli (separates cerebellar hemispheres)
3. Falx cerebri (separates the 2 hemispheres of the brain)

Question 14

Connetion of the 2 hemispheres

Answer 14

Corpus callosum

Question 15

Outer cortex of brain (compossition and characteristics)

Answer 15

1. Gray matter surrounds an interior that is mostly white matter, except for a few small protions (basal nuclei)
2. Surface is marked by ridges called gyri separated by grooves called sulci

Question 16

Cerebrum divisions

Answer 16

internally each hemispheres is divided into 3 regions.

1. Superficial cortex of gray matter
   
   • Cerebral cortex - outermost layer of gray matter
   • Makes up superficial area and functional areas
   • Contains 70% of the neurons in CNS
2. Internal white matter
3. Basal nuclei (islands of gray matter deep within the white matter)

Question 17

Cerebral cortex functions

Answer 17

1. Sensory: allow for conscious recognition of stimuli
2. Motor: Control voluntary, motor functions
3. Association: integration

Question 18

Broca’s area

Answer 18

• Region of the brain that contains motor neurons involved in the control of speech.
• This area, located in the frontal part of the left hemisphere of the brain,

Question 19

Wernicke’s area

Answer 19

• Region of the brain that contains motor neurons involved in the comprehension of speech.
• The Wernicke area is located in the posterior third of the upper temporal convolution of the left hemisphere of the brain.
• Damage to the temporal lobe may result in a language disorder known as Wernicke aphasia.
• An individual with Wernicke aphasia has difficulty understanding language; speech is typically fluent but is empty of content and characterized by circumlocutions, a high incidence of vague words like “thing,” and sometimes neologisms and senseless “word salad.”

Question 20

Commisural fibers

Answer 20

• Connect corresponding gray areas of the two hemispheres, enabling them to function as a coordinate whole (includes the copus callosum)

Question 21

• Connect corresponding gray areas of the two hemispheres, enabling them to function as a coordinate whole (includes the copus callosum)

Answer 21

Commisural fibers

Question 22

Association fibers

Answer 22

• Connect different parts of the same hemisphere

Question 23

Projection fibers

Answer 23

• Nerve fibers that connect the cerebral cortex with the subcortical centers, the brain stem, and the spinal cord’

Question 24

Reversed

• Connect different parts of the same hemisphere

Answer 24

Association fibers

Question 25

Reversed

• Nerve fibers that connect the cerebral cortex with the subcortical centers, the brain stem, and the spinal cord’

Answer 25

Projection fibers

Question 26

Midbrain (functions)

Answer 26

• The midbrain is the smallest region of the brain that acts as a sort of relay station for auditory and visual information.
• The midbrain controls the visual and auditory systems as well as eye movement.
• Portions of the midbrain called the red nucleus and the substantia nigra are involved in the control of body movement.
• The darkly pigmented substantia nigra contains a large number of melanin-producing neurons are located (melanin is a precursor for dopamin). The degeneration of neurons in the substantia nigra is associated with Parkinson’s disease.

Question 27

Reticular Formation (location, action)

Answer 27

• It extends from the central core of the medulla oblongata, pons and midbrain.
• Controls brain alertness; it is inhibited by sleep, alcohol, tranquilizers

Question 28

Limibic System

Answer 28

• Limbus = “ring”
• group of subcortical structures (e.g. hypothalamus, hyppocampus and the amygdala)
• Involved in olfaction, emotion, behavior, and various autonomic functions.

Question 29

Midbrain (anatomy)

Answer 29

1. Corpora quadrigemina: composed of
   
   • Superior coliculi (visual reflexe center that coordinate head and eye movement)
   • Inferior coliculi (auditory relay from hearing receptors to sensory cortex)
2. Substantia nigra: contains high [] of melanin pigment which is a precursor of dopamine.
   
   • Functionally linked to basal nuclei (putamen)
   • damage to sustantia nigra = Parkinson’s disease.

Question 30

Flaccid paralysis

Answer 30

Damage of ventral horn neurons, or ventral roots –> nerve impulses don’t reach muscles, thus not move voluntary or involuntary –> muscle atrophy

Question 31

Spastic paralysis

Answer 31

Damage in the neurons of the primary motor cortex. Spinal reflexes continue to stimulate muscle irregularly. Muscles remain healthier longer but no voluntary control.

Question 32

paralysis

Answer 32

Any localized damage to the spinal cord or its roots leads to paralysis (loss of motor function)

Question 33

paresthesias

Answer 33

Any localized damage to the spinal cord or its roots leads paresthesias (loss of sensory function).

Question 34

Paralysis vs Paresthesias

Answer 34

Any localized damage to the spinal cord or its roots leads to paralysis (loss of motor function) or paresthesias (loss of sensory function).

Question 35

Region that contains part of the system that helps maintain cerebral alertness and regulates skeletal and visceral muscle activity. (location)

Answer 35

Reticular Formation (medulla oblongata, ponds, midbrain)

Question 36

• Reticular Formation (location, function)

Answer 36

• medulla oblongata, ponds, midbrain
• Region that contains part of the system that helps maintain cerebral alertness and regulates skeletal and visceral muscle activity