Chapter 2: CNS Organization

What are the 5 organizations principles of the nervous system?

1. Each functional system involves several brain regions that carry out different types of information processing 2. Identifiable pathways link the components of a functional system 3. Topographical maps are formed 4. Functional systems are hierarchically organized 5. Sensory and motor activities on one side of the body are mediated by the opposite side

How many layers does the cortex have?

6

What is the cerebrospinal fluid and where does it come from?

CSF surrounds all exposed surfaces of the CNS to provide cushion to delicate neural structures, comes from choroid plexus

What are the cranial nerves? Do they contain sensory fibers, and, if so, what do they inervate?

I. Olfactory, smell, nasal cavity II. Optic, vision, retina III. Oculomotor IV. Trochlear V. Trigeminal, general sensation, skin of the face VI. Abducens VII. Facial, taste, anterior tongue VIII. Vestibulocochlear, hearing and balance, cochlea and vestibule IX. Glossopharyngeal, taste, posterior tongue X. Vagus, taste, root of tongue and epiglottis XI. Accessory XII. Hypoglossal

What general functions are associated with the right hemisphere of the cerebral cortex?

analysis by touch, auditory cortex (left ear), spatial visualization and analysis, visual cortex (left visual field)

What are the divisions of the spinal cord? In humans, how many pairs of spinal nerves are found in the each division? How many pairs of nerves total?

cervical (8 pairs), Thoracic (12 pairs), lumbar (5 pairs), sacral (5 pairs), coccygeal (1) pairs); 31 total pairs

If you damage the cortex on one side of the head, sensory and motor deficits appear on the opposite side of the lesion. Why?

decussation and contralateral organization

What are the three layers of cranial meninges?

dura mater, arachnoid mater, pia mater

What are the 4 lobes of the cerebral cortex? What sulci divide the 4 lobes?

frontal, parietal, temporal, occipital lobes; central sulcus (frontal and parietal), lateral sulcus (frontal and temporal), parieto-occipital sulcus (parietal and occipital), cingulate sulcus (cingulate cortex and limbic lobe)

What is the blood brain barrier and how does it arise?

isolates CNS neural tissue from general circulation, keeps out toxins; composed of tight junctions, occludins, and claudins proteins

What is the general function of the parietal lobe?

knowing right from left, sensation, reading, body orientation

What 3 divisions of the CNS are found in the brainstem?

medulla, pons, midbrain

What are the cranial nerves?

nerves that are categorized according to structures they serve and in some case function

What is the general function of the frontal lobe?

problem solving, emotional traits, reasoning, speaking, voluntary motor activity

What are the 4 divisions of the spinal gray matter?

somatic sensory, visceral sensory, somatic motor, visceral motor

What general functions are associated with the left hemisphere of the cerebral cortex?

speech center, writing, auditory cortex (right ear), general interpretive center (language and mathematical calculation), visual cortex (right visual field)

What are the divisions of the autonomic nervous system? What distinguishes the two?

sympathetic (fight and flight) and parasympathetic (rest and digest)

What are the 3 dural sinuses and where are the located?

transverse sinus , inferior sagittal sinus, superior sagittal sinus; located in the dural folds

What is the general function of the temporal lobe?

understanding language, behavior, memory, hearing

Where is cerebrospinal fluid found in the nervous system?

ventricles

What is the general function of the occipital lobe?

vision, color perception