Chapter 13: Central Nervous System Flashcards
____ consists of the somatic sensory nerve cell bodies outside the CNS
Dorsal root ganglion
White matter of the spinal cord is composed of ____
Nerve fibers (myelinated)
What are the 3 layers of the meninges
- Dura mater
- Arachnoid mater
- Pia mater
Dura mater
Tough mother - outer layer
Leathery
- dense fibrous connective tissue
Arachnoid mater
between dura and pia mater
- web-like thread
Pia mater
Gentle mother - inner layer
4 main components of the CNS
- Brain stem
- Diencephalon
- Cerebellum
- Cerebrum
____ is the outer layer of the cerebrum and cerebellum
Gray matter
- Also called cortex 2-4mm thick
How many ventricles are in the brain
4
- Two lateral, a midline and a fourth ventricle
Key features: Medulla
- Above spinal cord
- descending motor tracts cross over on the anterior or ventral side - decussation
- Cranial nerves VIII - XII (8-12) vagus nerve
Key features: Pons
- Fourth ventricle sets between pons and cerebellum
2. Reticular formation for arousal states
T or F: Midbrain is the 3rd part of the brain stem
True
How many hemispheres does the brain have
2
____ coordinates information on balance and movement and the fibers to and from it are ipsilateral
Cerebellum
Ipsilateral
Same side of the body
3 components of the diencephalon
- Thalamus
- Hypothalamus
- Pineal gland (epithalamus)
____ sensory gateway to the cortex
Thalamus
- Communications relay through thalamic nuclei and are edited by the thalamus
5 lobes of the cerebral hemisphere
- Frontal
- Parietal
- Temporal
- Occipital
- Insula
Sulcus
Shallow grooves on the surface of the cerebral hemisphere
Gyrus
twister ridges of brain tissue
Pre-central gyrus: ____ function
Motor
postcentral gyrus: ____ function
Sensory
2 principles in brain circuitry
- Somatotopy
2. Contralateral projection
Somatotopy
Entire body is mapped onto the sensory and motor cortex
- Results in cortical “homunculus”
Contralateral projection
From peripheral sensors to opposite side postcentral gyrus
- Contralateral motor output from precentral gyrus cortex to opposite extremities
Speech comprehension
Wernicke’s area
Production of speech
Broca’s area
Wernicke’s and Broca’s area are to the ___ hemisphere
Left
Processing: right hemisphere
Spatial, artistic, intuitive, “big picture” cortical processing
Processing: left hemisphere
Details and symbolic representation
_______ consists of commissural fibers that connect the 2 cerebral hemispheres
Corpus callosum
Components of the limbic system
- Cingulated gyrus
- Hippocampus
- Amygdala
- Septal nuclei
another name for the limbic system
Emotional brain
Amygdala
Processes fear
Hippocampus
Encoding and processing memories
Function: Reticular formation (brainstem)
Maintaining consciousness
- Generating a state of alertness and arousal from sleep
Cerebrospinal fluid is made by the ________ in the roofs of the brain ventricles
choroid plexuses
T or F: Cerebrospinal fluid is a filtrate from brain capillary blood flow like kidney tubule ultrafiltrate from glomerular capillaries
True
T or F: Cerebrospinal fluid circulates through brain ventricles and over spinal cord and brain subarachnoid space
True
Cerebrospinal fluid is reabsorbed in _______
Arachnoid villi
Ascending sensory pathways require 3 neurons
- Sensory neuron
- Ascending neuron
- Thalamic relay to the sensory cortex (postcentral gyrus)
Descending motor pathway require 2 neurons
- Upper motor neuron to anterior horn
2. Lower motor neuron
Ascending sensory pathways require ____ neurons
Three
Descending motor pathway require ___ neurons
Two
