Chapter 8: CNS Flashcards
Choroid Plexus
epithelial cells in the roofs of the ventricles around a core of blood capillaries and connective tissue
- secrete cerebrospinal fluid into the ventricles and central canal of the spinal cord
Path of cerebrospinal fluid circulation:
- lateral ventricles into the 3rd ventricle, through interventricular foramen
- cerebral aqueduct into the 4th ventricle
- 4th ventricle into central canal
Cerebrum
derived from the telencephalon
- largest portion of the brain (80%)
- higher mental functions
Corpus Callosum
internal connection between right and left cerebral hemispheres
Cerebral Cortex
outer region of the cerebrum
- 2-4 mm of gray matter with underlying white matter
Gyri
raised folds of the cerebral cortex
Sulci
depressed grooves of the cerebral cortex
Gyri + Sulci
Convolutions
Frontal Lobe
Voluntary motor control of skeletal muscles; personality; higher intellectual processes; verbal communication
Precentral Gyrus
located in the frontal lobe
- responsible for motor control
Parietal Lobe
Somesthetic interpretation; speech understanding; interpretation of textures and shapes
Postcentral Gyrus
located in the parietal lobe
- responsible for somesthetic sensation
Temporal Lobe
Auditory interpretation; memory of auditory/visual experiences
Occipital Lobe
Vision and eye coordination
MRI
Magnetic Resonance Imaging
- different brain regions have differences in H+ alignment, aligned by magnets
- clear definition between gray and white matter
EEG
Electroencephalogram
- electrodes on the scalp detect synaptic potentials produced by cell bodies and dendrites in the cerebral cortex
Alpha waves
awake, relaxed
- high in parietal and occipital lobes
10-12 cycles p/sec
Beta waves
visual stimulation and mental activity
- high in frontal lobe
13-15 cycles p/sec
Theta waves
sleeping adults, attention, memory, stress
- high in occipital and temporal lobes
5-8 cycles p/sec
Delta waves
sleep, brain damage in awake adults
- all over the cerebrum
1-5 cycles p/sec
REM
Rapid Eye Movement
- state where dreams occur
- theta waves observed
breathing/HR may be irregular
consolidation of nondeclarative memory
Non-REM
Resting sleep
- 4 stages determined by type of EEG waves
- stages 3 + 4 = slow-wave sleep = delta waves
breathing/HR is very regular
consolidation of spatial and declarative memory (short-term to long-term memory)
Sleep stages repeat every ____ish minutes and cycles through __ times per night
90 minutes
5 times per night
Limbic system
involved in emotional drives
- amygdaloid, hippocampus, anterior insula, cingulate gyrus
- very active in REM sleep
Lateralization
Each side of the precentral gyrus controls movements on the contralateral side of the body
- through the corpus callosum
Left hemisphere dominance
Language, Analytical ability, Speech, Describing visual appearance
Right hemisphere dominance
Visuospatial tasks, recognizing faces
Broca’s area
motor speech area
- located in the left frontal gyrus
Broca’s aphasia
non-fluent aphasia = slow, poorly articulated speech
- no impairment of understanding, only impairs motor aspects of speech (not other mouth motor tasks)
Wernicke’s Area
language comprehension
- located in left superior temporal gyrus
Wernicke’s aphasia
fluent aphasia = rapid speech with no meaning
- language comprehension is destroyed (spoken and written)
Nondeclarative
Implicit
- memory of simple skills and conditioning
Declarative
explicit
- things that can be verbalized
1. Semantic (facts)
2. Episodic (events)
Amygdaloid body
involved in the formation of memories with emotional components
Diencephalon
includes
- epithalamus, thalamus, hypothalamus
- 3rd ventricle and part of pituitary gland
Thalamus
paired masses of gray matter making up most of the walls of the 3rd ventricle
Relay Centre
In the thalamus
- through which all sensory information (except smell) passes through to the cerebrum
Epithalamus
Contains the pineal gland (secretes melatonin)
Hypothalamus
Maintains homeostasis
- regulates the autonomic system and pituitary gland
- by release of inhibiting/stimulating hormones
Adenohypophysis
anterior pituitary
- receives the regulatory hormones from the hypothalamus
- in turn, regulate secretion of pituitary hormones to endocrine glands
Hypothalamo-hypophyseal tract
Transportation of ADH and oxytocin from hypothalamus to the posterior pituitary gland
Neurohypophysis
posterior pituitary gland
- stores ADH and oxytocin until released by hypothalamus stimulation
7 Pituitary Gland Hormones
ACTH
ADH
GH
LH
FSH
Oxytocin
Prolactin
Mesencephalon
Midbrain
- located between diencephalon and pons
- 2 systems of dopaminergic neurons (involved in motor coordination and reward system)
Hindbrain
mesencephalon + myelencephalon
- pons + cerebellum + medulla oblongata
Pons
houses sensory and motor tracts
- heading to/from the spinal cord
- 2 respiratory control centers (Apneustic and Pneumotaxic)
Cerebellum
receives input from proprioceptors in joints, tendons, and muscles
- coordinates movement
- motor learning and proper timing/force
Medulla oblongata
nuclei required for autonomic regulation of breathing and cardiovascular response
- damage = death
Ascending Spinal Cord Tracts
- carry sensory impulses
- prefix: Spino-
- suffix: which brain region it synapses on
Descending Spinal Cord Tracts
- carry motor impulses
- prefix: which brain region it comes from
- suffix: -spinal
Cranial nerves
part of the PNS and arise directly from nuclei in the brain
- most are mixed neurons
- vision, olfactory, and hearing are sensory only
Spinal nerves
Part of the PNS and arise directly from the spinal cord
- cervical, thoracic, lumbar, sacral, and coccygeal
- All mixed nerves
Dorsal root
sensory fiber carrier into CNS
Ventral root
motor fiber carrier out of the CNS
Reflex arc path
- Sensory receptor
- Sensory neuron
- Interneuron in CNS
- Somatic motor neuron
- Effector (muscle or gland)
Reflex arc
unconscious motor response to a sensory stimuli
Somatic = effector is a skeletal muscle
Autonomic = effector is a smooth/cardiac muscle or gland
