Download VIII. Functional Brain Systems

Anatomy 32 Lecture
Chapter 13 - The Central Nervous System: Brain
I.
Overview
A. Embryonic Development of the Brain
B. Basic Parts & Organization of the Brain
1. Cerebrum
2. Diencephalon
3. Brain Stem
4. Cerebellum
C. Functional Brain Systems
II. _____________ Development of the Brain
A. In the developing embryo, the neural plate forms and becomes the _________
________, which forms the brain and spinal cord
B. The ______ develops at the cephalic end of the tube, and by the 4th week, three swellings
are evident:
1.
____encephalon (______brain), which eventually becomes the
a.
____encephalon, which forms the cerebral hemisphere and contains the lateral
ventricles
b.
___encephalon, which forms the thalamus, hypothalamus epithalamus, and
pituitary gland, and contains the third ventricle
2.
____encephalon (____brain), which forms the superior & inferior colliculi and
cerebral peduncles, and contains the cerebral aqueduct
3.
________encephalon (______brain), which becomes the
a.
_____encephalon, which forms the pons & cerebellum and contains the upper 4th
ventricle
b.
______encephalon, which forms the medulla oblongata that merges with the SC
and contains the lower 4th ventricle
III. Basic Parts & Organization of the Brain
A. The brain may be divided into four major parts:
1. ______________ - largest, superior part of brain
2. _______________ – thalamus, hypothalamus, & epithalamus
3. _______________ – midbrain, pons, & medulla oblongata
4. ______________ - 2nd largest, most posterior part of brain
B. The brain is enclosed by the cranium and meninges, and bathed in cerebral spinal fluid
(____). The _____________ include:
1. ________ mater – outermost tough fibrous CT layer
2. __________ mater – CT layer deep to the dura mater; between the two layers is the
__________ space; deep to the arachnoid is the subarachnoid space, containing CSF
& blood vessels
3. ______ mater – layer of highly vascular, delicate CT, deep to the ________________
space
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C. CSF circulates within the hollow _______ of the brain, the central canal of the SC, and in
the subarachnoid space of the whole CNS
1.
CSF serves as a medium for exchange of __________ and waste products between
the blood and nervous tissue
2.
CSF maintains a homeostatic environment in the brain, along with the _________
barrier, which consists of brain capillaries with tight junctions that only allow small
nutrient molecules, ions, and lipid soluble molecules to pass into the brain
IV. Cerebrum
A. Consist of 5 paired lobes within left & right ____________. The cerebrum is involved in
higher brain functions, including:
1.
Perception of __________ impulses and instigation of voluntary ___________
responses
2.
3.
4.
Memory, ____________, and reasoning abilities
_____________ and limbic (emotional) functions
The two hemispheres control ____________ sides of the body and different brain
functions
a.
b.
_________ controls analytical and verbal skills
_________ controls spatial and artistic intelligence
B. Structure of the Cerebrum
1.
Cerebral _________ - 2-4 mm thick surface layer composed of gray matter; contains
billions of neurons.
2.
Paired _______ of the cerebrum are mostly named for the skull bones they are under:
a.
___________ lobe
b.
+_____________lobes
c.
______________ lobes
d.
______________ lobes
e.
__________ (deep within the lateral sulcus)
3. The cortex contains _______ (ridges), deep grooves called ___________, and
shallower _________
4. Major fissures and sulci of the cerebrum include:
a.
The ___________ _______ separates the cerebrum into right and left
hemispheres. Dura Mater called the ___________ extends into this fissure
b.
c.
d.
e.
The ______ ________ separates the frontal and parietal lobes
The _____________ separates the frontal and temporal lobes
The parieto-occipital sulcus separates the ___________ and occipital lobes.
The ___________________ separates the cerebrum from the cerebellum.
5. Two prominent gyri are the _____central and ______central gyri (separated by the
central sulcus)
6. Beneath the cortex lies the cerebral _______ matter, ________ that connect parts of the
brain with itself and other parts of the nervous system.
7. _______________ fibers (tracts) transmit impulses from one cerebral hemisphere to
the other. Three of these are the:
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a.
b.
________ _____________
a.
b.
___________ ventricles (1 & 2) extend into left and right cerebral hemispheres
c.
The third ventricle connects with the cerebral __________ (of Sylvius) in the
midbrain
d.
The _________ ventricle in the hind brain connects with the cerebral aqueduct
and is continuous with the SC __________
e.
________________, small capillary knots & ependymal cells lining the roof of
the ventricles, create the CSF that circulates through the ventricles and central
canal.
Anterior & posterior _______________
8. Spaces called ____________, which contain CSF, are found within and inferior to the
cerebrum
The _______ ventricle is deep within the diencephalon and connects with the
lateral ventricles via the interventricular foramina (of Monroe)
C. _____________ of the Cerebrum
1. ____________ lobes - form the anterior portion of each cerebral hemisphere.
Major
functional areas include:
2.
a.
_____________ cortex is involved in intellect, complex reasoning, and
personality
b.
____________ gyrus - contains ______ areas involved in the control of voluntary
muscles (i.e.: primary motor cortex)
c.
__________ area - a motor speech area at the base of the precentral gyrus just
above the lateral sulcus in the ______ hemisphere
___________ lobes - posterior to the frontal lobes. Functional areas:
a.
___________ gyrus - contains ___________ areas responds to incoming stimuli
from cutaneous and muscular receptors (i.e.: primary somatosensory cortex)
b.
_____________ area, at the junction of parietal and temporal lobes in the left
hemisphere, is where unfamiliar words are sounded out
c.
Primary gustatory cortex – receives _________ impulses
3.
____________ lobes - inferior to parietal lobes; contains the ____________ areas
(i.e.: primary auditory cortex) that receive auditory fibers from the cochlea of the ear
4.
_______________ lobes - posterior cerebrum
a.
b.
5.
Superior to the cerebellum and separated from it by a dura mater layer called the
tentorium ______________.
__________ areas (i.e.: primary visual cortex) here integrate eye movements and
correlate visual images with other sensory stimuli
The _________ is a medial structure deep to the parietal lobe. It is thought to
integrate other cerebral activities and be involved in language and the sense of
balance, as well as some visceral functions
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D. _________ matter of the Cerebrum - three types of fiber ______ named according to
location and direction they conduct impulses
1.
___________ fibers - conduct impulses between neurons within a hemisphere (e.g.:
fibers between Broca’s & Wernicke’s areas)
2.
________________ fibers - connect the neurons & gyri of one hemisphere with those
of the other (e.g.: _________ callosum)
3.
___________ fibers - form the ascending and descending tracts of the brain & spinal
cord
E. ________ ___________ - specialized paired masses of gray matter located deep within
the cerebral white matter; involved in voluntary ________ movements; consists of the
following
1.
Corpus ________ - several masses of nuclei that appear striped; includes:
a. ____________ nucleus - the upper mass
b. ____________ nucleus - deep to the caudate nucleus; divided into
1) __________ pallidus – medial part
2) _____________ – lateral part
2.
3.
______________ nucleus - at the tip of the caudate nucleus
Damage to the basal nuclei causes motor movement dysfunction (_________), such
as that found in Parkinson’s & Huntington’s diseases
V. _______________ - area of brain above the brain stem; contains the thalamus, hypothalamus,
and epithalamus (some books include the pituitary gland).
A. ____________ - paired organ that constitutes nearly 4/5 of the diencephalon; positioned
just below the lateral ventricles
1.
Contains nuclei that serve as ________________ for all sensory impulses, except
smell, to the cerebral cortex.
2.
Nuclei include the medial & lateral _________________, which receive auditory &
visual information, respectively.
B. ________________ - found inferior to the thalamus, has 4 major regions (mammillary,
tuberal, supraoptic, and preoptic); is one of the major regulators of _______________
1.
Mammillary region - most posterior portion of hypothalamus; contains __________
bodies, which relay info. related to sense of _________.
2.
Tuberal region - contains the infundibulum (stalk that connects hypothalamus to
pituitary gland) and _________ _________, which secretes hypothalamic regulating
hormones.
3.
_____________ region - contains many nuclei (paraventricular, supraoptic, anterior
hypothalamic, & suprachisamatic). Axons extend through the ________________ to
posterior pituitary.
4.
________ region - contains the preoptic, periventricular, medial preoptic, and lateral
preoptic nuclei.
5.
Functions of hypothalamus include:
a.
Control of ______ - Axons extend from hypothalamus to sympathetic and
parasympathetic nuclei in brain stem and spinal cord; so hypothalamus can control
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and integrate the ANS, which regulates contraction of smooth muscle, cardiac
muscle, and glandular secretions.
b.
Control of ___________ Gland via hypothalamic hormones:
1) ______________ hormones (factors) control hormones (FSH, LH, ACTH,
& TSH) released by the anterior pituitary (adenohypophysis).
2) __________ & Antiduretic hormones produced by the paraventricular and
supraoptic nuclei are transported via axons through the infundibulum to the
posterior pitutary.
c.
Regulation of _______ & behavior (rage, aggression, pain, pleasure, & sexual
arousal)
d.
Regulation of hunger, _______, & satiety - thirst centers of hypothalamus
monitor osmotic pressures.
e.
f.
Control of body _____________
_______ control - the superchiasmatic nucleus establishes daily (diurnal) sleep
patterns.
C. _____________ - posterior portion of diencephalon, forms a roof over the 3rd ventricle
1. Contains the __________ gland, which secretes ___________, a hormone that
influences diurnal cycles.
2.
Posterior _____________, inferior to the pineal gland, connects the right & left
superior colliculi of the midbrain
VI. __________ – includes the midbrain, pons, and medulla oblongata.
A. ___________ structures between the diencephalons and pons are:
1. Cerebral ___________ - interconnects the 3rd & 4th ventricles
2. Corpora _______________ - four rounded elevations on the posterior midbrain
a. The ___________ colliculi are the two upper eminences, concerned with
__________ reflexes
b. The ___________ colliculi are the two lower eminences, responsible for
___________ relexes
3. Cerebral ______________ - pair of structures composed of ascending and descending
projection fiber tracts that and connect the cerebrum to other parts of the brain
4.
____________________ - between the cerebral peduncle and cerebral aqueduct;
connects cerebrum & cerebellum; concerned with motor coordination and posture
5.
______________ - inferior to the red nucleus; thought to inhibit forced involuntary
movements (affected in Parkinson’s disease)
B. ____- rounded bulge between the midbrain and medulla oblongata.
1.
Consists of white fiber tracts that connect it with the cerebellum and medulla
oblongata (___)
2.
3.
Nuclei of the pons function with those of the MO to regulate ___________
_____________ that have nuclei in the pons include CN _____.
C. ____________ oblongata – between the pons and spinal cord
1. The medulla resembles the spinal cord, except for two triangular elevations called
___________ on the posterior side and an oval enlargement called the __________
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2. The pyramids contain ascending and descending tracts, which ______________,
allowing one side of the brain to receive info. from and send info. to opposite sides of
the body.
3. The _____ ventricle within the MO is continuous with the cerebral aqueduct
superiorly and the central canal inferiorly
4. Cranial nerves __________ arise from the MO
5. Important nuclei in the MO include the nucleus __________ & ________, which
relay sensory info. to the thalamus, then to the cerebral cortex via thalamic nuclei
6. Three other nuclei function as ____________ centers of the MO for controlling
visceral functions:
a. _______ center – adjusts the force and rate of the heartbeat
b. ___________ center - sends impulses via the SC and spinal nerves to the
arteriole walls, causing them to constrict and elevate BP
c. _____________ center - controls the rate and depth of breathing
7. Other MO nuclei are involved in sneezing, coughing, swallowing, and ___________
VII. ___________ - second largest brain structure, found in the inferior, posterior cranial cavity
A. A ____________ fissure and associated tentorium cerebelli dura mater separates the
cerebellum from the cerebrum
B. The cerebellum consists of two hemispheres, between which the falx _____________
dura mater extends
C. Between the hemispheres is a constricted region called the ______
D. _________ are the convoluted folds of the cerebellum
E. The cerebellum has a thin outer layer of gray matter, the cerebellar __________
F. A thick deeper layer of white matter forms branches called the _______________
G. The cerebellar _____________ are 3 paired nerve tracts that allow the cerebellum to
communicate with the rest of the brain
1. ___________ convey info. to the thalamus, then to motor areas of the cerebral cortex
2. ___________ convey impulses of voluntary movement from the cerebrum through the
pons to the cerebellum
3. ____________ connect the cerebellum with the MO and SC
H. The main function of the cerebellum is to _______________ skeletal muscle contractions
and process impulses from ____________ within muscles, tendons, and joints
VIII. Functional Brain Systems
A. _____________ Formation network of nuclei & ascending and descending nerve fibers
within the brain stem that functions as the reticular activating system (RAS) in
___________ the cerebrum
1.
2.
Allows the cerebrum to be in a state of alert consciousness and to selectively
____________ sensory impulses
Helps the _____________ to maintain muscle tone and produce coordinated
contractions of skeletal muscles
B. ____________ System - found in cerebral hemispheres and diencephalon; controls
_________, pleasure & pain. Maintains memories with the assistance of the
____________ and cerebrum