A&P Chapter 12 Learning Outcomes
During rest about ____ of total blood flow in the body goes to the brain
20%
Each half of the thalamus has _____ main groups of nuclei separated by 2 thin layers of _______
3; white matter
The cerebral aqueduct connects ________.
3rd and 4th ventricles
cavity between two masses of thalamus
3rd ventricle
How many parts does the diencephalon have?
4
continuous with central canal of spinal cord
4th ventricle
The cerebrum has 2 halves (left and right cerebral hemisphere) and each has _____ lobes with groups of neurons with specific tasks
5
Functions carried out by the central nervous system (CNS)
Integrative functions
Functions carried out by the peripheral nervous system (PNS)
Motor and sensory functions
Stimulation of a muscle cell contraction or a gland secretion
Motor functions
3 Functional Categories of the nervous system
Motor functions, sensory functions, and integrative functions
detection of sensations within and outside the body
Sensory functions
From what sources does the input the brain receives and process come from?
Sensory neurons of the PNS, interneurons from other parts of the brain, and interneurons from the spinal cord
Where does the brain send its "decision" or output?
To other interneurons of the brain or spinal cord or to a muscle or gland via motor neurons of the PNS
What are the two cerebellum hemispheres connected by?
Vermis
3 lobes of the cerebellum
anterior lobe, posterior lobe, and flocculondular lobe
hormone that influences water balance in the body
antidiuretic hormone (ADH)
After association nuclei process info, it sends it mainly to ______ of cerebral cortex
association areas
process information related to emotions, memory, and integration of sensory information from multiple sources
association nuclei
Function of brainstem
basic involuntary homeostatic functions, control of certain reflexes, monitoring movement, and integrating and relaying info to other parts of the nervous system
Mammillary bodies input arrives at _______ from outside nervous system (endocrine system) receptors that detect schange in ________ and receptors which detect blood's ________.
body temperature; osmotic concentration
Right and left corticospinal tracts lie on each side of the _______ and ______.
brain and spinal cord
Cerebellar peduncles connect cerebellum to the _______ and form only route that info flows into in and out of cerebellum.
brainstem
connects brain and spinal cord
brainstem
posterior boundary of the frontal lobes
central sulcus
Cerebellar white matter bond into 3 large tracts of white matter known as ________.
cerebellar peduncles
Makes up posterior and inferior portion of the brain
cerebellum
posterior and inferior portion of the brain composed of right and left hemispheres
cerebellum
The red nucleus communicates with ________ and _________ as well as other structures regulating movement
cerebellum and spinal cord
The thalamus is the "main entrance" or output to _________. What does this allow the thalamus to control?
cerebral cortex (almost all info for cerebral cortex goes through thalamus first); information that reaches cerebral cortex and where it goes (ultimately regulates cortical activity)
Sources the hypothalamus receives input from
cerebral cortex and basal nuclei
The cerebellum functions with ______, ________, ________, and _______ in the coordination of movement
cerebral cortex, basal nuclei, brainstem, and spinal cord
Sources of input received by thalamic nuclei
cerebral cortex, cerebellum, basal nuclei, structures of the limbic system, and sensory system (except for smell)
The corticospinal tract descends through the _____, ______, and ________.
cerebral hemispheres, brainstem, and spinal cord
enlarged superior portion of the brain
cerebrum
4 divisions of the brain
cerebrum, diencephalon, cerebellum, and brainstem
Whats the function of nonspecific nuclei?
controlling arousal, consciousness, and the level of responsiveness and excitability of cerebral cortex
Nonspecific nuclei send information to broad areas of ______ and rest of the brain
cortex
Almost all pathways to and from the brain and spinal cord pass through the brainstem. One is the ________, which originates in the primary motor cortex.
corticospinal tract
Several _________ are found in the midbrain
cranial nerve nuclei
Numerous ________ originate from the brainstem, their nuclei have many sensory, motor, and autonomic responsibilities
cranial nerves
Descentind tracts are located in the anteriormost portion of the midbrain in area known as _______.
crus cerebri
Anterior pons contain ________ from crus cerebri, some of which pass through the pons on their way to _______.
descending motor tracts; spinal cord
tracts of white matter originating from the cerebrum
descending tracts
central core of the brain buried beneath central hemispheres
diencephalon
physical center of the brain almost completely hidden from external view by cerebral hemispheres
diencephalon
3 subdivisions of brainstem
duperior midbrain, middle pons, and inferior medulla oblongata
The pituitary gland secretes hormones that influence secretion from other _______ throughout the body
endocrine glands
superior to thalamus
epithalamus
What gender has a higher brain weight to body weight ratio?
female
Function of the cerebellum
figures importantly in planning and coordination of movement (particularly for complex activities such as playing an instrument or a sport)
Cerebellar surface has ridges called ______ ("leaves"), separated by shallow ______.
folia; sulci
The brainstem extends to the level of __________, after which it becomes the spinal cord
foramen magnum of occipital bone
anteriormost lobes of each central hemisphere
frontal lobes
Function of reticular formation
functions include regulation of respiration, blood pressure, sleep/wake cycle, pain perception, and consciousness
Cerebellar interior has an outer layer of _________, ________ and inner _______ with clusters of ________ or ______ are embedded
gray matter; cerebellar cortex; white matter; gray matter; deep cerebellar nuclei
Functions of neurons of insulas
have functions relating to taste and our viscera (internal organs)
What is the function of the cerebrum?
higher mental functions (learning, memory, personality, cognition, language, and conscience) and major roles in sensation and movement
Mammillary bodies receive input from _______ with which they play a role in regulating ________ and _______.
hippocampus; memory and behavior
What increase or decrease secretion of other hormones from the pituitary gland?
hypothalamic releasing or inhibiting hormones
The posterior of the gland is made up of ________.
hypothalamic tissue
a collection of nuclei that sits anterior and inferior to thalamus
hypothalamus
With a midsagittal section, the brainstem is located ________ to diencephalon, ___________ to cerebellum, and ______ to spinal cord.
inferior; anterior; superior
visible only when frontal, parietal, and temporal lobes are pried apart at the lateral fissure
insulas
Insulas are ______ by the other lobes
insulated
"decision-making" processes
integrative functions
Processes included in integrative functions
interpretation of sensory info, planning and monitoring movement, maintenance of homeostasis, and higher mental functions such as use of language and learning
Why is it called the red nucleus?
it s cells have iron-containing pigment that gives it a pinkish appearance
separate the frontal and parietal lobes
lateral fissure
What gender has larger brains?
males
2 small projections; connect hypothalamus to limbic system
mammillary bodies
inferiormost portion of the brainstem; blends with spinal cord after it passes through foramen magnum
medulla oblongata
Substantia nigra ("black substance") nucleus has dark color hue due to pigment similar to _______ found in its neurons
melanin
The pineal gland secretes _________ that helps regulate ________.
melatonin; sleep/wake cycle
the midbrain is also known as ______.
mesencephalon
superiormost and shortest component of brainstem, inferior to the diencephalon; surrounds cerebral aquequct
midbrain
area of midbrain between the cerebral aqueduct and substantia nigra
midbrain tegmentum
Other descending motor tracts enter cerebellum via ___________.
middle cerebellar peduncles
Red nucleus is active in ________ in other animals, its role in humans is not yet understood
movement
What is the brain primarily composed of?
nervous tissue
receive information from basal nuclei, cerebellum, and motor cortex
nonspecific nuclei
posterior lobe of each cerebral hemisphere
occipital lobes
hormone that in women stimulates contraction of uterus during childbirth; in both sexes may promote emotional bonding
oxytocin
paired lobes posterior to the frontal lobes
parietal lobes
separate the occipital lobe from the parietal lobe
parieto-occipital sulcus
Functions of neurons of the temporal lobes
perform functions related to hearing, language, memory, and emotions
attached to inferior portion of hypothalamus by infundibulum (extension)
pituitary gland
inferior to midbrain; anterior surface rounded and prominent
pons
major gyrus that sit just posterior to the central sulcus
postcentral gyrus
just anterior to the central sulcus
precentral gyrus
Functions of neurons of occipital lobe
process all information relating to vision
The anterior surface of the medulla have elevated ridges known as _____.
pyramids
posterior to the substantia nigra
red nucleus
Other nuclei in middle cerebellar peduncles participate in ________ and some are involved in ________ like sleep and arousal
reflexes; complex functions
The brainstem also controls numerus _________ or programmed, automatic responses to stimuli and functions in _______, _________, and _______.
reflexes; movement, sensation, and maintaining alertness
Middle cerebellar peduncles contain certain nuclei that help __________, including those required for breathing
regulate movements
Function of hypothalamic nuclei
regulating much of the autonomic nervous system, the sleep/wake cycle, thirst and hunger, and body temperature (vital to our survival)
receive incoming info, process and integrate it, and send it to specific motor or sensory areas of cerebral cortex
relay stations
Function of neurons of frontal lobes
responsible for planning and executing movement and complex mental functions such as behavior, conscience, and personality
Function of neurons of parietal lobes
responsible for processing and integrating sensory information and function in attention
What is the function of the diencephalon?
responsible for processing, integrating, and relaying info to different parts of the brain; homeostatic functions; regulation of movement; biological rhythms
Some cranial nerve nuclei function overlaps with _______ functions
reticular formation
Throughout the brainstem is found a group of connected nuclei called the ________.
reticular formation
Midbrain tegmentum contains numerous, many of which are part of _________, as well as ascending and descending _______.
reticular formation; white matter tracts
Functions of nuclei of the midbrain
roles in movement, sensation, and certain reflexes
Some specific relay nuclei only receive ______ stimuli; others receive _______ information
sensory; motor
The brain and spinal cord are anatomically a ________ structure
single, continuous
_____ to brainstem can cause death
small lesions
Cerebellar cortex is folded extensively so branching white matter resembles ______, thus called ______.
tree branches; arbor vitae ("tree of life")
internal cavities filled with a protective cerebrospinal fluid
ventricles
Colliculi are involved in ___________ functions
visual and auditory
2 additional hormones of hypothalamus
Antidiuretic hormone (ADH) and Oxytocin
________ travel through parts of the brainstem. Some synapse on brainstem nuclei, others destined for the cerebral cortex or the spinal cord
Cerebellar fibers
5 lobes of the cerebral cortex
Frontal lobes, parietal lobes, temporal lobes, occipital lobes, and insulas
endocrine organ; major part of epithalamus (located at posterosuperior portion of diencephalon)
Pineal gland
The hypothalamus is _______ than thalamus
smaller
3 groups of thalamic nuclei
specific relay nuclei, association nuclei, and nonspecific nuclei
posterior to crus cerebri; neurons work closely with basal nuclei to a control movement
substantia nigra
2 pairs of rounded projections that protrude from its posterior surface
superior and inferior colliculi
6 structures of midbrain
superior and inferior colliculi, descending tracts, substantia nigra, red nucleus, cranial nerve nuclei, and midbrain tegmentum
Folia separated by shallow sulci increase cerebellar ______.
surface
Colliculi form part of ________, of midbrain
tectum or "roof"
paired lobes on lateral surfaces of the hemisphere
temporal lobes
Information of association nuclei arrives indirectly from other ________ or directly from other parts of the ______.
thalamic nuclei; brain
Colliculi project to the _________.
thalamus
consists of 2 egg-shaped masses of gray matter (makes up 80% of diencephalon)
thalamus
4 components of the diencephalon
thalamus, epithalamus, hypothalamus, subthalamus
a soft, whitish-gray organ that resides in the cranial cavity and directly or indirectly controls most of the body's functions
the brain
nuclei of this control many basic homeostatic functions, including maintenance of heart rate and breathing rhythm
the brainstem