The cns is protected by...
a bony encasement and connective tissue called meninges
What surrounds the CNS?
Cerebrospinal fluid (CSF)
The gray matter is made up of...
neuron cell bodies
white matter is made up of...
myelinated axons
The cortex of the brain is made up of gray or white matter?
gray
Neurotransmitters are also known as...
neuropeptides
What are the four major regions of the brain?
-cerebrum
-diencephalon
-brain stem
-cerebellum
Requirements of the CNS.
Communication, metabolism
CNS accounts for what percent of body weight?
2
The CNS needs about what percent of cardiac output? What does this imply?
20%; large metabolic demand
True or False: the CNS is sensitive to toxins.
true
The cerebrum accounts for what percent of brain mass?
80%
List the functions of the cerebrum. (5)
• Perception of sensations
• Initiate movement
• Memory
• Thought & reason
• Emotion
What divides the frontal and parietal lobes of the cerebrum?
central sulcus
How are the cerebral hemispheres connected?
corpus callosum
What seperated the two cerebral hemispheres?
longitudinal cerebral fissure
What are the convulutions of the cerebrum called? (2)
gyri-folds
sulci-grooves
The medulla is composed of ____ matter
white
What is the purpose of the convulutions of the cerebrum?
increase surface area
The cranial meninges, listed from deepest (closest to the brain) to superficial (farthest from the brain and closest to the skull), are the...
pia mater, arachnoid mater, and dura mater
pia mater is made up of...
areoloar c.t, highly vascularized
What are the 5 lobes of the cerebrum?
Frontal
Parietal
Temporal
Occipital
Insula
Function of frontal lobe:
initiates voluntary movement
Parietal;
responds to sensory stimuli
Temporal;
auditory sensations
Occiptal;
visual sensations.
Insula;
not on surface; memory function
The ________ gyrus is located behind the central sulcus and is responsible for...
postcentral, somatosensory processing
The __________ gyrus is located in front or anteriorly to the central sulcus is responsible for...
precentral, controlling voluntary movements on the opposite of the body
List features of the white matter of cerebrum: (3)
-association fibers
-commissural fibers
-projection fibers
Where are association fibers located?
within a cerebral hemisphere
Where are commissural fibers located?
b/w cerebral hemispheres
Describe projection fibers.
ascending and descending tracts
What transmit impulses from cerebrum
to spinal cord and
from spinal cord to cerebrum?
projection tracts
Basal nuclei is found where?
deep cerebrum
Describe basal nuclei...
mass of gray matter deep to cerebrum
control involuntary movement of skeletal muscle
The thalamus is part of what brain structure?
diencephalon
Describe the thalamus
relay center (sensory stimuli) between cerebrum and other brain areas
Language processing is normally located where on the cerebrum?
Left hemisphere
What is the motor speech area also known as?
Broca's area
The function of the motor speech area is to...
translate thought patterns into speech
The motor speech area or broca's area is located where?
What is the wernicke's area responsible for? Where is located?
concept of words
What is the angular gyrus responsible for? Where is it located
center for integration of auditory, visual, and somatesthetic information
Describe the thalamus.(3)
-paired organ
-gray matter
-sensory relay to cerebym
-autonomic response to intense pain
Describe the hypothalamus and pituitary gland common functions (3)
Regulation of visceral activity
Emotional and instinctual functions
Secretes hormones
Describe the functions of the epithalamus.
Neuroendocrine function (via pineal gland)
List the four components of the diencephalon.
thalamus
hypothalamus
epithalmus
pituitary
The corpora quadrigemina is made up of the...
superior and inferior colliculi
The hypothalamus functions as the ____________ center.
homeostatic
True or false: the pituitary is directed by hypothalamus.
true
The pineal body produces what common hormone?
melatonin
The pituitary gland is attached at a structure called the...
infundibulum
What skull structure holds the pituitary gland?
sella turcica
What are the two parts the pituitary gland can be divided into?
adenohypophysis (anterior, gray)
neurohypophysis (posterior, white)
The mesencephalon or midbrain houses nuclei for
autonomic functions
Function of superior colliculi
They are called visual reflex centers because they help visually track moving objects and control reflexes such as turning the eyes and head in response to a visual stimulus.
Function of inferior colliculi
auditory reflex center
ex: BANG!=you turning at noise
What is the function of red nucleus?
-motor coordination
-maintain posture
What is the function of the substantia nigra?
inhibit forced involuntary movements.
What are the three main structures found in the midbrain? (3)
-corpora quadrigemina
-red nucleus
-substantia nigra
List main components of brain stem: (3)
-midbrain
-pons
-medulla oblongata
The metencephalon consists of what two structures?
pons and cerebellum
Describe pons:
-bulge on inferior surface of brain
-two sets of white matter tracts
-nuclei of cranial nerves
-respiratory centers
-peduncles carry fibers to cerebellum
What is the second largest structure in the brain after the cerebrum?
cerebellum
The cerebellum consists of ___ hemispheres
two
The cerebellum has a thin outer cerebellar _____.
cortex
What structure connects the cerebellum to the rest of the brain?
cerebellar peduncles
Function of cerebellum
coordinates skeletal muscle contraction (movement)
the cerebellum is or is not part of brainstem?
IS NOT
Define decussation
Decussation refers to a crossing within the central nervous systen
Describe the medulla oblangata nuclei and tracts:
form all descending and ascending
connections between spinal cord and brain
True or False: The medulla oblongata has many descussations.
true
The medulla oblongata relays to the _________ (nucleus gracilis and cuneatus)
thalamus
The medulla oblongata has __________ centers for visceral functions
autonomic
The medulla oblongata has some triangular elevations called...
pyramids
Describe the limbic system (4)
• The limbic system is composed of multiple cerebral and diencephalic structures.
• It processes and experiences emotions.
• It is involved in motivation, emotion, and memory with an emotional association.
• It affects memory formation by integrating past memories of physical sensations with emotional states.
What is a fornix?
Fornix-group of communicating fibers
Limbic system:
What is reticular formation? *3*
-The reticular formation is a network of neurons that spans across the brainstem. It is involved in many functions such as consciousness, sensory and motor function, emotion processing,
cardiovascular control, and more.
-Function in arousing the
cerebrum
-Generate a continuous
flow of impulses
Were is reticular formation found?
spinal cord,
pons,
midbrain,
thalamus
Reticular formation is involved in the response to...
environment
The subarachnoid space is filled with what?
cerebral spinal fluid (CSF)
The pia mater is highly...
vascular
The dura mater is in contact with...
bone (periosteal layer).
Dura
mater in brain has two layers (dural sinus) and is ___ found on the
meninges of the spinal cord
not
Spinal
Cord Meninges:
Epidural
space (no connection between dura and vertebrae)Denticulate
ligaments
What are the ventricles of the brain?
lateral ventricle (left and right)
third ventricle
fourth ventricle
central canal
Where is the lateral ventricle found?
cerebrum
Where is the third ventricle found?
diencephalon
Where is the fourth ventricle found?
Between
pons and cerebellum
Where is the central canal found?
spinal cord
What is the mesencephalic aqueduct also known as?
cerebral aqueduct
How does CSF exit?
nfourth ventricle through three foramina:
nMedian aperature
nTwo lateral aperatures
How is CSF produced?
nproduced by filtration of blood plasma
through specialized capillaries – choroid plexus
________ cells aid in CSF movement
ependymal
How does CSF return to circulation?
nreturns to circulation through arachnoid villi (specialized
venous capillaries)
The subdivision of the brain that does not initiate somatic motor movements, but instead coordinates and fine-tunes those movements is which of
the following?
a. medulla oblongata
b. cerebrum
c. cerebellum
d. diencephalon
c. cerebellum
3. The visual reflex center is housed within which structure?
a. cerebellum
b. superior colliculus
c. hypothalamus
d. pons
b. superior colliculus
After a severe blow to the head, a patient suddenly does not experience sensations of hunger and seems unable to tell if he is dehydrated. The
attending physician should suspect damage to or a lesion within what general region of the brain?
a. frontal lobe
b. medulla oblongata
c. Wernicke area
d. hypothalamus
d. hypothalamus
Which of the following statements is true about the blood-brain barrier?
a. It prevents all toxic substances from reaching brain tissue.
b. It is formed from the perivascular feet of microglia and ependymal cells.
c. It is deficient in the regions of the choroid plexus, hypothalamus, and pineal gland.
d. It produces and circulates cerebrospinal fluid.
c. It is deficient in the regions of the choroid plexus, hypothalamus, and pineal gland.
Which structures are descending motor tracts on the anterolateral surface of the midbrain?
a. olives
b. inferior colliculi
c. cerebral peduncles
d. tegmenta
c. cerebral peduncles
.Which cerebral lobe is located immediately posterior to the central sulcus and superior to the lateral sulcus?
a. frontal lobe
b. temporal lobe
c. parietal lobe
d. insula
c. parietal lobe
Which specific area of the brain may be impaired if you cannot tell the difference between a smooth and a rough surface, using your hands only?
a. precentral gyrus
b. postcentral gyrus
c. motor speech area
d. prefrontal cortex
a. precentral gyrus
. Which structures are the isolated, innermost gray matter areas near the base of the cerebrum, inferior to the lateral ventricles?
a. auditory association areas
b. cerebral nuclei
c. substantia nigra
d. corous callosum fibers
b. cerebral nuclei
). Which type of white matter tracts connect corresponding lobes of the left and right cerebral hemispheres?
a. commisural tracts
b. longitudinal fasciculi
c. projection tracts
d. arcuate fibers
a. commisural tracts