Chapter 14
The brain communicates with the rest of the body via ____ pairs of cranial nerves, in addition to the major input and output via the spinal cord.
12
The brain is only 2% of the adult weight, but it receives 15% of the blood and consumes ______% of the oxygen and glucose.
20
The cerebral cortex is a layer covering the surface of the hemispheres, constituting ___ of the mass of the brain and containing ________ _______ _______ ______ ____
40%; 14 to 16 billion neurons.
How much CSF is produced per day? And how much is in the brain at one time ?
500 mL; 100-160mL
temporal lobe
A region of the cerebral cortex responsible for hearing and language.
frontal lobe
A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement
occipital lobe
A region of the cerebral cortex that processes visual information
The midbrain contains the cerebral ________, continuations of the medial lemniscus and reticular formation, and motor nuclei for the oculomotor (CN III) and trochlear (CN IV) nerves that control _____ movements.
Aqueduct; eye
CSF is reabsorbed by _______________ granulations.
Arachnoid
The white matter exhibits a fernlike pattern called the ______ _____.
Arbor vitae
During development, ____________ induce formation of the tight junctions in these endothelial cells.
Astrocytes
They are often called what?
Basal Ganglia
CSF serves three purposes. What are these three purposes?
Buoyancy, Protection, Chemical protection
Three brain centers are classified as basal nuclei: what are they and what are they collectively called?
Caudate nucleus, putamen, and Globus pallidus; Corpus striatum
A small amount of CSF fills the ______ _______ of the spinal cord, but all of it escapes through three pores in the walls of the fourth ventricle: a median aperture and two lateral apertures.
Central Canal
What is the canal called that connects the third ventricle to the fourth ventricle?
Cerebral aqueduct
The __________ is about 83% of the brain's volume and consists of two cerebral hemispheres.
Cerebrum
The ________ _________ are another point of entry. Here, the brain is protected by the blood-CSF barrier formed by tight junctions between the ependymal cells.
Choroid plexus
In the cranial cavity, the _______ mater consists of two layers, the outer periosteal layer and the inner meningeal layer.
Dura
__________ cells modify this filtrate so that CSF has more sodium and chloride, but less potassium, calcium, and glucose and very little protein. CSF is circulated through the CNS by?
Ependymal; cilia
All nerve fibers connecting the brain to the spinal cord pass through the __________.
Medulla
The fourth ventricle narrows caudally to form the central canal that extends through the ________ __________ into the spinal cord.
Medulla oblongata
Cranial Nerve 1
Olfactory; smell
The epithalamus is a very small mass of tissue composed of the _________ gland, the habenula (which serves as a relay from the limbic system to midbrain), and a thin roof over the third ventricle.
Pineal
The _________ cells of the precentral gyrus are called upper motor neurons.
Precentral
Externally, the anterior surface has a pair of ridges called the __________.
Pyramids
Motor functions include what?
Senses of hearing, equilibrium, touch, pressure, temperature, taste, and pain
It consists of more than 100 small neural networks that include five functions. What are these functions?
Somatic motor control, Cardiovascular control, Pain modulation, sleep and consciousness, and Habituation
The arachnoid mater and pia mater are similar to those of the spinal cord. How would you describe both of these layers?
The Arachnoid mater is a transparent membrane over the brain surface, deep to the dura. ; The pia mater is a thin, very delicate membrane, not usually visible without a microscope
The lateral ventricles connect to the _______ ventricle, a median space inferior to the ______ _________, via the interventricular foramina.
Third; Corpus callosum
CSF secreted in the lateral ventricles flows through the interventricular foramina into the _______ ventricle and then down the cerebral aqueduct to the ________ ventricle.
Third; Fourth
What cranial nerves begin or end in the pons?
V(Trigeminal) ,VI(Abducens),VII(Facial),VIII(Vestibulocochlear)
Signals enter and leave the medulla not only via the spinal cord, but also through four pairs of cranial nerves that begin or end there: What are these nerves?
VIII(Vestibulocochlear nerve), IX(Glossopharyngeal), X(Vagus nerve), XII(Hypoglossal)
What is cerebrospinal fluid (CSF)? What does it fill?
a clear colorless liquid that fills the ventricles and canals of the CNS and bathes its external surface
The pituitary gland is attached to the hypothalamus by what?
a stalk (infundibulum)
Cerebellar lesions cause deficits in?
ability to plan, judgment and language input and output
In the third and fourth ventricles, circumventricular organs (CVOs) lack the barrier, and this allows what?
allows the blood direct access to brain neurons
What do the lateral ventricles form?
an arc in each cerebral hemisphere
The BBS is an obstacle to delivery of medications such as __________ and ______ drugs.
antibiotics; cancer
Adjacent to these are ___________ areas where the sensory input is interpreted.
association
The _________ is all of the brain except the cerebrum and cerebellum.
brainstem
Posteriorly, the pons consists of two pairs of thick stalks called __________ ___________ that connect the pons and midbrain.
cerebellar peduncles
The cerebellum is connected to the brain stem by three pairs of stalks, the __________ ____________.
cerebellar peduncles
The _________ occupies the posterior cranial fossa inferior to the cerebrum. It is the second-largest region of the brain, constituting 10% of its volume but containing over 50% of the brain's neurons.
cerebellum
"Higher" brain functions such as sleep, memory, cognition, emotion, sensation, motor control, and language are associated with the _______ _______, but not exclusively. They involve interactions between the ________ ______ and other regions such as the basal nuclei, brainstem, and cerebellum.
cerebral cortex; cerebral cortex
It provides feedback loops between the _________ cortex and the _________ nuclei (deep cerebral motor centers).
cerebral; basal
Sensory functions include what?
chewing, salivation, swallowing, gagging, vomiting, respiration, speech, coughing, sneezing, sweating, cardiovascular and gastrointestinal control and head, neck, and shoulder movements
What does the corpus callosum do?
connects left and right hemispheres of the brain
What is the tract that connects the two hemispheres together?
corpus callosum
Gray matter forms a surface layer called the _________ over the cerebrum and cerebellum.
cortex
The cerebellum has a surface ______ of gray matter and a deeper layer of white matter.
cortex
What are the three membranes of the meninges?
dura mater, arachnoid mater, pia mater
In some places the two layers of the _____ are separated by _______ sinuses.
dura; Dural
The _______ mater is pressed closely against the cranial bone, but is not attached except in limited places such as?
dura; around the foramen magnum, the sella turcica, the crista galli, and the sutures of the skull
Only the meningeal layer continues into the vertebral canal, where it forms the ______ sheath.
dural
The hypothalamus is the major control center of the ___________ and autonomic nervous systems and is concerned with a variety of visceral functions.
endocrine
Tight junctions are absent from ependymal cells elsewhere, allowing what?
exchange between brain tissue and CSF
What is the intermediate mass?
fibers that connect the right and left thalami
Certain prominent sulci divide each hemisphere into _____ distinct lobes.
five
The medulla begins at the ______ _________ and extends about 3 cm rostrally, ending at a groove between the medulla and pons.
foramen magnum
What are the five lobes and what are they involved in?
frontal lobe, parietal lobe, occipital lobe, temporal lobe, Insula
Neural integration is carried out in the cerebral _______ matter, found in the cerebral cortex, basal nuclei, and limbic system.
gray
What can the brain be divided into?
hemispheres
What are some of the things that the hypothalamus is involved in? Example - hormones, hunger.... Can you name a few more?
hormone secretion, thermoregulation, food, and water intake, sleep and circadian rhythms, memory, emotional behavior and sexual response
What does the blood-brain barrier (BBB) do and what does it consist of?
keeps unwanted things from leaving the blood; tight junctions and astrocytes
The cerebellum is the _______ part of the hind brain and consists of right and left cerebellar hemispheres connected by a wormlike bridge, the vermis.
largest
The cerebrum is the
largest and most conspicuous part of the human brain.
The basal nuclei are masses of cerebral gray matter buried in the white matter, _______ to the thalamus
lateral
What does the deep longitudinal fissure separate?
left and right hemispheres
The thalamus is involved in the memory and emotional functions of the ________ system.
limbic
In terms of gross anatomy, the cerebrum has two cerebral hemispheres separated by the ____________ fissure but connected by the _________ callosum.
longitudinal cerebral; Corpus
What is the reticular formation? What does it include?
loose web of gray matter that runs vertically through all levels of the brain stem; Cardiac center, Vasomotor center, and respiratory centers
A 10-second interruption in blood flow can cause what? An interruption of 1 to 2 minutes can do what?
loss of consciousness; can significantly affect neural function
What does an electroencephalogram (EEG) do and what can it be useful in?
measures the electrical activity of the brain; studying normal brain function and diagnosing degenerative brain diseases, and other abnormalities
The Thalamus plays a key role in what?
mediating sensation, motor activities, cortical arousal, learning, and memory; the gateway to the cerebral cortex
Its major components are what? The brainstem ends at the what?
midbrain, pons and medulla oblongata; foramen magnum
White matter has a bright pearly white color due to?
myelin
The thalamus is the "gateway to the cerebral cortex" - what does this mean?
nearly all input passes through the thalamus into the cerebral cortex
White matter in the brain is composed of _______, or bundles of axons.
nerve fibers
Deeper masses called __________ are surrounded by white matter.
nuclei
The hypothalamus forms part of the walls and floor of the third ventricle and extends anteriorly to the ________ chiasm and posteriorly to the mammillary bodies.
optic
parietal lobe
portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position and taste
Insula
regions of cortex located at the junction of the frontal and temporal lobes
What are gyri?
ridges of the brain
The medulla contains neural networks involved in many ______ and ______ ________.
sensory and motor functions
what is a sulci?
shallow grooves
What is the primary sensory cortex?
sites where sensory input is first received and one becomes conscious of the stimulus
The reticular formation in the pons contains additional nuclei concerned with what?
sleep, respiration, and posture
What is the choroid plexus?
spongy mass of blood capillaries on the floor of each ventricle
What does the brain barrier system do?
strictly regulates what can get from the bloodstream into the tissue fluid of the brain
These apertures lead into the _________________ space on the brain and spinal cord surface.
subarachnoid
What is cognition?
the range of mental processes by which we acquire and use knowledge
Much of the cerebrum, most of the cortex of the insula and of the parietal, occipital, and temporal lobes, is concerned with ___ ______
the senses.
The diencephalon, which encloses the third ventricle, has three major derivatives;
the thalamus, hypothalamus, and epithalamus
The cerebral white matter makes up most of the volume of the cerebrum and is composed of glia and myelinated nerve fibers organized into?
three kinds of tracts.
The general (somatosensory, somesthetic, or somatic) senses are distributed over the entire body and include what?
touch, pressure, stretch, movement, heat, cold, pain
Rostral
toward the nose
Caudal
toward the tail
The special senses are limited to the head: What are these senses?
vision, hearing, equilibrium, taste and smell
The BBS is highly permeable to what substances? It is slightly permeable to what?
water, glucose and lipid-soluble substances such as oxygen, carbon dioxide, alcohol, caffeine , nicotine, and anesthetics
