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