Lecture Exam Five (14.4 The Forebrain)

The forebrain consists of these two embryonic structures

Diencephalon and Telencephalon

These three structure arise from the embryonic diencephalon

(1) Thalamus

(2) Hypothalamus

(3) Epithalamus

The thalamus consists of at least ____ nuclei

23

This is the "gateway" to the cerebral cortex as nearly all input to the cerebrum passes by way of synapses in the nuclei of this structure

Thalamus

The thalamus also serves in motor control by relaying signals from the _________ to the ___________ and providing feedback loops between the cerebral cortex and basal nuclei

cerebellum, cerebrum

The thalamus is involved in the memory and emotional functions of the _________ system.

limbic

This structure forms the floor and part of the walls of the third ventricle

Hypothalamus

The hypothalamus extends anteriorly to the _______________ and posteriorly to the ____________________.

optic chiasm, mammillary bodies

The pituitary gland is attached to the hypothalamus by this stalk between the optic chiasm and mammillary bodies

Infundibulum

This is the major control center of the endocrine and autonomic nervous system

Hypothalamus

These are the seven main functions of the hypothalamus

(1) Hormone secretion

(2) Autonomic effects

(3) Thermoregulation

(4) Food and water intake

(5) Sleep and circadian rhythms

(6) Memory

(7) Emotional behavior and sexual response

The hypothalamus secretes hormones that control this structure (thereby regulating growth, metabolism, reproduction, and stress response)

Anterior pituitary gland

The hypothalamus secretes hormones that are stored within this structure (Usually concerned with labor contractions, lactation, and water conservation)

Posterior pituitary gland

The hypothalamic thermostat consists of a collection of neurons concentrated within this nucleus that monitors body temperature

Preoptic nucleus

This nucleus within the hypothalamus contains receptors for hormones that increase hunger and energy expenditure

Arcuate nucleus

These hypothalamic neurons monitor blood osmolarity and stimulate water seeking and drinking behavior when the body is dehydrated

Osmoreceptors

Dehydration stimulates the hypothalamus to secrete this hormone which conserves water by reducing urine output

Antidiuretic hormone

This nucleus within the hypothalamus controls our 24-hour rhythm of activity

Suprachiasmatic nucleus

This is the main function of the mammillary bodies

Relay signals from the hippocampus (Important memory center of the brain) to the thalamus

The epithalamus is a small mass mainly composed of these two structures

(1) Pineal gland

(2) Habenula

This structure serves as a relay from the limbic system to the midbrain

Habenula

This embryonic structure becomes the cerebrum

Telencephalon

These are the five anatomically and functionally distinct lobes of the cerebrum

(1) Frontal lobe

(2) Parietal lobe

(3) Occipital lobe

(4) Temporal lobe

(5) Insula

This is the seat of our conscious thought; explicit or declarative memory; cognitive and emotional processes; and in speech production and other voluntary control of nearly all the bodies skeletal muscle

Frontal lobe

The frontal lobe extends caudally until it reached this landmark

Central sulcus

This lobe of the cerebrum is concerned with taste, somatic sensations; multisensory integration; spatial perception and awareness of body orientation; language processing; and numerical awareness

Parietal lobe

This is the principle visual center of the brain

Occipital lobe

This lobe of the cerebrum is concerned with hearing; smell; emotion; learning; language comprehension; memory consolidation; and storage of memories

Temporal lobe

This landmark separates the temporal lobe from the frontal and parietal lobes

Lateral sulcus

This area if the brain plays a role in taste; pain; visceral sensation; consciousness; emotional responses and empathy; and cardiovascular homeostasis

Insula

This is a small mass of cortex deep to the lateral sulcus

Insula

Gray matter can be found in these three places within the cerebrum

(1) Cerebral cortex

(2) Basal nuclei

(3) Limbic system

The cerebral cortex possesses these two principle types of neurons

(1) Stellate cells

(2) Pyramidal cells

The cells within the cerebral cortex have spheroidal cell bodies with short axons and dendrites projecting in all directions

Stellate cells

These cells of the cerebral cortex receive sensory input and process information on a local level

Stellate cells

These are the only cerebral neurons whose fibers leave the cortex and connect with other parts of the central nervous system

Pyramidal cells

These are the three bundles/tracts myelinated nerve fibers of cerebral white matter form

(1) Projection tracts

(2) Commissural tracts

(3) Association tracts

These tracts within cerebral white matter extend vertically between higher and lower brain and spinal cord centers

Projection tracts

These tracts within the cerebral white matter cross from one cerebral hemisphere to the other

Commissural tracts

The great majority of commissural tracts pass through this structure within the brain

Corpus callosum

This is the main function of commissural tracts

Allow the two sides of the brain to communicate with each other

These tracts within the cerebral white matter connect different regions within the same cerebral hemisphere

Association tracts

These fibers in the cerebral white matter connect different lobes of a hemisphere to each other

Long association fibers

These fibers in the cerebral white matter connect gyri within a single lobe to each other

Short association fibers

This is a ring of structure located on the medial side of each hemisphere and is important for emotion and learning

Limbic system

These are the most prominent components of the limbic system

(1) Cingulate gyrus

(2) Hippocampus

(3) Amygdala

True or False : Most limbic system structures have centers for both reward and aversion

True

These are masses of cerebral gray matter that are buried deep in the white matter

Basal nuclei

These are the three basal nuclei

(1) Caudate nucleus

(2) Putamen

(3) Globus pallidus

This term refers to the three basal nuclei due to their striped appearance

Corpus striatum

These two basal nuclei are collectively referred to as lentiform nucleus because of their lens shape

Putamen and Globus pallidus