MEDEX A&P - Ch 14 - Brain & Cranial Nerves
What would a person do if they had damage to the speech center?
They would be able to make sounds but not words.
How do the lateral ventricles communicate with the third ventricle?
Through an interventricular foramen
How does cerebrospinal fluid get into the subarachnoid space?
Through two lateral apertures and a media aperature
What is the primary function of the *Thalamic Nuclei*?
To relay information to the basal nuclei and cerebral cortex
What dural sinus lies within the tentorium cerebelli?
Transverse sinus
The interior of the cerebrum is composed of mostly what?
White matter.
Hypothalamic Reticular stimulation can cause what emotions?
rage, fear, pain, sexual arousal and pleasure. Heightened alertness and generalized excitement, lethargy and sleep.
*Nutshell: Pons
• *Links* cerebellum with: midbrain, diencephalon, cerebrum, spinal cord. • 3 *white matter tracts* (Descending, Ascending, Transverse) • Control of respiration - adjust medulla oblongata • Automatic processing of incoming sensations, outgoing motor commands • Relay sensory info. and issue somatic motor commands. Cranial nerve 5-8 • Relay sensory and motor info. to cerebellum.
What protects the brain?
• *Physical protection*: - Bones of the cranium - Cranial Meninges - Cerebrospinal Fluid • *Biochemical* isolation - Blood-brain Barrier
Function: *Medula Oblongata*
• Connects the brain to the spinal cord. • Relays sensory information to thalamus and to other portions of the brain stem • Autonomic centers for regulation of visceral function (cardiovascular, respiratory and digestive system activities)
Function: *Cerebellum*
• Coordinates complex somatic motor patterns • Adjust output of other somatic motor centers in the brain and spinal cord
Function: *Pons*
• Latin "bridge" connects cerebellum to the brain stem • Relays sensory information to cerebellum and thalamus • Subconscious somatic and visceral motor control centers
Medulla Oblongata characteristics
• Most inferior of brain regions • All communication between the brain and spinal cord involves tracts that ascend or descend through the MO. • The center for coordination of complex autonomic reflexes and control of visceral functions.
What are possible CSF pathologies?
• Problem with reabsorption in infancy causes *hydrocephalus* or "water on the brain" Leads to enlarged skulls • In adults failure of resorption or blockages of CSF circulation can distort and damage the brain
Function: *Midbrain*
• Processing of visual and auditory data • Generation of reflexive somatic motor responses • Maintenance of consciousness
Primary brain vesicles
• Prosencephalon (forebrain) -->>Cerebrum ->> Lateral ventricles -->>Diencephalon ->>Third ventricles • Mesencephalon (midbrain) -->> Midbrain ->> Cerebral aqueduct -->>Cerebellum and Pons -->> Fourth ventricle • Rhombencephalon (hindbrain) -->> Medulla Oblongata -->>Fourth ventricle
*Nutshell*: Medulla Oblongata
• Relays information from midbrain and other to cerebellum. • Regulate HR and force of contraction • Sets basic respiratory pace • Relays somatic information to thalamus • Relays info. from spinal cord to higher centers via cranial nerves 8-12. • Contains nuclei and centers that regulate vital autonomic functions and extends into the pons and midbrain. • Link the brain with the spinal cord.
Explain CSF transport mechanisms
• Transports nutrients, chemical messengers and waste products • Ependymal lining is freely permeable • CSF in constant chemical communication with interstitial fluid that surrounds the neurons and neuroglia of the CNS • Because of the free exchange between the interstitial fluid and CSF changes in composition of CSF occurs.
What is the anatomical difference between the medulla oblongata and spinal cord?
• White matter - Ascending and descending tracts within columns link brain with spinal cord. •
What are the three different classifications of axons/fibers found in the white matter of the cerebrum? Describe each briefly
*Association fibers* - Interconnects areas of cerebral cortex within a single cerebral hemisphere *Commissural fibers* - Interconnects and permits comunication between the cerebral hemispheres *Projection fibers* - Links the cerebral cortex to the diencephalon, brain stem, cerebellum, and spinal cord
Midbrain function: White Matter
*Cerebral Peduncles* - Connects primary motor cortex with motor neurons in brain and spinal cord; carries ascending sensory information to thalamus.
Limbic System Components
*Diencephalic components* -Thalamus -Hypothalamus *Cerebral Components* -Limbic lobe cortical areas Cingulate gyrus -Parahippocampal gyrus -Dentate gyrus -Tracts -Nuclei ----Amygdaloid body ----Hippocampus *Other Components* --Reticular formation
Cranial Nerve mnemonic
*O*h, *O*nce *O*ne *T*akes *T*he *A*natomy *F*inal, *V*ery *G*ood *V*acations *A*re *H*eavenly!" *O*h *O*nce *O*ne *T*akes *T*he *A*natomy *F*inal, *V*ery *G*ood *V*acations *A*re *H*eavenly!"
The *Rhombencephalon* develops into what regions and what ventricles at birth
*Region*: Medulla Oblongata *Ventricle*: Fourth ventricle
The *Prosencephalon* develops into what regions and what ventricles at birth
*Regions*: Cerebrum, Diencephalon *Ventricles*: Lateral Ventricle, Third ventricle
The *Mesencephalon* develops into what regions and what ventricles at birth
*Regions*: Midbrain, Cerebellum and Pons *Ventricles*: Cerebral aqueduct, Fourth ventricle
What are the functions of the *Glossopharyngeal Nerve (IX)*?
*Sensory: Mixed (sensory and motor) to head and neck* *Posterior 1/3 of tongue*, part of the pharynx and palate, carotid arteries of the neck Somatic motor: Pharyngeal muscles *involved with swallowing*
What are the functions of the *Vestibulocochlear Nerve (VIII)*?
*Special sensory*: Balance and equilibrium and hearing
Midbrain function: Gray Matter
*Tectum (roof)* --*Superior Colliculus* - Integrates visual information with other sensory input, initiates reflex to visual stimuli --*Inferior Colliculus* - Relay auditory information to medial geniculate nuclei, Initiates reflex responses to auditory stimuli *Walls and Floor* --*Substantia Nigra* - Regulates activity in basal nuclei - *Red Nucleus* - Sub conscious control of upper limb position and background muscle tone - *Reticular formation* - Automatic processing of incoming sensations and outgoing motor commands; can initiate involuntary motor responses to still; helps maintain consciousness
Steps to CSF (condensed)
1) CSF produced in choroid plexus 2) CSF circulates through ventricles, materials diffuse 3) CSF reaches sub-arachnoid space, fourth ventricle 4) CSF flows around brain, spinal cord and caudal equine 5) CSF absorbed into blood
Steps to formation and circulation of CSF
1) Choroid plexus produces and maintains CSF by ependymal cells. 2) CSF circulates through the ventricles and fills the central canal of the spinal cord 3) CSF reaches sub arachnoid space through two lateral apertures and a single median aperture in the roof of the fourth ventricle 4) CSF flows through subarachnoid space in the brain, spinal cord and caudal equine 5) Extensions of the arachnoid membrane (arachnoid villi) penetrate meningeal layer of the dura mater and extend into the superior sagittal sinus.
Functions of the Limbic System
1) Establishing emotional states 2) Linking the conscious, intellectual functions of the cerebral cortex with the unconscious and autonomic functions of the brain stem. 3) Facilitating memory storage and retrieval.
Functions of Hypothalamus
1) Subconscious control of skeletal muscle contractions 2) Control of autonomic function 3) Coordination of activities of the nervous and endocrine systems 4) Secretion of the hormones Antidiuretic hormone (ADH) and Oxytocin (OXT) 5) Production of emotions and behavioral drives 6) Coordination between voluntary and autonomic functions 7) Regulation of body temperature 8) Control of the circadian rhythms.
Functions of CSF
1) Supporting the brain 2) Cushioning the brain and spinal cord against physical trauma 3) Transporting nutrients, chemical messengers and wastes
Cerebellum - Primary Functions
1. Adjusting the postural muscles of the body. - coordinates rapid automatic adjustments to maintain balance through - alterations in muscle tone and position by modifying activities of motor centers in the brain stem. 2. Programming and fine-tuning movements controlled at the conscious and subconscious levels - Refines learned movement patterns like riding a bicycle. - Performs function indirectly by regulating activity along motor pathways in the brain stem. - Compares motor commands with proprioceptive (position sense) information from spinal cord and makes adjustments to make movement smooth.
Where is CSF produced?
A *Choroid Plexus* is an area within each ventricle that produces CSF
Choroid plexus
A combination of specialized ependymal cells and permeable capillaries *involved in the production of cerebronspinal fluid*
Ataxia
A disturbance in muscular coordination
Neural cortex
A layer of gray matter covering the brain
Cerebral cortex
A layer of gray matter covering the surfaces of the cerebral hemispheres
Reticular formation
A loosely organized mass of gray matter that contains embedded nuclei
Electroencephalogram (EEG)
A printed report of the electrical activity of the brain. The electrical patterns observed are called "brain waves".
What connects the third and fourth ventricle?
A slender canal in the midbrain called the CEREBRAL AQUEDUCT
Reticular activating system (RAS)
A specialized component of the reticular formation
Seizure
A temporary cerebral disorder accompanied by abnormal movements, unusual sensations, inappropriate behavior, or some combination of these symptoms. Nature of the signs and symptoms depend on the region of the cortex involved.
Fornix
A tract of white matter that connects the hippocampus to the hypothalamus.
How does the Basal Nuclei relate to Parkinson's disease?
Activity of the basal nuclei is inhibited by neurons in the substantial nigra of the midbrain which releases the neurotransmitter *dopamine*. If the substantial nigra is damaged or the neurons secrete less dopamine, the basal nuclei become more active. The result is a gradual generalized increase in muscle tone.
What are the two primary functions of the cerebellum?
Adjusting the postural muscles of the body Programming and fine-tuning movements controlled at the conscious and subconscious levels
Which cortex and lobe performs: *Integration and processing of sensory data; processing and initiation of motor activities*?
All lobes, and all association areas.
What are the 5 major groups of thalamic nuclei?
Anterior group Medial group Ventral group Posterior group Lateral group
Integrative centers
Areas that receive information from many association areas and direct extremely complex motor activities. Located in the lobes and cortical areas of both cerebral hemispheres.
Where is the blood-CSF barrier?
Around the capillaries of the choroid plexus
Pons Main Components: *Tracts*
Ascending, depending and transverse tracts. • Longitudinal tracts interconnects with other portions of the CNS • The middle cerebellar peduncles are connected to the *transverse fibers* which cross the anterior surface of the pons. • These fibers are axons that link nuclei of the pons with the cerebellar hemisphere of the opposite side.
What are cranial reflexes?
Automatic responses to stimuli that involve the sensory and motor fibers of cranial nerves. They include both monosynaptic and polysynaptic reflex arcs.
What are the three groups of nuclei in the medulla oblongata/What are the functions of the medulla oblongata?
Autonomic nuclei controlling visceral activities Sensory and motor nuclei of cranial nerves Relay stations along sensory and motor pathways
What is the difference between CSF and Plasma?
Blood plasma contains high concentrations of soluble proteins but CSF does not. Concentrations of individual ions and levels of amino acids, lipids and waste products are also different.
Some of the neurons in the General interpretive area innervates the speech center also called ____ ____.
Broca's area
Blood-Brain Barrier (BBB)
Capillary endothelial cells sthat are extensively interconnected by tight junction **so only lipid-soluble compounds can diffuse across the membranes of endothelial cells into the interstitial fluid of the brain and spinal cord
What are the three reflex centers and what do they control?
Cardiac centers - Regulate heart rate and force of contraction Vasomotor centers - Regulate distribution of blood flow Respiratory rhythmicity centers - Set the pace of respiratory movements
Cerebrovascular diseases
Cardiovascular disorders that interfere with the normal blood supply to the brain
Function: *Hypothalamus*
Centers controlling emotions, autonomic functions and hormone production
What are the ventricles filled with?
Cerebrospinal fluid (CSF)
What are the six parts of the brain?
Cerebrum Diencephalon Midbrain Pons Medulla oblongata Cerebellum
Longitudinal fasciculi
Connects the frontal lobe to the other lobes of the same hemisphere
Cerebral peduncles
Connects the primary motor cortex with motor neurons in the brain and spinal cord; carries ascending sensory information to thalamus
Generally, what are some functions of the cerebrum?
Conscious thoughts & all intelectual functions and it is also involved in the processing of somatic sensory & motor information
Components of Diencephalon
Consists of: • Epithalamus • Thalamus • Hypothalmus
Middle cerebellar peduncles
Contains transverse fibers and carries communications between the cerebellum and pons
What is the function of the prefrontal cortex of the frontal lobe?
Coordinates information of relayed from the association areas of the entire cortex. Performs abstract intellectual functions as predicting the consequences of events or actions.
What are the two pairs of sensory nuclei in the midbrain?
Corpora quadrigemina
What are three functions of cerebrospinal fluid?
Cushions delicate neural structures Supports the brain Transports nutrients, chemical messengers, and waste products
Fissures
Deep grooves
What does the metencephalon derive from and later becomes?
Derived from the rhombencephalon that is adjacent to the mesencephalon Dorsal portion forms into the cerebellum and ventral portion forms into the pons
What does the myelencephalon derive from and later becomes?
Derived from the rhombencephalon that is closer to the spinal cord Forms into the medulla oblongata
Where is the falx cerebelli and what is its purpose?
Divides the two cerebellar hemispheres **along the midsagittal line inferior to the tentorium cerebelli**
What makes up the cranial meninges?
Dura mater Arachnoid mater Pia mater
Beta waves (higher frequency)
During attention to stimuli or tasks; Intensive concentration replace alpha waves. They also appear when concentrating on a task, under stress or in a state of psychological tension.
What are three important points about the cerebral lobes?
Each cerebral hemisphere receives sensory information from, and sends motor commands to, the opposite side of the body The two hemispheres have different functions, even though they look almost identical The correspondence between a specific function and a specific region of the cerebral cortex is imprecise
What is *Hemispheric Lateralization*?
Each of the two hemispheres are responsible for specific functions that are not ordinarily performed by the opposite hemisphere.
What is the *"Pacemaker"* mechanism?
Electrical activity in the two hemispheres is generally synchronized by a "pacemaker" mechanism that appears to involve the thalamus. Asynchrony between the two hemispheres can indicate localized damage or other cerebral abnormalities.
Gyri
Elevated ridges
What are the three functions of the limbic system?
Establishes emotional states Links the conscious, intellectual functions of the cerebral cortex with the unconscious and autonomic functions of the brain stem Facilitates the memory storage and retrieval
How does the tentorium cerebelli extend across the cranium?
Extends across the cranium at right angles to the falx cerebri
What are the three largest dural folds?
Falx cerebri Tentorium cerebelli Falx cerebelli
How do the basal nuclei carry out their functions?
Feedback loop in the cerebral cortex.
Prefrontal cortex functions and lobotomy.
Feelings of frustration, tension, anxiety, interpreting ongoing events and predictive ability. Severing the connections between the prefrontal cortex and other brain regions remove these emotions. Prefrontal lobotomy was used in the mid 20th century as a "cure" for violent or antisocial behavior.
Arachnoid villi
Fingerlike extensions of the arachnoid membrane that penetrate the meningeal layer of the dura mater and extend into the superior sagittal sinus
Folia
Folds of the cerebellum surface
Midbrain function example
For example, your immediate, reflexive responses to a loud, unexpected noise (eye movements and head turning) are directed by nuclei in the mid- brain. This region also contains centers that help maintain consciousness.
Which cortex and lobe performs: *Voluntary Control of Skeletal Muscles*?
Frontal Lobe: Primary motor cortex
What lobe is the primary motor cortex located?
Frontal lobe Neurons of the primary motor cortex direct voluntary movements by controlling somatic motor neurons in the brain stem and spinal cord. *(pyramidal cells)*
List the cranial nerves in order from I-XII
I - Olfactory nerve II - Optic nerve III - Oculomotor nerve IV - Trochlear nerve IV V - Trigeminal nerve V VI - Abducens nerve VI VII - Facial nerve VIII - Vestibulocochlear nerve IX - Glossopharyngeal nerve X - Vagus nerve XI - Accessory nerve XII - Hypoglossal nerve
What does the *Hippocampus* do?
Important in learning, especially in storage and retrieval of new long-term memories.
Where is the fourth ventricle found?
In between the pons & cerebellum and then extends into the medulla oblongata
The blood-brain barrier remains intact throughout the CNS except in what four exceptions?
In portions of the hypothalamus Capillaries in the posterior lobe of the pituitary gland Capillaries in the pineal gland Capillaries at the choroid plexus
Where is the gustatory cortex located?
In the anterior portion of the insula and adjacent portions of the frontal lobe
Where is the headquarters of the Reticular Activating System (RAS) located?
In the midbrain
Where is the pineal gland?
In the posterior portion of the epithalamus
Limbic system
Includes nuclei and tracts along the border between the cerebrum and diencephalon
What is the name of the narrow stalk that connects the hypothalamus to the pituitary gland?
Infundibulum
Superior colliculus
Initiates reflex response to visual stimuli; Integrates visual information with other sensory inputs
Inferior colliculus
Initiates reflex responses to auditory stimuli; Relays auditory information to medial geniculate nuclei
What is the function of the *Lateral group nuclei*?
Integrates sensory information and influences emotional states
What is the function of the *Posterior Group - Pulvinar*?
Integrates sensory information for projection to associate areas of cerebral cortex
What is the function of the nuclei in the *Medial group*?
Integrates sensory information for projection to the frontal lobes Provides awareness of emotional states by connecting emotional centers in the hypothalamus with frontal lobes.
What does the *Diencephalon* do?
Integrates sensory information with motor output at the subconscious level Consists of: • Epithalamus • Thalamus • Hypothalamus
What occurs in the *prefrontal cortex*?
Integration of information from sensory association areas and performs abstract intellectual function such as predicting the consequences of possible responses.
Transverse fibers
Interconnects pontine nuclei with the cerebellar hemisphere on the opposite side
Function of the hypothalamus
Involved with emotions, autonomic function, and hormone production
What is the function of the basal nuclei?
Involved with the subconscious control of skeletal muscle tone and the coordination of learned movement patterns, Example: coordination of arm and thigh movements.
What happens when there is damage to the Wernicke's area?
It affects the ability to interpret what is seen or heard, even though the words are understood as individual entities
What does the *Thalamus* do?
It is located on each side of the diencephalon and is the final relay point for sensory information ascending to the primary sensory cortex. It acts as a filter passing only a small portion of the arriving sensory information. It also coordinates activities of the basal nuclei and cerebral cortex by relaying information between them.
What does the Limbic System do?
Known as the *Motivational System* It is a group of tracts and nuclei that function in emotion, motivation and memory. **The sensory and motor cortex and association areas of the cerebral cortex enable you to perform complex tasks but **the limbic system makes you WANT to do them**
Dural sinuses
Large collecting veins located within the dural folds
Inferior cerebellar peduncles
Links the cerebellum with the medulla oblongata and spinal cord
Superior cerebellar peduncles
Links the cerebellum with the nuclei in the midbrain, diencephalon, and cerebrum
What separates the two cerebral hemispheres?
Longitudinal fissure
Basal nuclei
Masses of gray matter that are embedded in the white matter of the cerebrum
What does the mesencephalon form into?
Midbrain
What 3 parts make up the brain stem?
Midbrain Pons Medulla oblongata
What are the functions of the *Trigeminal Nerve (V)*?
Mixed - Sensory and Motor Has three branches opthalamic, maxillary, and mandibular. All three are connected to sensory nuclei. *Innervates muscles of mastication (mandibular branch)
What are the functions of the *Vagus Nerve (X)*?
Mixed: Sensory and Motor Sensory: Part of the pharynx, auricle and external acoustic meatus, diaphragm, and visceral organs in thoracic and abdominopelvic cavities Visceral motor: Muscles of the palate, pharynx, digestive, respiratory, and cardiovascular systms in the thoracic and abdominal cavities
What are the functions of the *Facial Nerve (VII)*?
Mixed: Sensory and Motor Sensory: Taste receptors on anterior 2/3 of tongue Somatic motor: Muscles of facial expression Visceral motor: Lacrimal (tear) gland & nasal mucous glands and submandibular and sublingual salivary glands
What are the functions of the *Accessory Nerve (XI)*?
Motor Motor to muscles of the neck and upper back Internal branch innervates voluntary muscles of palate, pharynx, and larynx External branch controls sternocleidomastoid and trapezius muscles
What are the functions of the *Hypoglossal Nerve (XII)?
Motor Tongue movements
What are the functions of the *Trochlear Nerve (IV)*?
Motor - Eye movements/Innervates the superior oblique muscle of each eye
What are the functions of the *Abducens Nerve *VI)*?
Motor - Eye movements; Innervates the lateral rectus muscle of each eye
What are the functions of the *Oculomotor Nerve (III)*?
Motor - Eye movements; intrinsic eye movements (Diameter of the pupil); innervates four of the six extrinsic muscles of the eye
Pons Main Components: *Cerebellum Relay*
Nuclei and tracts that process and relay information sent to *or* from the Cerebellum • The pons links the cerebellum with the: - brain stem - cerebrum - spinal cord
Pons Main Components: *Respiration*
Nuclei involved with control of respiration • Each side of the pons contains 2 respiratory centers: - *Apneustic center and Pneumotaxic center* • These centers modify the activity of respiratory rhythmicity center in the medulla oblongata
What two nuclei pass somatic sensory information to the thalamus?
Nucleus gracilis and nucleus cuneatus
Theta waves
Observed in children and in intently frustrated adults.
Which cortex and lobe performs: *Conscious perception of visual stimuli*?
Occipital Lobe: Visual cortex
What lobe is the visual cortex located?
Occipital lobe
Alpha waves
Occur in healthy awake adults who are resting with their eyes closed. Alpha waves disappear during sleep but they also vanish when the individual begins to concentrate on some specific task.
*Delta waves* (very large amplitude, low frequency)
Occurs in deep sleep of all ages. and in certain pathological conditions
Where is the *Pineal gland* in the Diencephalon and what does it do?
On the posterior portion of the Epithalamus. • It is an endocrine structure that secretes the hormone melatonin.
Which cortex and lobe performs: *Conscious perception of touch, pressure, pain, vibration, taste and temperature*?
Parietal Lobe: Primary sensory cortex
What lobe is the primary sensory cortex located?
Parietal lobe
What is the function of the nuclei in the *Anterior group*?
Part of the limbic system
Dural folds
Parts of the dura mater that extends into the cranial cavity which provides additional stabilization and support to the brain
What does the *Amygdaloid body* do?
Plays a role in regulating heart rate in responding to "fight or flight" response by sympathetic division of the ANS and in linking emotions with specific memories.
General interpretive area / *Wernicke's area*
Present in only one hemisphere, typically the left. Receives information from all the sensory association areas. It plays an essential role in your personality by integrating sensory information and coordinating access to complex visual and auditory memories.
What is the function of the *Posterior Group - Medial geniculate nuclei*?
Projects auditory information to the auditory cortex Relays auditory information received from the internal ear.
Where does the falx cerebri project into?
Projects between the cerebral hemispheres in the longitudinal fissure
What is the function of the nuclei in the *Ventral group*?
Projects sensory information to the primary sensory cortex; relays information from cerebellum and basal nuclei to somatic motor area of cerebral cortex Also relays sensory information about touch, pressure, pain, temperature and proprioception (position) to sensory areas of the cerebral cortex.
What is the function of the *Posterior Group - Lateral geniculate nuclei*?
Projects visual information to the visual cortex Receives visual information over the optic tract which originates at the eyes.
What are the three primary brain vesicles?
Prosencephalon AKA forebrain Mesencephalon AKA midbrain Rhombencephalon AKA hindbrain
What is the function of the tentorium cerebelli?
Protects the cerebellar hemispheres and separates them from the cerebrum
What are the three nuclei in the posterior group?
Pulvinar nuclei Lateral geniculate nuclei Medial geniculate nuclei
Gustatory cortex
Receives information from taste receptors of the tongue and pharynx
What is the function of the substantia nigra?
Regulates activity in the basal nuclei
Midbrain - what does it do?
Regulates auditory and visual reflexes and controls alertness
Function: *Thalmus*
Relay and processing centers for sensory information
Tectum
Roof of the midbrain
What are the 4 groups of components in the pons?
Sensory and motor nuclei of cranial nerves Nuclei involved with the control of respiration Nuclei and tracts that process and relay information sent to or from the cerebellum Ascending, descending, and transverse tracts
Pons Main Components: *Sensory*
Sensory and motor nuclei of cranial nerves 5-8 *Innervates:* - Jaw muscles - Anterior surface of face - Extrinsic eye muscles lateral rectus - Sense organs of internal ear (vestibular and cochlear nuclei)
What are the three ways the hypothalamus centers may be stimulated?
Sensory information from the cerebrum, brain stem, and spinal cord Changes in the compositions of the CSF and interstitial fluid Chemical stimuli in the circulating blood that move rapidly across highly permeable capillaries to enter the hypothalamus
Sulci
Shallow depressions
What nuclei receives visceral sensory information that reaches the CNS from the spinal nerves and cranial nerves?
Solitary nucleus
What is the primary function of the *Olfactory Nerve (I)*?
Special sensory: Smell
What is the primary function of the *Optic Nerve (II)*?
Special sensory: Vision
What produces CSF?
Specialized ependymal cells secrete CSF into the ventricles. They also remove waste products from CSF and adjust its composition over time
Cerebrovascular accident (CVA)
Stroke; When blood supply to a portion of the brain is shut off
What are the 8 functions of the hypothalamus?
Subconscious control of skeletal muscle contractions Control of autonomic function Coordination of activities of the Nervous and Endocrine systems Secretion of two hormones (Antidiuretic hormone and oxytocin) Emotional and behavioral drives Coordination between voluntary and autonomic functions Regulation of body temperature Control of circadiann rhythm
What is the function of the red nuclei?
Subconscious control of upper limb position and background muscle tone
What are the two dural sinuses in the falx cerebri?
Superior sagittal sinus and inferior sagittal sinus
What is the area anterior to the cerebral aqueduct called?
Tegmentum
What does the proencephalon form into?
Telenchepalon and diencephalon
Which cortex and lobe performs: *Conscious perception of auditory and olfactory stimuli*?
Temporal Lobe: The Auditory cortex and Olfactory cortex
What lobe is the auditory and olfactory cortex located?
Temporal lobe
Fill in the blank: The left and right _________ makes up the walls of the diecephalon.
Thalamus
The diencephalon consists of what three parts/components?
Thalamus, epithalamus, and hypothalamus
What connect the Third Ventricle to the Fourth Ventricle?
The Cerebral Aqueduct
What does the *Hypothalamus* do?
The Hypothalamus contains important control and integrative centers. Centers may be stimulated by: 1) sensory information from the cerebrum, brain stem and spinal cord 2) Changes in compositions of CSF and interstitial fluid 3) Chemical stimuli in the circulating blood that move rapidly across highly permeable capillaries to enter the hypothalamus (where there is no blood-brain barrier)
Cerebellum Damage
The cerebellum can be permanently damaged by trauma or stroke. Drugs such as alcohol can also temporarily affect it. The result is *ataxia*, a disturbance in muscular coordination. In severe ataxia the individual cannot sit or stand without assistance.
Cerebellum - what does it do?
The cerebellum is an automatic processing center. Coordinates learned and reflexive patters of muscular activity at the subconscious level.
What will the telencephalon form?
The cerebrum
What to gyri make up the posterior and inferior portions of the limbic lobe?
The dentate gyrus and parahippocampal gyrus
Internal capsule
The entire collection of projection fibers
Where is the arbor vitae and why is it called arbor vitae?
The internal white matter of the cerebellum and it is called arbor vitae, which means tree of life, because the sectional view resembles a tree
What structure connects the Lateral Ventricles to the Third Ventricle?
The interventricular foramen
What does the Cerebrum do?
The largest region of the brain, contains motor, sensory and association areas.
What nuclei relays information to the cerebellar cortex about somatic motor as they are issued by motor centers at higher levels?
The olivary nuclei
The primary sensory cortex is the surface of what gyrus?
The postcentral gyrus
The primary motor cortex is the surface of what gyrus?
The precentral gyrus
What separates the two lateral ventricles found in each cerebral hemisphere?
The septum pellucidum
What is the function of the speech center?
The speech center regulates the patterns of breathing and vocalization needed for normal speech. It also involves coordinating the activities of the respiratory muscles, the laryngeal and pharyngeal muscles of the tongue, cheeks, lips and jaws.
What is the final relay point for ascending sensory information that will be projected to the primary sensory information?
The thalamus
What is the ventricle in the diencephalon called?
The third ventricle
What separates the left and right Thalamus?
The third ventricle
What does the inter-ventricular foramen connect?
The two Lateral Ventricles and the the Third ventricle
What are the apneustic and pneumotaxic centers in charge of?
They adjust activities of the respiratory rhythmicity centers in the medulla oblongata
What is the function of the corpora quadrigemina?
They process visual and auditory sensations