Chapter 6 Flashcards
Neural tube is on
Dorsal side
Gut tube is on
Ventral side
Three primary brain vesicles
Prosencephalon
Mesencephalon
Rhombencephalon
Forebrain
Prosencephalon
Midbrain
Mesencephalon
Contains corpora quadrigemina
Rhombencephalon
Hindbrain
Telencephalon turns to
Cerebrum
Diencephalon turns to
Eye cup,
Thalamus, hypothalamus, epithalamus ,
Pineal gland
Mesencephalon
Turns to midbrain
Metencephalon turns to
Pons and cerebellum
Myelencephalon turns into
Medulla oblongata
Prosencephalon turns to
telencephalon and diencephalon
Rhombencephalon turns to
Metencephalon and myelencephalon
When does the Neural tube separate into 5 secondary brain vesicles
5 weeks
Thalamus
Executive secretary of brain. Passes all sensory info except for smell to the cerebral cortex.
Helps direct the activity of motor cortices from the cerebellum and the basal nuclei.
Mediates sensation, motor activities, cortical arousal, learning and memory. Gateway to cerebral cortex
Integration happens at
Cerebral cortex
Hypothalamus
Small, filled with nuclei. Core regulatory center for homeostasis. Controls body temp, thirst hunger.
3.Controls endocrine system function through various hormones
Where do nervous and endocrine systems meet?
Hypothalamus
Neurosensory neurons. Located in
Hypothalamus
Neurosensory neurons function
Release hormones like tropins
Tropins
Hormones that cause the release of other hormones into anterior and posterior pituitary
Fast control system
Nervous system
System responsible for sustained changes
Endocrine systems
Corpora quadrigemina
Visual and auditory reflex centers
Pineal gland
Release of melatonin.(maintain circadian rhythm)
Midbrain location
Between diencephalon and pons
Pons
Bridge, connects medulla with midbrain. Connects upper and lower central nervous system
Cerebellum
Coordination and motor movements in the body
Medulla oblongata
Most inferior part of brain stem
Brain stem parts
Midbrain, pons, medulla oblongata
Contain critical homeostatic mechanisms for basic life functions
Pons and medulla
Pontine respiratory group location
In pons , medulla also has one
Medulla contains
Cardiac inhibitory center
Respiratory center
Cardiac accelerator center
Has critical controls for basic life functions
Brain stem
Spina bifida
Neural tube doesn’t close properly, causes bulge known as meningocele
Meningocele
Filled with fluid and parts of meninges. Part of meninges outside of vertebral foramen
Myelomeningocele
Parts of meninges+ some fibers of spine.
Likely to cause developmental delays
Gyrus
Singular raised area on brain
Singular fold in brain
Sulcus
Folds in cerebral cortex do what?
Increase surface area
Cerebral cortex is made of
Grey matter
Gray matter is made of
Cell bodies and unmyelinated axons
Cerebrum
Largest part of brain. Has lobes
Deep to cerebral cortex is
White matter
White matter is mostly
Myelinated axons
Central sulcus
Divides frontal lobe from parietal lobe
Separates parietal lobe and frontal lobe
Temporal lobe with lateral sulcus on top of it
Divides cerebrum
Fissure divides into right and left hemispheres
Transverse fissure location
Between cerebrum and cerebellum
Cerebellum function
Motor coordination. Skeletal muscle movement
Medulla oblongata exits brain through
Foramen magnum of occipital bone
Neurocranium
Part of skull enclosing cranial cavity
After medulla oblongata exits the neurocranium it is called the
Spinal cord
Corpus callosum
Bridge of fibers. Connects right and left hemispheres. Lets two hemispheres communicate. Reaches into every major cortex. Integrates countless processes
Nerve fiber really means
Axon of individual neurons
Largest white matter structure in the brain
Corpus callosum
Why is corpus callosum important
Different functions develop in different hemispheres. However, certain actions can be mapped to a different area and of the brain that wasn’t damaged
Region of higher order thinking especially in cerebral cortex takes place in
Frontal lobe
Motor cortex in which lobe?
Frontal
What does motor cortex do?
Maps motor neurons to various parts of body
Primary motor cortex in
Precentral gyrus
Primary motor cortex is responsible for
Voluntary movement
Primary somatosensory cortex location
Post-central gyrus
Primary somatosensory cortex function
Info from sensory receptors in skin, skeletal muscles and joints
Homunculus size of body parts is proportional to
Number of neural connections
Prefrontal cortex
Procedural memory, learning piano etc
Parietal lobe includes
Sensory cortex
Broadman’s cyto tectonic maps
Map out how neurons connect to various regions of brain
Broca’s area
Motor speech area. Damage in this area can prevent stroke victims from speaking. Directs muscles in speech production
Wernicke’s area
Can say word but not always understand when this area is affected
Primary visual cortex
Info from optic nerves is processed
Moves towards middle to visual association areas
Triangle under corpus callosum
Hypothalamus “beak”
Label areas or cerebral cortex
See pictures
Thalamus location
Under corpus callosum
Behind “eye”
Thalamic adhesion
Connects both parts of thalamus medially. Flattened band of tissue
“Eye”
What is at end of hypothalamus?
Pituitary gland
Insula (see picture)
Lobe that hides in plain sight . Self awareness, interoception,pain processing
Nuclei
Pockets of grey matter
Nuclei
Pockets of grey matter buried deep in white matter
Ventricles filled with
Cerebrospinal fluid
Infundibulum
Connects pituitary gland to diencephalon
Coronal
Frontal
Cingulate gyrus
Helps regulate emotions and pain. Continuous arched lobe above corpus callosum. Gives emotional value to different experiences
Limbic lobe
Cingulate gyrus. Emotional brain. Has hippocampus and amygdala
Limbic system
What does pineal gland do?
Responds and regulates circadian rhythm
Arbor vitae
White matter in cerebellum that looks like tree. Brings sensory and motor info to and from cerebellum
Anterior lobe releases
Human growth hormone
Luteinizing hormone
Follicle stimulating hormone
Prolactin
Thyroid stimulating hormone
Posterior pituitary releases
Anti diuretic hormone
Oxytocin
Where are ADH and oxytocin made?
Hypothalamus
Four twins
Corpora quadrigemina
Superior coliculli
Rapidly process visual info. Top part of corpora quadrigemina
Inferior colliculi
Rapidly process auditory information
Lateral ventricle
Two lateral ventricles in each side of the brain
Third ventricle
Around thalamic adhesion
Fourth ventricle
Provides CSF around base of cerebellum
Cerebral aqueduct
Cavity that connects the third and fourth ventricles
CSF circulation extends also
Around surface of brain and surface of spinal cord. Down middle of cord in central canal
Describe the circulation of csf
Central part,
Outside of brain in sub arachnoid space, down through central canal and around edge of spinal cord and outside edge of spinal cord
Function of CSF
-Maintain ionic balance in nervous tissue
cushioning for brain tissue
-remove metabolic wastes from nervous tissue
How is CSF made?
Certain regions of lateral ventricles,
Third ventricle, some in fourth ventricle
Horns on lateral ventricles
Anterior and posterior horns
Choroid plexus
Layer of epyndymal cells with capillaries underneath. Astrocytes connect capillaries to epyndymal cells to produce CSF.
Capillary knot in brain ventricle, makes CSF.
Hang on roofs of ventricles
What happens to CSF? Gets made and
Recycled
Arachnoid granulations
Recycle CSF. Reabsorb CSF. Avoid accumulation of metabolic wastes.
Look like cauliflower block or broccoli, structures of arachnoid mater. Poke out through dura mater into superior saggital sinus
What makes CSF?
Choroid plexus
Why does CSF circulate?
Avoid accumulation of pressure and wastes
Fine tunes motor movements. Makes adjustments
Cerebellum
Keeps constant 3D map of where body parts are . Tells you to walk inclined slightly forward during windy day
Cerebellum
Signals of cerebellum
Afferent and efferent
Afferent signal of cerebellum goes through
Inferior olive of medulla oblongata
Descending signals of cerebellum to correct body movement move from
Out medulla oblongata and out through spinal cord to skeletal muscle
Why is brain highly vascularized?
It uses a lot of energy
Percentage of calories consumed by brain
25%
Preferred source of energy for brain?
Glucose
Anastomosis
Union or joining of nerves, blood vessels or lymphatic vessels
Why is circle of Willis important?
Lets blood flow to other parts of brain if one is clogged
Have foramen in transverse processes
Cervical vertebra. House vertebral arteries
Saggital suture
Down center of skull, fibrous joint in between parietal bones
Meningeal layers
Dura mater
Arachnoid mater
Pia mater
Dura mater contains
Veins and arteries
Trabeculae
Fibrous strands that connect to pia mater below “column”
Tough mother
Dura mater
Arachnoid mater
Spider mother
Tender mother
Pia mater. On surface, over every gyrus and sulcus of cerebral cortex and spinal cord
Pia mater contains
Nerves
Most blood vessels in meninges are in
Subarachnoid space
Are there lymphatic vessels in brain?
Yes..think about lymphatic vessels when you think about blood vessels
Subarachnoid space
Space that has capillaries and trabeculae on top of pia mater
Meninges follow into fissures yes or no?
Yes
What does ethmoid bone do?
Has Crista galli. Attaches to falx cerebri acts as shock absorber. Connects meninges to front of skull
Cock’s comb
Crista galli
Falx cerebri
Meninges dip into longitudinal fissure between cerebral hemispheres. Anteriorly attaches to Crista galli of ethmoid bone
Meningitis
Inflamation of any of the meninges
Compact bone is on
Outside
Trabeculae of bone is on
Inside
Subdural hematoma
Blood building up between the dura mater
Arachnoid mater
Meningeoma
Unwanted growth in meninges. cancer
In cranium, dura mater is
Directly adhered to inner surface of bones that make neurocranium
In spinal cord, dura mater is
Around spinal cord, but not attached to inside of vertebral foramen. Adipose tissue in epidural space between bone and dura mater. Arteries, veins and lymphatic vessels.
Why is dura mater not attached directly to vertebral foramen?
Allows for movement. Back can change shape.
Falx cerebelli
In between two parts of cerebellum.
Functions of sinuses
Make skull lighter,
Covered with mucous membranes, drain to nasal cavity.
Act as resonance chambers for sound.
Explain CSF circulation
- CSF made in choroid plexus
- CSF circulates down and around the spinal cord. Down middle of spinal cord through central canal and around the edge
3.eventually into arachnoid granulations
Superior saggital sinus function
Harvests deoxygenated blood as it’s leaving the brain
Which arteries bring fresh oxygenated blood to brain?
Internal carotid artery, vertebral artery
Epyndymal cells associated with
Capillaries
What happens when fluid is caught up by arachnoid granulations?
CSF is reabsorbed and re-enters venous blood flow at that point
What causes CSF circulation?
Muscles involved in breathing.. More exercise, more CSF circulates
Tracts in spinal cord have which types of tracts
Ascending and descending tracts
What do tracts in spinal cord do?
Carry info to and from the brain. Similar to nerves. And to and from peripheral nervous system nerves
Where is white matter on spinal cord?
Outside
Where is grey matter on spinal cord inside
Horns
Types of horns
Posterior horns (long)
Lateral horn (sides)
Anterior horns (short, front)
What does central canal in spinal cord do?
CSF flows through center, gets more blocked up over time
Gray commisure
Bridge of grey matter from one side of spinal cord to the other
Anterior median fissure
Between anterior horns of spinal cord
Posterior median sulcus
Sulcus between both posterior horns
Nerves around spinal cord
Dorsal root and ventral root
Dorsal root ganglion
Emerges from dorsal root of spinal nerves
Cell bodies of unipolar sensory neurons arrive through. Which sense what’s happening in body like digestive tract or blood vessels. Both somatic and skeletal muscles
What comes out of spinal cord
Fibers, neurons, dorsal root
Vertebral arteries are only found in which vertebra?
Cervical.
What is between vertebral bodies?
Intervertebral discs
Herniated disc
Presses against disc
Transverse foramen
Where arteries go
Vertebral foramen
Where spinal cord goes
Layers of Spinal cord
1.Vertebrae,
2.Epidural space(contains fat, blood vessels and lymphatic vessels)
3. Dura mater
4. Arachnoid mater
5. Subarachnoid space (CSF circulation here)
6. Pia mater
7. White matter
8. Grey matter
Ventral root shape
Thinner than dorsal root
What does ventral root carry?
Efferent direction.
Mostly motor neurons
Spinal nerve
Ventral root+ dorsal root
Lateralization
Each hemisphere has unique abilities not completely shared by partner
Left hemisphere has greater control over
Language abilities, math, logic. Compose sentence, add numbers, memorize a list
Right hemisphere has more control over
Visual spatial skills, intuition, emotion, artistic musical skills
Aqueductal stenosis
Prevents flow of CSF between 3rd(looks like chicken head) and fourth ventricles (looks like chicken neck or diamond)
How do lateral ventricles connect with third ventricle?
Interventricular foramen
How does third ventricle connect to fourth ventricle?
Cerebral aqueduct. Runs through midbrain
Multimodal association cortex
Sensations, thoughts and emotions come together to make us who we are
Function of cerebral cortex
Holds conscious mind. “Executive suite” of nervous system. Lets us be aware of ourselves and sensations
Accounts for 40% of brain mass
Cerebral cortex
Connect corresponding grey areas of 2 hemispheres
Commisural fibers. Let two hemispheres work together to do things
Largest commisure in body
Corpus callosum
Connect different cortical lobes
Long association fibers
Basal nuclei function
Start, stop and monitor intensity of movements caused by cortex. Stop unnecessary movement
Post-central gyrus of parietal lobe function?
Sensory
Cerebral aqueduct
Slender cavity of midbrain. Connects third and fourth ventricles
Frontal lobe function
Thinking, planning, organizing, problem solving, short term memory
Spinal nerves
31 nerve pairs that arise from the spinal cord
Precentral gyrus of cerebrum function
Motor functions
Damage to left primary motor cortex leads to
Paralysis of voluntary muscle control on right side of body
Destruction of premotor cortex results in
Loss of motor skills programmed by that region. Does not affect muscle strength or ability to do certain things.
Damage to Primary visual cortex
Very back, leads to functional blindness. Receives info from retina of eye
Visual association area
Uses past visual experiences to interpret visual stimuli
Damage to visual association area
Can see but can’t comprehend what they’re looking at
All structures from CNS originate from
Neural tube
Contrecoup injury
Brain bounces and hits opposite side
Primary auditory cortex
Gets info from hearing receptors in inner ear. Pitch, loudness, location
Auditory association area
perception of the sound stimulus. Memories of past sounds are stored there for reference.
Wernicke’s area is part of which cortex?
Auditory cortex
Primary olfactory cortex is where?
Medial aspect of temporal lobe
Gustatory cortex is
In insula, deep to temporal lobe
Vertibulat cortex location
Conscious awareness of balance. Posterior part of insula and adjacent parietal cortex
Which landmark separates cerebral hemispheres
Longitudinal fissure
Projection fibers
Projection tracts. White matter tracts that connects cortex with many other areas in CNS , deep nuclei, brain stem, cerebellum, spine
Projection fibers enter cerebral hemispheres from
Lower brain or cord centers, leave cortex to travel to lower areas
Association fibers
Connect different parts of the same hemisphere.
Short association fibers connect
Adjacent gyri
Long association fibers
Bundled into tracts, connect different lobes on same hemisphere
Damage to posterior association area can result in
Feeling that body part doesn’t belong
Recognizing patterns and faces. Understanding and language
Filter out incorrect or inappropriate responses passing only best response to the cortex
Basal nuclei
Disorders of basal nuclei include
Huntington’s disease Parkinson’s disease
Multimodal association cortex
Sensations emotions and thoughts make us who we are.
Multimodal association cortex allows us to
Receive store and connect with previous experience and knowledge. Sensations thoughts and emotions become conscious
Posterior association area function
Encompasses parietal, temporal, occipital lobes. Pattern recognition. Localizing us in space ..
Tumors or lesions in anterior association area cause
Mental and personality disorders loss of judgment attentiveness and inhibitions
Function of reticular formation
Keeps cerebral cortex alert and conscious
Enhances excitability of cerebral cortex
Hypothesis for psychosomatic illnesses
Increased activity from hypothalamus from stress may increase activity of hypothalamus is governing other functions like blood pressure
Cephalizataion
Concentration at front of head of neurons
Mass of average adult human brain
1500g
Encephalo
Brain
Caudal
Towards tail
Posterior portion of neural tube becomes
Spinal cord
What causes psychosomatic illness
Increased activity in hypothalamus from stress might increase the activity in hypothalamus governing other functions like blood pressure
Psychosomatic illnesses , why?
Psychological condition leads to physical symptoms
Most limbic system output goes through hypothalamus. Switchboard for autonomic and emotional response. Can cause high BP and heartburn
Inability to filter out sensory information may implicate which brain structure?
Reticular activating system
Reticular activating system
Filters out sensory input, repetitive, familiar/weak signals get ignored. Unusual impulses reach consciousness. Would notice if watch fell off, but wouldn’t notice it when you’re wearing it.
Tells you what to pay attention to
What gets you to disregard 99% of sensory stimuli?
Cerebral cortex & RAS
Limbic system
Emotional visceral brain
Epithalamus
Has pineal gland.
What does amygdaloid body do?
-assess danger
-elicit fear response
-recognize fear
-responds to perceived threats with fear or aggression
Cingulate gyrus cingulate gyrus
Resolves mental conflicts when frustrated.
Expresses emotions when frustrated
What part of brain triggers emotional responses by odors
Limbic system
Rhinencephalon
Smell brain, in limbic system
Main visceral control center of the body
Hypothalamus
Autonomic reflex center
Medulla oblongata
How do medulla and hypothalamus work together?
Hypothalamus gives instructions through giving instructions through medullary reticular centers
Enables us to be aware of ourselves, sensations, communicate, remember, understand, initiate voluntary movements
Cerebral cortex
Provides timings and appropriate patterns for skeletal muscle contractions
Cerebellum
What do nuclei of pons do?
Some are part of reticular formation and others help medulla oblongata maintain normal rate of breathing
Cerebellar peduncules
Connect cerebellum to brainstem. Three paired fiber tracts
Ipsilateral
From and to same side of body
Describe fiber distribution to and from cerebral cortex?
Contralateral
Superior cerebellar peduncules
Connect cerebellum and midbrain. No direct connection to cerebral cortex. Carry instructions from neurons in deep cerebellar nuclei to cerebral motor cortex using thalamic relays
Middle cerebellar peduncules
One way communications from pons to cerebellum. Advises cerebellum of voluntary motor activities initiated by motor cortex
Inferior cerebellar peduncules
Connect medulla and cerebellum. Give sensory information to cerebellum from muscle proprioceptors &
2. Vestibular nuclei
Periaqueductal grey matter
Pain suppression links fear receiving amygdaloid body and ANS pathway that controls fight or flight
Red nucleus
Rich blood supply.
Relay nuclei in descending motor pathways that cause limb flexion. Embedded in reticular formation
System of small nuclei scattered through core of brain stem
Reticular formation
Substantia nigra
Linked to basal nuclei.
Cause of Parkinson’s disease?
Degeneration of dopamine releasing neurons substantia nigra
Pyramidal tract
Relay info from motor cortex to skeletal muscle
Pons function
Has some nuclei that are part of reticular formation and some that help medulla oblongata maintain normal rhythm of breathing
Pons
Bridge
Deep projection fibers of pons
Pathway to higher brain centers and spinal cord
Superficial ventral fibers
Relay conversations between motor cortex and cerebellum
Thalamus function
Sorts and edits sensory information ascending to cerebral cortex
Epithalamus associated with which gland?
Pineal, secretes melatonin to induce sleep
Midbrain function
Controls visual reflexes that coordinate head and eye movement when following moving objects
Medulla oblongata function
Autonomic reflex center that helps keep homeostasis. Cardiovascular center, respiratory centers, sneezing, vomiting, hiccups, swallow and coughing
Which cranial nerve pairs issue from pontine nuclei?
Trigeminal, abducens, facial
Which part of the brain makes dopamine?
Substantia nigra inside of midbrain white matter
Functions of brain stem
Rigidly programmed behaviors for survival
Grey on inside, white on outside
Associated with 10 of the 12 cranial nerves
Main functions of hypothalamus
1.Control autonomic nervous system
2.Initiate physical responses to emotions
3.Regulate body temperature
4.Regulate food intake
5.Regulate water balance and thirst
6.Regulate sleep wake cycles
7.Control endocrine system function
Superior colliculi
coordinate head and eye movements when we visually follow a moving object, even if we are not consciously looking at it.
Tectum
Midbrain’s roof
Drugs that inhibit this region promote unconsciousness
Reticular activating system
Location of limbic system
Medial aspect of each cerebral hemisphere and diencephalon.
Amygdaloid body
Almond shaped nucleus..responds to perceived threats. Angry or fearful facial expressions with fear or aggression
Is emotional visceral brain
Limbic system
Expressing emotions through gestures. Resolving mental conflicts
Cingulate gyrus
What area of the brain is affected in capgrass syndrome?Think that loved ones are impostors. Loss of connection between image one sees and emotions associated with that image
Amygdaloid body and other parts of limbic system
Which parts of the cerebellar cortex influence the motor activities of trunk and girdle muscles
Medial parts of each hemisphere
Which parts of the cerebellum’s cortex adjusts posture to maintain balance?
Flocculonodular lobes
Which part of the cerebellar cortex plans movements instead of executing them
Lateralmost
Which part of the cerebellar cortex influences distal parts of limbs and skilled movements
Intermediate parts of each hemisphere
Which part of the cerebellar cortex influences movement of the trunk and girdle muscles
Medial portions
Sensory axons carrying information about touch pain and temperature synapse on reticular activating system neurons in the
Brain stem
Explain cerebellar processing
Cerebellum receives information from proprioceptors
Cerebellar cortex calculates Force direction and extent of muscle contraction
When motor cortex says smooth cerebellum must ensure coordinated movement. Keep posture in mind when calculating movement
All fibers entering and leaving the cerebellum are
ipsilateral
In motor cortex muscle is controlled by the ___ brain
Contralateral brain. Damage to one side affects the opposite side
What does it mean for cerebellar control to be ipsilateral?
The right side of cerebellum affects right side of body
Peduncles
Connect cerebellum to rest of brain
Severe injury to reticular activating system results in
Permanent unconsciousness. Sends continuous stream of impulses to cerebral cortex. Keeps cortex alert and conscious.
Reticular formation extends through
Central core of medulla oblongata, pons, midbrain
Does not only receive motor information for proprioception
Cerebellum. Please roll in thinking language and emotion. May compare actual output with expected output
The startle reflex involves which part of the midbrain?
Inferior colliculi. Send info from hearing receptors to auditory cortex. Reflexive responses to sound
Gray matter areas of the diencephalon enclose which of the following structures?
Third ventricle
Which areas of the brain help regulate the sleep wake cycle
The epithalamus and the hypothalamus
What is the major pathway between the higher brain centers and the spinal cord
Pons
What is the major pathway between the cerebellum and the motor cortex
Pons
Ponds is chiefly made up of which kind of tracts?
Conduction tracts
Parts of diencephalon
Thalamus
Hypothalamus
Epithalamus
Primary somatosensory cortex function
Receive information from skin and proprioceptors
Tell the brain of body’s position in space. Neurons identify the body region being stimulated.
Spatial discrimination
Being able to identify the body region being stimulated
Proprioceptors
Sensory receptors located in a joint, muscle or tendon. Related to locomotion, posture and muscle tone
Master gland that controls endocrine system
Pituitary gland
