First test Flashcards
L1 - Learning objectives
- Describe the major divisions of the nervous system
- Identify/describe the major external and internal features of the spinal cord
- Explain the consequences of spinal cord damage
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Organization of Nervous System
The central nervous system (CNS) is the:
The peripheral nervous system (PNS) is the:
Organization of Nervous System
The central nervous system (CNS) is the:
- INTEGRATING and COMMAND centre
The peripheral nervous system (PNS) is the:
- COMMUNICATION system linking all parts of the body to the CNS, via NERVES
Major subdivisions of the CNS
BRAIN:
Major subdivisions of the CNS
BRAIN:
- Cerebrum:
- Cerebral Hemispheres
- Diencephalon
- Brainstem:
- Midbrain
- Pons - Hindbrain
- Medulla Oblongata - Hindbrain
- Cerebellum:
- How much does the brain weigh?
- The Cerebrum takes up what percentage of the brain volume?
- What percentage of neurons does the cerebellum contain?
- 15 kg
- 83%
- 50%
What is grey matter?
What is white matter?
What is grey matter?
- (Neuron cell bodies)
- Group of cell bodies =
- Nucleus (CNS)
- Ganglion (PNS)
What is white matter?
- (myelinated Axons)
- Bundle of axons =
- Tract (CNS)
- Nerve (PNS)
Brain section summary:
What are the sections?
Brain section summary:
What are the sections?
- Axial (or Horizontal or Transverse)
- Side to Side
- Coronal
- Top to Bottom
- Sagittal
- Front to Back
- NOTE: there is also midsagittal
Orientation (direction): cerebrum
- Draw it L1, page 30
Orientation (direction): brainstem/spinal cord
- Draw it L1, page 31
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Spinal Cord Anatomy
The spinal cord extends from the:
What is the width and length of the spinal cord?
How many pairs of spinal nerves?
What does the spinal cord provide?
Spinal Cord Anatomy
The spinal cord extends from the:
- Foramen magnum to 1st or 2nd lumbar vertebra
What is the width and length of the spinal cord?
- Width of thumb
- ~42cm long
How many pairs of spinal nerves?
- 31
What does the spinal cord provide?
- Provides TWO-WAY street of information to and from the brain
What are the 31 pairs of spinals nerves?
What are the 31 pairs of spinals nerves?
- 8 cervical spinal nerves
- 12 thoracic spinal nerves
- 5 lumbar spinal nerves
- 5 sacral spinal nerves
- 1 Coccygeal spinal nerves
What are the two enlargements where nerves for upper and lower limbs arise?
What are the two enlargements where nerves for upper and lower limbs arise?
- Cervical enlargement
- Lumbar enlargement
What is the structure of the Conus medullaris (medullary cone)?
Where is the conus medullaris located?
What does the Conus medullaris allow?
What is the structure of the Conus medullaris (medullary cone)?
- Tapering conical structure
Where is the conus medullaris located?
- Below the lumbar enlargement
What does the Conus medullaris allow?
- Allows the filum terminale (terminal filum) to anchor the spinal cord to the coccyx (tail bone)
Cauda equaina (horse tail)
Roots of the nerves that arise from the?
Cauda equaina (horse tail)
Roots of the nerves that arise from the?
- Lumbar, sacral & coccygeal regions of the spinal cord and travel down the verebral column
Draw and label a transverse cross-section of a spinal cord
- Lecture 1, page 37
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Spinal cord - Grey Matter
Posterior (dorsal) horns:
Anterior (ventral) horns:
Spinal cord - Grey Matter
Posterior (dorsal) horns:
- incoming terminals from peripheral sensory neurons + interneurons
Anterior (ventral) horns:
- Motor neurons that go to the periphery + interneurons
Spinal Cord - Sensory Input & Motor Output
Draw
- L1, Page 41
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Spinal cord - White matter
What are the columns?
- Draw them
Spinal cord - White matter
What are the columns?
- Lateral columns
- Posterior (dorsal) columns
- Anterior (ventral) columns
Comparing Cross-section of Spinal Cord
- Draw, L1, page 43
- Where is there enlarged grey matter?
What does this mean?
Comparing Cross-section of Spinal Cord
Where is there enlarged grey matter?
- In cervical and Lumbar regions
What does this mean?
- More neurons are supplying muscles of upper (cervical) and lower (lumbar) limbs
Comparing Cross-section of Spinal Cord
What does white matter increase in?
What does this reflect?
Comparing Cross-section of Spinal Cord
What does white matter increase in?
-Increases in dorsal columns from lumbar to cervical regions
What does this reflect?
- Reflects increasing addition of sensory fibres from caudal to rostral truck regions
Spinal Cord Injury (SCI)
Paralysis?
Paraesthesia?
Spinal Cord Injury (SCI)
Paralysis?
- Loss of motor function
Paraesthesia?
- Sensory loss
Lecture 2 objectives
- Identify the ventricular system and describe the circulation/drainage of CSF
- Recognize the external surface features of the brain
- Identify/describe the three layers of meninges and their specializations
- Explain the clinical significance of meninges and the ventricular system
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Ventricular System
Brain:
Spinal Cord:
Contains?
Ventricular System
Brain: 4 ventricles - Lateral (2) - Third - Fourth
Spinal Cord:
- Central Canal
Contains?
- CSF
Ventricular system
- Have a look at L2, page 4
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Cerebrospinal Fluid (CSF)
Clear liquid (modified plasma) produced by … …. in each ventricle
Fills …. ….. & ….. ….., as well as the …. ….
Drained into … …. through the …. …..
Sampling of CSF - …. …..
Cerebrospinal Fluid (CSF)
Clear liquid (modified plasma) produced by CHOROID PLEXUS in each ventricle
Fills CEREBRAL VENTRICLES & SPINAL CANAL, as well as the SUBARACHNOID SPACE
Drained into VENOUS SINUS through the ARACHNOID GRANULATIONS
Sampling of CSF - LUMBAR PUNCTURE
Communication/Continuity of Ventricles
What are the small openings or channels?
Communication/Continuity of Ventricles
What are the small openings or channels?
- Cerebral aqueduct
- Interventricular foramen
- Lateral aperature
Lateral Ventricles:
Is a Body + 3 horns
What are the three horns?
Where does the choroid plexus?
Lateral Ventricles:
Is a Body + 3 horns
What are the three horns?
- Anterior horn
- Inferior horn
- Posterior horn
Where does the choroid plexus?
- Body & inferior horn
Third Ventricle
- Between?
- Where is the choroid plexus?
Third Ventricle
Between?
- Lateral ventricle and cerebral aqueduct
Where is the choroid plexus?
- In roof
Fourth Ventricle
Roof formed by?
Floor formed by?
Fourth Ventricle
Roof formed by?
- Superior medullary velum
- Inferior medullary velum
(Choroid plexus)
Floor formed by?
- Brainstem
Fourth Ventricle
Lies between?
Three openings?
Fourth Ventricle
Lies between?
- Cerebellum - pons & medulla
Three openings?
- 2 lateral apertures
- Foramina of Luschka
- 1 median aperature
- Foramen of Magendie
Flow of CSF
Flow of CSF
1) Choroid plexus
2) Third ventricle
3) Mesencephalic aqueduct
4) Lateral aperture
5) Median aperture
6) Central canal of spinal cord
7) Subarachnoid space of spinal cord
8) Superior sagittal sinus
9) Arachnoid villus
10) Subarachnoid space
External features of the Brain - Gyri/Sulci
Gyri =
Sulci =
Fissure:
External features of the Brain - Gyri/Sulci
Gyri = Hill tops
- Singular form - gyrus
Sulci = Valleys
- Singular form - sulcus
Fissure:
- Separates large regions of the brain
Superior Surface of the brain
Kinda draw L2, Page 17
What lobes?
What sulcus?
Superior Surface of the brain
What lobes?
- Frontal
- Parietal
- Occipital
What sulcus?
- Central sulcus
Lateral Surface
Kinda draw L2, Page 18
What lobes?
What sulcus?
What fissure?
Lateral Surface
What lobes?
- Occipital lobe
- Parietal lobe
- Frontal lobe
- Temporal lobe
What sulcus?
- Lateral
- Central
What fissure?
- Transverse fissure which separates the cerebrum from the cerebellum
Medial Surface
What lobes?
What sulcus?
What fissure?
What else can you see?
Medial Surface
What lobes?
- Parietal
- Occipital
What sulcus?
- Parieto-occipital sulcus
What fissure?
- Transverse
What else can you see
- Diencephalon
- Cerebellum
- Brainstem
ventral Surface
What lobes?
What else can you see?
What is it best for?
ventral Surface
What lobes?
- Frontal
- Temporal
What else can you see?
- Brainstem
- Cerebellum
What is it best for?
- Best view for cranial nerves & blood vessels
Insula Cortex - Insula
Buried w/in? and forms what?
Covered by portions of what lobes?
Insula Cortex - Insula
Buried w/in? and forms what?
- Buried deep w/in the lateral sulcus & forms part of its floor
Covered by portions of what lobes?
- temporal
- Parietal
- Frontal
Test Yourself
- Lecture 2, page 22
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Meninges
Protection of?
What are the three layers?
Meninges
Protection of?
- The brain and spinal cord
What are the three layers?
- Dura mater (external)
- Arachnoid mater (middle)
- Pia mater (inner)
External Meninge: Dura Mater (tough mother)
Thick layer of?
VERY tough providing?
External Meninge: Dura Mater (tough mother)
Thick layer of?
- Connective tissue surrounding the brain
VERY tough providing?
- Main support and protection
Dura Mater: two layers
What are the two layers?
The two layers of dura mater separate and form large dural …..?
Dura Mater: two layers
What are the two layers?
- Periosteal
- Meningeal
The two layers of dura mater separate and form large?
- Venous sinuses
Dura Mater: Meningeal Layer Folds
Extends … to form partitions
- Subdivide the cranial cavity
- Limit excessive movement of the brain within the cranium
Forms a …. between:
Two cerebral hemispheres … ….
Cerebellum & cerebrum
….. …..
Two cerebellar hemispheres
…. ……
Dura Mater: Meningeal Layer Folds
Extends INWARDS to form partitions
- Subdivide the cranial cavity
- Limit excessive movement of the brain within the cranium
Forms a PARTITION between:
Two cerebral hemispheres FALX CEREBRI
Cerebellum & cerebrum
TENTORIUM CEREBELLI
Two cerebellar hemispheres
FALX CEREBELLI
Falx Cerebri
Lies in:
Partially separates:
Attaches to a bony projection:
Attaches to upper surface of?
Falx Cerebri
Lies in:
- Median sagittal plane (in longitudinal fissure)
Partially separates:
- Cerebral hemispheres
Attaches to a bony projection:
- Crista galli (roosters crest), anteriorly
Attaches to upper surface of?
- Tentorium cerebelli in the midline, posteriorly
Tentorium cerebelli
What plane?
Separates?
Tentorium cerebelli
What plane?
- Horizontal plane
Separates?
- Separates cerebrum from cerebellum
Falx Cerebelli
What fold?
Separates?
Falx Cerebelli
What fold?
- Smaller dural fold runs along the vermis of the cerebellum
Separates?
- Separates two cerebellar hemispheres
Subdural Space
What is subdural space?
Structure?
What can cause enlargement?
Subdural Space
What is subdural space?
- The space bw meningeal dura mater & arachnoid mater
Structure?
- Very narrow, contains a film of fluid
What can cause enlargement?
- May be enlarged by bleeding (= subdural haemorrhage/hematoma)
Middle Meninge: Arachnoid Mater (arachnida = spider)
Describe the membrane:
Connected to the?
Middle Meninge: Arachnoid Mater (arachnida = spider)
Describe the membrane:
- Delicate transparent membrane (does not dip into sulci)
Connected to the?
- Connected to the pia mater by fine strands of connective tissue (ARACHNOID TRABECULA)
Subarachnoid space
Space between?
Structure?
Contains?
Bleeding results in?
Subarachnoid space
Space between?
- Between the arachnoid mater and pia mater
Structure?
- Wide space, filled w/ cerebrospinal fluid (CSF) - watery “cushion”
Contains?
- Blood vessels (poorly protected)
Bleeding results in?
- Results in blood in the CSF (subarachnoid haemorrhage)
What is a Cisterna?
What is a Cisterna?
- An enlarged Subarachnoid Space
Arachnoid Villi & Granulations
Arachnoid Villi:
Arachnoid Granulations:
Arachnoid Villi & Granulations
Arachnoid Villi:
- Knob-like projections of the arachnoid mater
Arachnoid Granulations:
- Collections of arachnoid villi
- Drain CSF into venous sinuses
Inner Meninge: Pia mater (gentle mother)
Sends prolongations into brain tissue along with blood vessels (forming …. ….)
Helps form the roof of the ventricles, closely associated with …. …. & …..
Inner Meninge: Pia mater (gentle mother)
Sends prolongations into brain tissue along with blood vessels (forming PERIVASCULAR SPACE)
Helps form the roof of the ventricles, closely associated with CHOROID PLEXUS & EPENDYMA
Can you recognize Dural Meninge Layers L2, page 39
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Spinal Meninges
There is no?
Spinal Meninges
There is no?
- NO dural periosteal layer
Spinal Meninges: Epidural Space
Between?
Contains?
Largest at?
Spinal Meninges: Epidural Space
Between?
- B/w spinal dural sheath and vertebral bony wall
Contains?
- Fat tissue & venous plexus
Largest at?
- L2
Spinal Meninges: Subarachnoid Space
Between?
Contains?
Spinal Meninges: Subarachnoid Space
Between?
- B/w the arachnoid and pia mater meninges
Contains?
- Cerebrospinal fluid (CSF)
What is a Lumbar Cistern?
Where?
What is a Lumbar Cistern?
- Enlarged Subarachnoid Space
Where?
- Caudal to spinal cord (below L2)
Spinal Meninges: Pia Mater Specializations
What specializations?
Spinal Meninges: Pia Mater Specializations
What specializations?
- Denticulate ligament
- triangular shaped: supports spinal cord w/in dural sheath
- Filum Terminale
Meningitis
Characterized by?
Most common infection of?
Usually caused by?
Common symptoms?
Diagnosis?
Treatment?
Meningitis
Characterized by?
- Inflamation of the pia-arachnoid mater
Most common infection of?
- The CNS
Usually caused by?
- Bacterium or a virus
Common symptoms?
- Fever, headache, vomiting and stiff neck
Diagnosis?
- Performing a lumbar puncture, examining the CSF
Treatment?
- Antibiotics quickly, to prevent infection spreading across pia mater to injure neurone in brain
Meninges Trive L2, page 47
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Human Embryo
Develops into two-layered embryonic disc after how many days after fertilization?
What layer gives rise to the nervous system?
Human Embryo
Develops into two-layered embryonic disc after how many days after fertilization?
- 11 days
What layer gives rise to the nervous system?
- Embryonic ectoderm
CNS Development (19-20 days)
Draw the dorsal surface & Transverse section on L3, page 4
The entire nervous system arises from?
The ectoderm thickens to form the?
The neural plate gives rise to neural folds and the?
CNS Development (19-20 days)
The entire nervous system arises from?
- Embryonic ectoderm
The ectoderm thickens to form the?
- Neural plate
The neural plate gives rise to neural folds and the?
- Neural groove
CNS Development (22-26 days)
Neural crest gives rise to?
The neural plate folds inward to form the?
Epithelial cells lining the neural tube generate all the?
CNS Development (22-26 days)
Neural crest gives rise to?
- Neurons destined to reside in ganglia
The neural plate folds inward to form the?
- Neural tube
Epithelial cells lining the neural tube generate all the?
- Neurons of the CNS
Neural Tube
The rostral portion forms the?
The caudal portion forms the?
The cavity forms the?
Neural Tube
The rostral portion forms the?
- Brain
The caudal portion forms the?
- Spinal cord
The cavity forms the?
- Ventricular system
Neural Tube Defects
Anencephaly (without brain):
Failure of?
Neural Tube Defects
Anencephaly (without brain):
Failure of?
- Failure of the rostral neural folds to fuse rostrally
Neural Tube Defects
Spina Bifida (forked spine):
What fails to close?
Neural Tube Defects
Spina Bifida (forked spine):
What fails to close?
- The caudal portion of the neural tube fails to close
Spinal cord development (week 6)
Draw L3, page 9
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Embryonic Development of Human Brain
Draw table on L3, page 10
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Brain development
At 5 weeks what has developed?
At 13 weeks what has developed?
At birth what remains prominent?
What else occurs?
Brain development
At 5 weeks what has developed?
- Telencephalon
- Diencephalon
- Mesencephalon
- Metencephalon
- Myelencephalon
- Spinal cord
At 13 weeks what has developed?
- Cerebral hemisphere
- Outline of diencephalon
- Midbrain
- Cerebellum
- Pons
- Medulla oblongata
- Spinal cord
At birth what remains prominent?
- Cephalic flexure (midbrain level)
What else occurs?
- Convolutions - increase the surface area of the brain
CNS Development
What area is the last to develop?
CNS Development
What area is the last to develop?
- Prefrontal areas
Blood supply of the brain
What percentage of blood flow does the brain receive?
What percentage of the body’s oxygen and glucose does the brain consume
How long of an interruption to blood flow will cause unconsciousness?
How long of an interruption to blood flow will cause impaired neural function?
How long of an interruption to blood flow will cause irreversible brain damage?
Blood supply of the brain
What percentage of blood flow does the brain receive?
- 15% (~750 mL/min)
What percentage of the body’s oxygen and glucose does the brain consume
- 20%
How long of an interruption to blood flow will cause unconsciousness?
- 10 seconds
How long of an interruption to blood flow will cause impaired neural function?
- 1-2 minutes
How long of an interruption to blood flow will cause irreversible brain damage?
- 4 minutes
What are the Cerebral Arteries?
What are the Cerebral Arteries?
- Basilar Artery
- Internal Carotid artery
What are the Cerebral Arteries?
What are the Cerebral Arteries?
- Basilar Artery
- Internal Carotid artery
- Vertebral arteries
Cerebral arteries:
The basilar artery divides into two?
Cerebral arteries:
The basilar artery divides into two?
- Posterior cerebral arteries
Cerebral Arteries:
The internal carotid artery branches into?
Cerebral Arteries:
The internal carotid artery branches into?
- Anterior & middle cerebral arteries
Circle of Willis
What does the posterior cerebral artery connect to?
Maintains blood supply to entire brain if?
Circle of Willis
What does the posterior cerebral artery connect to?
- Posterior cerebral artery connects to internal carotid artery via posterior communicating arteries, & along with anterior cerebral arteries
Maintains blood supply to entire brain if?
- 1 artery is having problems
Posterior Cerebral Artery
Supplies?
Posterior Cerebral Artery
Supplies?
- Medial aspect of the hemisphere (posterior 1/3), occipital lobes, inferior temporal lobe regions, brainstem, 3rd and lateral ventricles
Anterior Cerebral Artery
Supplies?
Anterior Cerebral Artery
Supplies?
- Medial aspects of cerebral hemisphere (anterior 2/3 only) & basal nuclei
Middle cerebral Artery
Supplies?
Middle cerebral Artery
Supplies?
- Almost all the lateral surface of cerebral hemisphere
Blood-Brain Barrier (BBB)
Formed by?
Selective for?
Keeps out?
Ineffective against?
Blood-Brain Barrier (BBB)
Formed by?
- Tight junctions b/w endothelial cells of cerebral capillaries
Selective for?
- Nutrients (glucose, essential aa & electrolytes
Keeps out?
- Large molecules, certain chemicals and drugs
Ineffective against?
- Fats, fatty acids, and fat-soluble
Stroke-related dysfunction
Anterior cerebral artery:
Middle cerebral artery (most common stroke):
Posterior cerebral artery:
Stroke-related dysfunction
Anterior cerebral artery:
- Contralateral hemiplegia (one artery) or bilateral paralysis (two arteries) & impaired sensation
- Greatest in the lower limb
Middle cerebral artery (most common stroke):
- A severe contralateral hemiplegia & impaired sensation
- Most marked in the upper limb & face
- Severe aphasia (language deficit) if the dominant hemisphere is affected
Posterior cerebral artery:
- Contralateral homonymous hemianopsia (visual loss in half the visual field in both eyes)
What is the Blood drainage of the brain?
What is the Blood drainage of the brain?
Fine veins (brain) > pial venous plexuses What is the Blood drainage of the brain > cerebral veins > dural venous sinuses > internal jugular vein > Heart
Emissary Veins
Blood from where drain venous sinuses?
Potential source of?
Rupture =?
Emissary Veins
Blood from where drain venous sinuses?
- Blood from scalp and facial skin around the nose and upper lip drain venous sinuses
Potential source of?
- Infection into the cranial cavity
Rupture =?
- Subdural hematoma
Venous sinuses
B/w?
Receive venous blood from?
Receive?
Venous sinuses
B/w?
- Two layers of dura mater
Receive venous blood from?
- Brain and scalp
Receive?
- CSF
Draining the Superior & Deep structures
1) Superior sagittal sinus
lies along the?
Joins the?
Arachnoid villi drain?
Draining the Superior & Deep structures
1) Superior sagittal sinus
lies along the?
- Superior margin of the falx cerebri
Joins the?
- Transverse sinus
Arachnoid villi drain?
The CSF into the superior sagittal sinus
Draining the Superior & Deep Structures
2) Inferior sagittal sinus
Lies along?
Joins?
Draining the Superior & Deep Structures
2) Inferior sagittal sinus
Lies along?
- The inferior margin of the falx cerebri
Joins?
- Straight sinus
Draining the Superior & Deep Structures
3) Straight Sinus
w/in?
Joins?
Draining the Superior & Deep Structures
3) Straight Sinus
w/in?
- tentorium cerebelli
Joins?
- Left transverse sinus
Draining the Superior & Deep Structures
4) Transverse sinus
Left continuous with?
Right continuous with?
Draining the Superior & Deep Structures
4) Transverse sinus
Left continuous with?
- Straight sinus
Right continuous with?
- Superior sagittal sinus
Draining Superior & Deep Structures
5) Sigmoid sinus
Forward continuation of?
Opens into?
Draining Superior & Deep Structures
5) Sigmoid sinus
Forward continuation of?
- transverse sinus
Opens into?
- Internal jugular vein
Draining the Inferior Structures
6) Cavernous sinus
Lateral to?
Drains into?
Draining the Inferior Structures
6) Cavernous sinus
Lateral to?
- Pituitary gland, linked with VENOUS CHANNELS
Drains into?
- Superior (TRANSVERSE sinus) & Inferior petrosal (INTERNAL JUGULAR V) sinuses
Summary on L3, page 42
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name the sinuses L3, page 43
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Spinal Cord Blood Supply
What descends to spinal cord?
Spinal arteries branch into?
Spinal Cord Blood Supply
What descends to spinal cord?
- Vertebral artery
Spinal arteries branch into?
- Posterior
- Anterior
- Radicular
arteries
Blood supply to the Spinal Cord
Anterior spinal arteries supply?
Posterior spinal arteries supply?
Radicular arteries supply?
Blood supply to the Spinal Cord
Anterior spinal arteries supply?
- Anterior (ventral) and lateral columns, gray matter (except for the dorsal horns)
Posterior spinal arteries supply?
- Posterior (dorsal) horns and posterior (dorsal) columns
Radicular arteries supply?
- The spinal nerves
Spinal Cord Blood Drainage
Anterior and posterior spinal veins drain blood into the?
Spinal Cord Blood Drainage
Anterior and posterior spinal veins drain blood into the?
- internal vertebral venous plexus
Spinal Cord Stroke
What percentage of all strokes?
Typically?
Symptoms depend on?
Spinal Cord Stroke
What percentage of all strokes?
- 1-2%
Typically?
Ischemic
Symptoms depend on?
- Blood vessel and level of spinal cord affected
L4 learning objectives
- Identify the external features of each cerebral lobe
- Explain the general functions of each cerebral lobe
- Identify the cortical regions involved in producing and controlling the following functions
- Movement
- General sensory perception
- Vision
- Auditory info
- Language
- Describe the consequences of damage to the structures identified above
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What are Motor areas?
What are Sensory areas?
What are association areas?
Conscious behaviour involves?
What are Motor areas?
- Voluntary motor functions
What are Sensory areas?
- Conscious awareness of sensation
What are association areas?
- Integrating diverse information for purposeful action
Conscious behaviour involves?
- The entire cortex
Functions of Lobes of the Cerebrum: FRONTAL lobe
The frontal lobe contains?
What are the Frontal lobe gyri?
Functions of Lobes of the Cerebrum: FRONTAL lobe
The frontal lobe contains?
- Contains voluntary motor functions and areas for language, planning, mood/personality, social judgement and smell
What are the Frontal lobe gyri?
- Superior frontal gyrus
- Middle frontal gyrus
- Inferior frontal gyrus
Frontal Lobe - Precentral Gyrus (Primary Motor Cortex):
Controls skilled voluntary movements of?
What muscles does it control?
The motor innervation of the body is?
Frontal Lobe - Precentral Gyrus (Primary Motor Cortex):
Controls skilled voluntary movements of?
- Skeletal muscles
- Supplying about 30% of axons to corticospinal tract
What muscles does it control?
- Controls muscles in body areas having the most precise motor control - the face, tongue & hands
The motor innervation of the body is?
- Contralateral
Frontal lobe - Precentral gyrus (Primary Motor Cortex)
What is Motor Homunculus?
What is Somatotopy?
Area of cortex related to specific region is proportional to?
Each pyramidal neuron projects its axon to?
Frontal lobe - Precentral gyrus (Primary Motor Cortex)
What is Motor Homunculus?
- Little person
What is Somatotopy?
- Mapping of body area to brain regoin
Area of cortex related to specific region is proportional to?
- The amount of motor control over that region
Each pyramidal neuron projects its axon to?
- Spinal cord
Anterior Cerebral Artery
Supplies?
Anterior Cerebral Artery
Supplies?
- The MEDIAL aspect of cerebral hemispheres (anterior 2/3 only) & basal nuclei
Middle Cerebral Artery
Supplies?
Middle Cerebral Artery
Supplies?
- Supplies almost all the LATERAL surface of cerebral hemispheres
Frontal Lobe - Precentral Gyrus (Primary Motor Cortex - DAMAGE
Occlusion/rupture of a branch of the ANTERIOR cerebral artery:
Occlusion/rupture of a branch of the MIDDLE cerebral artery:
Frontal Lobe - Precentral Gyrus (Primary Motor Cortex - DAMAGE
Occlusion/rupture of a branch of the ANTERIOR cerebral artery:
- Contralateral hemiplegia
- Greatest in LOWER limbs
Occlusion/rupture of a branch of the MIDDLE cerebral artery:
- Contralateral hemiplegia
- Greatest in UPPER limbs & FACE regions
Frontal Lobe - Inferior Frontal Gyrus:
What makes up the Inferior Frontal Gyrus?
Frontal Lobe - Inferior Frontal Gyrus:
What makes up the Inferior Frontal Gyrus?
- Opercular } Brocas
- Triangular } Brocas
- Orbital
Frontal Lobe - Brocas Area
What parts of the inferior frontal gyrus?
Generates motor program for?
Transmits to primary cortex for?
Becomes active when?
Present in?
Frontal Lobe - Brocas Area
What parts of the inferior frontal gyrus?
- Opercular
- Triangular
Generates motor program for?
- Larynx, tongue, cheeks & lips for speech production
Transmits to primary cortex for?
- Action
Becomes active when?
- Preparing to speak
Present in?
- One hemisphere only (usually the left)
Frontal Lobe - Brocas Areas
Damage to Brocas area =?
Difficulty generating?
Comprehension generally?
Frontal Lobe - Brocas Areas
Damage to Brocas area =?
- Expressive (non-fluent) aphasia
- Aphasia = language impairment
Difficulty generating?
- Written and spoken words
Comprehension generally?
- Intact
Functions of Lobes of the Cerebrum: PARIETAL lobe
Contains areas for?
Functions of Lobes of the Cerebrum: PARIETAL lobe
Contains areas for?
- Sensory reception and integration of sensory info, some languange and mathematic functions
What are the two lobules of the parietal lobe?
What are the two lobules of the parietal lobe?
- Superior parietal lobule
- Inferior parietal lobule
Parietal Lobe - Postcentral Gyrus (Primary Somatosensory Cortex)
SENSORY HOMUNCULUS
The area of the cortex dedicated to the sensations of various body parts is proportional to:
Receives sensory info from?
What is Spatial discrimination?
Parietal Lobe - Postcentral Gyrus (Primary Somatosensory Cortex)
SENSORY HOMUNCULUS
The area of the cortex dedicated to the sensations of various body parts is proportional to:
- How sensitive that part of the body is
Receives sensory info from?
- Contralateral side
What is Spatial discrimination?
- Neurons can identify the body region being stimulated
Parietal Lobe - Postcentral Gyrus (Primary Somatosensory Cortex)
DAMAGE
Occlusion/rupture of a branch of the ANTERIOR cerebral artery:
Occlusion/rupture of a branch of the MIDDLE cerebral artery:
Parietal Lobe - Postcentral Gyrus (Primary Somatosensory Cortex)
DAMAGE
Occlusion/rupture of a branch of the ANTERIOR cerebral artery:
- Contralateral sensory loss
- Greatest in LOWER limbs
Occlusion/rupture of a branch of the MIDDLE cerebral artery:
- Contralateral sensory loss
- Greatest in UPPER limbs & FACE regions
Parietal Lobe - Superior Parietal Lobule (Somatosensory Association Cortex)
Integrating different sensory inputs (relayed by the primary somatosensory cortex) to produce a comprehensive understanding of?
What is DAMAGE (middle cerebral artery): TACTILE AGNOSIA:
Parietal Lobe - Superior Parietal Lobule (Somatosensory Association Cortex)
Integrating different sensory inputs (relayed by the primary somatosensory cortex) to produce a comprehensive understanding of?
- Position of limbs
- Location of touch or pain
- Shape, weight & texture of an object
What is DAMAGE (middle cerebral artery): TACTILE AGNOSIA:
- Unable to recognize objects w/out looking at them
- (agnosia = inability to recognize)
Parietal Lobe - Inferior Parietal Lobule (Multimodal Association Cortex)
What gyri does it comprise of?
Processes different kinds of stimuli (auditory, visual, sensormotor, etc) simultaneously for:
DAMAGE (middle cerebral artery):
Parietal Lobe - Inferior Parietal Lobule (Multimodal Association Cortex)
What gyri does it comprise of?
- Supramarginal
- Angular
Processes different kinds of stimuli (auditory, visual, sensormotor, etc) simultaneously for:
- Understanding the multiple properties of spoken and written words
- Classifying and labeling things
- Mathematic ability
DAMAGE (middle cerebral artery):
Agnosia, sensory neglect, dysgraphia (writing deficits), dyslexia, (reading deficits), dyscalculia (mathematic deficits)
Functions of Lobes of the Cerebrum: TEMPORAL lobe
Contains areas for?
Functions of Lobes of the Cerebrum: TEMPORAL lobe
Contains areas for?
- Hearing, smell, learning, memory, language & emotional behaviour
Temporal Lobe
What gyri?
What Sulci?
Temporal Lobe
What gyri?
- Superior temporal gyrus
- Middle temporal gyrus
- Inferior temporal gyrus
What Sulci?
- Superior temporal sulcus
- Inferior temporal sulcus
Temporal Lobe - Primary Auditory Cortex
Superior margin of the?
Processes?
Sensitive to?
Unilateral damage (MIDDLE cerebral artery) =
Bilateral damage =?
Temporal Lobe - Primary Auditory Cortex
Superior margin of the?
- Superior temporal gyrus
Processes?
- Auditory info
Sensitive to?
- Pitch, rhythm & loudness
Unilateral damage (MIDDLE cerebral artery) = - Hearing loss
Bilateral damage =?
- Cortical deafness
Temoral Lobe - Wernicks Area Auditory Association Cortex
Posterior part of the?
Sensory?
Permits recognition of?
Creates?
Temoral Lobe - Wernicks Area Auditory Association Cortex
Posterior part of the?
- Superior Temporal Gyrus
Sensory?
- Sensory language area
Permits recognition of?
- Spoken & written language
Creates?
- Plan of speech
Temporal Lobe - Wernickes Area
Damage to wernickes area =?
Temporal Lobe - Wernickes Area
Damage to wernickes area = Receptive (fluent) aphasia
- Speech normal & excessive, but makes little sense
- No understanding of the meanings of words nor able to repeat them
Damage to arcuate fasciculus = ?
Damage to arcuate fasciculus = Associative (conduction) aphasia
- Speech and understanding normal, but cannot repeat words or phrases spoken by others
Other language Areas
Frontal Cortex:
Parietal Cortex:
Other parts of the Temporal Lobe:
Other language Areas
Frontal Cortex:
_ Brocas area and supplementary motor area
- Language motor production
_ Lateral prefrontal cortex
- Complex processing of language comprehension & word analysis
Parietal Cortex:
_ Supramarginal & Angular gyri
- Interpretation of spoken and written language
Other parts of the Temporal Lobe:
_ Association cortex
- Coordinates auditory & visual aspects of language when naming objects or reading
W/in the Temporal Lobe
Fornix:
Septum pellucidum:
W/in the Temporal Lobe
Fornix:
- Fibres to & from the hippocampus
Septum pellucidum:
- Membrane that separates lateral ventricles
Functions of Lobes of the Cerebrum: INSULAR lobe
Modulates:
Functions of Lobes of the Cerebrum: INSULAR lobe
Modulates:
- Emotions, homeostasis, cognition, perception, & self-awareness
Insular Lobe
Buried deep w/in the?
Covered by portions of the?
Insular Lobe
Buried deep w/in the?
- LATERAL sulcus & forms part of its floor
Covered by portions of the?
- Temporal lobe
- Parietal lobes
- Frontal lobe
Functions of Lobes of the Cerebrum: Occipital lobe
Is the primary?
Functions of Lobes of the Cerebrum: Occipital lobe
Is the primary?
- Visual center of brain
Primary visual cortex
The gyri form the walls of the?
Primary visual cortex
The gyri form the walls of the?
- Calcarine sulcus
POSTERIOR Cerebral Artery supplies?
POSTERIOR Cerebral Artery supplies?
- The MEDIAL aspect of the hemispher (POSTERIOR 1/3), occipital lobes, inferior temporal lobe regions, brainstem, 3rd and lateral ventricles
Occipital Lobe
Primary visual cortex damage (posterior cerebral artery) =
Visual association areas w/in the occipital lobe:
Visual association area damage (POSTERIOR cerebral artery) = ?
Occipital Lobe
Primary visual cortex damage (posterior cerebral artery) =
- Cortical blindness
Visual association areas w/in the occipital lobe:
- Communicate w/ primary visual cortex
- Interpret visual stimuli & identify things we see, except for faces (temporal association cortex)
Visual association area damage (POSTERIOR cerebral artery) = Visual agnosia;
- hemianopsia = visual deficit)
Stroke-related Dysfunction
POSTERIOR cerebral artery:
Stroke-related Dysfunction
POSTERIOR cerebral artery:
- Contralateral homonymous hemianosia 9visual loss in half the visual field in both eyes)
Know the external Features of the Cerebral Lobes
- L4, page 52
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Know the Deficit
- L4, page 53
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L5 learning objectives
- Identify the three types of white matter tracts
- Identify and describe the components, and general functions of the diencephalon
- Describe the components, connections, function & dysfunction of the basal ganglia
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Cerebral White Matter
A major contributor to?
Responsible for communication:
Consist largely of?
Cerebral White Matter
A major contributor to?
- Cerebral volume
Responsible for communication:
- (i) b/w cerebral area
- (ii) b/w the cerebral cortex & lower CNS centres
Consist largely of?
- Myelinated axons bundled into large tracts
Cerebral White Matter
PROJECTION TRACTS
Extend vertically from brain to spinal cord w/in the one hemisphere, forming the?
Cerebral White Matter
PROJECTION TRACTS
Extend vertically from brain to spinal cord w/in the one hemisphere, forming the?
- Internal capsule
Cerebral White Matter
COMMISSURAL TRACTS
Cross from?
Corpus callosum is a wide band of?
Cerebral White Matter
COMMISSURAL TRACTS
Cross from?
- One hemisphere to the other
Corpus callosum is a wide band of?
- Myelinated axon tracts
COMMISSURAL TRACTS - CORPUS COLLOSUM
- Have a look at L5 slide 6
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Commissural Tracts
- ATERIOR COMMISSURE
Includes axons that connect?
Commissural Tracts
- ATERIOR COMMISSURE
Includes axons that connect?
- The middle & inferior temporal gyri of the two sides
Cerebral White Matter
ASSOCIATION FIBRES
Connect?
Cerebral White Matter
ASSOCIATION FIBRES
Connect?
- Connect lobes & gyri w/in the hemisphere
Summary: Tracts of the Cerebral White Matter
L5, page 10
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Diencephalon
Consist of 4 parts:
Associated with the?
Diencephalon
Consist of 4 parts:
- Thalamus
- Hypothalamus
- Epithalamus
- Subthalamus
Associated with the?
- 3rd ventricle
Thalamus
Structure?
Makes up what percentage of the diencephalon?
Forms the?
Thalamus
Structure?
- Egg-shaped
Makes up what percentage of the diencephalon?
- 80%
Forms the?
- Superolateral walls of the third ventricle
Thalamus
Contains?
Interthalamic adhesion (intermediate mass):
Play a key role in?
Thalamus
Contains?
- About a dozen nuclei
Interthalamic adhesion (intermediate mass): - A midline connection which joins each thalamus to the other
Play a key role in?
- Relaying sensation
- Motor activities
- Cortical arousal
- Learning & memory
Hypothalamus
Located?
Forms the?
Extends from the?
Superior to the?
Hypothalamus
Located?
- Below the thalamus (hypothalamic sulcus)
Forms the?
- Inferolateral wall of the third ventricle
Extends from the?
- Optics chiasma
Superior to the?
- Brainstem
Main Homeostatic Roles of Hypothalamus
Autonomic control centre:
Emotional response:
Body temperature regulation:
Regulation of food intake:
Regulation of water balance and thirst:
Regulation of sleep-wake cycles:
Control of endocrine system functioning:
Main Homeostatic Roles of Hypothalamus
Autonomic control centre:
- Respiration, cardiovascular
Emotional response:
- Limbi system
Body temperature regulation:
- Thermosensitive neurons
Regulation of food intake:
- appetit & satiety centres
Regulation of water balance and thirst:
- Thirst centre
Regulation of sleep-wake cycles:
- With pineal gland
Control of endocrine system functioning:
- ovaries, testes to produce egg, sperm, stress hormones
Epithalamus
Structure?
Includes?
Contains?
Pineal gland generate?
Epithalamus
Structure?
- A small, cone-shaped body
Includes?
- Pineal gland and the roof of the third ventricle
Contains?
- Dense calcium salts (pineal sand) in adults (radiopaque)
Pineal gland generate
- MELATONIN - the sleep - inducing signal (peak level at night)
Diencephalon who am I
L5, page 22
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Basal Ganglia
Important for?
Basal ganglia =?
Corpus Striatum =?
Other commonly used terms:
Striatum =?
Pallidum =?
Basal Ganglia
Important for?
- Motor control and attentional processes
Basal ganglia =?
- Corpus striatum + subthalamic nuclei + substantia nigra
Corpus Striatum =?
- Lentiform (putamen & globus pallidus) + caudate nuclei
Other commonly used terms: Striatum =? - Putamen + caudate nucleus Pallidum =? - Globus pallidus external (GPe) & internal (GPi) divisions
Basal Ganglia: Corpus Striatum
- L5, page 24
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Basal Ganglia: Corpus Striatum
- L5, page 24
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Corpus Striatum
Draw
- L5, page 26
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Corpus Striatum
What makes up the Internal capsule?
Corpus Striatum
What makes up the Internal capsule?
- Anterior limb
- Genu
- Posterior limb
Corpus Striatum
Posterior limb of internal capsule is b/w?
Anterior limb of internal capsule is b/w?
Corpus Striatum
Posterior limb of internal capsule is b/w?
- Lentiform nucleus and thalamus
Anterior limb of internal capsule is b/w?
- Lentiform & caudate nuclei
Locate the Putamen, Globus pallidus & caudate nucleus
L5, page 29
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Locate the Globus pallidus, Caudate nucleus, thalamus, Putamen & Internal capsule
- L5, page 30
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Basal ganglia: Connectivity with the Motor Cortex
Access to motor neurons in the cerebral cortex is through the?
What loop is this?
Basal ganglia: Connectivity with the Motor Cortex
Access to motor neurons in the cerebral cortex is through the?
- Thalamus
What loop is this?
- cortical-basal ganglia-thalamic-cortical loop
Motor Control by Basal ganglia
Output inhibits?
Acts as a brake so to?
The brake can be released by?
Motor Control by Basal ganglia
Output inhibits?
- Unnecessary movements
Acts as a brake so to?
- Produce ordered, finely controlled movement only when needed
The brake can be released by?
- Input from the cerebral cortex and the substantia nigra to start movement
At rest: What inhibits the thalamus? What does this mean?
What activates the putamen? What does the putamen inhibit? What does it activate?
What does this cause?
What does the basal ganglia influence?
At rest: What inhibits the thalamus? What does this mean?
- Globus pallidus inhibits thalamus, no motor cortex activity
What activates the putamen? What does the putamen inhibit? What does it activate?
- Cortex activates putamen, which inhibits the globus palladus, releasing thalamus from inhibition, activating motor cortex
What does this cause?
- Movement
What does the basal ganglia influence?
- The function of spinal cord motor neurons INDIRECTLY (compared to cerebral cortex, direct synaptic input)
Parkinsons Disease
What type of degeneration?
Motor deficits:
Treatment:
Parkinsons Disease
What type of degeneration?
- Substantia nigra dopamine neuron degeneration
Motor deficits:
- Rigidity
- Tremor
- Difficulty initiating movement
- Postural instability
- Shuffling gait
- Stiff facial expression (mask-like face)
Treatment:
- 1) replacement of dopamine
- 2) Stem cell therapy
- 3) Deep brain stimulation
Basal Ganglia True or False
L5, page 37
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