Brain And Behaviour

Front 1

Describe conscious proprioception?

Back 1

Information about limb position sense carried in the dorsal column - medial lemniscus system is considered "conscious" proprioception because it reaches the cerebral cortex.

Front 2

Describe unconscious proprioception

Back 2

1) Ia, Ib, & II fibres send afferents to Clarke's nucleus where they synapse
2) Those axons then travel to the cerebellum via the dorsal spinocerebellar tract (C8 to L3)
3) Fibres below L3 travel in the F. gracilis) to L3 where they synapse in Clarke's nucleus.
4) Fibres above C8 travel with F. cuneatus, synapse in accessory cuneate nucleus (equivalent to Clarke's), fibres then travel in cuneocerebellar tract to cerebellum.

Front 3

Describe the path of the Spinothalamic Tract

Back 3

1) Arises from Lamniae I, IV- VI
2) Crosses midline in the AWC
3) Projects to VPL
4) Projects to primary somatosensory
Note - pain, temp and light touch sensations mainly carried by A-delta fibres.

Front 4

Describe myasthenia gravis

Back 4

Myasthenia gravis is characterized by moderate to profound weakness of skeletal muscles, is caused by circulating antibodies that react with post-synaptic nicotinic acetylcholine receptors

Front 5

What does injury to one side of the corticospinal cord cause?

Back 5

1) Weakness (hemiparesis) or paralysis (hemiplegia) of the ipsilateral upper and lower extremities

Front 6

What does bilateral cervical spinal cord damage result in?

Back 6

bilateral cervical spinal cord amage above C4 - C5 may result in paralysis of all four extremities (quadriplegia)

Front 7

Describe the paleospinothalamic and spinoreticulothalamic tracts

Back 7

Paleospinothalamic and spinoreticulothalamic tracts:
1) These two tracts are thought to have a role in the sensation of dull aching, poorly localized pain related to that mediated by C fibers.
2) Also have a role in affect and cortical arousal association with pain.
3) These are subsets of spinothalamic fibers which project to the medial nuclei of the thalamus (DM and intralaminar)
4) They then project to the association areas if the cortex.

Front 8

Name three modulators of the pain process

Back 8

1) At the spinal cord level
2) The spinomesencephalic tract
3) Central modulation

Front 9

Explain how the spinal cord modulates pain processing.

Back 9

1) Modulation is done by the interneurons in SG (Laminae II) of the dorsal horn which receive descending inhibition signals.These act on incoming pain and temp information and modulate both fast and slow pain.
2) Efferents from the PAG to reticular formation of nuclei in the rostral medulla / caudal pons. These send descending information to the dorsal horn (SG) of the spinal cord.
3) Large diameter afferents which conduct touch can also modulate pain through connections with the SG and dorsal horn laminae.

Front 10

Explain how the spinomesencephalic tract modulates pain processing.

Back 10

1) A subset of fibers synapses in the midbrain reticular formation and PAG
2) The PAG region has reciprocal connections with the limbic system through the hypothalamus
3) PAG also sends a descending projection to the dorsal horn (substantia gelatinosa (SG), Lamina II)
4) It also receives input from the cortex, hypothalamus and limbic structures

Front 11

What aspects of central modulation affect pain processing?

Back 11

1) Opiate receptors and endogenous opiate peptides are found diffusely throughout the brain.
2) These are in highest concentration in the PAG, rostral ventral medulla, spinal cord dorsal horn and areas of the hypothalamus that project to the PAG.

Front 12

What system carries pain from the head?

Back 12

pain from the head is carried by the trigeminal system.
- The spinal tract and nucleus of V correspond to the SThT and mediate fast pain
- The indirect pathways of the spinal cord (reticular formation, medial thalamus and widespread areas of the cerebral cortex) carry the information for slow pain.

Front 13

Describe the components from the trigeminal (V) nucleus and nerve

Back 13

1. Sensory Components (from Head)
a) Main (chief) sensory - touch & pressure
b) Spinal nucleus and tract V - pain & temp from head
c) Mesencephalic nucleus - proprioceptive
2. Motor nucleus of V (motor to muscles of mastication)

Front 14

Describe the components of the facial (VII) nucleus and nerve

Back 14

1) SSA - taste from anterior 2/3 of tongue
2) Main motor nucleus - Facial expression
3) Secreto-motor nucleus (visceral motor) - to submandibular and sublingual salivary glands and lacrimal gland.

Front 15

Name the blood supply to the caudal medulla

Back 15

1) Anterior spinal artery (ASA)
2) Vertebral Artery (VA)
3) Posterior spinal artery (PSA)

Front 16

Name the blood supply to the Rostral Medulla

Back 16

1) Anterior spinal artery (ASA)
2) Vertebral Artery (VA)
3) Posterior inferior cerebelllar artery (PICA)

Front 17

Name the blood supply to the Pons

Back 17

1) Basilar artery (Primary)
2) Anterior inferior cerebellar artery (AICA)
3) Superior cerebellar artery (SCA)

Front 18

Name the blood supply to the midbrain

Back 18

1) Posterior cerebral artery

Front 19

Name the principles that allow for cerebellar lesions to be localized

Back 19

1. Ataxia is ipsilateral to the side of a cerebellar lesion
2. Midline lesions of the cerebellar vermis mainly cause unsteady gait and eye movement accompanied by vertigo, nausea and vomiting.
3. lesions lateral to the cerebellar vermis mainly cause ataxia of the limbs (appendicular ataxia)

Front 20

name the four functional groups of the cerebellum

Back 20

1. Lateral hemispheres
2. Intermediate hemispheres
3. Vermis
4. flocculonodular lobe.

Front 21

What is the function of the lateral hemisphere of the cerebellum?

Back 21

Motor planning for extremities

Front 22

What is the function of the intermediate hemisphere of the cerebellum?

Back 22

Distal limb coordination

Front 23

What is the function of the vermis?

Back 23

Vermis = Proximal limb and trunk coordination

Front 24

Blood supply to the cerebellum is supplied by which three arteries?

Back 24

1. The posterior inferior cerebellar artery (PICA)
2. The anterior inferior cerebellar artery (AICA)
3. The superior cerebellar artery (SCA)

Front 25

Name the main components of the basal ganglia

Back 25

Caudate,
lentiform nucleus (Putamen, Globus-pallidus),
Subthalamic nucleus,
Substantia nigra,

Front 26

What is "hemiballismus"?

Back 26

An unilateral wild flinging movements of the extremities contralateral to a lesion in the basal ganglia, typically involving the subthalamic nucleus

Front 27

Name the four parallel channels through the basal ganglia

Back 27

1. Motor channel (putamen)
2. Oculomotor (caudate, body)
3. Prefrontal (Caudate, head)
4. Limbic (Nucleus accumbens; central caudate, ventral putamen)

Front 28

Define: bradykinesia

Back 28

"slowed movements"

Front 29

Define: Hypokinesia

Back 29

"decreased amount of movements"

Front 30

Define: Akinesia

Back 30

"Absence of movements"

Front 31

What are components of the pyramidal system?

Back 31

1. Motor cortex
2. Pyramidal tract
3. Anterior horn cells

Front 32

What are components of the extra-pyramidal system?

Back 32

1. Basal ganglia
2. Thalamus

Front 33

Describe the characteristic pathology of the pyramidal system

Back 33

1. Spasticity - velocity dependent resistance to movement; more obvious with quick movements
2. Weakness
3. Paralysis

Front 34

Describe the characteristic pathology of the extra-pyramidal system

Back 34

1. Rigidity - not velocity dependent; constant resistance
2. NO Weakness but clumsiness and involuntary movements
3. NO Paralysis; increased or decreased movements

Front 35

Name the three cerebellar peduncles

Back 35

1. Inferior cerebellar
2. middle cerebellar
3. Superior cerebellar

Front 36

What is the Flocculonodular lobe of the cerebellum responsible for?

Back 36

Flocculonodular lobe = balance and vestibulo-ocular reflexes

Front 37

What areas of the brain does the anterior cerebral artery supply?

Back 37

The ACA supplies the medial surface if the hemisphere from the frontal pole to the parieto-occipital sulcus

Front 38

Where is the most common site of aneurysms?

Back 38

The anterior communicating artery (which connects the two anterior cerebral hemispheres is the most common site of aneurysms of the circle of Willis.

Front 39

What portions of the motor / sensory cortices does the ACA irrigate?

Back 39

The leg-foot areas

Front 40

What areas of the brain does the middle cerebral artery supply?

Back 40

The MCA supplies the lateral convexity of the hemisphere which includes:
1. Broca's and Wernicke's areas
2. The face and arm areas of the motor and sensory cortices
3. The frontal eye field

Front 41

Name the components of the basal ganaglia

Back 41

Components of the Basal Ganglia:
1. Caudate nucleus
2. Putamen
3. Globus Pallidus

Front 42

Groupings of the basal ganglia: define the striatum

Back 42

striatum = caudate nucleus + putamen+globus pallidus

Front 43

Groupings of the basal ganglia: define the lentiform nucleus

Back 43

the lentiform nucleus = Globus pallidus + putamen

Front 44

What are the basal ganglia involved in?

Back 44

The basal ganglia are involved in the modulation of voluntary motor activity

Front 45

What is the blood supply for the globus pallidus (lateral and medial segments)?

Back 45

The middle cerebral artery (MCA)

Front 46

What is the blood supply of the subthalamic nucleus?

Back 46

The posterior cerebral artery and posterior communicating arteries

Front 47

What is the blood supply of the caudate, putament and internal capsule?

Back 47

Branches of the MCA (medial and lateral striae)

Front 48

Name the three functions of the cerebellum

Back 48

1. Maintenance of posture and balance
2. Maintenance of muscle tone
3. Coordination of voluntary motor activity

Front 49

Describe anterior vermis syndrome

Back 49

Usually involves leg region
Results from atrophy of rostral vermis - most commonly by alcohol abuse
Causes gait, trunk and leg dystaxia

Front 50

Describe posterior vermis syndrome

Back 50

Usually involves the flocconodular lobe
Results from brain tumors
Causes trunkal ataxia

Front 51

Describe hemispheric syndrome

Back 51

Usually involves one cerebellar hemisphere
Result of brain tumor or abscess
Causes arm, leg and gait ataxia and IPSILATERAL cerebellar signs

Front 52

What do the inferior peduncles carry?

Back 52

1. Afferent fibres from:
A. spinal cord (Spinocerebellar, Cuneocerebellar tracts)
B. inferior olive
C. the vestibular nuclei
2. Efferent fibres from
A. Vestibulocerebellar tract
B. Olivocerebellar tract
C. Post-spinocerebellar

Front 53

What fibres do the middle cerebellar peduncles carry?

Back 53

Carry pontocerebellar fibres that originate in contralateral pontine nuclei and terminate in cerebellum

Front 54

What fibres do the superior peduncles carry?

Back 54

1. Afferent fibres from
A. Anterior spinocerebellar tract
B. Acoustic & optic information
2. Efferent fibres from
A. Red nucleus
B. Thalamus

Front 55

What cerebellar structures does PICA supply?

Back 55

Most of the inferior surface of cerebellar
1. hemispheres
2. Vermis
3. Rostal medulla

Front 56

What cerebellar structures does PICA supply?

Back 56

More lateral portions of the inferior surface of the cerebellum, including; flocculus, caudal parts of inferior and middle cerebrllar peduncles

Front 57

What structures are supplied by the SCA?

Back 57

They supply the superior surface of the cerebellum, most cerebellar nuclei, rostral parts of the middle cerebellar peduncle and all of the superior peduncle.

Front 58

What three arteries supply the cerebellum?

Back 58

1. PICA
2. AICA
3. SCA

Front 59

What to the vestibulocerebellar afferents provide information from?

Back 59

- provide information about the position of the head and body in space
- help to orient eye movements during locomotion

Front 60

What occurs when there is a lesion of the vestibulocerebellum?

Back 60

- Disturbances in vestibular function / balance and eye movements
A) limb ataxia - incoordination
B) Staggering wide based gait
C) May sway when walking
D) Truncal ataxia
E) Nystagmus

Front 61

Spinocerebellar connections carry what kind of information?

Back 61

Carry proprioceptive information from spinal cord to cerebellum. Called unconscious proprioception

Front 62

What characterizes a lesion of the spinocerebellum?

Back 62

Anterior lobe syndrome (Spinocerebellar disturbance)
results in postural instability:
A) Limb ataxia
B) Staggering wide based gait

Front 63

What are the afferents of the spinocerebellar connections?

Back 63

Dorsal
- Ia, II fibres from muscle spindles
- Proprioception
- Fibers from clarke's column
(travel through ICP)
Anterior
- IIb fibres from golgi tendon organ
- Muscle force
(travel through SCP)

Front 64

What do the corticopontine connections do?

Back 64

Influence planning, initiation, timing and coordination of voluntary movement

Front 65

What are the vestibulospinal tracts important for?

Back 65

Are important mediators of postural adjustments and head movements.
1. lateral = facilitates extensors
2. Medial = influences neck and axial muscles

Front 66

What role do the reticulospinal tracts play?

Back 66

Play a role in influencing voluntray movement and muscle tone

Front 67

Rubrospinal tract plays what function?

Back 67

Has a minor role in influencing voluntary movement
(facilitates flexor and extensor muscle activity)
Probably of minor importance in humans

Front 68

Describe the mamillary body of the hypothalamus?

Back 68

- receives input from hippocampal formation via fornix
- projects to anterior nucleus of thalamus

Front 69

Where are the hemorrhagic lesions caused by Wernicke's encephalopathy located?

Back 69

They are located in the mamillary body of the hypothalamus

Front 70

Describe the Fornix of the Hypothalamus

Back 70

- Major fibre system of the hypothalamus
- Largest projection to the hypothalamus
- It projects
Hippocampal to mammillary nucleus, anterior nucleus of thalamus and septal area

Front 71

Describe the mamillothalamic tract of the hypothalamus

Back 71

- Major fibre system of the hypothalamus
- Projects from the mamillary nuclei to tha naterior nucleus of the thalamus
- Part of papez circuit

Front 72

What are the four main functions of the hypothalamus?

Back 72

1. Autonomic function (anterior / posterior hypothalamus)
2. Temperature regulation
3. Water balance
4. Food intake regulation

Front 73

In general terms what role does the limbic system play?

Back 73

The limbic system is considered the anatomic substrate that underlies behavioral and emotional expression
It is expressed through the hypothalamus by way of the autonomic NS

Front 74

Describe the olfactory nerves (CN I)

Back 74

- bipolar neurons
- Dendrites extend to surface - specialized as receptors
- Axons collected into bundles that form the olfactory nerve. These cross the cribiform plate and synapse in olfactory bulb where processing occurs
- Olfactory tract carries information to primary olfactory cortex

Front 75

Describe the components of the olfactory nerve (CN I)

Back 75

1. SSA: mediates smell

Front 76

Describe the components of the optic nerve (CN II)

Back 76

1. SSA: Vision and light relfexes

Front 77

Describe the components of the occulomotor nerve (CN III)

Back 77

1. GSE:
Eye muscles: medial, superior, inferior rectus muscles as well as the inferior oblique.
Upper eyelid: levator palpebrae muscle
2. GVE: sphincter muscle of iris (miosis) and ciliary muscle (accomodation)

Front 78

Describe the components of the trochlear nerve (CN IV)

Back 78

1. GSE: innervates superior oblique muscle (depresses and abducts eye)

Hint 78

remember: LR6, SO4 all others 3

Front 79

Describe the components of the Trigeminal nerve (CN V)

Back 79

1. SVE: special visceral
- muscles of mastication
2. GSA General somatic afferent
- sensory innervation of face

Front 80

Describe the components of the abducent nerve (CN VI)

Back 80

1. GSE: innervates the lateral rectus muscle of the eye (abducts the eye)

Hint 80

Remember LR6, SO4, All others 3

Front 81

Describe the components of the facial nerve (CN VII)

Back 81

1. GSA: posterior surface of external ear
2. GVA: minor role (not clinically important)
3. SVA: taste buds from anterior 2/3 of tongue
4. GVE: lacrimal, submandibular and sublingual glands
5. SVE: stapedius muscle of middle ear, muscles of facial expression

Front 82

Describe the components of the vestibulocochlear nerve (CN VIII)

Back 82

1. SSA: equilibrium and balance, hearing

Front 83

Describe the components of the glossopharyngeal nerve (CN IX)

Back 83

1. GSA: external ear
2. GVA: Carotid sinus
3. SVA: tase from posterior 1/3 of tongue
4. SVE: stylopharyngeus muscle
5. GVE: parotid gland

Front 84

Describe the components of the accessory nerve (CN XI)

Back 84

1. SVE: mediates head and shoulder movement, and innervates laryngeal muscles

Front 85

Describe the components of the hypoglossal nerve (CN XII)

Back 85

1. GSE: mediates tongue movements

Front 86

How many spinal nerves are there?

Back 86

31 in total:
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Front 87

What does the posterior horn of the spinal cord do?

Back 87

Receives and processes sensory information

Front 88

What does the anterior horn of the spinal cord do?

Back 88

The cell bodies of nerves inverating skeletal muscles are found here

Front 89

Define: Clarke's Nucleus

Back 89

Clarke's nucleus is a small section of grey matter located in lamina VII of the intermediate zone spinal cord which is found ventral to the gracile column and cuneate column and is involved in unconscious proprioception. It is found at the level of T1-L2 (lumbar vertebrae) on the spinal cord.

Front 90

What makes up the posterior arterial supply of the CNS?

Back 90

1. Vertebral arteries (give rise to: Anterior / posterior spinal arteries, PICA)
2. Basilar artery (Give rise to AICA, Pontine arteries, SCA)
3. POsterior cerebral arteries

Front 91

What makes up the anterior arterial supply of the CNS?

Back 91

1. The internal carotids (give rise to ACA, MCA)

Front 92

Spinal cord vasculature: describe the anterior spinal artery

Back 92

- branches off each vertebral artery to join and form ASA
- Runs in anterior median fissure
- Supplies 2/3 of paramedian and lateral areas

Front 93

Spinal cord vasculature: describe the posterior spinal arteries

Back 93

- Arise from veretbral arteries or PICAs
- Run in posterolateral sulci
- Supply posterior 1/3 of cord (dorsomedial and dorsolateral areas)

Front 94

What is the function of the dorsal column - medial lemniscus pathway

Back 94

mediates tactile discrimination, vibration sensation, form recognition and joint / muscle sensation)

Front 95

What receptors feed the dorsal column - medial lemniscus pathway

Back 95

Pacini's
Meissner's tactile corpuscle
joint capsules
muscle spindles
Golgi tendon organs

Front 96

What is the function of the lateral spinothalamic tract?

Back 96

mediates pain and temperature sensation

Front 97

What receptors feed the lateral spinothalamic tract?

Back 97

Free nerve endings
- the lateral spinothalamic tract recieves input from the fast and slow conducting pain fibres (A-delta and C)