PHRM 845 Exam 3 Roche

Question 1

What composes the Hindbrain?

Answer 1

• medulla

- pons, cerebellum

Question 2

What composes the midbrain?

Answer 2

-substantia nigra

Question 3

What composes the forebrain?

Answer 3

• cerebral cortex
• basal ganglia
• limbic system
• diencephalon

Question 4

medulla (autonomic functions)

Answer 4

• includes centers for controlling respiration, cardiac functionm vasomotor responses, and reflexes
• part of the reticular system and brain stem

Question 5

pons “bridge”

Answer 5

• relays signals from the forebrain to the cerebellum

- part of the brain stem

Question 6

cerebellum

Answer 6

• governs motor coordination for producing smooth movements

- undergoes neurodegeneration in spinocerebellar ataxias

Question 7

SN pars compacta

Answer 7

• provides input to the basal ganglia, supplies dopamine to the striatum
• involved in voluntary motor control
• undergoes neurodegeneration in PD

Question 8

SN pars reticulata

Answer 8

-output function, relays signals from the basal ganglia to the thalamus

Question 9

cortex (cerebrum)

Answer 9

-involved in processing and interpreting info (decision making, higher level functions)

Question 10

basal ganglia

Answer 10

voluntary motor control, some cognitive functions

Question 11

limbic system

Answer 11

• emotions (amygdala)

- memory (hippocampus)

Question 12

diencephalon

Answer 12

• thalamus: relay station to and from cortex

- hypothalamus: regulates internal homeostasis, emotions, hormonal control and direct neural regulation

Question 13

How are “decisions” made in the brain

Answer 13

the senses receive info about the environment, which is passed through the thalamus to the cortex and back. this is called a cortico-thalamic loop

Question 14

efferent neuron tracks

Answer 14

transmit signals from the cortex to the periphery

Question 15

afferent neuron tracks

Answer 15

transmit signals from the periphery to the cortex

Question 16

meninges

Answer 16

layers of membranes that surround the brain

• dura (outer layer below skull)
• arachnoid: middle
• pia: inner layer

Question 17

What artery does blood enter the brain through?

Answer 17

carotid

Question 18

astrocytes

Answer 18

• provide neurons with growth factors, antioxidants
• remove excess glutamate (excitotoxic neurotransmitter)
• support the blood-brain barrier

Question 19

oligodendrocytes

Answer 19

-produce myelin sheath that insulates axons

Question 20

microglia

Answer 20

• provide growth factors
• clear debris by phagocytosis
• role in neuroinflammation

Question 21

how is neurotransmission triggered

Answer 21

-electrical depolarization of the neuron by an influx of Na ions that changes the charge polarity of the membrane

Question 22

EPSP

Answer 22

excitatory postsynaptic potential

-works when an excitatory neurotransmitter acts on an ionotropic receptor, allowing Na ions to cross the membrane

Question 23

IPSP

Answer 23

inhibitory postsynaptic potential

• induces hyperpolarization by allowing Cl ions to cross the membrane
• they can decrease the magnitude of a subsequent EPSP

Question 24

GABA

Answer 24

• major inhibitory neurotransmitter in the brain
• depresses neuronal excitability by increasing the flux of Cl ions into the neuron
• there are A and B receptors
• drugs affecting GABA are generally CNS depressants and include: sedative hypnotics, anticonvulsants, anxiolytics

Question 25

glycine

Answer 25

- inhibitory neurotransmitter released by interneurons in the spinal cord - like GABA, induces hyperpolarization by allowing the inward flow of Cl ions - antagonized by toxic alkaloid strychnine

Question 26

glutamate

Answer 26

- major excitatory aa neurotransmitter in the brain - excess glutamate can cause neuronal damage by allowing excessive Ca influx into the neuron - metabotropic (GPCRs) or ionotropic (NMDA and AMPA)

Question 27

acetylcholine

Answer 27

- both muscarinic and nicotinic receptors | - an example is a cholinesterase inhibitor

Question 28

dopamine

Answer 28

- drug targets include D1-D5 receptors and dopamine transporter - DA neurons arise from the ventral tegmental area and the SN - drugs that interact with DA pathways include: antipsychotics and D2/D3 and D1 receptor agonists for PD

Question 29

norepinephrine

Answer 29

- drug targets include the a and b adrenergic receptors (GPCRs) and the norepinephrine transporter - NE axons arise from the locus coeruleus in the brain stem - NET inhibitors are used to treat depression

Question 30

serotonin, 5-HT

Answer 30

- drug targets are serotonin receptors and serotonin transporter - 5-HT axons arise from a group of cell bodies in the brainstem called raphe nuclei - serotonin systems are involved in sleep, vigilancem mood, and sexual function - drugs include: 5-HT2a antagonsits as atypical antipsychotics, 5-HT1D agonists for migraine, SERT uptake inhibitors for depression, 5-HT2A agonists are hallucinogenic

Question 31

multiple sclerosis

Answer 31

-immune-mediated inflam disorder involving destruction of the myelin sheath that surrounds neuronal axons

Question 32

sclerosis

Answer 32

scars that accumulate in the white matter of MS patients

Question 33

Genes linked to MS encode what immune related proteins?

Answer 33

- MHC (HLA)-DR15/DR6 - interleukin-2a receptor - interleukin-7a receptor

Question 34

relapsing-remitting MS

Answer 34

- involves relapses of neurological dysfunction lasting weeks or months and affecting the brain, optic nerves and/or spinal cord. - multifocal areas of damage are revealed by magnetic resonanace imaging, generally in white matter - initial symptoms disappear, but less remission with each relapse - most cases of RRMS eventually enter a phase of SPMS

Question 35

Secondary progressive MS

Answer 35

- characterized by less inflammation than RRMS | - involves slowly progressive neurological decline and CNS damage with little remission

Question 36

Primary progressive MS

Answer 36

- resembles SPMS at the initial stage of the disease | - mean age of onset is later then RRMS

Question 37

Clinically isolated syndrome (CIS)

Answer 37

- initial episode of neurologic symptoms lasting more than 24hrs - involves inflammation and demyelination in the optic nerve, cerebrum, cerebellum, brainstem or spinal cord - most cases progress to MS

Question 38

Marburg variant of MS

Answer 38

- aggressive form of MS involving a high degree of inflammation - may resemble a brain tumor in a brain scan

Question 39

Autoimmune phase

Answer 39

- antigens released from CNS are presented to B and T cells in lymph nodes. - B and T cells w/high affinity receptors for these antigens are expanded and migrate to CNS sites where they-reencounter and are activated by their target ligands - activated B and T cells then carry out immune functions at the CNS sites

Question 40

Degenerative phase

Answer 40

- CNS damage is triggered by activated B and T cells or by other insults such as infection or stroke - antigens released from damaged sites in the CNS further prime immune cells in the periphery, thus completing a vicious cycle