Lecture Chapters 12 and 13 Flashcards
Nervous System
What are the branches of structural Organization of the Nervous System?
Central and Peripheral
What are the branches of Functional Organization of the Nervous System?
- Sensory (Input)
- Somatic and Visceral
- Motor (Output)
- Somatic and Autonomic
What are the structural classification of neurons?
Multipolar Neuron
Bipolar Neuron
Unipolar Neuron
Anaxonic Neuron
Which neurons are unipolar?
Sensory Receptors
Which neurons are anaxonic?
Interneurons
Which type of neurons are afferent?
Sensory (ascending)
Which type of neurons are efferent?
Motor (descending)
What is the relation (in numbers) between neurons and glial cells?
Glial cells outnumber neurons 10:1
What do astrocytes do/have?
Perivascular Feet
Blood-Brain Barrier
Calcium Reservoir
What do ependymal cells do?
Allow nutrients to enter the brain
What do microglial cells do?
Macrophages in the brain (Pathogen-killing)
What do oligodendrocytes do?
Mylenates Axons within the brain and spinal cord
MS attacks these cells
What do neurolemmocytes do?
Myelinate axons in the PNS
What do satellite cells in the PNS do?
Electrically insulate cell bodies
Regulate nutrient and waste exchange
What is resting membrane potential determined by?
Unequal distribution of ions in the ECF and cytosol
Inability of most anions to leave the cells
Na+K+ ATPases (sodium-potassium pump)
What are the four segments of a neuron?
Receptive
Initial
Conductive
Transmissive
What kind of response do ionotropic receptors induce?
Open channels
Direct Response
What kind of response do metabotropic receptors induce?
Indirect action
G-protien signaling
What is the type of circuit involved in a reflex?
Parallel-After-Discharge circuit
What enzymes synthesize and degrade ACh?
Synthesized by enzyme choline acetyltransferase
Degraded by the enzyme acetylcholinesterase
What neurotransmitter is involved with anxiety?
Decreased GABA activity
Which neurotransmitters are cetecholamines (adreniline)?
Dopamine
Norepinephrine
Epinephrine
Which neurotransmitters are Indolamines (Pleasurable Activities)?
Serotonin
Histamines
Which neurotransmitters are Neuropeptides?
Substance P (pain)
Endorphines (natural opiates)
Gut-brain peptides (somatostatin and cholecytokinin)
When does gastrolation occur in a fetus?
21 days after fertilization
What gives rise to the brain and the spinal cord?
The neural tube
What is anencephaly, and what is the prognosis?
Missing large amounts of brain tissue
Stillbrith or neonatal death
What is encephalocoele, and what is the prognosis?
Brain material outside of the cranial cavity
High mortality rate from meningitis
What is spina bifida cystica, and what is the prognosis?
Failure of closure of the neural tube in the caudal region, resulting in protruding spinal cord
Often accompanied by hydrocephaly
Variable levels of disability, but treatable
What is microcephaly, and what is it caused by?
Small cranial cavity
Zika virus
What is the most common type of brain cancer, and what cells does it affect?
Malignant Glioma
Astrocytes
What is the other name for neurolemmocytes?
Schwann Cells
What are the two mylenation defects, and where in the nervous system do they occur?
MS: CNS
Buillain Barre Syndrome: PNS
How do microglia function?
Moving to the area needing attention (macrophaging)
What axons can regenrate?
PNS axons, but it depends on amount of damage, and distance from structure it innervates
What are the steps in axon regeneration?
- Axon severed
- Proximal end sealed off by membrane fusion
- Neurilemma and endoneurium form
- Axon regenerated at 2-5mm per day
- Innervation restored
When is the inactivation of Na+ channels?
During the refractory period
What kinds of channels are on the different segments of neurons?
- Receptive: chemically-gated channels, production of graded potentials, K+ and Cl-
- Initial: axon hillock: voltage-gated Na+ and K+
- Conductive: voltage-gated Na+ and K+
- Transmissive: Ca2+ pump and voltage-gated Ca2+ channels
What are postsynaptic potentials?
Graded potentials in postsynaptic neurons
What does the degree of change in the RMP depend on?
Amount of neurotransmitter bound
What is spacial summation?
Multiple Presynaptic neurons release neurotransmitter at various locations
What is temporal Summation?
Single Presynaptic neuron repreatedly releases neurotransmitter at one location
A new drug has been discovered (a competitive agonist) that binds with higher affinity and resultls in stronger activation of metabotropic ACh receptors on the receptive segment of a neuron. Which results could be seen because of the drug?
1) Potassium Channels Opening
2) G protein activation
4) Inhibitory post-synaptic potential
When does spina bifida occur?
21 days
What cells produce CSF?
Ependymal cells
What is the Chiari malformation?
Cerebellum “sucked down” into the spinal cavity due to spina bifida
What are cerebral (basal) nuclei?
- Distinct masses of grey matter in each cerebral hemisphere
- Tracts of cerebral white matter
What are the functions of the prefrontal cortex?
Intellect, complex learning, recall, personality, ability to anticipate consequences of events
What makes up the diencephalon?
Epithalamus, Thalamus, Hypothalamus
What is the main function of the hypothalamus?
Homeostasis
What is the cause of SAD
Irregular hypothalamus function
What is the main function of the cerebellum?
Fluidity of movement
What is the main function of the limbic system?
Emotion
What is the main function of the reticular formation?
Focus on a specific conversation in a crowded room
What are the folds of the cerebellar cortex called?
Folia
The cerebellum is the ____ largest part of the brain.
Second
