Term
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Definition
| Motor neuron + innervated muscles |
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Term
| Why does the motor unit vary in different muscles? |
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Definition
| Varies based on size; stapedius will have 2-3 muscles/motor neuron and gastrognemius will have ~1000 muscles/motor neuron |
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Term
| What are the three types of muscle fibers? What size neurons are associated with them? |
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Definition
| Red (slow twitch - small motor neuron), intermediate (fast twitch fatigue resistant - intermediate size motor neuron), and white (fast twitch, fatigable - large motor neuron) |
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Term
| What is the size principal upon which recuriting muscle fibers during contraction is based? |
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Definition
| Smallest neurons are recruited first |
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Term
| T or F a single motor unit has only one type of muscle |
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Definition
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Term
| T or F Individual muscles are composed of only one type of muscle fiber |
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Definition
| F Individual muscles are composed of all three fiber types |
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Term
| What are the three types of receptors that are sending information about the state of the muscle to the CNS? |
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Definition
Primary, secondary, and Golgi Every muscle, w/ few exceptions, contains all three types |
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Term
| What do spindle organs and Golgi tendon receptors detect? |
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Definition
Spindle organs - muscle length and rate of change of muscle length Golgi tendon receptors - muscle tension and rate of change of tension |
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Term
| Where do the primary and secondary muscle spindle receptors and Golgi tendon organs feed into? |
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Definition
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Term
| From where do the primary and secondary afferent muscle spindle stretch receptors arise from? |
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Definition
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Term
| What motor neurons comprise the motor neuron pool? |
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Definition
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Term
| What do the alpha motor neurons do? |
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Definition
| Innerate the contractile muscle fibers including slow, fast-twitch fatigue resistant, and fast-twitch |
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Term
| What do gamma motor neurons do? |
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Definition
| Innervate the muscles of stretch receptors and are of two types: fusimotor and dynamic fusimotor |
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Term
| Are alpha or gamma motor neurons larger? |
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Definition
|
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Term
| What fibers are the sensory basis of the stretch receptor refelexes of the spinal cord? |
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Definition
|
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Term
| Where does sensory innervation of the spindle come from? |
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Definition
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Term
| A single muscle stretch receptor is made of of two types of fibers. What are they? |
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Definition
| Nuclear bag and nuclear chain fibers |
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Term
| To which afferents and fusimotor efferents are the neuclear bag fibers and the nuclear chain fibers associated? |
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Definition
Nuclear bag: Group 1a afferents and dynamic fusimotor efferents Nuclear chain: Group II afferents and static efferents |
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Term
| What does a stretch of muscle reveal about the components of primary (1a) and secondary (Group II) fibers? |
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Definition
Primary (1a) - dynamic and static components Secondary (Group II) - static only (muscle length) |
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Term
| Which fiber responds best to a brief stretch? |
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Definition
| the 1a fibers (Group II is minimally affected) |
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Term
| Tendon tap reflexes are initiated by which spindle stretch receptors? |
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Definition
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Term
| What does the limbic system control? |
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Definition
| Motivation, memory and movement |
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Term
| Why is the limbic system difficult to study in the lab? |
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Definition
| Because its structures are interconnected and it is difficult tomeasure emotions |
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Term
| What are the elements of the limbic system? |
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Definition
Amygdala, hippocampus, cingulate gyrus, prefrontal cortex, septal nuclei, anterior nucleus of the thalamus, mammillary bodies |
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Term
| What is the Papez circuit? |
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Definition
| Circuitry of the limbic system |
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Term
| Where are the amygdala and the hippocampus? |
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Definition
|
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Term
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Definition
| Axons coming from the hippocampus to mammillary bodies and to the septal nucleus |
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Term
| What is the mammillothalamic tract? |
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Definition
| Axons from the mammillary bodies to the anterior nucleus of thalamus |
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Term
| What three pathways make up the Papez circuit? |
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Definition
- Fornix - axons from hippocampus to mammillary bodies or septal nucleus
- Mammilothalamic tract -mammillary bodies to anterior nucleus of thalamus
- Thalamus to prefrontal cortex and singulate gyrus
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Term
| What organ is always involved in the lymbic system? |
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Definition
|
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Term
| What type of innervation do the limbic areas receive? |
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Definition
| Monoaminergic (norepi, dopa, seratonin) and cholinergic (ACh) |
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Term
| Where are the cell bodies making NE located? |
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Definition
| The pons in the locus cerulius |
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Term
| Where are the cell bodies making serotonin located? |
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Definition
| In the raphe nuclei from pons to midbrain |
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Term
| What is the monoamine hypothesis of depression? |
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Definition
| In people with depression there is a decrease in NE, serotonin, or in the receptor activity for NE or serotonin |
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Term
| What are the therapies used for treating the monoamine hypothesis of depression? |
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Definition
- MAO inhibitor - Decrease monoamine oxidase (which metabolizes NE and 5HT)
- Tricyclic antidepressants - block reuptake of NE and 5HT to increase them in the synaptic cleft
- SSRIs - specific seratonin reuptake inhibitor, ie Prozac
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Term
| What is the dopamine hypothesis of schizophrenia? |
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Definition
| It is caused by an increase in dopamine or dopamine receptor activity? |
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Term
| What is the strategy for treating schizophrenia? |
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Definition
| Block DA receptors (halperidol for ex) |
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Term
What is the etiology of Alzheimers?
|
|
Definition
| Neurodegeneration that includes limbic structures (hippocampus) and loss of ACh |
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Term
| Where are the cell bodies releasing ACh found? |
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Definition
| Septal nucleus and nucleus basalis |
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Term
| To what organ do septal nucleus and nucleus basalis project? |
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Definition
|
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Term
| The mesolimbic system is the center for what: |
|
Definition
| motivation and positive reinforcement |
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Term
| Where is the mesolimbic system located? |
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Definition
|
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Term
| What NT is made in the VTA? |
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Definition
|
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Term
| To where does the VTA project to release dopamine? |
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Definition
| Septal nucleus, cingulate nucleus, and nucleus accumbins |
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Term
| How does addiction work (ie cocaine and amphetamines)? |
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Definition
| Increase DA in synapse by blocking DA reuptake |
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Term
| What happens when the VTA is lesioned? |
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Definition
| There is a decrease in addictive behavior |
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Term
| The amygdala is the center of what? |
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Definition
|
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Term
| What is urback-Wieth disease? |
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Definition
| Bilateral amygdala lesions causing the patient to not show fear conditioning |
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Term
| Continual electric shocking of the amygdala paired with a neurtal tone will cause what? |
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Definition
| Conditioned fear to the tone causing inc HR and freezing behavior |
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Term
| What happens to fear that is already conditioned if the amygdala is lesioned? |
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Definition
|
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Term
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Definition
| Couldn't form new memories after surgery to temporal lobe (esp declarative memory ie facts) |
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Term
| For what is the hippocampus important? |
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Definition
|
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Term
| A lesion in the hippocampus results in what? |
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Definition
| Loss of declarative memory |
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Term
| What is Korsakoff's syndrome? |
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Definition
| Disorder of immediate memory causing disorientation and confabulation and inability to form new memories |
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Term
| What is the etiology of Korsakoff's syndrome? |
|
Definition
| Lesion in anterior nucles of thalamus and/or mammillary body |
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Term
| Korsakoff's syndrome is primarily found in who? |
|
Definition
| Alcoholics - deficiency in the vitamin thiamin due to inadequate diet |
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|
Term
| What are the symptoms of Kluver Bucy Syndrome? |
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Definition
| Oral tendencies, changes in emotions, hypersexuality, visual agnosia (inability to discriminate visual stimuli) |
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|
Term
| What is the etiology of Kluver Bucy Syndrome? |
|
Definition
| Damage to temporal cortex including amygdala and hippocampus |
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Term
| What are the progressivesymptoms of Alzheimers? |
|
Definition
- Loss of memory
- Anxiety and/or depression
- Loss of motor fucntion
- Complete loss of cognitive function
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Term
| A loss of prefrontal cortex (Phineas Gage) results in: |
|
Definition
- More impulsive behavior
- Loss of planning
- Inc in profanity
- Dec in social responsibility
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Term
| What system maintains homeostasis? |
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Definition
|
|
Term
| The hypothalamus integrates what to control what? |
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Definition
| Integrates info from peripheral and central receptors to control ANS, limbic system and pitutiary gland |
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|
Term
| What is the median eminence (infundibulum)? |
|
Definition
| Where the hypothalamus and pituitary intersect |
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|
Term
| Is the anterior or posterior pituitary a true endocrine gland? |
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Definition
| Anterior, releases directly into blood stream |
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|
Term
| Where are oxytocin and vasopressin synthesized? |
|
Definition
| Magnocellular neurons in the supraoptic and paraventricular nuclei |
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|
Term
| How are the post pit hormones transported? |
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Definition
| Via axons through the median eminence to the post pit. where they are released into the blood stream |
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Term
| What are the stimuli and effects of vasopressin? |
|
Definition
Inc in blood osmolarity or dec in volume or pressure Inc in water retention or vasoconstriction |
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|
Term
| What are the stimuli and effects for oxytocin? |
|
Definition
uterine stimulation --> uterine contraction Suckling --> Milk ejection from mammary gland Genital stimulation leading to orgasm --> contractile elements in genitalia |
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Term
| What are the somatomammotropins? |
|
Definition
| Growth hormone and prolactin |
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Term
| Stimuli and effects of growth hormone? |
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Definition
| Exercise, stress, slow wave sleep --> growth of tissues and metabolism |
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|
Term
| Stimuli and effects of prolactin? |
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Definition
| Suckling and stress --> Cause milk production |
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|
Term
| What are the glycoproteins? |
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Definition
|
|
Term
| Stimuli and effects on TSH? |
|
Definition
| Cold temperature --> synthesis and secretion of thyroid hormone |
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|
Term
| What are the effects of FSH? |
|
Definition
| spermatogenesis and ovarian development |
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|
Term
| What are the effects of LH? |
|
Definition
Stimulation of testosterone Ovulation and inc stim of progesterone |
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Term
| What is pro-opiomelanocortin (POMC)? |
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Definition
| The common precursor to ACTH and Beta-endorphin |
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Term
| What are the opiomelanocortin peptides? |
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Definition
|
|
Term
| Stimuli and effects of ACTH? |
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Definition
| Stress and inc. secretion of adrenal corticol hormone: cortisol |
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|
Term
| Stimuli and effects of B-endorphin? |
|
Definition
Stimuli: stress Effect: opiate-like peptide --> analgesia |
|
|
Term
| TRH, GnRH, CRH (corticotropin rel hormone), and GHRH cause increases in what? |
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Definition
TRH --> TSH GnRH --> FSH LH CRH --> ACTH and B endorphin GHRH --> GH |
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|
Term
| Where are hypothalamic releasing factors synthesized? |
|
Definition
| In the parvocellular neurons |
|
|
Term
| Where do axons transporting hypothalamic releaasing factors terminate? |
|
Definition
|
|
Term
| Where are hypophyseal releasing factors released? |
|
Definition
| Into the hypophyseal portal blood system |
|
|
Term
| What is the junction between the parvocellular neurons (1st capillary bed) and 2nd capillary bed? |
|
Definition
|
|
Term
| Where is somatostatin released from? What is its affect? |
|
Definition
| Hypothalamus; its inhibitory and causes decrease in GH |
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|
Term
| What is the only hormone with both inhibitory and excitatory inputs? Is this net excitatory or inhibitory? |
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Definition
|
|
Term
| What is the affect of dopamine? |
|
Definition
|
|
Term
| What is only hormone under net inhibitory control? |
|
Definition
|
|
Term
| Loss of secretion of what hormone occurs in diabetes insipidus? What are the symptoms? Treatment? |
|
Definition
Vasopressin Polyuria, excesive urination, polydipsia Give analog of vasopressin (antidiuretic w/o vasoconstriction) |
|
|
Term
| What is the etiology of diabetes insipidus? |
|
Definition
Head trauma resulting in pit stalk section losing connection between magnocellular neurons and post. pit. OR Autoimmune loss of magnocellular neurons |
|
|
Term
| Hyperprolactinemia causes: |
|
Definition
| inc in prolactin in blood causing decrease in FSH and LH causing cessation of menstruation and inappropriate lactation |
|
|
Term
| What is the etiology and tx of hyperprolatinemia? |
|
Definition
Etiology: Pit. microadenoma and inc secretion of prolactin Tx: give dopamine or dopamine receptor agonist |
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|
Term
| What is the general concept of hypothalamic control systems? |
|
Definition
- Measured by feedback detectors
- Compare to set point (desired value)
- Integrator or error detector generates error signal
- Error signal drives controlling elements to correct
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|
|
Term
| As temperature decreases what happens to core and shell? |
|
Definition
| Core shrinks and shell increases in size |
|
|
Term
| What are the primary and secondary sites of heat loss? |
|
Definition
Primary - skin Secondary - lung |
|
|
Term
| What are the primary and secondary efferent mechanisms for regulating heat loss or production? |
|
Definition
- Primary
- Secondary
- Sweating
- Inc cellular metabolis
- Shivering-induced thermogenesis
- Non-shivering thermogenesis
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|
|
Term
| How does the vasomotor mechanism regulate heat loss? |
|
Definition
| Changes blood flow to the skin; inc vasodilation to lose heat and dec vasodialtion to retain heat |
|
|
Term
| What causes vasoconstriction and vasodilation to control body temp? |
|
Definition
Vasoconstriction --> Norepi from postganglionic sympathetic nn. Vasodilation: VIP (vasoactive intestinopeptide) from postgang symp nn (ACh also released but doesnt act directly on vasodilation only a cotransmitter) |
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|
Term
| What is the sympathetic effector of sweating? |
|
Definition
| ACh from sympathetic post-gang. ACh |
|
|
Term
| What are the effectors to increase cellular metabolism? |
|
Definition
| Inc thyroid hormone to inc cellular metabolism and inc heat production |
|
|
Term
| What is the mechanism and effector for shivering induced thermogenesis? |
|
Definition
Asynchronous skeletal muscle contraction (stim extensors and flexors together w/o movement) ACh is effector |
|
|
Term
| What is the mechanism and effector for nonshivering thermogenesis? |
|
Definition
BAT - has a protein that uncouples glucose oxidation from formation of ATP to generate heat instead Effectors are: NE and thyroid hormone |
|
|
Term
| What are the hot and cold receptors in the skin? What tract do they make up? |
|
Definition
Cold: A delta Warm: C fibers Spinothalamic tract |
|
|
Term
| What is in the anterior hypothalamic - preoptic area? |
|
Definition
| Central thermal receptors responding to inc in warming and cooling |
|
|
Term
|
Definition
| Through endogenous pyrogens |
|
|
Term
| Where do endogenous pyrogens come from? |
|
Definition
| Macrophages in response to bacterial or viral particles (lipopolysaccharides ofthe wall of bacteria/virus) |
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|
Term
| Where do enodgenous pyrogens (cytokines) act? What is the result? |
|
Definition
????Act on neurons in the AH/POA (anterior hypothalamic-preoptic area) resulting in a decreased firing rate of warm-sensitive neurons and inc. firing rate of cold-sensitive neurons
?????????? |
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