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Endocrine
MEDSCI 142
Question | Answer |
---|---|
The nervous system *two types* | *PNS= Peripheral nervous system *CNS=Central nervous system |
PNS | *Peripheral Nervous system -cranial & spinal nerves -ganglia |
CNS | *Central Nervous System -Brain -Spinal cord |
Sensory | -Afferent neurons -in |
Motor | -Efferent Neurons -out (1)Somatic (2)Autonomic |
Somatic | -motor -voluntary -skeletal muscle |
Autonomic | -motor -involuntary -para/sympathetic -cardiac muscle -smooth muscle -glands |
Alarm responce (immediate action) | INCREASED: HR,BP,Bsugar,water retention, sweating. DECREASED: digestion, salivation DILATION:pupils, bronchi. *vasoconstriction |
Relaxation (maintenance) | -INCREASED: digestion, salivation -DECREASED: HR -CONSTRICTION: pupils, bronchi -vaso dilation |
Relaxation (maintenance) | -INCREASED: digestion, salivation -DECREASED: HR -CONSTRICTION: pupils, bronchi -vaso dilation |
Stress response | -sympathetic activation -mobilise resources for action -glucose & O2 consumption -reduce tissue damage -ward off danger OR flee |
2 STAGES of stress response | (1)alarm (2)resistance |
(1)alarm | -immediate -sym activation -adrenal medulla sustains>epinephrine>norepinephrine |
(2)resistance | -slower, longer lasting -hypothal,pit.,andrenal cortex -cortisol production |
ANS | -autonomic nervous system -involuntary -limbic,hypothal.,s.cord -2 neuron pathways |
ANS pathways | spinalcord--(pre-ganglionic myelinated neuron)-->autonomic ganglion--(postganglionic non-myelinated ganglion)-->Effectors |
Effectors | ACh=for parasymp to sweat glands Norepinephrine=all other symp fibres |
Raynaud's | -excessive symp stim -emotional stress -exposure to cold -chronic vasoconstriction -ischemia(lack of blood in hands and feet) |
Hormone types | -circulating -local |
Circulating hormones | -to receptors -via blood -on distant target cells |
Local hormones (2TYPES) | -PARACRINE: receptors on nearby target cells -AUTOCRINE: same cell |
Effectors | ACh=for parasymp to sweat glands Norepinephrine=all other symp fibres |
Raynaud's | -excessive symp stim -emotional stress -exposure to cold -chronic vasoconstriction -ischemia(lack of blood in hands and feet) |
Hormone types | -circulating -local |
Circulating hormones | -to receptors -via blood -on distant target cells |
Local hormones (2TYPES) | -PARACRINE: receptors on nearby target cells -AUTOCRINE: same cell |
Cholera: toxin | -permanently activates Gprotein -high cAMP -pumps Cl- into intestines with water chronic diarrhoea |
Lipid soluble Hormones | -needs solution transporter -diffuse into cell -activates receptors on nucleus -alters gene expression -new proteins alter cell activity |
Water soluble Hormones | -no carrier -binds to receptors on cell surface -activate Gprotein>adenyl cyclase -ATP converted to cAMP -acivates kinases -P enzymes -catalyse reactions producing physiological responses |
Hypothalamus-pituitary axis | -hypo=8hormones releasing & inhibiting control pituitary -together regualte growth development, metabolism ,homeostasis |
Enhancing alarms response | -releasing norepinephrine & epinephrine into blood stream |
Adrenal gland MEDULLA | -STIMULATED:Ach from preganglionic nuerons -RELEASES: Norepinephrine, Epipinephrine -ACTION: enhance symp ANS alarm responce |
Adrenal gland CORTEX stimulation 1 | -STIMULATED: increase in K+ -releases corticoids (aldosterone) -ACTION: incr blood Na+ & water, decr. K+}incr blood vol & pressure |
Adrenal gland CORTEX stimulated 2 | -STIMULATED: Ach from pituitary |
Adrenal gland CORTEX stimulation 1 | -STIMULATED: increase in K+ -releases mineralo corticoids (aldosterone) -ACTION: incr blood Na+ & water, decr. K+}incr blood vol & pressure |
Adrenal gland CORTEX stimulated 2 | -STIMULATED: ACTL from pituitary -RELEASES:glucocosorticoids (cortisol) -ACTION: resistance to stress reaction, dampens inflammation &immun response |
Actions of cortisol (seven) | (1)Protein breakdown (2)Gucloneogenesis (3)Lipolysis (4)Stress resistance (4)Vasoconstriction (5)Anti-inflammatory (6)Immune depression |
(1)protein Breakdown | -in muscle fibres -AAs-->blood -used for synthesis of proteins & ATP production |
(2)Gluconeogenesis | -liver cells -AAs/lactic acid-->glucose -used for ATP production |
(3)lipolysis | -breakdown of triglycerides -&fatty acids from adipose into blood |
(4)stress resistance | -increased ATP & glucose combats stresses e.g. bleeding, trauma, infection, disease, temp extremes, fasting |
(5)vasocontrition | -leads to rise in BP |
(6)Anti-inflammatory | -limits WBC to tissue -retards tissue repair & wound healing |
(7)Immune Depression | -increased susceptibility to infection |