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 |