Internal Regulation Flashcards
What three factors are important for the chemical reactions necessary for life?
Temperature
Concentration of solutes
Energy
Homeostasis
The biological process to keep variables of the body in a fixed range
Sensory transduction and signaling changes outside of the optimal range
Integrated response to restore to optimal range (negative feedback)
Set point
A body variable that requires a narrow range to maintain homeostasis
Hypothalamus plays a role in regulating what?
temperature
fluid balance
energy reserves
visceromotor hypothalamic response
fast physiological adjusting the balance of sympathetic and parasympathetic outputs of the ANS
humoral hypothalamic response
slow hormone release
behavioral hypothalamic response
motivating appropriate behaviors
What nucleus initiate the autonomic and endocrine responses?
paraventricular
What part of the PVN controls the ANS?
Doral and ventral PVN cells
What part of the PVN releases hormones that affect the hormones of the anterior pituitary?
medial parvocelluar cells
What part of the PVN releases hormones directly from the posterior pituitary?
Magnocellular cells
What motivates the somatic motor response?
lateral hypothalamus
What are the two main output neurons of the lateral hypothalamus and where do they go?
orexin and melanin-concentrating hormone
both cell types project widely and can go to the dorsolateral prefrontal cortex (where motor plans are formed)
Two types of ANS and function
Sympathetic: fight or flight
Parasympathetic: rest and digest
What regulates the endocrine glands?
via the pituitary, the hypothalamus
Anterior pituitary function
secretes and synthesizes hormones based on the hormones secreted by the hypothalamus
posterior pituitary function
stores and secretes but does not synthesize hormones
Autonomic temperature responses
Sweat
+/- blood flow to the skin
Endocrine tempertature response
+/- metabolism
Which nuclei of the hypothalamus control temperature?
medial pre optic and anterior nuclei
Which nucleus manages the autonomic and endocrine temperature responses?
paraventricular nuclei
Where are temperature behavioral responses initiated?
lateral hypothalamus
Where is shivering initiated?
dorsomedial nucleus
Osmotic thirst
Increased concentrations of solutes
Hypovolemic thirst
Decreased fluid volume
How does salt affect hydration?
Sodium flusges the area outside the cell, drawing water out of the cell, and the cells shrink.
What parts detect water loss?
organum vasulosum and subfornical organ
What do osmoreceptors activate?
Endocrine: paraventricular and supraoptic nuclei (conserve water)
Lateral hypothalamic area (desire to drink)
What controls blood pressure?
Baroreceptors in the walls of blood vessels
Excited by stretch and inhibited by relaxation
How does low blood pressure make you thirsty?
Hypovelimia = less baroreceptor activity
Stimulates the medulla to activate various nuclei of the hypothalamus
Glucose is stored where as glycogen
Liver and skeletal muscles
Glucose is stored where as triglycerides
Fat
Lipostatic hypothesis
The brain monitors the amount of fat of fights against changes in these levels
What chemical does fat release to communicate to the brain?
Leptin
Which hormone stimulates hunger from the stomach?
Gherlin
Which nerve manages satiety?
Digestion
Which hormone manages satiety in the intestines?
cholecystokinin
Which hormones manages hunger/satiety in the blood?
Insulin
Lateral hypothalamic system
lesions cause severely reduced appetite and reduced fat stores
Ventromedial hypothalamic syndrome
lesions in the arcuate nucleus cause severe overeating and weight gain
Energy needs are sensed by what nucleus
arcuate
Which nuclei effect energy?
Paraventricular and lateral hypothalamic
Nigrostriatal pathway for dopamine
substantia nigra to the stratum for motor selection
mesocorticolimbic pathway for dopamine
ventral tegmental area to cortex and limbic sites for reward and addiction
Why can you crave and not be hungry?
the ventral segmental area is affected by lateral hypothalamic area (hunger signals) and dorsal prefrontal cortex (positive outcomes) and can talk back and forth with the dorsolateral prefrontal cortex – can incite feeding behavior without hunger
Which amino acid is needed for serotonin?
tryptophan, which vary with the amount of carbs in our diet
