Mod 4. L34 Flashcards
neural regulation of breathing in air-breathing animals
specialized cells in the artery measure CO2 and O2 concentrations (as well as PH) in the blood and send information to the brain
this information influences the activity of neurons in the hindbrain that regulate the rate of rhythmic contractions and relaxations of muscles that control the diaphragm
direct input onto hindbrain neurons also influence the rate of breathing
neural regulation of breathing in water-breathing animals
water-breathing animals have O2 sensors in their gills
these O2 sensing cells then regulate the activity of hindbrain neurons that regulate the drawing in and expulsion of water
baroreceptors
for neural regulation of thirst and drinking
specialized cells in blood vessels which allow them to sense blood pressure.
these sensory cells are activated by the stretching of blood vessels, and they relay the stretch information to the brain
neural regulation of osmolarity
osmoregulatory state is inferred from cells that monitor osmolarity as well as cells that measure blood volume and pressure
baroreceptors and osmoreceptors
osmoreceptors
sensory receptors in parts of the hypothalamus that monitor the concentration of solutes (osmolarity) in the blood
neurons in the brain that express osmoreceptors directly monitor ion and water concentrations in the blood
neuroendocrine response to osmotic stress
the neuron is more turgid in hypo-osmolar environments, this inhibits vasopressin release
neuron is less turgid under hyper-osmolar environments, this promotes vasopressin release
Brain regulation of vasopressin release
neurons in the hypothalamus synthesize vasopressin. These neurons project to the posterior pituitary gland and directly release vasopressin into the bloodstream
Glucokinase
Acts as glucose sensor, concentration of glucose in the blood
In pancreatic b cells glucose sensibg relies on glucokinase
A number of neurons in hypothalamus also express glucokinases and sense glucose concentrations in the blood
