Chapter 16: Intro to Neuro

Hormones at birth

Gender differences of the shape of pelvic cavities are due to _____ and are advantageous in females for _____. - determines sex of mammals born; - when mammals are born; -studying why babies are born early;

anterior pituitary

Gland that releases hormones that regulate the activities of endocrine glands; controlled by the hypothalamus - gland that synthesized 6 hormones; - part of the endocrine system; - parvocellular neurosecretory cells in the H.T; - carries their hormones to the anterior pituitary via the hypothalamopituirary portal circulation;

lesions of hypothalamus

Lateral hypothalamus - no appetite or thirst and lethargy Ventromedial hypothalamus - Excessive drinking/eating and rage. - no dopamine release; the subject likes food, but they are not motivated to eat it;

TSH (thyroid stimulating hormone)

Stimulates thyroid gland to produce thyroid hormones

Catabolism

The sum total of all processes in an organism which break down chemicals to produce energy and simple chemical building blocks.

Anabolism

The sum total of all processes in an organism which use energy and simple chemical building blocks to produce large chemicals and structures necessary for life.

motivated behavior

behavior that is energized, directed, and sustained - when you actively shcoose to help with your homeostasis!; - you eat drink move for warmth; - this has to do with the SOMATIC nervous system (voluntary); in the lateral Hypothalamus;

visceromotor response

adjust the balance of sympathetic and parasympathetic outputs in autonomic nervous system - neurons in the H.T adjust teh balance of teh sympathetic and parasympathetic outputs in the ANS;

fall of leptin

releases inhibition of NPY and AgRP which stimulates feeding beh and decreases metab - orexingeric peptide release; - stimulates NPY and AgRP from the anterior c nucleus; - MCH and orexin are releases from teh lateral hypothalamic area; - stimulates feeding, and it lower the metabolism;

sensory transduction

the process by which sensory stimuli are transduced into slow, graded receptor potentials - regulated by sensory neurons in the periventricular zone of the hypothalamus; makes sure the body stays in it's optimal range;

neuroendocrine system

- Endocrine system releases hormones - Nervous system uses neurotransmitters - mediates the interactions between the neuro part of teh brain and the endocrine system

fat people

- high blood leptin from the fat cells that are released; - high MSH and CART neurons activity in teh hypothalamus; - there is a lower NPY/ARPY which is the antagonist of these hormones; - this stimulates the TSH and ACTH release in the anterior pituitary; this increases the sympathetic (flight or flight) in the body; low parasympathetic N.S; lower feeding behavior;

hypothalamic response to blood leptin levels

- leptin levels rise when the body fat is increase, and it falls when the body fat is decreased in the fat cells;

lean people

- lower blood leptin from the fat cells; there is less fat; - there is lower MSH and CART neuron activity from the A.C nuclei; there is a high NPY/ArGP neuron activity; higher parasymetheicg (relax); higher feeding activity from the lateral hypothalamus; - higher TSH/ACTH released;

orexin and MCH work sympathetically in the lateral thalamus to stimulate eating

- orexin= promotes meal initiation; regulates wakefulness; you can't eat if you aren't awake; - MCH= prolongs consumption; so you eat more;

Biggest Loser

- the condensates BMR was way too low after they lost all the weight; - it was hard for them to maintain weight loss; - there was a metabolic adaptation; - their bodies were used to way less calories to survive Thant before;

high angio II

- transduction in the subfornical organ; this increases the sympathetic division (high B.P); drinking; vasopressin is released;

high leptin

-Eat less -Be more active -Increase immune responses -Also a signal for pubertal onset - a rise in leptin levels in teh blood is detected by the A.C in the hypothamllamsu; - theses have teh MSH and CART peptides; - they protect to teh brain stem and spinal cord, and paraventricular nuclei of the hypothalamus; - this diminishes appetite; they Block other peptides that raise feeding behavior; as well;

hormones released from the anterior pituitary

-FSH -LH -ACTH -TSH -Prolactin -ENdorphins -GH

prandial state

-energy stores replenished during and right after a meal -blood is filled with nutrients - when your blood is filled with nutrients; during or after you consume a meal; - glycogen or triglycerides; - glycogen is in yoru liver nada skeletal muscles - triglycerides are in your fat tissues; - these are where your reserves are found;

Targets of Leptin

1) A.C= relates the MCH/CART 2) paraventricular nuclei of the H.T= PITUITARY GLAND (TSH and metabolism) 3) lateral hypothalamic area= motivation to eat 4) Brain Stem= sympathetic Nervous system;

Steps in Anterior Pituitary Hormone Release

1) hormone transport from the P.N.C to the capillaries; 2) hypophysiotropic hoormoes are released into the capillaries; 3) the hormone is transported in its blood; 4) either stimulation or inhibition other anterior pituitary hormone release of hormone secreting cells; 5) new hormones are released into the B.S;

responses to deviations in the homeostasis optimal range;

1) humoral response 2) visceromotor response 3) somatic motor response

Neuro-endocrine system

1) it receives the information from other neurons; 2) the A.P is produced; 3) the synapse releases hormones into teh bloodstream 4) this is slower; non voluntary; the concentration of hormones is diluted by the bloodstream;

triggering the lamb birth

1) paraventricular nuclei in fetal H.T secretes CRH; 2) CRH stimulates teh fetal pituitary to release ACTH; -ACTH stimulates the fetal adrenal gland to release cortisol; - HPA AXIS= stress control; - cortisol of the fetus comes to the plantar to teh mother; - progesterone inhibits uterine contractions in the mother; the cortisol inhibits progesterone and turns int into estrogen; - contractions occur due to this synthesis and inhibition;

two main mechanisms of hormone action

1) protein hormone action 2) steriod-horomoe action

glands

A cell, a group of cells, or an organ that produces a secretion for use elsewhere in the body or in a body cavity or for elimination from the body. Organs or tissues in the body that create chemicals that control many of our bodily functions - cells that secrete horomes;

gastric distention

A condition in which air fills the stomach, often as a result of high volume and pressure during artificial ventilation. - stretching of the stomach lining - richly innervated by mechanosensory aXONS VIA THE VAGUS NERVE to the brain -crnail nerve

Leptin

A hormone produced by adipose (fat) cells that acts as a satiety factor in regulating appetite. - it's a SATIETY FACTOR RELEASED WITH FULL FAT CELLS; - adipose cells release this hormone; - the protein encoded by the ob gene; released by the adipocytes that regulated body mass; but acting directly on neurons of the H.T that lower appetite and raise energy expenditure;

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward. - brain and endocrine system linkage; - pituitary gland is right below; - maintains homeostasis; - controls B.T and B.P; - motivation of behaviors and eating; - drinking and emotions;

the hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward. - it plays a role in regulating the body's temperature, fluid balance, and energy balance; and sensory transduction

Insulin

A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues - released into the B.S by the b-cells of the pancreases; - glucose in other cells of the body required insulin; - the levels of glucose are highly regulated by insulin levels; - the higher the glucose levels in the blood; teh lower the insulin;

Homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level

The MC4 receptor is activated by and inhibited by ________.

A.C neuron's peptides; - it is either inhibited; which stimulates feeding, or it is activated; which inhibits feeding; -in the lateral hypothalamus

posterior pituitary

ADH and Oxytocin are produced in the hypothalamus and stored here until needed - has magnocellular N.S cells; - cell bodies are in the H.T; - axon terminals are in the pituitary glands; - they hormone release of oxytocin and vasopressin; - axon terminal to th ebed of capillaries to eat brain stem to teh target cells;

peptides

Chains of amino acids that can function as neurotransmitters or hormones. - CRH, GH, ACTH

Hormones

Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another - they are chemicals released by cells and received on other cell's receptors; - these receptors can be inotropic or metatropic; - tho they're release and how they act are their differences;

hormones that inhibits appetite

MSH and CART peptides releasd by the curate nucleus of the hypothalamus;

antagonist peptides released by the A.C nucleus in the hypothalamus

MSH/CART and NPY/AgPR; - they bind to the MC4 receptors in post-synaptic neurons in the lateral hypothalamus; - MSH activates the receptor (inhibitory) - NPY inhibits the receptor (stimulates feeding)

what hormones does the AC nucleus release

MSH/CART to inhibit feeding NPY/AgRP to promote feeding

high blood tonicity

OVLT is stimulated next to the H.T; raised sympathetic stimulation; drinking; vasopressin is released;

cephalic stage

Occurs in mouth, salivary glands start digestion of carbs, disinfect food and lubricate food bolus so it can travel down esophagus. -anticipation of food; sights and smells; parasympathetic and sympathetic divisions are activated; - section of saliva for digestion and digestive juices in your stomach;

gastric stage

Stomach acid is secretes and starts digestion and stimulates pancreas. - these responses grow in tensiityw hen you start chewing; during your eating process these grow;

low leptin levels

Switch off alpha-MSH and CART but stimulate other neurons in the arcuate nucleus that inhibit TSH and ACTH secretion, activate PNS, stimulate feeding behaviour. These are orexigenic peptides. - LOOK FOR WFOOD; gets body ready for food; - turns off response mediated by the MSH/CART neurons released by the A.C in the hypothalamus; - they stimulate another type of arcuate nucleus neuron; - they release NEW peptides; NPY and ARGP; these are new peptides; - they are the opposite of MSH and CART neurons; - they inhabit the secretion of TSH/ACTH; - they activate PARASYMPATHETIC division of teh ANS

pituitary gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands. - controlled by the H.T; - releases hormones that regulate other glands; - 3 anatomical zones; - lateral, medial, and ventromedial; - they are all further split by distinct nuclei;

nucleus of the solitary tract

The nucleus in the brain stem that receives signals from the tongue, the mouth, and the larynx transmitted by the chorda tympani, glossopharyngeal, and vagus nerves. - in the medulla - the gal sensory axons active the neurons here; - this is important in widespread connections and integration between teh feeding and metabolism

lateral hypothalamus

The part of the hypothalamus that produces hunger signals - motivation or food;; - it releases an orexinergic peptide; orexin; - the higher the leptin; the more full the body is; the less orexin;

adipose tissue

Tissue that stores fat.

NPY/AgRP

What does serotonin block that usually increases appetite?

Cholecystokinin

a hormone that is secreted by cells in the duodenum and stimulates the release of bile into the intestine and the secretion of enzymes by the pancreas. - a peptide that inhibits meal frequency and size; - present in some cells the line our intestine; - the more fatty the food, the higher the trigger release; - this exerts and influence on vagal sensory axons; - it acts; w/ gastric distention synergistically;

hypothalamic-pituitary-adrenal axis

a major neuroendocrine pathway relevant to the stress response involving the hypothalamus, pituitary gland, and the adrenal cortex - controls the adrenal glAnd; 1) begins in the H.T; w/ the release of teh CRH; 2) produced by the parvoventricular nucleus; 3) carried to the anterior pituitary 4) triggers the release of ACTH from the hormone secreting cells in teh anterior pituitary 5) the ACTH arrives at the adrenal gland's cortex

ghlerin

a peptide that's in your stomach; - when your stomach is empty, you can hear them; - it's released into the bloodstream when your stomach is empty - the growling is the ghrrrelin - the higher the appetite and food consumption follows - there is an activation of the NPY/ARGP containing neurons of the A.C; this is like low leptin levels;

ob mice

a strain of mice whose obesity and low metabolic rate are caused by a mutation that prevents the production of leptin - lack leptin; due to a mutation in their ob gene; which codes for leptin;

Lesions of lateral hypothalamus

abolish behavioral regulation, but do not affect physiological responses such as shivering - that's parasympathetic - anorexia; low motivation ot eat;

high levels of H.T in the brain

after feeding; - release by fat cells into the brain stem; the receptors on neurons in teh arcuate nucleus on the H.T;

Classes of Hormones

amino acid derivatives, peptide hormones, lipid derivatives -peptides, amines, and steroids

drugs that increase serotonin release

an appetite suppressant; - the body thinks that it's already about to get food or has food inside e of it

ADH

antidiuretic hormone (vasopressin)

3 stages of eating

cephalic, gastric, and substrate

Hormonal and Hypothalamic Regulation of Body Fat and Feeding

feeding is stimulated when neurons in the H.T detects a drop isn hormones released by FAT cells; - fat cells are what tells your H.T that you need to replenish them;

CRH

corticotropin-releasing hormone; hypothalamus - released by the parvovenricular nuclei; - helps control stress - carried to teh anterior pituitary; - triggers release of teh ACTH hormone in th e anterior pituitary; - arises at eh adrenal gland/cortex/medulla; - receptors on the cortex; - release of cortisol from the adrenal cortex; - crosses het blood brain barrier;

anoretic peptides

diminish appetite - MSH/CART peptides

anoretic peptides

diminish appetite; MSH or CART; which re released by the A.C in the hypothalamus;

motivation is the

driving force behind behavior

reinforcement and reward for food

electrical self- stimulation by monkeys and rates; - they keep pressing the level that stimulated dopamine through the lateral hypothalamus; - dopamine release to the brain reinforces the behavior that causes the release;

natural rewards elevate dopamine levels

food, water, and sex; - these all reinforce behaviors

regulation of feeding behavior

glucose is very urgent for the brain; - you have to eat it to gain glucose; body stores this;

Why do we eat food?

hedonic - we derive pleaser - we have a drive reduction; we need to satisfy a craving;

the satiety signals

hormones that influence feelings of fullness and decisions about eating at a specific meal - they occur when we eat and begin the process of digestion; prandial period

somatic motor response

hypothalamic neurons respond to sensory signals by inciting an appropriate somatic motor behavioral response -Hypothalamic neurons (particularly within the lateral hypothalamus) respond to sensory signals by inciting an appropriate somatic motor behavioral response. -elicit an appropriate somatic motor behavioral response (shivering, drinking, eating, sexual response) - H.T neuron in teh lateral H.T respons to sensory signals by inciting a appropriate somatic motor response;

humoral response

hypothalamic neurons respond to sensory signals by stimulating or inhibiting the release of pituitary hormones into the bloodstream - hypothalamic neurons send signals by excitatory or inhibitory pituitary glands hormones through the bloodstream; - this deals with the pituitary gland;

stimulation for insulin release

increased blood glucose levels; along with stately signals

rise in leptin

inhibits feeding beh and increases metabolism - stimulates MCH and CART from the A.C - anoretic peptides act on the brain - activate a MC4 receptor lateral hypothesis - ACTH

what does the lateral hypothalamus control

insulin secretion, alters taste responsiveness, and facilitates feeding in other ways - somatic responses to feeding behavior; find water; look for food; digestive juices flowing;

does teh signal to be born come from the mother or the fetus?

it comes from the baby's pituitary gland; - and the H.T; - experimental evidence: - removal of the pituitary in fetus; higher pregnant gestation; - injection of ACTH shortens gestation; - or cortisol; - the ACTH usually comes from the anterior pituitary;

neurons that incite feeding are in the

lateral hypothalamus

the control of feeding by lateral hypothalamic peptides

lateral hypothalamus motivates us ot eat; - no well-organized nuclei; - lesions here cause less eating; - electrical stimulation trigger feeding; - electrical stimulation of this area causes stimulation of feeding; - this is where the signals from the leptin-sensitive cells in the A.C go in the hypothalamus; - it releases MCH; - the MCH informs the cortex in the brain of the leptin levels; - THIS IS MOTIVATION

the short term regulation of feeding behavior

leptin regulates the tendency to seek and consume food; - also you need it is regulate how long we eat, and it regulates what we eat; - the higher the drive to eat; teh higher the higher the orexigeric signals from fasting; the lower het leptin concentration; the lower the satiety sigma;s;

the hypothalamus and feeding

lesions of the lateral H.T= anorexia - lesions of the ventromedial H.T= obesity;

Steriods

lipids whose structures resemble chicken-wire fence. include cholesterol and sex hormones

highest levels motivation

neurons of the frontal lobe; voluntary movements; motivation is involved;

difference between neurotransmitters and hroome s

neurotransmitters; - their release is precise; - axon terminal to a synaptic terminal to an axon's post0synaptic terminal; - very fast time; - voluntary - larger concentration hormones: - release is diffuse; - extracellular fluid to capillaries to brain stem; - they are released diffusely and travel via the bloodstream to local or distance target cell; - they are only picked up by cells; with the right receptors in their synaptic terminals;

does injecting leptin in humans decrease obesity?

no, recuasse leptin levels are positively correlated in body weight with humans and fat mass; - letup is released by fat cells, and they have an intensity to leptin; - it don't receive the stigma; - "Leptin tells your brain that you have enough energy stored in your fat cells to engage in normal, relatively expensive metabolic processes," he says. "In other words, when leptin levels are at a certain threshold -- for each person, it's probably genetically set -- when your leptin level is above that threshold, your brain senses that you have energy sufficiency, which means you can burn energy at a normal rate, eat food at a normal amount, engage in exercise at a normal rate, and you can engage in expensive processes, like puberty and pregnancy". - there is a threshold that your body can take, so if you add more; teh body won't respond to teh increase in the molecule/hormone;

Lesions of ventromedial hypothalamus

obesity - responds as if starving; - stores fat to conserve energy;

drinking

occurs due to tho lowered blood volume; - when there are higher concentrations of collations in the blood stream;

Serotonin and food reward

one system in the brain that controls mood uses serotonin as a N.T; - serotonin is the link between food and mood; - it's why we are happy when we eat food; - we are mad when we don't ahem food - serotonin levels are lowered during the post-absorbative period; - they are higher during eh anticipation for food and during a meal;

amines

organic compounds with an amino group - synthesized from amino acids; - epinephrine, NA, thyroid homromesn;

orexigenic

pertaining to something that produces or stimulates an appetite

The Role of Dopamine in Motivation

pleasurable foods release dopamine into teh brain - dopamine is released in repose to pleasurable foods; - this has been recently challenged; - rats; w/ lesions in the H.T; when dopamine isnt released; still like food; it gives them pleasure; they lack MOTIVATION; - dopamine is inked to motivation, nw t how we perceive teh food;

lipostatic hypothesis

states that fat is the measured and controlled substance in the body that regualtes hunger a hypothesis proposing that body fat is maintained homeostatically at a specific level -fat is the measured and controlled substance in the body that regulates hunger - a mechanism to maintain the body's homeostasis; the brain monitors the amount of body fat, and it acts to defend this energy store; - the connection in-between body fat and feeding behavior; - protein which is encoded by the "ob" gene is the hormone that tells the brain from the fat cell that the stores are either normal and not;

orexigenic peptides

stimulate feeding behavior -NPY and AgRP

substrate stage

stomach is filled, and the nutrients begin to be absorbed into your R/S;

Cortisol

stress hormone released by the adrenal cortex

without leptin; the brain thinks

that the body doesn't have enough fat stores; - leptin tells the body that we have enough fat stores;

periventricular zone

the cells of the hypothalamus that lie right next to wall of the third ventricle - where sensory transduction occurs;

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

where do we get our glucose

the fat cells ; the hypothalamus regulates this source from leptin levels;

the less leptin

the higher the MCH and orexin from the lateral hypothesis. which stimulates feeding

steroid hormone action

the hormone passes through the membrane due to its chemical nature where it joins with an intracellular receptor then a DNA receptor protein which then activates or deactivates a gene - lipid-soluble through the lipid-membrane; - binds to teh crier proteins to take it through the B.S first; - binds ot T.F in teh nucleus; - this can inhibit or stimulate teh transcription of DNA; - this alters DNA expression

when does the lam b know it's ready to be born

the hypothalamus assesses the maturity of teh lamb's organs

what is teh target of the A.C's peptides

the lateral hypothalamus' Mc4 receptor

high temperature

the medial preoptic area is stimulated; the parasympathetic area is stimulated; sweating; seeking cold; low TSH release;

low temperature

the medial preoptic area is stimulates; the sympathetic division is stimulated; shivering and seeking hot; high TSH;

volumetric thirst

the motivation to drink water as a result of a decrease in blood volume - thrift triggered by hypovolemia ' - vasopressin is rebased into the posterior pituitary gland by magnoceuular N.S glands; - ADH release - this acts on the kidneys, just like the stress pathway, and this causes the kidneys to retain water; - this lowers the urine production;

ARC Nucleus (Hypothalamus)

the neurons group in the lateral hypothalamus that the leptin cells large to tell the brain; that the body is satiated from the fat cells' - releases the MSH and CART horomes

Set point (weight)

the point at which an individual's "weight thermostat" is supposedly set. When the body falls below this weight, an increase in hunger and a lowered metabolic rate may act to restore the lost weight.

serotonin disorders with release

they think they are already getting food; can lead to anorexia or bulimia;

osometric thirst

thirst produced by an increase in the osmotic pressure of the interstitial fluid relative to the intracellular fluid, thus producing cellular dehydration - the motivation to drink water when dehydrated; - uses OVLT; a vascular organ in the lamina terminals - it reacts to the hypertonicity of blood; - sneezed by OVLT neurons ; - water leaves the cells by osmosis; - the blood is hypertonic; - the OVLT neurons excite the MAGNOCELLULAR N.S cells in the H.T; - this relates the ACH; - this stimulated osmometric shift;

obesity

this results in higher leptin release by fat cells; - this causes a higher activation of the MSH and CART neurons from the ARC nucleus - then TSH and aCTH is secreted from the pituitary gland; this increases the metabolism rates and energy expenditure; humoral réponse: TSH/ACTH on glands relate visceromotor response: sympathetic division of the ANS raises; higher heart rate and metabolic movements; somatic motor response: lower feeding behavior; don't look for food;

During the fasting state, the energy stores of the ________ become the major source of glucose for the whole body.

triglyceride stores in your adipose (fat) tissues;

lowest levels motivation

unconscious reflexes by the sensory system;

protein hormone action

when a hormone can't penetrate the cell membrane so it binds to a receptor in the membrane causing an enzymatic conversion of ATP -> AMP which stimulates a signal transduction pathway - the hormone ions to receptors on the surface of a cell; - this acts like a regular N.T; - lipid-insoluble;

anabolism during the prandial state

when your body is full of nutrients, these nutrients go to your fat and glucose stores

catabolism during the fasting state

you need the nutrients from the fat stores, so they are broken down into glycogen and glucose for your neurons and cells;