bio chapter 45

multiple effects of hormones

-The same hormone may have different effects on target cells that have: -Different receptors for the hormone -Different signal transduction pathways

pituitary gland (anterior)

ACTH, TSH, GH, PRL, FSH, LH, MSH

pathway for water-soluble hormones

Binding of a hormone to its receptor initiates a signal transduction pathway leading to responses in the cytoplasm, enzyme activation, or a change in gene expression activate milk production

tropic effects only

FSH, LH, - gonads TSH, - thyroids ACTH - adrenal cortext

all the following hormones are either tropic or non-tropic only except

GH

tropic and nontropic effects

GH - liver, bones, other tissues

hormonal regulation of growth

Growth hormone (GH) is secreted by the anterior pituitary gland and has tropic and non-tropic effects It promotes growth directly and has diverse metabolic effects It stimulates production of growth factors

endocrine signaling

Hormones secreted into extracellular fluids by endocrine cells reach their targets via the bloodstream maintains homeostasis

In human hormone cascades, what is the correct sequence in which these structures become involved, starting with the organ at the beginning of the cascade? (not all organs are listed)

Hypothalamus, anterior pituitary gland, specific endocrine gland, nonendocrine target

neuroendocrine signaling

Neurosecretory cells secrete neurohormones that travel to target cells via bloodstream and diffuse from nerve cell ending many regulate endocrine signaling is a combo

parathyroid glands

PTH raises blood calcium level

PTTH

Prothoracicotropic hormone; was the first insect hormone to be discovered

synapses

Special junctions in which neurons communicate with other neurons

Pathway for Lipid-Soluble Hormones

The response to a lipid-soluble hormone is usually a change in gene expression When a steroid hormone binds to its cytosolic receptor, a hormone-receptor complex forms that moves into the nucleus There, the receptor part of the complex acts as a transcriptional regulator of specific target genes

intercellular communication

The ways that signals are transmitted between animal cells are classified by two criteria -The type of secreting cell -The route taken by the signal in reaching its target

cellular response pathways

Water-soluble hormones are secreted by exocytosis, travel freely in the bloodstream, and bind to cell-surface receptors Lipid-soluble hormones diffuse across cell membranes, travel in the bloodstream bound to transport proteins, and diffuse through the membrane of target cells They bind to receptors in the cytoplasm or nucleus of the target cells

hormone cascade

a form of regulation in which some multiple endocrine organs and signals act in series signals in brain stim the hypo to secrete a hormone that stims the release/inhiition of ant hormone ant pit in turn stims another hormone which affect target tissues

nervous system is

a network of specialized cells (neurons) that transmit signals along dedicated pathways regulate neurons, muscle cells, and endocrine cells

signaling by pheromones

a type of hormone some animals communicate with it serve many functions; marking trails to food, defining territories, warning of predators, attracting potential mates

adrenal glands

adrenal medulla and adrenal cortex

Epinephrine

adrenaline water-soluble and mediates body's response to short-term stress binds to receptors on plasma membrane in liver cells triggers the release of messenger molecules that activate enzymes and result in release of glucose into bloodstream

mineralcorticoidss

aldosterone - functions in ion and water homeostasis affect salt and water balance participate in homeostatic regulation of metabolism

which hormone is correctly paired with its function?

aldosterone increases sodium excretion by kidneys

hormones

also regulate homeostasis (stress, dehydration, low blood sugar)

testes

androgens: support sperm formation, promote development and maintenance of male secondary sex organs

ADH

antidiuretic hormone (vasopressin) regulates physiology and behavior increases water retention in kidneys, helps maintain blood osmolarity

feedback regulation and coordination with nervous system

are common in hormone pathways

what type of signaling is involved if the target receptor is located on the same cells that produced the hormone?

autocrine

chemical signaling

by hormones is the function of the endocrine system

endocrine disruptors

can be DES, a synthetic estrogen can be found in birth controls a molecule that interrupts the normal function of a hormone pathway

signal transduction

chain of events that converts the extracellular chemical signal to a specific intracellular response

animal hormones

chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body control all signals in t he body include physical and physiological ones

Pheromones

chemicals released into the environment

parathyroid hormones and vitamin d

control of blood calcium two antagonistic hormones PTH and calcitonin regulate the homeostasis of calcium (Ca2+) in blood

ecdysteroid

controls metamorphosis and molting and is triggered by JH inside larva are many tiisues that become parts. crawling larval become stationary when cells take over, complete program of dev while larva tissue go cell death becoming a moth

vertebrates

coordination of endo signaling realies of hypothalamus which sends signals to the pituitary glands

corticosteroid hormones from adrenal cortex

cortex reacts to endocrine signals (low blood sugar, decreased blood sugar and pressure, and shock) corticosteroids respond to stress triggered by a hormone cascade pathway (ATH stimulates endocrine cells to make corti)

glucocorticoids

cortisol - influences glucose metabolism and the immune system

DES

diethystilbestrol between 1938 - 1971 some pregnant women at risk for complications were prescribed DES can be injected or ingested daughters of women treated with DES are at higher risk for reproductive abnormalities (miscarriage, structural changes) and cervical and vaginal cancers

disorders of thyroid function and regulation

disruption in thyroid production and regulation can result in serious disorder malnutrition can alter thyroid function

why secretin happens

during digestion partially processed food goes to duodenum that has very acidic juices that must be neutralized to continue with digestion s cells (endo cells in lining) detect low ph of food and secrete secretin which travels in blood to target cells in pancreas that respond by releasing bicarbonate to raise the ph to neutralize stomach acid

short term stress response and the adrenal medulla

effects of epinephrine and nor glycogen breaks into glucose increased blood glucose increased blood increased breathing rate increased metabolic rate change in blood flow patterns, leading to increased alertness, decreased digestive, excretory, repro activity

long term stress response and the adrenal cortex

effects of mineralocorticoids: retention of sodium ions and water by kidneys effects of glucocorticoids (a hormone that can be given): proteins and fats broken down, leading to increased blood glucose partial suppression of immune system

the pancreas

endo and exo tissues are found in the same gland: ductless tissues secrete hormones and tissues with ducts secrete enzymes and bicarbonate

endocrine tissues and organs

endocrine cells are often grouped in ductless organs called glands like the thyroid, testes, ovaries EXOcrine glands (saliva glands) have ducts to carry secreted substances onto body surfaces or into cavities

simple endocrine pathway

endocrine cells respond directly to an internal or environmental stimulus by secreting a particular hormone brings about a physiological response

anterior pituitary

endocrine gland that synthesizes and secretes hormones in response to hormones from the hypothalamus

which systems controls chemical signaling by hormones

endocrine system

catecholamines

epinephrine (adrenaline) norepinephrine (noradrenaline) increase the amount of chemical energy available for current use profound effect on cardiovasc and respiratory system

adrenal medulla

epinephrine and norepinephrine raises blood glucose level, increses metabolic activites, constrict certain blood vessels

ovaries

estrogens - stimulate uterine lining growth, promote development and maintenance of female secondary sex characteristics progestins- promote uterine lining growth

antidiuretic hormone

example of neurohormone functions in kidney function and water balance and courtship behavior

Hyperthyroidism

excessive production of thyroid hormones can lead to high temperature, sweating, weight loss, irritability, high blood pressure

posterior pituitary

extension of hypothalamus secretes hormones made in hypothalamus

feedback regulation

feature of many control pathways positive & negative feedback can work together like with blood glucose levels get regulated by insulin and glucagon

hormone cascade pathway example

feedback regulation occur like when thyroid hormone levels drop

estrodiol

form of estrogen among the best characterize steroid hormone receptors

What are parts of the anterior pituitary glands?

fsh tsh acth gh

nitric oxide (NO)

functions as local regulator and neurotransmitter is triggered by endocrine

melatonin

functions relate to biological rhythms is secreted at night and amount depends on season can affect skin color in many vertebrates

Corticosteroids

glucocorticoids and mineralocorticoids

adrenal cortex

glucocorticoids and mineralocorticoids raises blood glucose level promote reabsorption of na^+ and excretion of k^+ in kidneys

arthritis treatment

glucocorticoids in body at higher levels can suppress certain components of the body's immune system and treat arthritis but it can cause long term effects on metabolism, so ibuprofen is generally preferred for chronic conditions

sex hormones

gonads produce most sex hormones (androgens, estrogens, progestins) all three are found in women and men but in different proportions

Prostaglandins

group of local regulators function in immune system, reproduction, and blood clotting

prolactin

has both a releasing and inhibiting hormone

multiple effects example

hormone epinephrine can increase blood flow to major skeletal muscles (basis for fight/flight), but decrease blood flow to the digestive tract

anterior pituitary hormones

hormones released by the hypothalamus control the release of all anterior hormones with releasing (prolactin) or inhibiting hormones control diverses processes (metabolism, osmoregulation, reproduction)

hypothalamus

hormones released from posterior pituitary regulates anterior pituitary

endrocrine signaling details

hormones secreted into extracellular fluids by endocrine cells reach targets by bloodstream the signaling maintains homeostasis, mediates responses to stimuli, and regulates growth and development regulate blood pressure and volume metabolism and allocation, solute concentration regulations in body fluid

Graves disease

hyperthyroidism caused by an autoimmunity protruding eyes

GH is

in excess can cause gigantism lack caused dwarfism (can be corrects if caught early)

Prostaglandins function

in immune system, promote inflammation and sensation of pain as injury response help regulate aggregation of platelets, a step in forming blood clots aspirin and ibuprofen prevent things and aspirin is good for people at risk of heart attack in reproduction, they help suspend cells so sperm can fertilize the egg

Coordination of Endocrine and Nervous Systems in Vertebrates

in many animals endocrine organs in the brain integrate function of the system with that of the nervous system

hormone cascade example

in reproduction the hypothalamus signals the anterior pituitary to release FSH and LH hormones that regulate hormone secretion by gonads

where are the receptors for lipid-soluble hormones located?

in the nucleus of the target cell (?)

progestins

include progesterone are primarily involved in preparing and maintaing the uterus

vasodilation

increases blood flow to tissues NO ability to promote this enables sexual function by increasing blood flow to penis

negative feedback

inhibits response by reducing initial stimulus the only thing restores to a preexisting state homeostasis uses this eg. secretin and ph

hormone class example

insulin is a polypeptide steroids like cortisal are lipids derived from steroid cholesterol epinephrine and thyroxine are amines and synthesized from a single amino acid, either tyrosine or tryptophan

pancreas

insulin: lowers blood glucose level glucagon: raises blood glucose level

thyroid hormone

is a pair of similar molecules derived from tyrosine t3 contains three iodine atoms t4 contains four

synthesis of estrogen and progestins

is controlled by 2 gonadtropin from ant pit that are follicle-stimulating and luteinizing hormones

chemical signals to communicate

it is diverse because of things like solubility, where it goes and the different processes that occur in a different place

JH

juvenile hormone modulates ecdysteroid activity high levels cause molting (still juvenile) low levels induce pupa formation

elephant seals

look very different from male and female increased hormone secretion (testosterone & estrogen) at puberty results in maturation and other changes that result in sexual dimorphism

catechlamines from the adremal medulla

medulla secretes catecholamines as response to stress-activated impulses from the nervous system mediate various fight/flight responses

MSH

melanocyte-stimulating hormone secreted by ant pit egulates skin color in amphibians, fish, and reptiles plays roles in hunger and metabolism and coloration in mammals

pineal gland

melatonin participates in regulation of biological rhythms

simple neuroendocrine pathway (oxytocin signaling)

milk release when baby suckles, it stimulates neurons in nipples, generating nerve impulses that reach hippothalamus. that triggers secretion of oxytocin which causes contraction of mammary gland cells, forcing milk into the gland

local regulators

molecules that act over short distances and reach their target cells solely by diffusion and act on target in seconds play role in physiological processes including blood pressure, reproduction and nervous system can be paracrine or autocrine

estrogens

mostly estradiol are responsible for maintaining female reproductive system and development of secondary sex characteristics

oxytocin

multiple functions relating to reproduction female milk production has targets in brain that influence behaviors related to maternal care, pair bonding, and sexual activity

hormone pathways involved in maintaining homeostasis (such as the secretin pathway in the digestive tract) are often characterized by which of the following?

negative feedback

which of the following pair matches the functions of nitric oxide

neurons and local regulator none of the above?

synaptic signaling

neurons form synapses there, neurons secrete molecules called neurotransmitters that diffuse short distances and bind to receptors on target cells is central to sensation, memory, cognition, and movement essential for nervous function

where do animal hormones secrete to

none of the above

endocrine and nervous

often overlap in function two basic systems for communication and regulation in the body

Hormones reach all parts of the body, but

only the target cells have receptors for the hormones

pituitary gland (posterior)

oxytocin and ADH

PTH

parathyroid hormone is in glands raises levels of blood ca2+ directly in bones and kidneys and indirectly in intestines causes mineral matrix in bones to break down and release ca2+ acts in kidneys to stimulate conversion of vitamin d which in turn acts on intestine stimulating uptake of ca2+ in blood as blood level rises negative feedback loop inhibits PTH production

what is the name of the hormone used by animals and ants to locate food?

pheromones

hormones and biological rhythms

pineal gland secretes melatonin release is controlled by a group of neurons in hypothalamus called SCN

Throxine (T4)

plays a role in regulating metabolism but in frogs it stimulates resorption of tadpole tail during metamorphosis

all of the following is true about prostaglandins expect

produces androgen

nontropic effects only

prolactin - mammary glands MSH - melanocytes

classes of local regulators

prostaglandins (modified fatty acids) others are polypeptides and gases like nitric oxide

hypothalamus in vertebrate

receives info from nerves throughout body and starts responses to appropriate enviro conditions eg. seasonal changes . it causes regulation of reproductive hormones required to breed

hormone cascade (simple)

redirects signals from hypothalamus to other endocrine glands this is why ant pit hormones that are organized this way are said to have tropic effect so FSH&LH of reproduction are gonadtropin

releasing/ inhibiting hormones

regulates release of anterior pituitary hormones like prolactin (PRL milk) the anterior hormones are controlled by at least one of these have direct access to the glands they control

positive feedback

reinforces a stimulus, leading to an even greater response e. oxytocin and milk

calcitonin

released by thyroid gland released when ca2+ gets too high inhibits bone breakdown and secretions in kidneys enhances ca2+ excretion is needed is childhood for extensive bone growth regulates PTH

endrocrine glands

respond to diverse stimuli in regulating homeostasis, development, and behavior

adrenal hormones

respond to stress associated with the kidneys consists of two glands adrenal medulla (inner) adrenal cortex (outer) gland is a fused endocrine and neuroendocrine gland

endocrine signaling mediate

responses to environment stimuli regulate growth and development trigger physical and behavioral changes like sexual maturity and reproduction regulate blood pressure and volume energy and metabolism and solute concentration regulations in body fluids

paracrine and autocrine signaling

secrete molecules, "local regulators," paracrine- target cell is near secreting cells autocrine- target cells is secreting

autocrine signaling

secreted molecules diffuse locally and trigger a response in the same cells that secrete them

polyphemus moth

sex pheromone released in the air by female enables her to attract males up to 2.8 miles away

why do they overlap

signaling of neurons can regulate the release of hormones

pituitary gland

size and shape of lima bean with two lobes of different function

prolactin and evolution

stimulates mammary gland growth and milk synthesis in mammals regulates fat metabolism and reproduction in birds and salt and water balance in freshwater fish

Testosterone

stimulates the development and maintenance of male secondary sex characteristics causes increase in muscle and bone mass. taken as a supplement which causes health risks (female steroid injection, decreased sperm count, severe acne) doping

simple neuroendocrine pathways

stimuli is received by a sensory neuron that stimulates a neurosecretory cells that secretes a neurohormone that diffuses into the blood and travels to target cells mostly positive feedback

SCN

suprachiasmatic nucleus functions as a biological clock and receives input from specialized light-sensitive neurons in retina of eyes

viagra

sustains erection by prolonging NO response pathway

what type of signaling involves the secretion of neurotransmitters diffuse across synapses and triggers response in muscle and glands

synaptic signaling

posterior pituitary hormones

synthesize 2 hormones ADH and oxytocin are stored to be released in response to impulses from hypothalamus

testes and androgen

synthesize androgens mainly testosterone

paracrine signaling

target cells are near secreting cells secreted molecules diffuse locally and trigger a response

sexual dimorphism

the distinct appearance of adult females and males (elephant seals)

evolution of hormone function

the functions of particular hormones have diverged to meet demand eg. thyroid hormone t4, prolactin ans msh

invertebrates

the pathway that controls molting of larva comes from larval brain where ncells produce PTTH, in prothoracic gland it directs ecdysteroid release metamorphisis is not triggered until JH drops

simple endocrine pathway (secretin signaling)

the release of acidic contents of the stomach into the duodenum stimulates endocrine cells there to secrete secretin This causes target cells in the pancreas, a gland behind the stomach, to raise the pH in the duodenum

how are r/i hormones released?

they are secreted near capillaries at the base of the hypothalamus the capillaries drain into short blood vessels (portal vessels) that goes into a 2nd capillary bed within the anterior pituitary (they have direct access to the gland they control)

classes of hormones

three major classes polypeptides, steroids, amines are groups by solubility polypeptides and amines are water-soluble steroid hormones are lipid-soluble

hormones travel

through the bloodstream (hemolymph)

thyroid gland

thyroid hormone (t3 t4): stimulates and maintains metabolic processes calcitonin: lowers blood calcium level

thyroid regulation: a hormone cascade pathway

thyroid hormone regulates many mammal functions (maintaining blood pressure, heart heart, muscle tone) can run into problems if thyroid hormone level drops in blood, hypothalamus secretes TRH causing ant pit to secrete TSH

TSH

thyroid stimulating hormone stimulates thyroid gland (when thyroid hormone levels drop) which scretes thy hormone to increase metabolic rate

TRH

thyrotropin releasing hormone

hypothyroidism

too little thyroid function, can produce symptoms such as weight gain, lethargy, cold intolerance

epinephrine and norepinephrine

trigger release of glucose and fatty acids into blood increase oxygen delivery to body cells direct blood TO heart, brain, skeletal muscles and AWAY from skin, digestive system and kidneys

which of the following statements about diabetes mellitus is correct?

type I diabetes features high blood glucose levels due to insufficient insulin production.

foraging ants

use pheromones to mark new food sources use them for guidance when a colony migrates to a new location

endocrine vs exocrine glands

usually secretes hormones directly into surrounding fluid have ducts that carry secreted things like sweat

molecules used in intercellular signaling

vary in molecular weight, chemical properties, and structures determine function

which of the following arrangement is true about hypothyroidism disorder

weight gain lethargy cold intolerance little thyroid hormone activity

how NO works

when oxygen levels fall, endothelial cells in blood vessel walls synthesize and release it after diffusing into smooth muscle cells it activates an enzyme that relaxes cells resulting in vasodilation

goiter

when people lack iodine low levels of thyroid hormones causes no negative feedback so TSH keeps getting released which in turn can cause neck swelling malnutrition can cause it