Anaphy Heart and Endocrine

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Hormones

chemical messengers secreted in small amounts into the extracellular fluid.

Hormones

diffuse into the blood to be transported to their target.

Target tissues or effectors

Hormones circulate through the bloodstream to specific sites called what?

Endocrine

Derived from the Greek words endo, meaning "within," and krino, "to secrete."

Exocrine Glands

Have ducts that carry their secretions to the outside of the body, or into a hollow organ, such as the stomach or intestines.

Endocrinology

The study of the endocrine system.

40 trillion

The body maintains homeostasis by coordinating the activities of nearly how many cells?

Chemical messengers

allow cells to communicate and regulate body activities

Gland

An organ consisting of epithelial cells that specialize in secretion

Autocrine chemical messengers

Stimulates the cell that originally secreted it, influences the activity of the same cell or cell type from which it was secreted

Autocrine

what type of chemical messenger is shown in the picture

Paracrine Chemical Messengers

acts locally in neighbouring cells, secreted into extracellular fluid and affects surrounding cells, has a localized effect on other tissues

Paracrine

what type of chemical messenger is shown in the picture

Neurotransmitters

chemical messengers secreted by neurons that activate an adjacent cell. May activate another neuron, muscle cell, or grandular cell. Secreted into a synaptic cleft instead of the blood stream and is technically a paracrine chemical messenger but treated as a separate categoryw

neurotransmitters

what type of chemical messenger is shown in the photo

Endocrine chemical messengers

secreted into the bloodstream by certain glands and cells, these messengers travel through the blood to their target cells

endocrine

what type of chemical messenger are shown in the photo

endocrine and nervous system

two most important control systems of the body

Humoral, neural, or hormonal stimuli

hormones of the endocrine system are secreted in response to _______, _______ and _____ to reegulate homeostasis

hypersecretion or hyposecretion

many disorders are caused by either these two secretions of homones

regulation of metabolism

controls the rate of nutrient utilization and energy production

control of food intake and digestion

regulates the level of satiation and the break down of food into individual nutrients

modulation of tissue development

influences the development of tissues such as those of the nervous system

regulation of ion levels

help monitor blood pH, as well as Na+, K+ and Ca2+ concentrations in the blood

control of water balance

regulates water balance by controlling the solute concentration of the blood and membrane permeability

regulation of cardiovascular functions

helps regulate the heart rate and blood pressure and prepare the body for physical activity

control of blood glucose and other nutrients

regulates the level of glucose and other nutrients in the blood

control of blood glucose and other nutrients

regulates the levels of glucose and other nutrients in the blood

control of reproductive functions

controls the development and functions of the reproductive systems in males and females

stimulation of uterine contractions and milk release

regulates uterine contractions during delivery and stimulates milk release from the breasts in lactating females

modulation of immune systems function

helps control the production of immune cells

Lipid-soluble and water-soluble hormones

two chemical categories of hormones

cell membrane

excludes most water soluble molecules but allows lipid soluble molecules to pass through

steroid hormones and thyroid hormones

two categories of hormones based on chemical structure

Steroid hormones

Derived from cholesterol

Thyroid hormones

derived from the amino acid tyrosine

amino acid derivatives, peptides, or proteins

what are the other hormones categorized as

Lipid-soluble hormones

nonpolar molecules

steroid, thyroid, fatty acid derivative hormones

hormones included in lipid-soluble hormones

small size and low solubility in aqueous fluids

What characteristics do unprotected lipid-soluble hormones have that make them easily removed from the blood

breakdown by enzymes, excretion into urine,

twomechanisms that could result in the removal of unprotected lipid-soluble hormones from the body

excreted in urine or in bile

what happens to the hormones that are degraded in the blood

binding proteins

proteins that chaperon lipid-soluble hormones in the blood stream

binding proteins

reduce the rate of degradation or removal from the blood

a few days to several weeks

life span of lipid-soluble hormones in the blood 

water-soluble hormones

polar molecules

protein hormones, peptide hormones, and most acid derivative hormones

what hormones are included in water-soluble hormones

humoral

refers to body fluids, including blood

neural

neurons release a neurotransmitter into the synapse with the cell that produce hormone

hormonal

when another hormone controls the release of another hormone

humoral inhibition

generally involves the actions of companion hormones

negative feedback mechanism

hormone’s secretion is inhibited by the hormone itself once blood levels have reached a certain point

positive feedback mechanism

amplifies feedback until the wanted results are given

tropic hormones

hormones that stimulate the secretion

releasing hormones

hormones that travel in the blood to the anterior pituitary gland

inhibition by humoral stimuli

to raise blood pressure, the adrenal cortex secretes aldosterone in response to low blood pressure.

Atrial Natriuretic peptide

hormone that lowers blood pressure

Aldosterone and ANH

works together to maintain homeostasis of blood pressure

Inhibition by hormonal stimuli

Hormones from the hypothalamus that prevent secretion of tropic hormones from the anterior pituitary gland are an example of?

Inhibiting hormones

hormones that prevent the secretion of tropic hormones from the anterior pituitary

thyroid hormones

can control their own blood levels by inhibiting their anterior pituitary tropic hormone

Receptors

proteins that bind specific hormones to initiate a cellular response

receptor site

the binding region on a receptor molecule for a specific hormone

Specificity

a selective binding of a hormone to its matching receptor

nuclear receptors

receptors located in the nucleus or cytoplasm that regulate gene transcription

Membrane-bound receptors

proteins that span the cell membrane with hormone-binding sites exposed to the outer surface

Lipid-soluble hormones

primarily stimulate protein synthesis

Simple diffusion

how does most steroid hormones enter their target cells

Transport proteins

how do thyroid cells enter their target cells

testosterone

stimulates synthesis of proteins responsible for male sexual characteristics

Aldosterone

stimulates kidney cells to synthesize protein that increase Na+ and K+

Thyroid hormones and Vitamin D

other hormones using nuclear receptor mechanisms

hormone response element

specific nucleotide sequences in DNA recognized by receptor projections

Membrane-bound receptors

these receptors activate responses in two ways. By altering the activity of G proteins at the inner surface of the membrane or by directly altering the activity of intracellular enzymes

Second messengers

molecules produced inside a cell once a hormone or chemical messenger binds to certain membrane-bound receptors

second-messenger system

a mechanism where the second messenger, not the hormone itself, activates the cellular response

Cyclic Adenosine monosphate

is a common second messenger

G proteins

many membrane-bound receptors act through what?

Alpha, Beta, and Gamma

what are the three subunits of G proteins called? from smallest to largest

Guanine nucleutides

what is one of the sub units of g proteins bind to

Adenylate cyclase

enzyme that converts ATP to cAMP

protein kinases

enzymes that regulate the activity of other enzymes

Phosphodiesterase

enzyme that breaks down cAMP to AMP

Signal Amplification

hormones that stimulate the synthesis of second messengers act quickly and have an amplification effect

membrane-bound receptors

ideal for fast responses such as fight or flight response

nuclear receptors

suited for long-term processes such as pregnancy maintenance

Heart at rest, Atria stimulated, atria contract, ventricles stimulated, ventricles contract

what is the coordination of stimulation and contraction of the heart

pacemaker potential

changes in membrane permeability are responsible for producing action potentials and is called what?

depolarization phase

Na+ and Ca2+ voltage-gated channels open

Plateau phase

Na+ channels close, Some K Channels open, and Ca2+ channels remain open

Repolarization phase

K+ channels are open and Ca2+ channels close

Plasma 55%, formed elements - 45%

Composition of blood

Water 91% Protein 7%

composition of liquid matrix in blood or plasma

composition of blood cells and cell fragments