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Flashcards in Chapter 15 Packet Deck (53):

Any chemical released by one cell that acts upon another cell (target cell)

Signaling molecules


Neurotransmitters are released by what and have what effect?

Axon endings of neurons; they have immediate effect on the adjacent cell (neuron, muscle, or gland) across the synaptic cleft


Released by many types of cells; they have their effect in the immediate area; e.g. prostaglandins

Local signaling molecules


Hormones are secreted by?

Endocrine glands, endocrine cells, and some neurons; they travel via the blood stream to distant target cells


What are the signaling molecules?

1) Neurotransmitters
2) Local signaling molecules
3) Hormones
4) Pheromones


These signaling molecules are released to the outside of the body



What effect do pheromones have?

They have an effect on other individuals of the same species.


While more overt effects of pheromones are seen in other species, in humans ?

The vomeronasal organ can detect some pheromones


What are the 3 common types of hormone interactions

1) Opposing interaction
2) Synergistic
3) Permissive interaction actions


What is opposing interactions

When the effect of one hormone opposed the effect of another


When the sum total of actions of two or more hormones is required to produce the desired effect on the target cells

Synergistic interaction


What is permissive interaction actions

When certain target cells must be primed by one hormone in order to be affected by another hormone


Endocrine organs

1) Hypothalamus
2) Pituitary gland
3) Pineal gland
4) Thyroid gland
5) Parathyroid gland
6) Thymus
7) Adrenal glands
8) Pancreatic islets
9) Ovaries
10) Testes


Hormones secreted by the Posterior pituitary gland and the main targets for each hormone

Antidiuretic (ADH): Kidneys
Oxytocin: Mammary glands, uterus


What is the primary action of the posterior pituitary gland

*H2O reabsorption and conservation.
* Induces milk movement into secretory ducts.
*Induces uterine contractions


Hormones secreted by the anterior pituitary gland

1) Trophic hormones: ACTH, TSH, FSH, LC
2) Prolactin (PRL)
3) Growth hormone (GH)


Main target for the Anterior pituitary hormones

1) Adrenal cortex
2) Thyroid gland
3) Ovaries, testes
4) Mammary glands
5) Most cells


Primary action from the Anterior pituitary gland

*Stimulates release of adrenal steroid hormones
*Stimulates release of thyroid hormones
*Stimulates gamete formation
*Stimulates ovulation, corpus luteum formation
*Stimulates testosterone secretion, sperm release
*Stimulates and sustains milk production
*Promotes growth, glucose/protein metabolism


Hormones secreted by the Pancreatic islets and their main target

Hormones: Insulin and Glucagon
Main target: Muscle, adipose, liver


Primary action for pancreatic islets gland

*Lowers blood sugar level
*Raises blood sugar level


Hormones secreted by the adrenal cortex gland and their main target

Hormone: Glucocorticoids, Mineralocorticoids (includes aldosterone)
Main target: Most cells, kidney


Primary action from the Adrenal cortex gland

*Promotes protein breakdown and conversion to glucose
*Promotes Na+ reabsorption, control of salt-water balance


Hormones secreted by the Adrenal medulla gland and their main target

Hormones: Epinephrine and Norepinephrine
Main target: Liver, Muscle, adipose tissue, blood vessel, smooth muscle


Primary action from the adrenal medulla

*Raises blood sugar and fatty acid levels
*Increases both rate and force of heart contractions
*Promotes constriction or dilation of blood vessels


Hormones secreted by the thyroid gland and their main target

Hormones: Thyroxine and Calcitonin
Main target: Most cells & bone


Primary action from the thyroid gland

*Regulates metabolism, growth & development
*Lowers blood Ca++ level


Hormone secreted by the Parathyroid gland and their main target

Hormone: Parathyroid h. (PTH)
Main target: Bone & kidney


Primary action by the parathyroid gland

Raises blood Ca++ level


Hormone secreted by the thymus gland and its main target

Hormone: Thymosins
Main target: Lymphocytes


Primary action from the thymus gland

Roles in immune response


Hormones secreted by the gonads testes (males) and ovaries (female) and their main targets

Gonads testes hormone: Androgens (includes testosterone
Ovaries (female): Estrogens & progesterone
Main targets: General, uterus & breats


Primary action by gonads (testes) and ovaries

*Role in development of genitals & maintenance of male/female sexual traits, sperm formation & growth
*Required for egg maturation & release, proliferation of uterine lining
*Prepares & maintains uterine lining for pregnancy, stimulates breast development


Hormones secreted by the pineal gland and its main target

Hormone: Melatonin
Main target: Hypothalamus


Primary action from the pineal

Influences daily biorhythms


Steroid hormones are synthesized from

Cholesterol (a form lipid), thus is lipid soluble


These hormones can readily diffuse through cell membranes and bind to an internal receptor molecule within the cell

Steroid hormones


The steroid will either diffuse into the cell nucleus and bind to a receptor there, or

It will bind w/the receptor in the cytoplasm, & then the hormone-receptor complex together will move into the cell nucleus


The hormone-receptor complex will interact with a

Specific segment of the cells DNA to either trigger protein synthesis or shut it off


Include derivatives of amino acids (amines & peptide hormones), larger proteins, or proteins bound to oligosaccharides (glycoproteins). These are H2O soluble

Proteinaceous hormones


The proteinaceous hormone receptor complex can enter the cell through

Endocytosis & the effect target cell activity


How can the hormone-receptor complex trigger activity by the target cell for proteinaceous hormones?

By altering membrane activity transport & channel proteins


Binding of the proteinaceous hormones to the membrane bound receptor can trigger with

Second messengers within the cell which has a go-between eliciting the target cells response


One hormone receptor complex can trigger many of what

Second messengers, thus triggering an amplified intracellular effect from the hormone


The master endocrine gland, the pituitary gland, is controlled by what

The hypothalamus


Hypothalamic neurons release hormones in two ways

1) Neurons synthesize ADH & oxytocin, then release the FIND ANSWER


The hypothalamus receives input for what

Positive and negative feedback control


Predominantly nervous tissue extensions of the hypothalamus

Posterior pituitary lobe


Predominantly glandular tissue that respond to releasing/inhibiting hormones from the hypothalamus

Anterior pituitary lobe


What are prostaglandins

16 kinds of fatty acids which have their effects on smooth muscle


What are the 4 characteristics of prostaglandins

1) influence localized blood flow by vasocanstriction or vasodilation
2) similar effect on smooth muscle of the bronchides
3) aggravate tissue inflammation & allergic reactions
4) contribue to: menstrual cramping; w/oxytocine, uterine contractins during labor; in cycles where no pregnancy occurs, death of the corpus luteum; presence of sperm may result in uterine contractions that help move sperm deeper into the uterine tubes


Growth factors influence growth of

Specific cells by regulating the rate at which certain cells divide


Growth factors target cells are in the immediate vicinity of

The releasing cells, they play a role in development by guiding the direction of growth


May be used someday to hasten wound healing, even perhaps spinal cord injuries

Growth factors