Bio without Chinese

What is a hormone?

A hormone is a secreted molecule that travels through the body and affects specific target cells.

What type of cells can hormones affect?

Hormones only affect cells with the correct receptor.

What is endocrine signaling?

Secreted molecules enter the bloodstream and affect distant target cells.

What is paracrine signaling?

Secreted molecules diffuse locally and affect neighboring cells.

What is autocrine signaling?

Secreted molecules affect the same cells that secreted them.

What is synaptic signaling?

Neurotransmitters cross synapses and affect target tissues.

What is neuroendocrine signaling?

Neurohormones enter the bloodstream and affect distant target cells.

In endocrine signaling, molecules diffuse into what?

Bloodstream.

In paracrine signaling, molecules affect which cells?

Neighboring cells.

In autocrine signaling, molecules affect which cells?

The cells that secrete them.

In synaptic signaling, what chemical is released?

Neurotransmitters.

In neuroendocrine signaling, neurohormones enter what?

Bloodstream.

What are the two criteria used to classify secreted cell signals?

Type of secreting cell and route taken by the signal.

What is an endocrine gland?

A ductless gland that releases hormones into the blood.

Do endocrine glands have ducts?

No.

How do endocrine glands transport hormones?

Through the bloodstream.

What do endocrine glands secrete?

Hormones.

What is the target site of endocrine glands?

Distant organs or systemic effects.

Give examples of endocrine glands.

Hypothalamus, pituitary gland, thyroid, parathyroid, pancreatic islets, and gonads.

What is an exocrine gland?

A gland that uses ducts to release substances.

Do exocrine glands have ducts?

Yes.

What do exocrine glands secrete?

Enzymes, sweat, mucus, and saliva.

What is the target site of exocrine glands?

Local area near the duct.

Give examples of exocrine glands.

Sweat glands and digestive glands.

What are the four major classes of hormones in this chapter?

Peptide hormones, amine hormones, steroid hormones, and glycoprotein hormones.

Are peptide hormones water-soluble or lipid-soluble?

Water-soluble.

Where are peptide hormones stored?

Secretory vesicles.

How do peptide hormones travel in plasma?

Free in plasma.

Where are peptide hormone receptors located?

Plasma membrane.

What response mechanism do peptide hormones use?

Second messenger.

How long is the half-life of peptide hormones?

Short, usually minutes.

Give examples of peptide hormones.

Insulin, glucagon, and growth hormone.

Are amine hormones water-soluble or lipid-soluble?

Usually water-soluble.

Where are amine hormones stored?

Secretory vesicles.

How do amine hormones travel in plasma?

Free in plasma.

Where are amine hormone receptors usually located?

Plasma membrane.

What response mechanism do amine hormones usually use?

Second messenger.

How long is the half-life of amine hormones?

Short, seconds to minutes.

Give examples of amine hormones.

Epinephrine, norepinephrine, and thyroxine.

What is special about thyroxine?

It is an amine hormone but acts like a lipid-soluble hormone.

Are steroid hormones water-soluble or lipid-soluble?

Lipid-soluble.

When are steroid hormones synthesized?

On demand.

How do steroid hormones travel in plasma?

Bound to proteins.

Where are steroid hormone receptors located?

Inside the cell, in the cytoplasm or nucleus.

What response mechanism do steroid hormones use?

They alter gene transcription.

How long is the half-life of steroid hormones?

Long, hours to days.

Give examples of steroid hormones.

Estrogen, progesterone, testosterone, cortisol, and aldosterone.

Are glycoprotein hormones water-soluble or lipid-soluble?

Water-soluble.

Where are glycoprotein hormones stored?

Secretory vesicles.

How do glycoprotein hormones travel in plasma?

Free in plasma.

Where are glycoprotein hormone receptors located?

Plasma membrane.

What response mechanism do glycoprotein hormones use?

Second messenger.

How long is the half-life of glycoprotein hormones?

Moderate, hours.

Give examples of glycoprotein hormones.

FSH, LH, and TSH.

Can water-soluble hormones pass through the cell membrane?

No.

Where do water-soluble hormones bind?

Receptors on the cell membrane.

Do water-soluble hormones require second messengers?

Yes.

Name second messengers used by water-soluble hormones.

cAMP, IP3, DAG, and Ca²⁺.

Are water-soluble hormone responses fast or slow?

Fast.

Are water-soluble hormone responses short-lasting or long-lasting?

Short-lasting.

Give examples of water-soluble hormones.

GH, insulin, glucagon, adrenaline, oxytocin, FSH, and LH.

Can lipid-soluble hormones pass through the cell membrane?

Yes.

Where do lipid-soluble hormones bind?

Intracellular receptors in the cytoplasm or nucleus.

Do lipid-soluble hormones require second messengers?

No.

Are lipid-soluble hormone responses fast or slow?

Slow.

Are lipid-soluble hormone responses short-lasting or long-lasting?

Long-lasting.

What do lipid-soluble hormones affect?

Gene transcription and protein production.

Give examples of lipid-soluble hormones.

Estrogen, progesterone, testosterone, glucocorticoids, mineralocorticoids, and thyroxine.

What is the first step of the epinephrine pathway?

Epinephrine binds to a receptor on the cell membrane.

What does the epinephrine receptor activate?

G protein.

What does G protein activate in the epinephrine pathway?

Adenylyl cyclase.

What does adenylyl cyclase convert ATP into?

cAMP.

What is cAMP in the epinephrine pathway?

Second messenger.

What does cAMP activate?

Protein kinase A.

What does protein kinase A lead to?

Glycogen breakdown.

What does glycogen break down into?

Glucose.

Why does epinephrine use signal transduction?

It is water-soluble and cannot enter the cell directly.

What type of hormone is estradiol?

Lipid-soluble steroid hormone.

Can estradiol pass through the cell membrane?

Yes.

Where does estradiol bind?

Intracellular receptor.

What forms when estradiol binds its receptor?

Hormone-receptor complex.

Where does the estradiol hormone-receptor complex go?

Nucleus.

What does the estradiol hormone-receptor complex bind to?

DNA.

What does estradiol change?

Gene transcription.

What is made after estradiol changes transcription?

mRNA and proteins.

Name the major endocrine glands shown in the body diagram.

Hypothalamus, pituitary, thyroid, parathyroid, thymus, adrenal, pancreas, ovaries, and testes.

What does the hypothalamus control?

Anterior pituitary gland.

What hormones does the hypothalamus use to control the anterior pituitary?

Releasing hormones and inhibiting hormones.

What does the hypothalamus produce for the posterior pituitary?

ADH and oxytocin.

What does the posterior pituitary release?

ADH and oxytocin.

What does ADH do?

Promotes water reabsorption in kidney tubules and collecting ducts.

What does oxytocin do?

Stimulates uterine contraction and milk ejection.

What does GH stand for?

Growth Hormone.

What does GH do?

Promotes growth and metabolic function.

What does TSH stand for?

Thyroid-Stimulating Hormone.

What does TSH do?

Stimulates the thyroid gland to secrete thyroid hormones.

What does ACTH stand for?

Adrenocorticotropic Hormone.

What does ACTH do?

Stimulates the adrenal cortex to secrete adrenocortical hormones.

What does FSH stand for?

Follicle-Stimulating Hormone.

What does FSH do generally?

Stimulates gamete production and sex hormone secretion.