Ch. 16 A&P 2

Endocrine System

PRLH

Prolactin releasing hormone

Hypo-secretion of PRL

Poor milk production

Hypersecretion of PRL

Innapropriate/excess milk production

ACTH

Adrenocorticotropic Hormone

CRH

Corticotropic releasing hormone

CIH

Corticotropic inhibiting hormone

ACTH target

Adrenal cortex

ACTH effect

Release of corticosteroids

Hypersecretion of ACTH

Cushings disease

Hyposecretion of ACTH

rare

TSH

Thyroid stimulating hormone

TRH

Thyroid releasing hormone

TIH

Thyroid inhibiting hormone

TSH target

Thyroid gland

TSH effect

Normal development and secretions from thyroid gland

TSH hypersecretion

Graves disease or similar effects

TSH hyposecretion

Child: cretinism Adult: myxedema

Initiates responses rapidly (Nervous or endocrine system)

Nervous

short duration responses (Nervous or endocrine system)

Nervous

Acts via action potentials and neurotransmitters (Nervous or endocrine system)

Nervous

Act over short distances (Nervous or endocrine system)

Nervous

Initiates responses slowly (Nervous or endocrine system)

Endocrine system

Long-duration responses (Nervous or endocrine system)

Endocrine

Acts via hormones (Nervous or endocrine system)

Endocrine

Act over long distances (Nervous or endocrine system)

Endocrine

Produce nonhormonal substances (exocrine or endocrine glands)

Exocrine

Have a duct to carry secretion to membrane surface (exocrine or endocrine glands)

Exocrine

Produces hormones (exocrine or endocrine glands)

Endocrine

Ductless; hormones secreted directly into surrounding extracellular fluid (exocrine or endocrine glands)

endocrine

Autocrines

Chemicals that exert effects on same cells that secrete them

Paracrines

Locally acting chemicals that affect neighboring cells

Lipid-soluble hormones

All steroid hormones and thyroid hormone

Water soluble hormones

Amino-acid based hormones EXCEPT thyroid hormone

Location of receptors in lipid-soluble hormones

Inside cell

Location of receptors in water-soluble hormones

On plasma membrane

Up-regulation

Target cells add receptors in response to persistently low hormone levels

Down-regulation

Cells remove receptors in response to persistently high levels

Amplification effect

A single hormone causes millions of molecules to be generated

Humoral stimulus

Hormone release caused by altered levels of certain critical ions or nutrients

Neural stimulus

Hormone release caused by neural imput

Hormonal stimulus

Hormone release caused by another hormone

Hypothalamus is connected to pituitary gland via _

infundibulum

Tropic hormones

Cause release of another hormone

Which two anterior pituitary hormones are NOT tropic hormones

Growth hormone (GH) and Prolactin (PRL)

What are the six anterior pituitary hormones

GH, TSH, ACTH, FSH, LH, PRL

Effects of hyposecretion of GH

Pituitary dwarfism in children

Effects of hypersecretion of GH

Gigantism in children; acromegaly in adults

Parafollicular cells produce what hormone

calcitonin

Calcitonin effects

produced in response to high blood calcium levels, stimulates osteoblasts, decreases calcium absorption in SI, allows calcium to be excreted in urine

Which is more active, T3 or T4

T3 (10x)

Calcitonin is produced in response to _

High blood calcium levels

Calcitonin is an antagonist to _

Parathyroid hormone (PTH)

PTH is released due to _

Low blood calcium levels

Adrenal cortex three zones

Zona glomerulosa, zona fasciculata, zona reticularis

zona glomerulosa produces _

mineralocorticoids (aldosterone)

zona fasciculata produces _

glucocorticoids

zona reticularis produces

gonadocorticoids

Adrenal medulla

inner region of nervous tissue that is part of sympathetic NS, secretes 2 amine hormones (epinephrine & norepinephrine); helps cope with stressful situations

FSH effects of hyposecretion

Failure of sexual maturation

FSH effects of hypersecretion

No important effects

FSH target organ

Ovaries and testes

FSH is stimulated by _

GnRH

LH target organ

Ovaries and testes

LH effects of hyposecretion

Failure of sexual maturation

LH effects of hypersecretion

No important effects

Temporary endocrine organ during pregnancy

Placenta

The pineal gland secretes _

melatonin

Pinealocytes secrete _

melatonin

Pancreas location

behind stomach

Alpha cells in the pancreas produce _

glucagon (raise blood glucose)

Beta cells in the pancreas produce _

insulin (lower blood glucose)

Type 1 diabetes

No insulin produced

Type 2 diabetes

Target cells do not respond normally to insulin

Endocrine glands

Secrete products into surrounding tissue fluids

Exocrine glands

Secrete onto a membrane surface

Hormone synthesized from cholesterol

Testosterone

Most common stimulus

Hormonal

Prolactin effect

Hormone specifically for stimulating milk production

Hormone that stimulates ovarian follicle maturation and production of estrogens

FSH

Location of receptors in lipid-soluble hormones

Inside cells

Increase in epinephrine and norepinephrine results in:

Increase in blood pressure

Huge urine output that decreases blood volume and causes dehydration

Polyuria

Hormones associated with anterior pituitary gland

GH, FSH, PRL

Hyposecretion of ADH effects

Diabetes insipidus

What is secreted by the adrenal medulla

Epinephrine

ADH

Anti-diuretic hormone

Hormone that causes kidneys to release less water, decreasing urine output

ADH

How do amino acid-based hormones communicate with a target cell

by binding to receptors in the plasma membrane

How to lipid-soluble hormones communicate with a target cell

by binding to receptors inside the cell

Type of hormonal interaction that occurs when more than one hormone acting on a target cell produce an amplified effect

Synergism

Where are the receptors for water-soluble hormones located

on the plasma membrane

When a hormone cannot exhibit its full effect without another hormone being present

Permissiveness

Function of adrenocorticotropic hormone

Causes the adrenal cortex to produce hormones

What would cause a surge of PRL

A decrease in PIH

What gland produces adrenocorticotropic hormone

Anterior pituitary

FSH and LH belong in which category of hormones

gonadotropins

Which two hormones are released from the posterior pituitary

ADH and oxytocin

ADH is secreted in response to what conditions

Dehydration and low blood pressure

Where is LH released from

Anterior pituitary

LH function

causes ovulation and intersitial cells to produce testosterone in the testes