Chapter 16 endocrine system

The endocrine system

is a control system that uses chemical messengers called hormones

Hormones

Chemical messangers

The endocrine system consists of

Widely scattered endocrine glands regulate the important processes of the body

Main processes regulated by the endocrine system

Reproduction

Growth and Development

Mobilization of Body Defenses

Maintenance of electrolyte and water balance

Cellular metabolism and energy balance

Other hormone producing structures

Adipose Tissue, Digestive Organs, Kidneys, Heart, Skin and Liver, Placenta

Adipose Tissue

Leptin

Leptin

Suppresses hunger

Digestive organs

Gastrin, secretin

Secretin

Stimulates movements and secretions of the digestive system

Kidneys

Erythropoietin

Erythropoietin

Stimulates RBC production

Heart

ANP

Anp

decreases Na+ reabsorption. Blood Vl and Blood Pressure decrease .

Skin, Liver, and Kidneys

Vitamin D

Vitamin D

Stimulates CA absorption from the digestive system

Placenta

HCG, Estrogen, Progestrone, and Prostaglands

HCG

Hormone of pregnancy

Estrogen and Progesterone

Maintain healthy pregnancy

Prostaglands

Labor contractions

Circulating hormones

carried by blood and act on distant target cells

Circulating hormones are

Long distant hormones

Endocrine glands are

Ductless and secrete into interstitial fluid

Local hormones

Do not circulate in the blood

Local hormones are

Short distant hormones

Paracrines

Act on neighboring target cells

Autocrines

Act on the same cell that produced the hormone

Lipid soluble

Steroid and thyroid hormones

Lipid Soluble produced by

Ovaries, Testes, and Adrenal Cortex

Thyroid gland

Makes thyroid hormones

Steroid hormone

Makes steriods

Water soluble

Amines, peptides, and proteins

Amines

Modified from a single amino acid

Peptides

Short chains of amino acids

Proteins

Longs chains of amino acids

Ficosaniods

Made by arachiodonic acid released by cell membranes

arachidonic acid

Fatty acid

Ficosanoids ex

Prostaglandins and luekotrieches

Luekotriches

involved in inflammation

Paracrine example

Prostaglandis

Autocrine example

Interleukin 2

Steroid hormones modified from cholesterol are

Aldosterone, Estrogen, and Testrone

Thyroid hormones contain

Iodines

Proteins example

Insulin and growth hormones

Eiconoids

Are modified from a specific fatty acid arachnoid

Lipid soluble hormones use

Direct gene activation

Water soluble hormones use

Second messenger activation

Direct Gene Activation by Lipid Soluble hormones step 1

Hormone diffuses through plasma membrane of a target cell

Direct Gene Activation by Lipid Soluble hormones step 2

Binds to receptor inside a target cell

Direct Gene Activation by Lipid Soluble hormones step 3

Transcription of a specific gene

Direct Gene Activation by Lipid Soluble hormones step 4

New protein is made by ribsome

What is 1st messenger

Water soluble

Cynic Amp

Second messenger

Secondary messenger by water solubles step 1

Hormones (first messenger) binds itself to receptor on cell surface of a target cell

Secondary messenger by water solubles step 2

This causes second messenger to be made in the cell (cyclic amp)

Secondary messenger by water solubles step 3

2nd messenger activates protein kinase

Secondary messenger by water solubles step 4

Protein kinase activates a protein

Humoral stimulus

Responds to an imbalance in the body

Humoral Stimulus example

Low Blood CA—→ Parathyroid Gland secretes Parathyroid hormone ——> Increase Blood CA

Nureal Stimulus

Responds to the nervous system

Nueral Stimulus example

Sympathetic Nervous System (fight or flight) stimulates Adreneal Medulla to release Norepinephrine and Epinephrine

Hormonal Stimulus is the ____

Most common

Hormonal Stimlus

responds to a specific hormone

Hormonal Stimulus ex

Hormones from Hypthalamus causes Anterior Piturary gland to secretes hormones stimulate other endocrine glands to secrete hormones

Hypothalamus

Makes water soluble hormones

Pituitary gland

Makes water soluble hormones

Nuerohypophysis

Posterior pituitary and infundibulum

Tract

A bundle of axons in the CNS

The hypothalamic-hypophyseal tract

Is a nueral connection between the hypothalamus and posterior pituarity

Adenohypopsis

Anterior pituitary

The hypopseal portal veins

Is vascular connection between hypothalamus and anterior pituitary

Hypothalamus makes

ADH and Oxytoxin

Posterior Pituarity

secretes ADH and oxytoxin into the blood

The Hypothalamus makes 2 hormones that are sent by hypothalamic- hyposeal tract to posterior pituarity

ADH and Oxytoxin

ADH stimulus

Humoral stimulus: Dehydration

ADH effect

Increases Facultative water reasbportion kidneys produce small amounts of concentrated urine

Oxytoxin

Labor contractions, causes milk ejection to be release from mamary gland

The hypothalamus make 2 hormones that are transported by the hypophyseal portal vein to anterior pituitary

Releasing hormones (RH) and Inhibiting Hormones (IH)

Releasing Hormone

Stimulates anterior pituitary to make and secrete a specific hormone

Inhibiting Hormones

Inhibits anterior pituitary from making a specific hormone

Water Soluble hormones secreted by _____ in response to RH or IH being secreted from ____

Anterior Pituarity, Hypothalamus

Growth Hormones

Stimulates the growth of cells

Thyroid stimulating hormone

Stimulates thyriods to make and secrete a specific thyroid hormone

ACTH

Stimulates adrenal cortex to make steriods