Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg....

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THE ENDOCRINE SYSTEM

Transcript of Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg....

Page 1: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

THE ENDOCRINE SYSTEM

Page 2: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Endocrine vs exocrine glands

•Endocrine glands produce and secrete hormones into the bloodstream•eg. the pituitary gland

•Exocrine glands secrete through ducts •eg. salivary glands

Page 3: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Hormones

Hormones – chemical signals released by specialized cells of the body to exert an effect on cells in other parts of the body

•There are 2 classes of hormones:

a) Steroid hormones • derived from cholesterol• multi-aromatic structure• lipid soluble

Page 4: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

a) Steroid hormones

Mode of action:

•Diffuse through cell membrane of cells (phospholipid soluble)

•Combine intercellularly with receptor molecule

• Initiates transcription of specific gene(s)

•Effect achieved by resulting protein(s)

Page 5: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Hormones

Hormones – chemical signals released by specialized cells of the body to exert an effect on cells in other parts of the body

•There are 2 classes of hormones:

a) Protein hormones• made of amino acids• water soluble

Insulin

Growth hormone

Parathyroid hormone

Page 6: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

b) Protein hormonesMode of action:

•Attach to specific membrane receptors(hormone acts as ‘first messenger’)

•Signal transduction results in intercellular molecule activation(molecule is ‘second messenger’)

•Molecule up/down regulates protein activity within cell

•Effect is achieved by activated proteins

Page 7: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Glands of the endocrine system

Pituitary gland•Attached to the hypothalamus•Two-lobed (anterior & posterior)•Each lobe releases different hormones

Posterior pituitary•Stores/release hypothalamus-made hormoneseg. antidiuretic hormone, ADH, oxytocin

Anterior pituitary• Makes its own hormones but release is

controlled by hypothalamuseg. growth hormone, follicle-stimulating hormone, luteinizing hormone

Page 8: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Glands of the endocrine system

Pancreas•Small gland containing endocrine & exocrine cells

•Endocrine tissue called islets of Langerhans and contains 2 types of cells:

-cells produce insulin • released when blood sugar is high• causes muscle, liver and other organs to

take up glucose (reducing blood sugar)

-cells produce glucagon• released when blood sugar is low• causes glycogen in aforementioned

tissues/organs to be converted to glucose (raising blood sugar)

Page 9: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Glands of the endocrine system

Adrenal glands•Located above each kidney•Consists of adrenal medulla and adrenal cortex

Medulla•Regulated by nervous system•Makes adrenaline (epinephrine) & noradrenaline (norepinephrine)

•Sypathetic nerves cause release of both hormones

•Causes conversion of glycogen to glucose & ups heart rate, breathing rate, etc.

Cortex•Produces sex hormones and hormones involved in stress conditions (eg. cortisol) and water reabsorption (eg. aldosterone)

Page 10: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Glands of the endocrine system

Thyroid/parathyroid glands•Located in neck• ‘Thyroid hormones’ effect growth & specific rates of function within the body (eg. calcitonin regulates bone-calcium homeostasis)

Ovaries•Located in lower abdomen of females•Produce estrogen and progesterone which regulate reproductive health (eg. the menstrual cycle)

Testes•Located in the scrotum of males•Produce testosterone which maintains libido, muscle strength and bone density

Page 11: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Nervous + Endocrine =

There are 3 main pathways of hormonal control:

1.Endocrine pathway•Stimulus

•Endocrine gland

•Blood vessel

•Target

•Response

Page 12: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Nervous + Endocrine =

There are 3 main pathways of hormonal control:

2.Neurohormone pathway•Stimulus

•Hypothalamus

•Blood vessel

•Target

•Response

Page 13: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Nervous + Endocrine =

There are 3 main pathways of hormonal control:

2.Neuroendocrine pathway•Stimulus

•Hypothalamus•Blood vessel

•Endocrine gland•Target

•Response

Page 14: Endocrine vs exocrine glands Endocrine glands produce and secrete hormones into the bloodstream eg. the pituitary gland Exocrine glands secrete through.

Try this…

Read pg. 938

Section 46.5