Human Biochemistry Hormones
Tuesday, April 10, 2012
THE ENDOCRINE SYSTEM
Tuesday, April 10, 2012
THE ENDOCRINE SYSTEM
Tuesday, April 10, 2012
THE ENDOCRINE SYSTEM• The ENDOCRINE SYSTEM = the organ
system that regulates internal environment conditions by secreting hormones into the bloodstream
Hormones play a huge role in maintaining homeostasis!
Hormones control many developmental changes like PUBERTY!
Hormones can have an effect on pretty much ALL the organ systems!
Tuesday, April 10, 2012
THE ENDOCRINE SYSTEM• HORMONE = chemicals released by one type
of cell (usually a gland) that has an effect on other cells of the body
• GLAND = an organ that secretes hormones and other useful substances
Endocrine hormones are produced in glands and secreted direction into the blood stream – thus, the circulatory system carries them to the various organs of the body!
Tuesday, April 10, 2012
MAJOR GLANDS OF THE HUMAN BODY
• HYPOTHALAMUS• PITUITARY GLAND• THYROID GLAND• PARATHYROID GLAND• PANCREAS• ADRENAL GLANDS• KIDNEYS• FEMALE OVARY• MALE TESTES
Tuesday, April 10, 2012
THE ENDOCRINE SYSTEM• Hormones are secreted into the bloodstream,
and can reach ALL the cells of the body, BUT they will only affect specific target cells
Cells each have specific hormone receptors on their cell
membranes or inside the cell.
This means they will only allow SPECIFIC hormone molecules
to attach. The number of receptors on an individual cell may vary. Cells may have receptors for one hormone and not another.
Tuesday, April 10, 2012
2 Types of Hormones
Protein hormones include insulin and growth hormone. These hormones are chains of amino acids.
Water soluble!
– PROTEIN HORMONES
Steroid hormones are made from cholesterol and include the sex hormones and cortisol.
Fat soluble!
– STEROID HORMONES
Tuesday, April 10, 2012
Steroid Hormones
1. Steroid hormones diffuse through the cell membrane of a target cell.
2. Inside the cytoplasm, the hormone attaches to its specific receptor.
3. The hormone-receptor complex then moves into the nucleus, where it activates a gene and initiates protein synthesis.Tuesday, April 10, 2012
Protein Hormones
1. Protein hormones attach to a specific receptor site in the target cell membrane.
2. The hormone-receptor complex promotes the formation of cyclic AMP from ATP.
3. Cyclic AMP acts as a secondary messenger, activating enzymes within the cell.Tuesday, April 10, 2012
The Pituitary Gland • The PITUITARY GLAND = a gland at the base
of the brain that secretes more types of hormones than any other endocrine gland!!!!!
The pituitary gland is only the size of a pea!!!!!!
The pituitary gland often called the MASTER GLAND!
Tuesday, April 10, 2012
The PITUITARY GLAND is divided into two lobes:
- ANTERIOR LOBE
- POSTERIOR LOBE
The PITUITARY GLAND and the HYPOTHALAMUS interact with each other to produce a variety of different
effects on distant body parts.
Pituitary Gland + Hypothalamus =
The Pituitary Gland
Tuesday, April 10, 2012
THE ENDOCRINE SYSTEMThe PITUITARY GLAND is connected by a stalk to the HYPOTHALAMUS.
The HYPOTHALAMUS is the area of the brain associated with homeostasis.
Here the interaction between the NERVOUS SYSTEM and the ENDOCRINE SYSTEM becomes obvious! The pituitary gland produces and stores hormones. The hypothalamus stimulates
the release of pituitary hormones via nerves.Tuesday, April 10, 2012
THE ENDOCRINE SYSTEMNeurons in the hypothalamus secrete HORMONE-RELEASING FACTORS into small blood vessels that lead to the anterior lobe of the pituitary gland.
The pituitary gland then releases a number of different hormones.
Tuesday, April 10, 2012
THE ENDOCRINE SYSTEMHYPOTHALAMUS
HORMONE-RELEASING FACTOR
SMALL BLOOD VESSELS
ANTERIOR LOBE OF PITUITARY GLAND
VARIOUS HORMONES ARE RELEASED
HORMONES ACT ON OTHER PARTS OF THE BODY
Tuesday, April 10, 2012
Additionally, nerve cells in the hypothalamus produce hormones that travel down the bloodstream and are secreted into the blood stream within the posterior lobe of the pituitary and released into the rest of the body.
Tuesday, April 10, 2012
ANTERIOR LOBE PITUITARY HORMONES
HORMONE TARGET FUNCTIONThyroid-stimulating hormone (TSH)
Thyroid gland -Stimulates the release of thyroxine from thyroid
- thyroxine regulates cell metabolism.
Adrenocorticotropic hormone (ACTH)
Adrenal cortex - Stimulates release of hormones involved in stress responses.
Somatotropin (STH), or growth hormone (GH)
Most cells - Promotes growth
Follicle-stimulating hormone (FSH)
Ovaries, testes - In females, stimulates follicle development in ovaries.
- In males promotes development of sperm in testes.
Luteinizing hormone (LH)
Ovaries, testes -In females, stimulates ovulation and formation of the corpus luteum
- in males, stimulates the production of the sex hormone testosterone
Prolactin (PRL) Mammary glands
Stimulates and maintains milk production in lactating females
Tuesday, April 10, 2012
POSTERIOR LOBE PITUITARY HORMONES
HORMONE TARGET FUNCTION
Oxytocin Uterus, mammary glands
-Initiates strong contractions- triggers milk release in lactating females
Antidiuretic hormone (ADH)
Kidneys - Increases water reabsorption by the kidneys
Tuesday, April 10, 2012
WATER BALANCE• Antidiuretic hormone (ADH) = helps to regulate the osmotic
pressure of body fluids by causing the kidneys to increase water reabsorption.
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ADH is released more water is reabsorbed in the kidneys urine produced is more concentrated
ADH is stored and released by the PITUITARY GLAND its release is signalled by the HYPOTHALAMUS
Tuesday, April 10, 2012
Thyroid Gland Hormones
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HORMONE TARGET FUNCTION
T3 Many different cells - Regulates basal metabolic rate & protein synthesis
T4 Thyroxine Many different cells - Regulates basal metabolic rate & protein synthesis
Tuesday, April 10, 2012
Adrenal Gland Hormones
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HORMONE TARGET FUNCTIONAdrenaline (epinephrine) Heart, liver,
many others- Fight or flight response - Boosts oxygen supply and glucose to the brain and muscles for a range of actions- Suppresses non-emergency bodily processes
Noradrenaline Muscles - Fight or flight response- Prepares skeletal muscles
Aldosterone Kidneys - increases water reabsorption by the kidneys- affects blood pressure
Tuesday, April 10, 2012
KIDNEYS AND BLOOD PRESSURE• the kidneys also play a role in the maintenance of blood pressure by
adjusting blood volumes.
» the hormone involved in this feedback loop is ALDOSTERONE
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ALDOSTERONE = is produced in the cortex of the adrenal glands and acts on the kidneys by increasing Na+ reabsorption from the distal tubule and collecting duct.
Tuesday, April 10, 2012
Pancreas Hormones
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HORMONE TARGET FUNCTION
Insulin (produced by beta cells)
Liver, muscle and fat tissue cells
- Causes glucose uptake from the blood to be stored in liver and muscle- Stops use of fat as energy source- Decreases blood glucose levels
Glucagon (produced by alpha cells)
- Stimulates the breakdown of glycogen into glucose- Increases blood glucose levels
Tuesday, April 10, 2012
Sugar Metabolism Regulation
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Tuesday, April 10, 2012
Sex Hormones
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HORMONE GLAND TARGET FUNCTION
Estrogen Follicle cells of Ovary
Body cells - stimulates ovulation - initiates secondary female characteristics- thickens endometrium
Progesterone Corpus luteum of Ovary
Uterus, cervix - inhibits ovulation-stimulates endometrium- supports pregnancy
Testosterone Testes, adrenal glands
Body cells - increase muscle mass, bone density, strength- male secondary sex characteristics
Tuesday, April 10, 2012
Who do we look like?
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Tuesday, April 10, 2012
Menstruation Cycle
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FSH causes estrogen to rise
1LH stimulates the egg release
2Progesterone increases
3Hormone production decreases and menstruation begins
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Tuesday, April 10, 2012
Oral Contraceptives
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Oral contraceptives (“the birth control pill”) are composed of synthetic progesterone and estrogen
They are similar enough to perform the same function: they inhibit FSH and LH and so inhibit ovulation
Should the Pill be over the counter? Tuesday, April 10, 2012
‘Roid Rage
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Anabolic steroids mimic testosterone and increase protein synthesis and build up cellular tissue
Anabolism = building up
Tuesday, April 10, 2012
Anabolic Steroids
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☻GOOD☻ ☹BAD☹ Can be used to trigger puberty
Stimulate bone growth and appetite in cancer patients
Increases LDL cholesterol
Increases blood pressure
Causes liver damage
Bad temper
Acne
Decreased sperm count
Increases muscle mass
Tuesday, April 10, 2012
Try it!
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Tuesday, April 10, 2012