Download Lesson 8.2 Major Endocrine Organs

McKenzie
Health Science 20
NAME:_________________
Lesson 8.2 Major Endocrine Organs
Objectives:
1. Identify the organs and glands of the endocrine system.
2. Identify the six hormones of the anterior pituitary.
3. Describe the location and function of the thyroid, parathyroid, thymus, pineal, and adrenal glands.
Identify the hormones produced by each of these glands.
4. Explain the endocrine and exocrine functions of the pancreas.
5. Identify the sex hormones produced by the gonads.
Saskatchewan Outcome:
“I can analyze the anatomy and physiology of a healthy human”
Saskatchewan Indicators:
“I can describe the anatomy (structure) and physiology (function) of the endocrine system”
Before this lesson, try to answer the following questions:
1. Which hormone makes you sleepy at night?
ANSWER:____________________________________________________________________
2. Which biological processes are associated with the “adrenaline rush”?
ANSWER:____________________________________________________________________
Key Terms:
 Adrenal cortex
 Anterior pituitary
 Parathyroid glands
 Posterior pituitary
 Thymus gland
References:
 Notes & handouts
 Textbook Pages: 275 – 285
 Study Guide Pages: 121 – 123
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Adrenal glands
Ovaries
Pineal gland
Scrotum
Thyroid gland
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Adrenal medulla
Pancreas
Pituitary gland
Testes
Tropic hormones
McKenzie
Health Science 20
NAME:_________________
Major Endocrine Organs
The Hypothalamus
The hypothalamus and the pituitary gland function in conjunction with one another, thereby associating
the body’s nerve tissue with hormones. The mechanism by which hormones are released from the
posterior and anterior lobes of the pituitary glands are quite different.
McKenzie
Health Science 20
NAME:_________________
The Pituitary Gland
Secretions from the posterior pituitary gland.
1. Antidiuretic Hormone (ADH): stimulates the kidneys to absorb more water
2. Oxytocin: stimulates uterine contraction during child birth and release of milk by mammary glands
These hormones are PRODUCED in the
hypothalamus, but released into the blood
from the posterior pituitary.
The hypothalamus contains special neurons
called NEUROSECRETORY CELLS which
produce the hormones. The hormones are
carried down the axons of these special
neurons to the posterior pituitary.
The circulatory system carries the hormones
to their specific TARGET ORGANS.
Secretions from the anterior pituitary gland.
1. Prolactin (PRO)
2. Adrenocorticotropin (ACTH)
3. Thyroid Stimulating Hormone (TSH)
4. Follicle-stimulating hormone (FSH)
5. Luteinizing hormone (LH)
6. Growth hormone (GH)
The anterior pituitary gland releases six hormones
which bring about many changes in the body.
The hypothalamus detects the effect of one of the
hormones from the anterior pituitary is required, it
releases a hormone-like substance called a
RELEASING FACTOR (hypophysiotrophic
hormones in the diagram).
These releasing factors travel through the very short
blood vessels (a portal system) that connect the
hypothalamus to the anterior pituitary.
The effect of this is to cause the release of the
required hormone
McKenzie
Health Science 20
NAME:_________________
The Thyroid
The thyroid is released at the base of the neck. It produces two important hormones
responsible for regulating metabolism, and growth and differentiation of cells.
1. Thyroxine: when released, increases metabolism and promotes growth and
differentiation of cells. It stimulates increased utilization of glucose by the cells,
and stimulates the production of more enzymes to increase metabolic reactions.
2. Triiodothyronine: appears to have a similar function to thyroxine
3. Calcitonin: maintains calcium balance along with parathyroid hormone (PTH). Calcitonin is released
when calcium levels rise. Calcitonin caused calcium in the blood to be deposited and absorbed into
the bone. As a result, calcium levels in the blood decreases.
McKenzie
Health Science 20
NAME:_________________
Adrenal Glands
Sudden simultaneous release of noradrenalin from all the sympathetic neurons (as in times of
fright) has a critical effect. It causes the release of the hormone adrenalin (epinephrine) from
the interior of the adrenal glands. The adrenal glands are located on top of the kidneys. The
noradrenalin and the adrenalin initiate and sustain what is known as the ‘Fight or Flight”
response. They prepare the body to respond to danger in the following ways:
1. Increase the heart rate so that more blood is supplied to the body more quickly.
2. Widen air passageways so that more air can be exchanged with each breath.
3. Sudden contraction of some muscles to tense the body up for action. Included in this is the
contraction of the diaphragm. A scared person will gasp, inhaling suddenly.
4. Contraction of the iris of the eye thus widening the pupil to maximize visual alertness.
5. Alter blood flow patterns. Contraction of the sphincter muscles in arterioles reduce blood
flow to surface tissues and the digestive system and allow increased blood flow to the
musculo-skeletal system.
The adrenal gland produces three important types of hormones:
1. Glucocorticoids
2. Mineralocorticoids
3. Sex hormones (small amount)
McKenzie
Health Science 20
NAME:_________________
Glucocorticoids: associated with blood glucose levels
Cortisol: increases the amount of amino acids in the blood to help the blood recover from stress. The
amino acids in the blood are converted into glucose by the liver and thereby increases the level of blood
sugar.
Minerolorticoids: associated with mineral (salt) levels in the blood
Aldosterone: secretions of aldosterone increase sodium retention and water reabsorption by the kidney,
thereby maintaining body fluid levels.
McKenzie
Health Science 20
NAME:_________________
Pancreas
The islets of Langerhans in the pancreas produce and secreted two hormones responsible for regulating
blood sugar levels  Insulin and Glucagon
Insulin: Stimulates the liver to take up more glucose and convert and store it as glycogen, thereby
DECREASING blood sugar levels
Glucagon: Stimulates the liver to breakdown glycogen and release it as glucose, thereby INCREASING
blood sugar levels.
Diabetes: a disease where the individual cannot produce enough insulin, or insulin at all. Currently,
there’s been development in islet transplants to replace the degenerated or malfunctioning cells.
McKenzie
Health Science 20
NAME:_________________
Others
Parathyroid Glands produce Parathyroid Hormone (PTH): PTH along with Calcitonin (Thyroid) maintain
calcium homeostasis. PTH is released when low calcium levels are detected in the blood. PTH increases
calcium levels in three ways:
1. Stimulating breakdown of bone tissues, moving calcium from bone t blood
2. Increasing calcium absorption in the intestines (req. vitamin D)
3. Stimulating kidney reabsorption of calcium from urine and excreting phosphorus
Thymus Gland produces Thymosin, a hormone essential for development of white blood cells, which
play an important role in the body’s immune response.
Pineal Gland produces Melatonin, the hormone responsible for making us sleepy. Melatonin levels are
highest at night.
Gonads are sex glands. In men the gonads are Testes, and in women, the gonads are ovaries. The
gonads release sex hormones which will be looked at more closely in the reproductive system unit. Sex
hormones are responsible for the development of the reproductive system, production of sex cells
(sperm & eggs), and secondary sex characteristics. In women, sex hormones are also responsible for
regulating the menstrual cycle.
Complete the Lesson
1. LAB: #9 & 10, p. 285
2. Study Guide: p. 121, 123
Additional work (homework)
1. Read p. 275 – 285 in your textbook
2. Complete the “Check Your Understanding” Questions, p. 279, 283
3. Correct your “Before this lesson” answers