McKenzie
Health Science 20
NAME:_________________
Lesson 8.1 Functions & Control of the Endocrine System
Objectives:
1. Explain how the endocrine and nervous systems work together to regulate bodily functions.
2. Describe the basic anatomy of the endocrine system.
3. Describe the functions of hormones, and explain how hormones move through the body.
4. Identify the two classifications of hormones.
5. Explain how hormones help maintain homeostasis.
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. What roles do the nervous and endocrine systems play in the fight-or-flight response?
ANSWER:____________________________________________________________________
2. What are hormones?
ANSWER:____________________________________________________________________
Key Terms:
 Amino-acid hormones
 Glucagon
 Humoral control
 Insulin
 upregulated
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Downregulated
Hormonal control
Hypothalamic nonreleasing hormones
Neural control
References:
 Notes & handouts
 Textbook Pages: 268 – 274
 Study Guide Pages: 117 – 120
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Epinephrine
Hormones
Hypothalamic releasing hormones
Steroid hormones
McKenzie
Health Science 20
NAME:_________________
The Endocrine System =
Endocrine Glands
-
Ductless glands
Internal secretion of hormones into the bloodstream
E.g. hypothalamus, pancreas, pituitary gland, adrenal gland, thyroid gland, pineal gland, testes
(male), ovaries (female)
Regulate many functions
See Figure 8.1 on p. 269 in your textbook
*some endocrine glands are also a part of the nervous system (hypothalamus, adrenal, pineal) to allow
the two systems to integrate their responses
Exocrine Glands
-
External secretion
Counterpart of endocrine glands
Secretions carried to the body’s surface and/or other organs through ducts
E.g. sweat glands, salivary glands, mammary glands, lacrimal glands, pancreas glands
*Pancreas is unique – both an endocrine and exocrine gland.
McKenzie
Health Science 20
NAME:_________________
Hormones
-
Chemical messengers: 2 types – steroid or amino-acid
Steroid hormones are lipid based (recall biological molecules 2.1 lesson)
Amino-acid are protein based (recall biological molecules 2.1 lesson)
Most hormones are protein based, except for reproductive hormones and adrenal gland hormones
Hormone Receptors
-
Transmitter cell that senses and responds to certain stimuli (recall chapter 1)
Hormone binds to receptor and influences activity of the target cell
o E.g. changed cell membrane’s permeability, increasing/decreasing enzyme activity,
increasing/decreasing protein production, stimulating/inhibiting secretory activity
Steroid Hormone Receptors
Protein Hormone Receptors
McKenzie
Health Science 20
NAME:_________________
Hormone Secretion Control
Endocrine glands are regulated in 3 different ways: neural control, hormonal control and humoral control
Neural Control
- The nervous system controls certain hormonal responses.
- E.g. fight or flight response: The SNS stimulates the adrenal medulla to release epinephrine and
norepinephrine, which prime the body to fight or flee
o Increased heart rate, blood pressure, respiration and blood flow to muscles
o Decreased blood flow to organs and digestive system, and dilation of pupils
Hormonal Control
- Hypothalamus will secreted releasing hormones of nonreleasing (inhibiting) hormones
- Hierarchy of command of the endocrine organs
See Figure 8.2 on p. 271 in your textbook.
Note: the pancreas (manager level/second target) is stimulated or inhibited by blood glucose levels rather than from the CNS or other glands
Humoral control
- Various substances in body fluids (e.g. blood) are monitored for homeostatic imbalance
- E.g. increased blood sugar levels => stimulate insulin secretion
McKenzie
Health Science 20
NAME:_________________
Hormones & Homeostasis
-
The human body constantly monitors internal environment to ensure homeostasis
Neural, hormonal or humoral controls trigger the release of hormones during homeostatic imbalance.
Increased hormone levels affect target sites and restore homeostasis
Homeostatic balance and rising hormone levels inhibit further hormone secretions via negative
feedback loop.
Negative feedback loop causes the gland to stop secreting hormones
Recall homeostatic mechanisms (Lesson 1.2)
Recall negative and positive feedback (Lesson 1.2)
*See figure 8.4 on p. 273 in your textbook
McKenzie
Health Science 20
NAME:_________________
Hypothalamic control of body temperature
Complete the Lesson
1. WATCH: Glands & Hormones (https://www.youtube.com/watch?v=eWHH9je2zG4)
2. Study Guide: p. 117, 119, 120
Additional work (homework)
1. Read p. 268 – 274 in your textbook
2. Complete the “Check Your Understanding” Questions, p. 270-274
3. Correct your “Before this lesson” answers
4. Complete #1-4, p. 274
McKenzie
Health Science 20
NAME:_________________
McKenzie
Health Science 20
NAME:_________________