LVN Program – 2 nd Semester
Endocrine
VNRS P025A

• Mrs.
• MOM
• G-ma
• P.T.A.
• C.N.A.
• Psych. Tech.
• LPN
• BSN
Mrs. Keele
• RN
• CN
• DON
• DSD
• DOE
• CRRN

Housekeeping
• Be on time
• Breaks are flexible
• Dr. Water only!
• Casual environment
• Ask questions!

Syllabus
Hours/Days:
Monday: 8:30 AM – 2:20 PM
Tuesday: 8:30 AM – 2:20 PM
One 20 min break in the AM and a 60 minute break for lunch

General Rule
• If you are unable to attend class, you must notify the instructor prior to class.
• Only excused absences will be given an opportunity to make up quizzes/tests.
– Cannot make up participation
• Homework will not be accepted late unless excused by the instructor.

Office Hours
• Lunch and Breaks
• Call me at home!
– 793-1664
• Please do not call
– after 10:00 p.m.
– on Sundays

Web site
• www.portervillecolege.edu/eKeele/
– Search engine
– PC web page – instructors web pages
• E-mail
– elizabethkeele@sbcglobal.net

• No need to bring books
• Cel phones on vibrate
• Tape players are encouraged
F.Y.I.

HONESTY!

Welcome to 2 nd Semester
• Harder?
• Critical thinking
• Full time job 

What is the Endocrine System?
• Similar to nervous system
• Function
– Communication
– Control

Endocrine vs. Nervous system
Speed
Endocrine
System
Nervous
System
Slower acting Fast acting
Duration Long lasting
Structure Gland  hormones
Short acting
Nerves  electrical impulses

Endocrine System
The link between the nervous system and the endocrine system:
The Hypothalamus

Endocrine vs. Exocrine
Endocrine:
• Secrete hormones
• Directly into the blood stream
• Target specific organs/receptors
• Specific action
• No DUCTS

Endocrine vs. Exocrine
Exocrine:
• Secrete fluids
• Via ducts!

Which type of gland would you expect to be more vascular?
A. Endocrine
B. Exocrine
C. Both are equally vascular
D. No fair asking a test question in the first hour of class!

Endocrine Glands
• Pineal
• Pituitary
• Thyroid
• Parathyroid
• Thymus
• Adrenal Medulla
• Adrenal Cortex
• Islets of Langerhans
• Ovaries
• Testes

General function of the Endocrine
System
• Secrete hormone
• Affect rate of ongoing processes

Epinephrine is a hormone secreted by the adrenal medulla. What affect would you expect epinephrine to have on the heart?
A. Change the color of the heart
B. Change the size of the heart
C. Change the speed of the heart beat
D. Change the strength of the heart beat

What is a hormone?
• Chemical 
• Bloodstream 
• Specific target cell / organ 
• Causes target cell to act 
• Specific action!
– h or i in body function

Hormones are involved in all aspects of metabolism
• Growth
• Reproduction
• Energy production
• Regulation of fluid and electrolyte balance
• Regulation of body pH
• Resistance to stress

Metabolism & Synthesis
"Hormones are involved in all aspects of metabolism ”
Metabolism:
Break-down of molecules to make energy
(burning)
Synthesis:
Building-up of molecules

How do hormones work?
Non-linear, 6 step process
Homeostasis
Sensor
Action
Hormone secretion
Target organ
Bloodstream

1. Homeostasis
• Change in homeostasis
– i.e.
• Body temperature lowers
• Heart rate slows
• Increased blood sugar levels

2. Sensors
• Sensors 
– Monitor homeostasis
• Identify change in homeostasis 
• Responds to change 
• Initiate a specific stimuli 

3. Hormone secretion
• Specific stimuli 
• Endocrine gland 
• Secretes hormone

4. Bloodstream
• Hormone secretion directly into the bloodstream 
• Circulated by the bloodstream 
• Body

5. Target organ
• Hormones in the blood stream 
• enter target organs/tissues that have
“ receptors ” for that hormone

6. Action
• The hormone (when it enters the target organ) 
• produces a specific action
• Action is usually opposite to the initial homeostasis change.
– (Body temperature lowers)  increased body temp.
– (Heart rate slows)  increase heart rate
– (Decreased blood sugar levels)  increase BS levels
– (Increase in blood glucose levels)  decrease BS levels
– (High blood pressure)  lowers BP
– (Dehydration)  increased hydration

1. Homeostasis
• Specific action 
• Restores homeostasis 
• Sensor i stimuli 
• i hormone secretion
– Negative feedback!

“ Negative Feedback Mechanism ”
• “ The effects of the hormone often will reverse the stimulus and ultimately lead to decrease secretion of the hormone.
”

“ Negative Feedback Mechanism ” i process
(homeostasis)
 h stimuli  h hormone secretion  h process
(homeostasis)
 i stimuli  i hormone secretion

How to assess the Endocrine
System?
• Not palpate
• Not ascultate
• HOW????
– Labs
– S&S

Key Concept!
• “ In the health physiological state, hormone concentration in the bloodstream is maintained at a relatively constant level.
”

Small Group Questions
1. Name three characteristics of the endocrine system.
2. What is the function of a hormone?
3. How do hormones work?
4. What is “ Negative Feedback Mechanism ” ?
5. How do the endocrine systems and the nervous system communicate?
6. What must happen to a gland in order for it to secrete a hormone?