LVN Program – 2nd Semester

EndocrineVNRS P025A

Mrs. Keele

• Mrs.• MOM• G-ma• P.T.A.• C.N.A.• Psych. Tech.• LPN• BSN

• 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 PMTuesday: 8:30 AM – 2:20 PMOne 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

F.Y.I.

• No need to bring books

• Cel phones on vibrate• Tape players are

encouraged

HONESTY!

Welcome to 2nd Semester

• Harder?

• Critical thinking

• Full time job

What is the Endocrine System?

• Similar to nervous system

• Function– Communication– Control

Endocrine vs. Nervous system

Endocrine System

Nervous System

Speed Slower acting Fast actingDuration

Long lasting Short acting

Structure

Gland hormones

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. EndocrineB. ExocrineC. Both are equally vascularD. 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 heartB. Change the size of the heartC. Change the speed of the heart beatD. Change the strength of the heart beat

What is a hormone?

• Chemical• Bloodstream• Specific target cell / organ• Causes target cell to act • Specific action!– or 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

Sensor

Hormone secretion

Bloodstream

Target organ

Action

Homeostasis

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 stimuli • 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”

process (homeostasis) stimuli hormone secretion process (homeostasis) stimuli 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 Questions1. 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?