1. Homeostasis and Body System Basics

2. The 2 benchmark areas for today:
#1) B2.3A: Describe how cells function in a narrow range of physical conditions, such as temperature and pH (acidity) to perform life functions.
#2) B2.3d: Identify the general functions of the major systems of the human body (digestion, respiration, reproduction, circulation, excretion, protection from disease, and movement, control, and coordination) and describe ways that these systems interact with one another.
Clarification: Systems described are limited to those involved in nutrition, cardiovascular and respiratory health.

3. Here They Are: Your Body Systems (Part 1).

4. And Your Body Systems (Part 2)

5. Homeostasis – the body’s response to a changing external environment to help maintain a stable internal environment

6. Examples: 1) Blood Sugar: in order to maintain a safe level our body uses insulin to reduce the amount of sugar in our blood and glucagon to increase it

7. 2) pH: if pH levels are too high our body can produce a natural buffer (carbonic acid bicarbonate buffer) to help regulate it
pH less than 7 = acidic
pH is 7 = neutral
pH more than 7 =alkaline

8. 3) Temperature: is regulated by our brain through our skin
Too Hot?
Increase blood flow to extremities to cool the blood
Widening of the blood vessels to increase flow to extremities and allow heat to escape
Increase in perspiration(sweating) to increase evaporation on the skin

9. Too Cold?
Decrease blood flow to extremities to help keep the vital organs warm
Restriction of blood vessels to divert blood to deeper tissues so less heat escapes
Increased cellular respiration to release more heat

10. Cardiovascular/Circulatory System – carries nutrients, oxygen, hormones and wastes through the body and distributes heat to help maintain homeostasis
Made up off the heart, blood vessels and blood
Like a chemical highway for the body

11. The Heart – pumps the blood throughout the body
Arteries – blood vessels that carry blood away from the heart
Veins – blood vessels that carry blood back to the heart
Capillaries – tiny blood vessels where material is exchanged between the blood and surrounding fluid

12. Heart rate (pulse) – stretching of the blood vessels leading away from your heart, caused from the pressure of your blood being pushed out of the left ventricle (number pulses per minute is the heart rate)

13. Blood – interacts with EVERY body system by picking up and delivering products throughout the body (ie carbon dioxide, oxygen, waste)
Plasma – the liquid portion of blood
Red Blood Cells – doughnut shaped blood cells that transport oxygen
White Blood Cells – destroys pathogens and helps the body develop immunities
Platelets – pieces of cytoplasm from bone marrow that are used for clotting

14. http://youtu. be/PgI80Ue-AMo Now how do I remember this… http://youtu

15. Respiratory System - brings oxygen into to the body and carries carbon dioxide out of the body

16. Works closely with the circulatory system, exchanging gases between air and blood
Helps to regulate blood pH
Regulates blood oxygen and carbon dioxide levels

18. Digestive System – takes in food, breaks it down into molecules that the body can use, and gets rid of undigested molecules and waste

19. Mouth, esophagus and stomach begin the process of digestion by breaking food into small molecules
Absorption of nutrients takes place in the small intestine primarily, aided by secretions from the liver and pancreas
Components of food that are not digested leave the body as waste

21. Excretory System – by removing toxic chemical, excretion enables the body to maintain its water and pH balance
The kidneys filter wasters out of the blood and balance water levels
Waste is removed through excretion of urine

22. Endocrine System – regulates metabolism (salt, water and nutrient balance in the blood), controls the body’s response to stress and regulated growth, development and reproduction

23. Endocrine glands and endocrine tissues produce and release hormones
Hormones get moved throughout the body by the circulatory system

25. Nervous System – is a highly organized network of signaling cells called neurons Neurons – nerve cells that send electrical signals in order to communicate with each other and with muscles and glands

26. Two main divisions of the nervous system 1) Central Nervous System (CNS) - responds to internal and external information

27. 2) Peripheral Nervous System (PNS) – contains sensory and motor nervous system and the rest of the body

28. A spinal reflex is an involuntary movement triggered by sensory input and produced by neural circulatory limited to the spinal cord

29. DiscoveryEducation – Investigating the Nervous System – Studying the Nervous System of Toads

30. What how might different body systems be involved in…
Running a away from a bear
Eating lunch with Ms. Pilarz
Taking a test in Biology
Getting poked by a sharp stick