September 2017 Journal: Why is your body temperature always around 98.6 degrees Fahrenheit?

Introduction to Anatomy and Physiology

What is Anatomy? Literally means to cut apart The study of internal and external structures of plants and animals How living things are put together

Two Types of Anatomy Microscopic Anatomy: Study of structures only seen with magnification aids. Macroscopic Anatomy: Study of structures visible to the naked eye Also known as Gross Anatomy Examples?

Would the following items fall under Microscopic or Macroscopic Anatomy? Stomach Bacteria Red Blood Cell Lungs Femur Cardiac Muscle Tissue Ear

What is Physiology? The study of how body parts function How the body works

How does anatomy relate to physiology?

Structure (anatomy) determines function (physiology) If the structure is not right, the function can’t be right either. Abnormal structure and function = disease Example: Sickle Cell

Homeostasis Physiological mechanisms that work to maintain a constant internal environment Examples?

Components of Homeostatic Mechanisms Receptor – detects stimuli and sends signal on an afferent pathway to the control center. Control Center – interprets signal and decides how to act. Effector – information flows from the control center along the efferent pathway to the effector.

How do homeostatic mechanisms work? If the body detects that its normal set-point is either to high or to low it will respond. Control Center Efferent Pathway Afferent Pathway Receptor (Start) Effector

Example When your body gets to hot, what happens? Send signal to control center in the brain Brain signals a response Sweat is released and blood vessels get bigger

Positive Feedback Loops Loop continues in the same direction and increases magnitude of change to the body

Negative Feedback Loops Loop moves in the opposite direction of a stimulus

Determine if the scenario represents a positive or negative feedback homeostatic system: A car starts rolling out of a driveway w/o a driver. A person decides to respond by pushing the car in the direction that makes it leave the driveway faster. Your blood calcium level is low so your body begins to break down bone tissue so that calcium is released into the blood. A neuron is stimulated and sodium goes rushing into the cell. The more it is stimulated the more sodium goes rushing in, thus enhancing the stimulus.