Homeostasis
What is Homeostasis? Maintenance of a stable internal environment. Regulated through control systems which have receptors -monitor change (nerves) control center - contains the “ideal value” (brain) Effectors - provide response (muscles, glands)
Negative Feedback Causes change in a direction opposite the initial change. Returns to the “ideal” value. Example: Normal body temp is 98.6 degrees F When hot, sweat to decrease temp When cold, shiver to increase temp
Positive Feedback Response to change is an increased departure from the normal condition. Example: Illness causes a fever. The increase in body temp stimulate the release of chemicals that will cause the body temp to continue to increase.
Homeostasis Video What is it, why important: https://www.youtube.com/watch?v=xvkZm417KgA Positive and Negative Feedback Loops https://www.youtube.com/watch?v=CLv3SkF_Eag
Nervous System
Function Gather and respond to information about the internal and external environment.
Structures of the Nervous System Brain Spinal cord Peripheral nerves (come off brain and spinal cord)
Lobes of the Brain Frontal Problem-solving, judgment, planning Temporal Speech and hearing Occipital Vision Parietal Sensory information
Other Brain Structures Cerebellum Controls muscle movement/balance Brainstem Controls basic life functions (heart rate, breathing, digestion)
Cardiovascular System
Structure and Function Structures: heart, blood vessels, blood Function: transport oxygen, nutrients, and waste.
Structures of the Heart Atria Receive blood Ventricles Pumps blood to body Aorta Largest artery in the body Superior/Inferior Vena Cava Bring blood to the heart from the body Pulmonary arteries and veins Transport blood to/from lungs
Blood Vessels Arteries: take blood from the heart Veins: take blood to the heart Capillaries: smallest blood vessels, where gas exchange occurs
Did you know… The human heart creates enough pressure to squirt blood 30 feet! Licorice can raise your blood pressure (blood pressure refers to the pressure in the arteries)
Respiratory System
Structures Nose, sinuses, larynx, trachea, bronchi, and alveoli.
Functions of the Respiratory System Obtain oxygen (needed for cell respiration) Remove carbon dioxide
Cool Respiratory System Facts An average adult has about 300 million alveoli! If all the capillaries on the alveoli were laid end to end they would be 620 miles long!