Unit 10 Physiology/ Human Body Systems Chapter 28

* Objectives and Questions: * 1. I can describe how the major body systems work together to provide cells with oxygen and remove waste such as carbon dioxide. * 2. I can describe the 5 levels of organization of an organism and give examples and include how the tissues differ at each level. * 3. I can define homeostasis and explain how it maintains the internal environment of an organism and give examples of positive and negative feedback loops.

1. Cells = each type of specialized cell has specific structure and task. EX: cells in lungs are specialized to transfer gasses 2. Tissues = groups of similar cells work together to perform a specific function EX: Connective tissues, muscle tissues, nervous tissues 3. Organs = multiple types of tissues functioning together to form an organ. EX: Heart, blood vessels, bones (many types of cells in layers of organ) 4. Organ systems = 2 or more organs work in coordination. Ex: Heart & lungs, nerves and muscles 5. Organism = made up of organ systems EX: Beautiful you!

Differentiation: process which turns embryonic stem cells into specialized cells, with different structure and function After egg is fertilized by sperm, the cells begins to divide. Differentiation occurs because specific genes in each cell are turned on. This generates differences among cells that makes them into specific functioning cells.

Major Organ Systems of the Body Pls. see page 856 in book for chart Digestive- extracts and absorbs nutrients from food Digestive- extracts and absorbs nutrients from food Respiratory-obtains oxygen, releases carbon dioxide Respiratory-obtains oxygen, releases carbon dioxide Nervous-collects and evaluates information and issues commands for a quick response Nervous-collects and evaluates information and issues commands for a quick response Circulatory-transports oxygen, carbon dioxide, nutrients, and cells Circulatory-transports oxygen, carbon dioxide, nutrients, and cells Endocrine-secretes chemicals called hormones Endocrine-secretes chemicals called hormones

Major Organ Systems of the Body Immune- defends against pathogens and cancer Immune- defends against pathogens and cancer Muscular-movement Muscular-movement Skeletal- protects and supports the body Skeletal- protects and supports the body Urinary/Excretory- removes wastes from blood, regulates concentration of the body’s fluids Urinary/Excretory- removes wastes from blood, regulates concentration of the body’s fluids Reproductive- produces gametes, nourishes and shelters fertilized egg (females) Reproductive- produces gametes, nourishes and shelters fertilized egg (females) Integumentary –Acts as a barrier against infection Integumentary –Acts as a barrier against infection

* Example of coordination: * Thermoregulation = maintain steady body temperature * At rest = body heat produced by liver, heart, brain and endocrine glands * In motion = skeletal muscles produce times the heat generated by rest of body * Hypothalamus monitors body temperature. Endocrine and nervous systems make adjustments when hot; muscular, respiratory and circulatory adjust when too cold.

* Homeostasis = When the body regulates and maintains the body’s internal environment. * Ex. – Temperature, fluids, salts, pH, nutrients, gases

Your body uses Feedback loop s to monitor body systems and make adjustments when the body moves to far away from its set point (normal ranges) There are negative and positive feedback loops - Negative feedback = stabilizing the body Ex. Sweating to cool body down - Positive feed back = destabilizing, changing the body to accommodate. Ex. After injury, increase in blood flow

* Glucose levels are controlled by 2 hormones: * Insulin and Glucagon (both released by pancreas) * When glucose levels are too high, pancreas releases insulin (makes cells take in more glucose, stores extra as glycogen in the liver) * When glucose levels fall, pancreas releases glucagon (stimulates liver to release stored glycogen) * Is this a positive or negative feedback example?

* Identify two negative feedback examples: * Identify two positive feedback examples: * Why are most body functions regulated by negative feedback?