Connection Activity What is homeostasis How is homeostasis

Connection Activity: What is homeostasis? How is homeostasis maintained in the body? Give one example of homeostasis.

Major Organ Systems All organs in organ systems develop from specialized cells and tissues that arose from a single cell, the Zygote. Differentiation is the process by which committed cells acquire the structures and functions of highly specialized cells.

Circulatory System Major Tissues and Organs: n Heart, blood vessel, blood, lymph nodes, lymphatic Primary Function: n Transport oxygen, nutrients, waste; helps regulate body temperature; collects fluids lost from blood vessels and returns it to the circulatory system

Digestive System Major Tissues and Organs: n Mouth, pharynx, esophagus, stomach, intestine, pancreas, gallbladder, liver Primary Function: n Breaks down and absorbs nutrients, salts, and water; eliminates some waste

Excretory System Major Tissues and Organs: n Skin, lungs, kidney, bladder Primary Function: n Eliminates waste products; helps maintain homeostasis

Integumentary System Major Tissues and Organs: n Skin, hair, nails, sweat and oil glands Primary Function: n Acts as a barrier against infection, injury, UV radiation; helps regulate body temperature

Muscular System Major Tissues and Organs: n Skeletal, smooth and cardiac muscles Primary Function: n Produces voluntary and involuntary movements; helps to circulate blood and move food through the digestive system

Nervous System Major Tissues and Organs: n Brain, spinal cord, peripheral nerves Primary Function: n Regulate body’s response to changes in internal and external environment; processes information

Respiratory System Major Tissues and Organs: n Lungs, nose, sinuses, pharynx, larynx, trachea Primary Function: n Brings in oxygen for cells and expels Carbon dioxide and water vapor

Skeletal System Major Tissues and Organs: n Bones, cartilage, ligaments, tendons Primary Function: n Supports and protects vital organs; allows for movement; stores minerals, serves as the site for red blood cell production

Endocrine System Chemical Control: similar to nervous control, coordinate body processes by transmitting messages from one part of the body to another ~ achieved through hormonal action

Regulation How we maintain homeostasis n nervous system w nerve signals control body functions (faster & short-lasting) n endocrine system w hormones w chemical signals control body functions (slower & longer-lasting)

Endocrine System: function to maintain homeostasis Endocrine glands: synthesize and secrete hormones (ductless) Hormones: chemicals secreted in one area of body which affect responses in other areas. n n n The circulatory system aids in the distribution of these hormones Delivered to target tissue which recognize specific hormones by receptor cells Hormones have specific shape that fit the receptors

Hormones Why are hormones needed? n n n chemical messages from one body part to cells in other parts of body communication needed to coordinate whole body maintaining homeostasis growth hormones

Endocrine System Endocrine system releases hormones n glands which secrete (release) chemical signals into blood w chemicals cause changes in other parts of body growth hormones n sex hormones n response hormones n metabolism hormones n and more…. n

Responding to hormones Lock and key system n hormone fits receptor on “target” cell target cell secreting cell can’t read signal nontarget cells can’t read signal

Major glands of the Endocrine system The hypothalamus integrates endocrine and nervous function

Maintaining homeostasis hormone 1 Feedback lowers body condition gland high specific body condition low raises body condition gland hormone 2

Negative Feedback Response to changed body condition n if body is high or low from normal level w signal tells body to make changes that will bring body back to normal level n once body is back to normal level, signal is gland turned off hormone 1 lowers body condition high specific body condition

Endocrine System Control Regulation ofinsulin Blood Sugar liver stores reduces body sugar appetite cells take up sugar from blood pancreas high liver blood sugar level (90 mg/100 ml) liver triggers releases hunger sugar liver Feedback low pancreas glucagon Diabetes: insulin deficiencyresults in an elevated blood sugar level (glucose)

Regulation by chemical messengers Neurotransmitters released by neurons Hormones release by endocrine glands endocrine gland neurotransmitter axon hormone carried by blood receptor proteins target cell

Body Regulation Nervous system & Endocrine system work together n hypothalamus w “master nerve control center” w receives information from nerves around body about internal conditions n communicates with pituitary gland w “master gland” w releases many hormones n sexual development, growth, milk hormones production, pain-relief hormones