Human Body Systems

Key Ideas of Homeostasis How do the skeletal and muscular systems help the body maintain homeostasis? How does the integumentary system help the body to maintain homeostasis? How do the nervous and endocrine systems help the body to maintain homeostasis? How do the digestive and excretory systems help the body maintain homeostasis? How do the circulatory and respiratory systems help the body to maintain homeostasis?

Skeletal/Muscular Systems These systems enable movement and provide support and protection for tissues and organs. Skeletal system has 5 main functions: Support (give body shape and structure) Protection (protect internal organs) Movement (joints allow for motion) Mineral storage (calcium, phosphorus) Blood cell production (marrow)

How do Muscles Cause Bones to Move? Muscles are attached to bones by tendons. Tendons are strips of very strong, flexible connective tissue. Pairs of muscles cause bones to move- one pair pulls and one pair pulls the other way (when one contracts the other relaxes).

Three Main Kinds of Muscle Tissue Skeletal- are voluntary, you can control them. They help move the body. Smooth- involuntary, you cannot control them, found in blood vessels, digestive system, bladder. Cardiac- involuntary, found in heart, you cannot control.

Integumentary System Functions of the skin: Protection Disease prevention Temperature control Waterproofing

Nervous System Consists of two main parts: Central nervous system- Brain and spinal cord. Peripheral Nervous system- axillary nerves (arms, legs).

The Neuron Nerve cells are the largest in the body.

Types of Neurons Motor- transmit messages from the CNS to muscles and other organs. Sensory- transmit messages from the sensory organs to the CNS.

Endocrine System Has five main functions: Regulate metabolism. Maintain salt, water, and nutrient balance in the blood. Control responses to stress. Regulate growth, development, reproduction. Produce hormones.

Digestive System The process of breaking down foods into molecules that the body can use. Uses both chemical and mechanical means.

Excretory System The removal of metabolic wastes. Metabolic wastes include: water, salts, CO2, nitrogenous wastes. Main organs are: Kidneys, Ureters, and Bladder, and Lungs.

Respiratory System The Respiratory System brings Oxygen into the body and and carries Carbon Dioxide out of the body. The Lungs are the main organs of the Respiratory System.

Cardiovascular System What Is the Cardiovascular System?The heart, blood vessels, and blood make up the cardiovascular system.The cardiovascular system carries nutrients, oxygen, hormones, and wastes through the body and distributes heat to maintain homeostasis.

Parts of the Circulatory System Arteries- carry blood away from the heart. Veins- carry blood to the heart. Capillaries- exchanges gases and nutrients from vessels to cells.

The Immune System Disease is caused by a disruption in a human body system that leads to a corresponding disruption in homeostasis. Disease falls into two categories: Infectious, can be transmitted from one organism to another. Infectious diseases are caused by pathogens. Non-infectious, cannot be transmitted from one organism to another. Pathogens can spread disease by air, contact with contaminated objects, ingesting contaminated food, by contact with a vector. A vector is an intermediate organism that transfers a pathogen from one organism to another.

We can avoid disease by practicing: Good hygiene Living a healthy lifestyle Eating completely cooked meat Getting enough sleep Exercising Eating a balanced diet Drinking plenty of water

How does the Immune System Work? Key Concept: The Immune System consists of Organs, Cells, and Molecules that fight infection. Your body has organs, cells, and tissues that protect you from pathogens. The body system that fights off infection is the Immune System.

Immunity Bodily Defenses: Skin- is the bodies 1st line of defense. Skin prevents pathogens from entering the body. Oil/sweat make it difficult for pathogens to survive on the skin’s surface. Pathogens enter the body through openings in the skin (cuts, scrapes), eyes, nose , mouth, and ears. Tears, mucous, and tiny hairs help to trap and remove pathogens.