Body Systems Overview Body Systems work together: If you damage one system, you may damage several for example, smoking irritates the lungs and destroys the cells of the immune system Levels of Organization Chemical Atoms & molecules Building blocks of matter Cellular Smallest independent unit of life Tissue: Consist of similar cells working together to function Epithelial Tissue Connective Tissue Muscular Tissue Nervous Tissue Lines body cavities Covers body surfaces Protection, secretion, Absorption Fills in spaces Binds & supports other tissues Dense, loose, blood, bone Contracts & provides movement Skeletal -skeletal muscles Cardiac -wall of heart Smooth - wall of internal organs Conducts electrical impulses Brain, spinal cord, peripheral nerves Organ Lung Group of tissues working together to function Page 1 of 7
Organ System respiratory system Group of organs working together to function Organism Group of organ systems working together to function (maintain life) There are 11 organ systems in the human body Skeletal System Major Functions: It provides shape and support Enables you to move Protects your internal organs Produces blood cells Stores certain materials until your body needs them Bones Tendons connect bones to muscles. Ligaments connect bone to bone. Cartilage cushions places where bones connect and offers flexibility. Muscular System Major Functions: Your muscles control all movements of the body tissues, organs and bones. Three types of muscle tissue skeletal muscle smooth muscle cardiac muscle Page 2 of 7
Circulatory (cardiovascular) System Transport Oxygen Nutrients Waste throughout the body Heart Blood Vessels Aorta Arteries Arterioles Capillaries Venules veins Blood Respiratory System Moves oxygen from the outside environment into your body Removes carbon dioxide and water from your body. Main parts: Nose Mouth Pharynx larynx Trachea Lungs Bronchi Bronchioles alveoli Diaphragm Digestive System Breaks down food into molecules the body can absorb. Passes these molecules into the blood to be carried throughout the body. Eliminates solid wastes from the body. Mouth Pharynx Esophagus Stomach Small intestine Large intestine Rectum Anus Pancreas Gall bladder liver Page 3 of 7
Excretory system Collects wastes produced by cells and removes these wastes from your body. The removal process is known as excretion. Kidney Ureter Bladder urethra Integumentary System Main functions: Covers body and prevents water loss. Protects body from injury and infection. Helps regulate body temperature. Eliminate wastes Gathers information about the environment Produce vitamin D Main parts: Skin Nails hair Immune system Protect you from foreign invaders. Special cells react to each kind of pathogen with defensive tactics targeted specifically at that type of pathogen. A pathogen is a bacterium, virus, or other microorganism that can cause disease. Main parts: White blood cells that target specific pathogens are called lymphocytes. T-cells and B- cells are two major types of lymphocytes. Each type has a specific job. Page 4 of 7
Lymphatic System Extensive drainage network that helps keep bodily fluid levels in balance and defends the body against infections. Filters out organisms that cause disease, produces certain white blood cells and generates antibodies Main parts Network of lymphatic vessels that carry lymph a clear, watery fluid that contains protein molecules, salts, glucose, urea, and other substances throughout the body. Works closely with the immune system and the circulatory system. Spleen stores many of the white blood cells needed for the immune response. Endocrine System Maintain a stable environment within the body or homeostasis. The hormones also help the body to regulate: o Growth o Sexual development o Metabolism o Sugar, salt and fluid levels in the blood Hypothalamus Pituitary gland Other glands Page 5 of 7
Reproductive System Make gametes (egg and sperm) and hormones Fertilization of the egg with sperm Differ structures in male to female with different functions. Male Testes Scrotum Sperm ducts Urethra Prostate and other glands penis Female Ovaries Fallopian tubes Fimbriae Uterus (womb) Cervix vagina Feedback Mechanisms Homeostasis is maintained by the endocrine system through the use of various feedback mechanisms. A feedback mechanism is in use when the biological reaction is actually being controlled by the end products of that reaction. Negative feedback loop are most common. original stimulus reversed most feedback systems in the body are negative used for conditions that need frequent adjustment Page 6 of 7
Receptor Structures that monitor a controlled condition and detect changes Control center determines next action Effector receives directions from the control center produces a response that restores the controlled condition Homeostasis Disruption produces stimulus Receptors detect stimulus Control center Brain or spinal cord Receives information from receptors Response Feedback Restores homeostasis Effectors Muscles or glands Produce response Sends messages to effectors TYPES OF FEEDBACK NEGATIVE Restores homeostasis Response opposite of stimulus Brings levels back to normal POSITIVE Continues to disrupt homeostasis Response reinforces stimulus Example uterine contractions during childbirth Rare Page 7 of 7