Organ Systems, Body Cavities, and Body Membranes PDF

ORGAN SYSTEMS, BODY CAVITIES, AND BODY MEMBRANES Organ :- a group of tissues performing a common function Organ systems : Organs with a similar function Some of these organ systems, such as the respiratory system, occupy specific cavities of the body, and others, such as the muscular and circulato...

ORGAN SYSTEMS, BODY CAVITIES, AND BODY MEMBRANES Organ :- a group of tissues performing a common function Organ systems : Organs with a similar function Some of these organ systems, such as the respiratory system, occupy specific cavities of the body, and others, such as the muscular and circulatory systems, are found throughout the body. The organs and cavities of the body are lined with membranes, many of which secrete fluid to lubricate the organ or organ system. Integumentary system • protects body • provides temperature homeostasis • synthesizes vitamin D • receives sensory input Organ: Skin Cardiovascular system • transport system for nutrients, waste • provides temperature , pH, and fluid homeostasis Organ: Heart Lymphatic and immune systems • defend against infectious diseases • provide fluid homeostasis • assist in absorption and transport of fats Organs: Lymphatic vessels, lymph nodes, spleen Digestive system • ingests, digests, and processes food • absorbs nutrients and eliminates waste • involved in fluid homeostasis Organs: Oral cavity, esophagus, stomach, small intestine, large intestine, salivary glands, liver, gallbladder, pancreas Respiratory system • exchanges gases at both lungs and tissues • assists in Ph homeostasis Organs: Lungs Urinary system • excretes metabolic wastes • provides pH and fluids homeostasis Organs: Kidneys, urinary bladder Reproductive system • produces and transports gametes • nurtures and gives birth to offspring in females Organs: Testes, penis, ovaries, uterus, vagina Skeletal system • provides support and protection • assists in movement • stores minerals • produces blood cells Organ: Bones Nervous system • receives,processes,and stores sensory input • provides motor output • coordinates organ systems Organs: Brain, spinal cord Endocrine system • produces hormones • coordinates organ systems • regulates metabolism and stress responses • involved in fluid and pH homeostasis Organs: Testes, ovaries, adrenal glands, pancreas, thymus, thyroid, pineal gland Body Cavities -The human body is divided into two main cavities: the ventral cavity and the dorsal cavity - Called the coelom in early development, the ventral cavity later becomes the thoracic, abdominal, and pelvic cavities. -The thoracic cavity contains the lungs and the heart. The thoracic cavity is separated from the abdominal cavity by a horizontal muscle called the diaphragm. The stomach, liver, spleen, pancreas, gallbladder, and most of the small and large intestines are in the abdominal cavity. The pelvic cavity contains the rectum, the urinary bladder, the internal reproductive organs, and the rest of the small and large intestines. Males have an external extension of the abdominal wall called the scrotum, which contains the testes. The dorsal cavity has two parts: (1) the cranial cavity within the skull contains the brain; (2) the vertebral canal, formed by the vertebrae, contains the spinal cord. Body Membranes Body membranes line cavities and the internal spaces of organs and tubes that open to the outside. These membranes are of four types: mucous, serous, and synovial membranes, and the meninges. Mucous membranes line the tubes of the digestive, respiratory, urinary, and reproductive systems. They are composed of an epithelium overlying a loose fibrous connective tissue layer. The epithelium contains specialized cells that secrete mucus. This mucus ordinarily protects the body from invasion by bacteria and viruses. Mucus usually protects the walls of the stomach and small intestine from digestive juices. This protection breaks down when a person develops an ulcer. Serous membranes line the closed cavities of the body. They support the lungs, heart, and abdominal cavity and its internal organs They secrete a watery fluid that keeps the membranes lubricated. Serous membranes support the internal organs and compartmentalize the large thoracic and abdominal cavities. Serous membranes have specific names according to their location. The pleurae line the thoracic cavity and cover the lungs. The pericardium covers the heart. The peritoneum lines the abdominal cavity and covers its organs. A double layer of peritoneum, called mesentery, supports the abdominal organs and attaches them to the abdominal wall. Synovial membranes composed only of loose connective tissue line the cavities of freely movable joints. They secrete synovial fluid into the joint cavity. This fluid lubricates the ends of the bones so they can move freely. In rheumatoid arthritis, the synovial membrane becomes inflamed and grows thicker, restricting movement. The meninges The meninges are membranes within the dorsal cavity. They are composed only of connective tissue and serve as a protective covering for the brain and spinal cord. Meningitis is a life-threatening infection of the meninges.