organ system

Examples of organ system in the following topics:

• Levels of Organization

  • Living organisms are made up of four levels of organization: cells, tissues, organs, and organ systems.
  • Using the circulatory system as an example, a cell in this system is a red blood cell, the heart's cardiac muscle is a tissue, an organ is the heart itself, and the organ system is the circulatory system.
  • An organism is made up of four levels of organization: cells, tissues, organs, and organ systems.
  • While most organ systems control a few specific physiological processes, some processes are more complex and require multiple organ systems to work together.
  • An organism contains organ systems made up of organs that consist of tissues, which are in turn made up of cells.

• Tissues in Levels of Organization

  • The next level is the organ system level.
  • Many organs working together to accomplish a common purpose create an organ system.
  • For example, the heart and the blood vessels of the cardiovascular system circulate blood and transport oxygen and nutrients to all the body cells.
  • Organs that fulfill related functions are called organ systems.
  • An organism is made up of interconnected organ systems.

• Organization of the Nervous System

  • A nervous system is what allows us to react to the changing environment around us.
  • The nervous system is an organ system that coordinates our actions by transmitting signals between different parts of our bodies.
  • The central nervous system (CNS) is composed of the brain, spinal cord, and retina.
  • Along with neurons, the nervous system relies on the function of other specialized cells called glial cells, or glia, that provide structural and metabolic support to the nervous system.
  • Gross organization of the nervous system, with the peripheral nervous system, the spinal, and the cortical levels.

• Overview of the Musculoskeletal System

  • The musculoskeletal system is an organ system enabling an organism to move, support itself, and maintain stability during locomotion.
  • The musculoskeletal system (also known as the locomotor system) is an organ system that gives animals (including humans) the ability to move, using the muscular and skeletal systems.
  • The musculoskeletal system is made up of the body's bones (the skeleton ), muscles , cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together.
  • Its primary functions include supporting the body, allowing motion, and protecting vital organs.
  • The skeletal portion of the system serves as the main storage system for calcium and phosphorus.

• Structure of the Lymphatic System

  • The lymphatic system consists of lymphatic vessels and associated lymphoid organs.
  • The lymphatic vessels are the lymphatic system equivalent to the blood vessels of the circulatory system and drains fluid from the circulatory system.
  • Lymphatic organs are the site of many important functions for the immune system.
  • Lymphoid tissue is found in many organs, particularly the lymph nodes, as well as in the lymphoid follicles in the pharynx, such as the tonsils.
  • Describe how the lymphatic system consists of lymphatic vessels and associated lymphoid organs

• Development of the Integumentary System

  • The integumentary system develops from all embryonic layers (ectoderm, mesoderm and neural crest cells).
  • The integumentary system is the largest organ system in the human body, and is responsible for protecting the body from most physical and environmental factors.
  • The largest organ in the body is the skin.
  • The integumentary system is both a barrier and a sensory organ.

• Parasympathetic Responses

  • The parasympathetic nervous system regulates organ and gland function during rest and is considered a slowly activated, dampening system.
  • The autonomic nervous system (ANS, or visceral nervous system, or involuntary nervous system) is the part of the peripheral nervous system that acts as a control system, functioning largely below the level of consciousness and controlling visceral functions.
  • The ANS is responsible for regulation of internal organs and glands, which occurs unconsciously.
  • The sympathetic nervous system can be considered a quick response, mobilizing system; and the parasympathetic a more slowly activated dampening system.
  • The postganglionic nerve then releases ACh to stimulate the muscarinic receptors of the target organ.

• Circumventricular Organs

  • Circumventricular organs (CVOs), are positioned at distinct sites around the margin of the ventricular system of the brain.
  • As a result, neurons located in circumventricular organs can directly sense the concentrations of various compounds, particularly peptide hormones, in the bloodstream without the need for specialized transport systems that move those compounds across the blood-brain barrier.
  • Therefore, they provide direct information to the autonomic nervous system from the systemic circulation.
  • These organs include:
  • The secretory organs are responsible for secreting hormones and glycoproteins into the peripheral vascular system using feedback from both the brain environment and external stimuli.

• Comparing the Somatic and Autonomic Nervous Systems

  • The peripheral nervous system (PNS, see ) is divided into the somatic nervous system and the autonomic nervous system.
  • The somatic nervous system controls all voluntary muscular systems within the body, and also mediates involuntary reflex arcs.
  • The autonomic nervous system (ANS) is the part of the peripheral nervous system that acts as a control system, functioning largely below the level of consciousness and controlling visceral functions.
  • It is classically divided into two subsystems: the parasympathetic nervous system (PSNS) and sympathetic nervous system (SNS).
  • The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system.

• Functions of the Nervous System

  • The primary function of the nervous system is to coordinate and control the various functions of our body.
  • The nervous system has three overlapping functions.
  • The nervous system is a highly integrated system.
  • Nervous system processes and interprets sensory input and decides what should be done at the each moment.
  • The nervous system activates effector organs such as muscles and glands to cause a response called the motor input.