Nervous System, Endocrine, Immune

Nervous System It is a system responsible for transmitting signals to allow the human body to function. It includes the central nervous system (CNS) and the peripheral nervous system (PNS). These systems coordinate the mentioned signals. Organs: Central Nervous System (CNS): Processes information and makes decisions. Brain : Controls thoughts, memory, emotions, learning, and both voluntary and involuntary movements. Spinal cord : Connects the rest of the body to the brain and handles reflexes. Peripheral Nervous System (PNS): Connects the CNS to the rest of the human body. Sensory nerves : Control the information from sensory inputs. Motor nerves: Transmit information to the muscles. Autonomic system: Regulates automatic functions (e.g., breathing). Endocrine System It is a system made up of glands and organs that release hormones for various functions such as development and growth, homeostasis, reproductive functions, stress response, and metabolism. Organs and hormones: Hypothalamus (neuro endocrine ): Connects the nervous and endocrine systems. Pituitary gland ( endocrine ): Controls other glands, growth, and reproduction. Thyroid gland ( endocrine ): Regulates metabolism and energy. Parathyroid glands ( endocrine ): Regulate calcium levels in the blood. Adrenal glands ( endocrine ): Produce hormones like cortisol and adrenaline. Pancreas (mixed: endocrine / exocrine ): Regulates blood sugar (insulin and glucagon). Gonads (ovaries in females/testes in males) ( endocrine ): Produce sex hormones like estrogen and testosterone. Pineal gland ( endocrine ): Controls sleep cycles through melatonin. Hormones: Endocrine: Released into the bloodstream and travel to specific organs or tissues to perform their function. Exocrine: Released from exocrine glands to specific body parts through ducts. These do not travel through the blood like endocrine hormones, but act locally. Immune System This system functions as a defense mechanism against diseases caused by bacteria, viruses, fungi, and parasites. It also eliminates non-functional cells and can remember past threats that the body has encountered. White blood cells, B/T lymphocytes, antibodies, and cytokines are involved. Organs and tissues: Bone marrow: Produces immune cells like white blood cells. Thymus: Helps mature T lymphocytes. Spleen: Filters blood and detects infections. Lymph nodes: Trap pathogens and activate immune responses. Tonsils and adenoids: Protect against infections in the mouth and throat. Types of immunity: Innate immunity: A fast-acting defense against any threat. It creates physical barriers (skin, mucous membranes) and general responses. Adaptive immunity: More specific and effective, but slower to activate. It creates immunological memory.