Homeostasis+

• Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes.
• Homeostasis involves keeping the blood glucose concentration, body temperature, and water levels constant.
• Homeostasis consists of automatic control systems making sure that the internal conditions of the body stay as constant as possible.
• The automatic control systems in the human body can involve the nervous system or hormones.
• Receptor cells detect changes in the environment, which could mean the body's internal conditions such as the concentration of glucose in the blood, or the body's external conditions like the temperature of the skin.
• A change in the environment is referred to as a stimulus.
• Receptor cells pass information to a Coordination Center, which could be the brain, spinal cord, or pancreas.
• The Coordination Center receives and processes the information from the receptor cells and sends instructions to the effector, which is a muscle or gland.
• The job of the effector is to carry out the response, which is to store the optimum level.
• The structure of the nervous system is related to its functions.
• The reflex arc is a common concept in the nervous system.
• Reflex actions are important in the nervous system.
• Homeostasis involves automatic control systems and the nervous system is a part of this.
• The nervous system consists of two parts: the Central Nervous System (CNS) which includes the brain and the spinal cord, and other nerves running to and from the central nervous system.
• Receptors detect a stimulus and electrical impulses are sent down new loans to the central nervous system.
• The central nervous system acts as the Coordination Center and sends electrical impulses down other neurons to affect us.
• Effectors in the nervous system are usually a muscle which contracts or a gland which secretes a hormone.
• The nervous system enables humans to react to their surroundings and coordinate their behavior.
• Receptors in the nervous system allow us to sense our environment.
• Sensory neurons in the nervous system are connected to receptors and receptors allow us to sense our environment.
• At the end of the sensory neurone, there's a junction call sign ups other sign ups a chemical is released and this chemical diffuses across to a relay neurone in the central nervous system where it triggers an electrical impulse.
• The electrical impulse now passes across the relay neurone and reaches another synapse where a chemical is released and this chemical triggers an electrical impulse in a motor neuron.
• The electrical impulse now passes down the motor neuron to an effector, in this case, a muscle, and the muscle now contracts.
• Pulling the hand away from the heat is the response in the reflex arc.
• In most cases, the brain makes decisions about what action to take, but in the case of reflexes, there is no decision-making by the conscious part of the brain, making reflexes automatic and rapid.
• Reflexes help to protect us from danger.
• The hormone insulin is used to control the blood glucose concentration.
• There are two types of diabetes: Type 1 and Type 2.
• In Type 1 diabetes, the pancreas does not produce enough insulin.
• In Type 2 diabetes, the body cells stop responding to the insulin produced by the pancreas.
• People with diabetes monitor their blood glucose concentration and inject themselves with insulin if blood glucose levels rise too high.
• The pancreas releases the hormone glucagon into the bloodstream when the blood glucose concentration falls too low.
• Glucagon triggers liver cells to convert glycogen stores back to glucose and this glucose is released into the blood, causing the blood glucose concentration to return to normal.
• If the blood glucose concentration rises, the pancreas releases the hormone insulin, which causes the glucose concentration to fall.
• When the glucose concentration falls to a certain level, the pancreas releases glucagon, which causes the glucose concentration to rise again because insulin and glucagon have opposite effects on the blood glucose concentration.
• Scientists say that the balance between insulin and glucagon forms a negative feedback cycle.
• Hormones are released by glands into the bloodstream, travel in the bloodstream and trigger effects in specific target organs, this is known as the endocrine system.
• During puberty, reproductive hormones cause secondary sexual characteristics to develop, for example, pubic hair in men and breasts in women.
• In humans, the ovaries produce the hormone estrogen and the testes produce the hormone testosterone.
• Every 28 days, an egg is released from the ovary, this is called ovulation.