Homeostatsis

• Homeostasis is the maintenance of a constant internal environment, which helps enzymes work best at certain temperature and water content for cells.
• Optimal conditions are the best conditions for cells to function sufficiently.
• A receptor is a cell or organ that can sense a change to the external environment.
• A coordination centre are areas that receive and process the info from receptors and send out signals to coordinate the response of the body.
• A stimuli is a change to the external environment.
• Homeostasis helps cells function sufficiently by maintaining optimal conditions.
• The nervous system controls voluntary actions and involuntary actions.
• The brain controls the body’s complex behaviour.
• The brain is made of billions of interconnected relay neurones.
• Each brain region differs in function.
• The parietal lobe processes sensory info.
• The temporal lobe provides visual memories and processes language.
• The occipital lobe processes visual info.
• The frontal lobe controls voluntary movements.
• The medulla oblongata is a part of the brain above the spinal cord and controls breathing and heart rates.
• Broca’s area, a part of the frontal lobe, controls speech.
• The cerebellum, a part of the back brain, coordinates muscular activity.
• The cerebrum, the outer layer of the brain, plays a role in consciousness.
• The pons is a part of the brainstem that links to the cerebellum and the medulla oblongata, and is responsible for sleep, respiration and swallowing.
• Neuroscience is the study of the brain.
• It is hard to study the brain because it is complex and delicate.
• Insulin is produced by the pancreas and acts on the liver, muscles and body cells to take up glucose from blood.
• Appropriate ions and water are retained to maintain optimum levels.
• Negative feedback control occurs when your body detects a change, it makes a change and returns itself to normal.
• Kidneys fix water balance by releasing anti-diuretic hormone (ADH) into blood which is transported to kidneys.
• Water concentration is monitored by the osmoregulatory centre of the brain.
• Less ADH released results in less dilute urine and urinating more.
• In kidney dialysis, blood is removed from the body by a machine which filters all urea then returning it.
• Homeostasis is the process that maintains a stable internal environment despite changes in the external environment.
• A permanent solution to kidney failure is transplant but can survive with only one.
• Proteins are removed by the process in the liver which forms ammonia, a toxic substance, and is immediately converted to urea which is excreted by the kidneys in the urine.
• All glucose and some ions and water are selectively reabsorbed back into blood in a process called selective reabsorption.
• Nephrons are the functional unit of the kidney where excess water, ions and urea are removed from blood.
• Excess protein from diet is broken down by the digestive system to form amino acids.
• Patients have to have suppressing drugs for the rest of their lives as their body will recognise the kidney as foreign and attack it unless they are closely related to the donor.
• In the kidney, all glucose, urea, ions and water are removed from blood in a process called filtration.
• Nephrons remove excess water, ions, and urea from your blood before returning it in your veins.
• Kidney failure is caused by injuries, communicable diseases and inherited disorders that all reduce the function of kidneys.
• All urea and excess ions and water are excreted in the urine.
• More ADH released results in a smaller volume of water released, making urine more concentrated and urinating less times.