What do you know and where are we going? AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Controlling internal conditions Homeostasis? The maintenance of constant internal environment. What is maintained? Waste removal – carbon dioxide and urea Water and ion content Body temperature Blood glucose levels How is it kept constant? AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Carbon dioxide Respiring cells produce CO 2. It is vital that this gets removed because CO 2 makes solutions acidic, this effects the working enzymes in the cells. AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Urea and urine? Urea is made in the liver. Urine is produced by the kidneys. Urine contains urea. Why is urea produced? Urea is the major organic component of human urine. This is because it is at the end of chain of reactions which break down the amino acids that make up proteins. These amino acids are metabolised and converted in the liver to ammonia, CO 2, water and energy. But the ammonia is toxic to cells, and so must be excreted from the body. The liver converts the ammonia to a non-toxic compound, urea, which can then be safely transported in the blood to the kidneys, where it is eliminated in urine. AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Kidneys – Where and how big? Polycystic kidneys AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

The human kidney AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

The human kidneykidney The kidneys' function are to filter the blood. All the blood in our bodies passes through the kidneys several times a day. The kidneys remove wastes, control the body's fluid balance, and regulate the balance of electrolytes. As the kidneys filter blood, they create urine, which collects in the kidneys' pelvis -- funnel-shaped structures that drain down tubes called ureters to the bladder. Each kidney contains around a million units called nephrons, each of which is a microscopic filter for blood. AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

A healthy kidney produces urine by; First filtering the blood Reabsorbing all the sugar Reabsorbing the dissolved ions needed by the body Reabsorbing as much water as the body needs Releasing urea, excess ions and water as urine Urine – copious and clear, why? Urobilins; yellow pigments that come from the breakdown of haemoglobin in your liver. AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Dialysis AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Living without kidneys AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Kidney transplantstransplants A kidney transplant is the transfer of a healthy kidney from one person (the donor) into the body of a person who has little or no kidney activity (the recipient). AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Controlling body temperature 37 o C core body, why? Factors that can alter your body temperature; Energy produced in your muscles during exercise Fevers caused by disease External temperature increase or decrease AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Controlling body temperature AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Controlling blood glucose AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Blood Sugar Keywords Glucose Glycogen Insulin Glucagon A sugar used in respiration to make energy A storage substance made of glucose, it is stored in the liver. A hormone (chemical messenger) it tells your body to change glucose into glycogen. It is made by the pancreas. A hormone that tells your liver to change glycogen back into glucose. Also made by the pancreas. AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Controlling Blood Glucose Levels Normal blood glucose level. ( mg/100cm 3 blood) Normal blood glucose level. ( mg/100cm 3 blood) Insulin produced by the _________ causes _______to change to ________. ________ released and _________ converted back to glucose Glucose rises (eat food) Glucose falls (exercise) AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)

Diabetes tes.aspx AQA B3.3 Controlling internal conditions – Joe Ewen, Rebecca Timms and Rebecca Barlett (Cheney School)