B3.3 Flashcards
suggest two ways in which the amounts of water gained and lost each day would be different in a very hot climate
-sweat more
-drink more water so urinate more
what goes in the body?
-oxygen for respiration
-molecules from digested food for growth and repair, glucose for respiration
-water from food and drinks through the gut wall and into the blood stream
what goes out of the body?
-carbon dioxide is a waste product of respiration
-water and waste products are filtered out of the blood and are excreted in the urine
what goes both in and out of the body?
energy is transferred between your body and the environment
homeostasis
the maintenance of a constant internal environment, despite external changes e.g. temperature, blood glucose and water content
what are the systems involved in homeostasis?
-endocrine system
-nervous system
what are the three main parts to a homeostasis control system?
-receptor
-processing centre
-effector
negative feedback
this is a mechanism where any change away from normal level is returned back to normal
what is blood glucose?
-small, soluble molecule that is carried in the blood plasma
-levels vary during the day –> especially after meals
why do blood glucose levels need to be maintained?
-at very low levels, cells would not have enough glucose for respiration
-at very high levels, overtime, this can damage blood vessels and nerves
factors that affect blood glucose concentration
-diet
-exercise
-rate of respiration
what are the hormones involved in blood sugar?
-insulin
-glucagon
how is insulin involved in blood glucose?
-stimulates conversion of glucose to glycogen in the liver
-stimulates cells to uptake glucose from the blood
-lowers glucose levels
how is glucogen involved in blood glucose?
-stimulates liver to break down glycogen into glucose and release it into the blood stream
-increases glucose levels
diabetes
a serious health condition when the levels of blood sugar are not controlled- they are too high
symptoms of diabetes
-high blood glucose concentration
-glucose present in urine
-excessive thirst
-excessive hunger
describe type I diabetes
-patients are unable to produce insulin
-usually develops during childhood
-usually due to immune system attacking the cells of the pancreas that make insulin
type I treatment
-regular blood glucose monitoring
-insulin injections
-if too much or too little insulin is injected this can lead to unconsciousness or death
describe type II diabetes
-either the pancreatic cells do not produce enough insulin
or
-body cells do not respond properly to insulin
-normally occurs later in life and is linked to obesity
type II treatment
-regulation of carbohydrate intake
-exercise
-weight loss
-insulin injections
alternative treatments for diabetes
-pancreas transplant
-stem cell therapy
role of the kidney
-remove excess water, urea and other waste from the blood
-filter the blood
-anything the body uses is reabsorbed
-the main organ in water homeostasis
capsule
outer membrane of the kidney, helps to maintain the kidney’s shape and protect it from damage
cortex
outer part of the kidney
