B3.3

Question 1

suggest two ways in which the amounts of water gained and lost each day would be different in a very hot climate

Answer 1

-sweat more
-drink more water so urinate more

Question 2

what goes in the body?

Answer 2

-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

Question 3

what goes out of the body?

Answer 3

-carbon dioxide is a waste product of respiration
-water and waste products are filtered out of the blood and are excreted in the urine

Question 4

what goes both in and out of the body?

Answer 4

energy is transferred between your body and the environment

Question 5

homeostasis

Answer 5

the maintenance of a constant internal environment, despite external changes e.g. temperature, blood glucose and water content

Question 6

what are the systems involved in homeostasis?

Answer 6

-endocrine system
-nervous system

Question 7

what are the three main parts to a homeostasis control system?

Answer 7

-receptor
-processing centre
-effector

Question 8

negative feedback

Answer 8

this is a mechanism where any change away from normal level is returned back to normal

Question 9

what is blood glucose?

Answer 9

-small, soluble molecule that is carried in the blood plasma
-levels vary during the day –> especially after meals

Question 10

why do blood glucose levels need to be maintained?

Answer 10

-at very low levels, cells would not have enough glucose for respiration
-at very high levels, overtime, this can damage blood vessels and nerves

Question 11

factors that affect blood glucose concentration

Answer 11

-diet
-exercise
-rate of respiration

Question 12

what are the hormones involved in blood sugar?

Answer 12

-insulin
-glucagon

Question 13

how is insulin involved in blood glucose?

Answer 13

-stimulates conversion of glucose to glycogen in the liver
-stimulates cells to uptake glucose from the blood
-lowers glucose levels

Question 14

how is glucogen involved in blood glucose?

Answer 14

-stimulates liver to break down glycogen into glucose and release it into the blood stream
-increases glucose levels

Question 15

diabetes

Answer 15

a serious health condition when the levels of blood sugar are not controlled- they are too high

Question 16

symptoms of diabetes

Answer 16

-high blood glucose concentration
-glucose present in urine
-excessive thirst
-excessive hunger

Question 17

describe type I diabetes

Answer 17

-patients are unable to produce insulin
-usually develops during childhood
-usually due to immune system attacking the cells of the pancreas that make insulin

Question 18

type I treatment

Answer 18

-regular blood glucose monitoring
-insulin injections
-if too much or too little insulin is injected this can lead to unconsciousness or death

Question 19

describe type II diabetes

Answer 19

-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

Question 20

type II treatment

Answer 20

-regulation of carbohydrate intake
-exercise
-weight loss
-insulin injections

Question 21

alternative treatments for diabetes

Answer 21

-pancreas transplant
-stem cell therapy

Question 22

role of the kidney

Answer 22

-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

Question 23

capsule

Answer 23

outer membrane of the kidney, helps to maintain the kidney’s shape and protect it from damage

Question 24

cortex

Answer 24

outer part of the kidney

Question 25

medulla

Answer 25

inner part of the kidney

Question 26

ureter

Answer 26

carries the urine to the bladder

Question 27

renal artery

Answer 27

carries blood containing urea and other substances to the kidney

Question 28

renal vein

Answer 28

carries blood away from the kidney after urea and other substances have been removed from the blood