2.75 Urine

1. Urine contains water, urea and salts.

2. The role of the brain influences the function of the kidneys through ADH

4. After the urine goes down the collecting duct, it goes into the bladder.

5. Salts and H2o effects the composition of the tissue fluid.

6. The removal of the urea is done through the excretion of metabolic waste.

2.74 ADH

1. ADH helps regulate the water content of blood.

2. The hormone is produced in the hypothalamus part of the brain. It flows through the blood stream and targets the kidney

3. The effect of the hormone is to control and alter the composition/quantity of water that is in blood. It has the ability to make the blood more or less concentrated.

4. Important when keeping the cells isotonic the the tissue around it.

5. ADH targets the collecting duct. It allows more water to come out of the collecting duct. The hormone makes the amount of water coming out increase

6. The water then goes into the blood stream

7. The consequence is that the urine coming out is more concentrated and it has a lower volume.

2.73 Glucose re-absorbiton

1. Happens in the PCT

2. The glucose is firstly selected

3. The glucose is taken and then put back into the blood stream.

4. In the PCT, glucose is removed and is taken back into the blood stream

5. This means that there is no glucose in urine.

2.72 Water re - absorption

1. Glomerular filtrate excrete too much water out of the collecting duct.

2. As the filtrate passes through, the water is removed from the filtrate.

3. The water is then taken back into the blood stream.

4. This is called selective reabsorption

2.71 Ultrafiltration

1. Nephron - carries out the filtration of the blood. Giving us 'clean' blood and waste. (urine)

2. Urine is largely composed of water, salts and Urea which contains the nitrogen waste.

3. The urine goes down the collecting duct and then through the pelvic and then out of the ureter.

4. Bowman's Capsule - the site of ultrafiltration

Bowman's capsule and the filtration of blood

1. Blood goes into the bowman's capsule from an artery - (high BP)

2. The bowman's capsule branches into a smaller ball of blood vessels. (the glomerular)

3. When the blood flows down the vessels, because the diameter is smaller, they gain pressure, making the blood come out with a higher blood pressure.

4. The consequence of this is that the high blood pressure forces the liquid within blood - plasma (H2O, Salts, Amino Acids, glucose and urea) to release all these substances into the inside of the bowman's capsule.

5. The substances in the plasma and the plasma itself get taken into the bowman's capsule, the name changes to glomerular filtrate

2.70 Nephron Structure

1. The aorta branches off into the renal artery and then goes into the kidney.

2.The kidney then filters the blood and the urine goes down the ureter. This then follows into the bladder.

3. The filtered blood then goes on and back into the renal vein.

4. The kidney has 3 different parts to it. the outside layer, the cortex, the middle layer, the medulla and the inner area, the pelvic.

5. In the pelvic, it collects the urine and drains it down the ureter

6. The different sections are there because the kidney is made up of millions of different tubular structures.

7. The tube starts at the pelvic and runs through the medulla in a mountain like pattern, then the tube goes into the cortex, where it is stopped. The end is called the bowman's capsule.

8. The tube is called the nephron

The Nephron

1.Mainly in the cortex, but dips into the medulla for the collecting duct and the loop of henle

2. 1st twisted section is called the proximal convoluted tubule, the second is called the distal convoluted tubule.

3.There are millions of Nephrons in the kidney.

2.69 The urinary System

1. The urethra soon leads to the penis or vagina after being stored in the bladder

2.68b Osmoregulation

1. Need to make sure that the water around the outside of the cell does not become too concentrated or not concentrated enough

2. it needs to be kept isotonic

3. The cell would not be stable if its hypertonic or hypotonic because the water would go into or out of the cell.

4. This is achieved by controlling the concentration of the blood.

5. The kidneys must control the composition

- Keeping an equal salt and water ratio

- this is done through osmoregulation

2.68a Excretion through the kidney --> Urea

1. Urea contains nitrogen

2. Amino Acids move through the liver

3. Taken out as Urea

4. Go into the kidneys and then is filtered and the blood is taken out. (put back into the body)

5. Urea then goes into the bladder

2.67b Humans organs of excretion

1. Lungs excrete CO2

2. Kidneys excrete water, salts and Urea (form of amino acids)

3. skin excretes water salts and sometimes urea - through sweating

2.67 Excretion in plants

1. Plants excrete through photosynthesis and Respiration, depending on what they do.

2. CO2 + H2O --> C6H12O6 + O2

3. This shows that the oxygen is the waste, and it is therefore excreted.

4. C6H12O6 + O2 --> ATP + H20 + CO2

5. Showing that plants excrete CO2 as a waste product of excretion

3.34 Causes of Mutation

3.33 Antibiotic Resistance

3.32 Types of Mutation

3.31 Evolution

3.30 Mutation

3.29 species variation

3.21b Genetic Probabilities

3.21a Genetic probabilities

3.20b Pedigree 2

2.20a Pedigree Diagrams

3.18c Codominance

3.19b F1 x F1 Cross

3.19a P1 x P1 Cross

3.18b Genotypes

3.18a Phenotypes

Genetic calculation

3.9b Female Reproductive System

1. Before a pregnancy occurs, the uterus is no larger than an orange - this grows during pregnancy

2. Ovary - meiosis - production of eggs - female gametes

3. Oviducts - carry eggs to the uterus - fertilization takes place there

4. Uterus wall - made of muscles - stretches during pregnancy - contracts during birth

5. Uterus lining - accepts and develops fertilized egg - Embryo goes into the wall

6. Sperm cells enter through the cervix - entrance to the uterus - sperm cells make their way through the oviducts to meet the egg

7. The penis goes into the vagina - sperm collected at top of vagina - makes way to the cervix.

3.9a Male Reproductive System

1. Bladder at the top - Stores urine

2. 2 testis - Carry out the process of meiosis - produces the gamete known as sperm cells

3. Sperm cells are stored in the epididymis

4. The tube from the testis is called the vas deferens - (contracts to move sperm to penis)

5. As the sperm cells move they pass the prostate - This adds 20 - 30% of the volume of semen - containing sugars and being alkaline - neutralize acidic secretions within the vagina

6. The seminal vesicles produce sugar based secretions - alkaline 70% of semen

7 Sperm cells + prostate + seminal vesicles = semen

8. Common tube = the urethra - common tube

9. Urethra carries semen and urine

10. Penis - carries sperm cells into vagina during intercourse