2.75 Urine

• Summary of the last 5:
• Kidneys influenced by the brain
• Blood is filtered in the kidney
• Removed molecules come out the ureter as urine
• Gets collected in the bladder
• Urine
• Contains salts, waters urea
• Composition depends on the condition of the individual
• affects composition of the tissue fluid
• Osmoregulation
• Removal of urea
• Excretion of metabolic waste

2.74 Antidiuretichormone

• Antidiuretichormone
• produced in a region of the brain (Hypothalamus)
• Flows through the blood stream to the Kidney
• Controls the quantity of the water in the blood
• Making the tissue fluid isotonic with the cells
• Adding this hormone increases amount of water reabsorbed from the duct 

2.73 Glucose Reabsorption

• Selective Reabsorption
• Glucose molecule is selected
• Will be moved to the glomeral filtrate and back into the blood
• Filtration
• Occurs in the Bowman's Capsule
• Filtrate contains glucose, salts, urea and water
• Formed from high pressures of the blood
• Urine exiting nephron
• No Glucose
• If present, indicates diabetise
• Proximal Convoluted Tubule
• 1st/twisted
• Glucose is stored in the fluid inside this
• Removed and taken back into the blood

2.72 Water re-absorption

• Bowman's Capsule
• Where ultrafiltration happens
• Blood foes in to the kidney
• High pressures
• Dissolved contents in the blood are forced out into the Broman's capsule
• Glomerula Filtrate
• Too much water is filtrated
• Filtrate passes along the tubule
• Reaches collecting duct
• Water is removed from filtrate
• goes down medula
• Returned back into the blood vessels
• Water has been reabsorbed into the blood

Animation:

http://www.hcc.uce.ac.uk/physiology/ADH2.gif

2.71 Ultrafiltration

• Nephron
• Filters blood
• Filtered: Clean / Urine: Waiste
• Urine
• Mixture of water, salts, and urea
• Urea = Nitrogen waste
• toxic
• Bowman's Capsulte
• Where ultrafiltration starts
• Blood arrives in the kidnes
• in Afferent arteriole
• at high pressure
• with wide blood vessel
• Passes through Glomerulus
• Passes out Efferent artiole
• Narrow blood vessel
• High pressures
• Forces the plasma out of the blood vessel
• Plasma enters the inside of the Bowman's Capsule
• Glomerula Filtrate

2.70 Nephron Structure

• Renal Vein
• Carries blood away from kidneys
• Transports it back to the right side of the heart
• Urea removed from the blood 
• Has the exact amount of salts and water
• Kidney removes the excess
• Controlled by the brain
• Antidiuretichormone (ADH)
• controls amount of water that is excreted
• Renal Artery
• Supplies blood to the kidneys
• Contains glucose and oxygen
• Must have pressure to filter blood
• Contains urea
• Toxic
• Must be excreted 
• Pelvis
• Region of the kidney in which urine is collected
• Note to remember: P. Elvis
• Ureter
• Carries urine to the bladder
• stays in bladder till excreted
• Medulla
• The inside part of kidney
• Where amount of salt and water is controlled
• Consists of billions of loops of henle
• ADH makes the loops pump more sodium ions
• Very concentrated urine is produced
• Cortex
• Outer part of the kidney
• Where the blood is filtered
• Ultra-filtration
• Only works when blood entering is at a high pressure
• Glomerulus
• Tiny ball of capillaries
• Found in the cortex
• Surrounded by "Browman's capsule"
• Glomeruli leaks
• RBC/WBC/Platelets stay in blood vessels
• Plasma leaks out into the capsules
• Most of  the "ultra-filtrate" liquid is re absorbed in the medulla
• put back in the blood 

2.69

• Urinary System
• Kidneys
• Has it's own blood supply
• Ureter
• A tube that carries Urine from kidney to bladder
• Urethra
• Urine is excreted through this
• Leads to the Vagina (Femlae)
• Leads to the Penis (Male)

2.68 Excretion and Osmoregulation in the Kidneys

• The Kidney excretes a molecule called Urea
• Contains Nitrogen
• Toxic to the body
• Cannot be stored
• From Amino Acids
• Blood circulates to the Liver
• Amno Acids in the blood are broken down in the liver
• Produces Urea
• Then transports to the Kidneys
• Filters Urea out of the blood
• Water added
• Urine is formed
• Collected in the bladder
• Urea no out of the body

• Osmoregulation-
• Osmo (Osmosis)
• Regulation (To control)
• To control Osmosis
• Tissue Fluids surrounding the cells must be Isotonic with the cytoplasm of the cells
• Water in = Water out
• Cells remain their function and shape
• Danger of Blood circulating into the tissue-
• Hypertonic (Concentrited) -
• too much water 
• Hypotonic (Dilute) -
• Removes to much water
• Not enough in the cell
• Isotonic conditions
• Archived by controlling composition of blood
• Blood forms the tissue fluid
• Kidney controls the composition
• Excess water and salts are removed

2.67 Excretion in plants and Humans

• Plants-
• Excretion-
• Uses Photosynthesis 
• Takes light energy, CO2 and water and turns it into Glucose
• (Light + Carbon Dioxide + Water -> Glucose + Oxygen)
• Oxygen becomes the waist product from this process 
• Aerobic Respiration-
• Glucose + Oxygen -> CO2 + Water + ATP
• Uses enzyme to convert Glucose and Oxygen to CO2, Water & ATP
• Water and CO2 Get's excreted 

• Humans-
• Lungs-
• Takes in Oxygen, excretes Carbon Dioxide
• Kidneys-
• Excretes Water and Urea (Amino Acids) and Salts
• Skin-
• Excretes Sweat (Water and salts) and Urea