Medsci

• Parts of the excretory system


  • Diaphragm
  • Aorta (from the heart)
  • Kidney
  • Renal artery
  • Renal vein
  • Ureter
  • Bladder
  • Muscle
  • Urethra
• Brain monitors the water content of the blood

  1. Osmoreceptors in the brain detect the water content of the blood is too low

  2. Osmoreceptors in the brain detect the water content of the blood is too high

  3. More ADH is released into the blood from the posterior lobe of the pituitary gland

  4. Less ADH is released into the blood from the posterior lobe of the pituitary gland

  5. Blood takes more ADH to the distal convoluted tubule and collecting duct of the kidney

  6. Blood takes less ADH to the distal convoluted tubule and collecting duct of the kidney

  7. The distal convoluted tubule and collecting duct becomes more permeable to water

  8. The distal convoluted tubule and collecting duct becomes less permeable to water

  9. Water in the collecting duct is reabsorbed into the surrounding tissue fluid by osmosis

  10. Water is retained in the collecting duct

  11. A small volume of concentrated urine is released

  12. A large volume of dilute urine is released
• This process operates by negative feedback
• The kidney


  Removes urea, a waste product of metabolism, and regulates the water content of the blood
• Parts of the excretory system

  • Diaphragm
  • Aorta (from the heart)
  • Vena cava (to the heart)
  • Kidney
  • Renal artery
  • Renal vein
  • Ureter
  • Bladder
  • Muscle
  • Urethra
• Cleaning the blood


  1. Blood from the aorta moves into the renal artery and into the kidney

  2. The kidney filters the blood and removes some water, urea and excess salts

  3. Cleaned blood returns to the heart in the vena cava

  4. The filtrate called urine leaves the kidneys in the ureters and is stored in the bladder

  5. Urine is passed out of the body through the urethra
• Nephron


  • There are about a million nephrons in each kidney
  • They filter the blood
• Parts of the nephron

  • Afferent arteriole
  • Efferent arteriole
  • Glomerulus
  • Bowman's capsule
  • Proximal convoluted tubule
  • Loop of Henle
  • Distal convoluted tubule
  • Collecting duct
  • Peritubular capillaries
• Red blood cells in urine indicates kidney damage or disease
• Glucose in the urine can indicate diabetes
• Types of joint


  • Gliding joints
  • Hinge joints
  • Ball and socket joints
  • Fibrous/fused joints
• Gliding joints


  Bones glide over each other collectively providing a wide range of movement
• Hinge joints


  Allow movement in one plane
• Enzymes


  Tertiary structure proteins with a very specific 3D shape, including an active site held together by peptide, hydrogen, ionic and disulphide bonds
• Hinge joints


  • Knee
  • Elbow

  
• Lock and key theory

  Substrate fits exactly into the active site of the enzyme forming an enzyme/substrate complex, the reaction occurs and the products are released, the enzyme remains unchanged

  
• Chemical elements


  Joined together to form biological compounds
• Induced fit theory


  Active site and substrate are not fully complementary in shape, reactive groups align and the substrate forces its way into the active site, both areas change structure slightly, the bonds in the substrate weaken and the reaction occurs at a lower activation energy
• Ball and socket joints


  Allows movement in more than one plane
• Biological compounds


  • Carbohydrates
  • Proteins
  • Lipids
• Monosaccharides


  • Triose
  • Pentose
  • Hexose
• Cutter face


  Outer surface of cell (plasma) membrane
• Activation energy


  Enzymes are catalysts, they lower the activation energy of reactions, but they remain unchanged in the reaction

  
• Sugar side chain


  Part of phospholipid in cell membrane
• Ball and socket joints

  • Hip
  • Shoulder
• Competitive inhibitors


  Complementary in shape to the active site of the enzyme, they prevent the formation of enzyme/substrate complexes by blocking the active site, they do not bind permanently
• Fibrous/fused joints


  Bones interlock, there is no movement
• Non-competitive inhibitors


  Bind to the enzyme away from the active site at an 'allosteric' site, this alters the shape of the active site so no enzyme/substrate complexes can be formed, some bind reversibly, others irreversibly

  
• Hydrophilic (polar) head of phospholipid

  Forms outer and inner surface of cell membrane
• Triose


  • 3C important in respiration and photosynthesis
• Fibrous/fused joints


  • Cranium
• Increase in substrate concentration

  Decreases the effect of competitive inhibitors as the substrate will collide more often than the inhibitor with the active site of the enzyme

  
• Hydrophobic (nonpolar) fatty acid tail of phospholipid


  Points towards each other in the phospholipid bilayer
• Vertebral column


  A support for the body that is flexible to allow bending and twisting but provides protection for the spinal cord
• Pentose


  • 5C important in nucleotides
• Increase in substrate concentration

  Has no effect on non-competitive inhibitors

  
• Extrinsic protein


  Protein found on either outer surface of the bilayer
• Intrinsic protein


  Protein that spans the whole phospholipid bilayer
• Sliding filament theory of muscle contraction

  Thin actin filaments slide in between the thick myosin filaments during muscle contraction
• Intracellular enzymes


  Work inside cells