excre

• Stenohaline - cannot tolerate substantial changes in external osmolarity
• Euryhaline - can tolerate substantial changes in external osmolarity
• Hypoosmotic - more water than solute
• Hyperosmotic - less water than solute
• Osmoregulation is the process by which an organism maintains its internal environment at a constant concentration despite fluctuations in environmental conditions.
• Isoosmotic - equal amount of water and solute; stable composition
• Isonotic - same concentration in and out of the cell
• Forms of Nitrogenous Waste

  • Ammonia
  • Urea
  • Uric Acid
• Ammonia

  
• Urea

  
• Uric Acid

  
• Transport Epithelia in Osmoregulation

  • Maintaining an osmolarity arries an energy cost
  • active transport manipulates solute concentrations in the body fluids
  • osmoregulation and metabolic waste disposal rely on transport epithelia

  
• an animal's nitrogenous wastes reflect its phylogeny and habitat
• diverse excretory systems are variation on a tubular theme
• PROTONEPHRIDIA

  • flatworms (phylum Platyhelminthes)
  • lack a coelom

  
• The Excretory Process

  Animals produce urine

  1. Hydrostatic pressure (blood pressure) drives a process of filtration
  2. Nitrogenous wastes forms a solution called filtrate
  3. Selective reabsorption recovers useful molecules from the filtrate and returns to the body fluid
  4. Nonessential solutes and wastes are eliminated by selective secretion

  
• METANEPHRIDIA

  • most annelids, such as earthworms
  • metanephridia are immersed in coelomic fluid
  • collecting tubule include a storage bladder that opens to the outside

  
• MALPIGHIAN TUBULES

  • insects and other terrestrial arthropods
  • remove nitrogenous wastes
  • osmoregulation

  
• EXCRETORY ORGANS

  1. Posterior vena cava
  2. Renal Artery and Vein
  3. Kidney
  4. Aorta
  5. Ureter
  6. Urinary Bladder
  7. Urethra
• KIDNEY STRUCTURE

  1. Renal cortex
  2. Renal Medulla
  3. Renal Artery
  4. Renal Vein
  5. Renal Pelvis
  6. Ureter
• NEPHRON TYPES

  1. Cortical nephron
  2. Juxtamedullary nephron
  3. Renal cortex
  4. Renal medulla
• MAMMALIAN EXCRETORY SYSTEM

  
• hormonal circuits link kidney function, water balance, and blood pressure
• Homeostatic Regulation of the kidney

  • combination of nervous and hormonal controls
  • a key hormone in of the kidney is antidiuretic hormone (ADH)

  
• Antidiuretic Hormone (ADH): A hormone that regulates the amount of water reabsorbed by the kidneys.
• NEPHRON ORGANIZATION

  1. Afferent arteriole from renal artery
  2. distal tubule
  3. efferent arteriole from glomerus
  4. collecting duct
  5. branch of renal vein
  6. vasa recta
  7. descending limb (descending & ascending: loop of henle)
  8. ascending limb
  9. peritubular capillaries
  10. proximal tubule
  11. bowman's capsule
  12. glomerulus
• NEPHRON ORGANIZATION

  
• the nephron and collecting duct

  
• how the human kidney concentrates urine: - filtration - osmosis - reabsorption

  
• PARTS OF PITUITARY GLAND

  
• PARTS OF PITUITARY GLAND

  1. optic chiasm
  2. hypothalamus
  3. infundibulum
  4. anterior pituitary
  5. sella turcica (spenoid bone)
  6. posterior pituitary
• The ADH Regulatory Circuitry

  when osmolarity rises above the normal range (285-295 mOsm/L), the osmoreceptor cells

  
• Hypertonic

  ➔ More concentrated outside

  ➔ Water will move out

  ➔ Cell will shrink
• Hypotonic

  ➔ Lower concentration outside

  ➔ Water will move into the cell by osmosis

  ➔ Sometimes cell will burst
• Hyperosmotic

  ➔ Shriveled cells

  ➔ High concentration outside
• Isosmotic

  ➔ Normal cells

  ➔ Water balance
• Hypoosmotic

  ➔ Cells swell and burst

  ➔ Low concentration outside
• OSMOCONFORMER

  ➔ Isosmotic with its surrounding

  ➔ Do not need to regulate osmolarity

  ➔ All marine animals

  ➔ Internal osmolality same with the environment

  ● No tendency to gain or lose water

  ➔ Live in a stable composition = constant internal osmolarity

  ● Freshwater = no salt
• OSMOREGULATOR

  ➔ To control internal osmolarity independent of that of the surroundings

  ➔ Live in environments that are uninhabitable for osmoconformers

  ➔ Hypoosmotic environments = they must discharge excess water

  ● Freshwater = excrete water para sa kanya lang yung salt

  ➔ Hyperosmotic environments = they must take in water

  ● Regulates the solvent & solute depending in the environment
• Urea = toxic (leads to failure of systems)

  ● Nitrogenous discharge

  ● Not toxic to sharks because their cells overpower it = trimethylamine oxide