Test info Average: 15 out of 30 Range: 3 – 24 Correction due: Friday Lab notebooks: Monday Add data to table coming around Data up on website later today 6th Period Pass out tests & scantrons record # correct at top of test record correct answers on test Richard, collect scantrons I will return at 1:40 – I’m touring the Leadership WS group Thank you!

Chapter 44: Osmoregulation and Excretion What is osmoregulation? How animals regulate solute concentrations & balance the gain & loss of water What is excretion? How animals get rid of nitrogenous waste of metabolism What is the difference between an osmoregulator & an osmoconformer? Osmoconformer – does not actively adjust its internal osmolarity Isoosmotic to environment Marine animals Osmoregulator – actively controls osmolarity NOT isoosmotic with environment

Figure 44.3 Osmoregulation in marine and freshwater bony fishes Gain of water and salt ions from food and by drinking seawater Osmotic water loss through gills and other parts of body surface Excretion of salt ions from gills Excretion of salt ions and small amounts of water in scanty urine from kidneys Uptake of water and some ions in food Osmotic water gain by gills large amounts of water in dilute (a) Osmoregulation in a saltwater fish (b) Osmoregulation in a freshwater fish Hypoosmotic to ocean loses LOTS of water at gills “Drinks like a fish” excretes salt & little urine Hyperosmotic to lake gain LOTS of water at gills LOTS of dilute urine

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? Dehydration Many adaptations to prevent this What are the different nitrogenous waste products that animals excrete? Ammonia Urea Uric acid

Figure 44.8 Nitrogenous wastes Proteins Nucleic acids Amino acids Nitrogenous bases –NH2 Amino groups Most aquatic animals, including most bony fishes Mammals, most amphibians, sharks, some bony fishes Many reptiles (including birds), insects, land snails Ammonia Urea Uric acid NH3 NH2 O C N H HN Ammonia – very soluble in water - VERY toxic - easily passes through membranes - 1 N at a time Urea - 100,000X less toxic than –NH3 - -NH3 + CO2 in liver - helps conserve water - 2 N at a time Uric acid- not very soluble in water - excreted in paste-like form - little water loss - stored in amniotic egg - 4 N at a time

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? What are the different nitrogenous waste products that animals excrete? What are the 4 main functions of excretory systems? Filtration Reabsorption Secretion Excretion

Figure 44.9 Key functions of excretory systems: an overview Filtration. The excretory tubule collects a filtrate from the blood. Water and solutes are forced by blood pressure across the selectively permeable membranes of a cluster of capillaries and into the excretory tubule. Reabsorption. The transport epithelium reclaims valuable substances from the filtrate and returns them to the body fluids. Secretion. Other substances, such as toxins and excess ions, are extracted from body fluids and added to the contents of the excretory tubule. Excretion. The filtrate leaves the system and the body. Capillary Excretory tubule Filtrate Urine 1 2 3 4

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? What are the different nitrogenous waste products that animals excrete? What are the 4 main functions of excretory systems? How have excretory systems evolved? Protonephridia – Planaria Metanephridia – Earthworm Malpighian tubules – insects Kidney - us

Figure 44.10 Protonephridia: the flame-bulb system of a planarian Nucleus of cap cell Cilia Interstitial fluid filters through membrane where cap cell and tubule cell interdigitate (interlock) Tubule cell Flame bulb Nephridiopore in body wall Tubule Protonephridia (tubules)

Figure 44.11 Metanephridia of an earthworm Nephrostome Metanephridia Nephridio- pore Collecting tubule Bladder Capillary network Coelom

Figure 44.12 Malpighian tubules of insects Digestive tract Midgut (stomach) Malpighian tubules Rectum Intestine Hindgut Salt, water, and nitrogenous wastes Feces and urine Anus tubule Reabsorption of H2O, ions, and valuable organic molecules HEMOLYMPH

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? What are the different nitrogenous waste products that animals excrete? What are the 4 main functions of excretory systems? How have excretory systems evolved? What is the structure and function of the kidney?

My tolerance for cell phones is GONE!!! The letter of the law will be followed!!

Figure 44.13 The mammalian excretory system Posterior vena cava Renal artery and vein Aorta Ureter Urinary bladder Urethra (a) Excretory organs and major associated blood vessels Juxta- medullary nephron Cortical Collecting duct To renal pelvis Renal cortex medulla 20 µm (b) Kidney structure Kidney Section of kidney from a rat Afferent arteriole from renal artery Glomerulus Bowman’s capsule Proximal tubule Peritubular capillaries SEM Efferent arteriole from glomerulus Branch of renal vein Descending limb Ascending Loop of Henle Vasa recta Distal tubule (d) Filtrate and blood flow (c) Nephron

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? What are the different nitrogenous waste products that animals excrete? What are the 4 main functions of excretory systems? How have excretory systems evolved? What is the structure and function of the kidney? What is the structure & function of the nephron?

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? What are the different nitrogenous waste products that animals excrete? What are the 4 main functions of excretory systems? How have excretory systems evolved? What is the structure and function of the kidney? What is the structure & function of the nephron? Glomerulus – filtration due to BP Proximal tubule – secretion & reabsorption Loop of Henle Descending – reabsorption Ascending – reabsorption Distal tubule – secretion & reabsorption Collecting duct - reabsorption

Figure 44.14 The nephron and collecting duct: regional functions of the transport epithelium Proximal tubule Filtrate H2O Salts (NaCl and others) HCO3– H+ Urea Glucose; amino acids Some drugs Key Active transport Passive transport CORTEX OUTER MEDULLA INNER Descending limb of loop of Henle Thick segment of ascending limb Thin segment limbs Collecting duct NaCl Distal tubule Nutrients HCO3 K+ NH3 1 4 3 2 5

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? What are the different nitrogenous waste products that animals excrete? What are the 4 main functions of excretory systems? How have excretory systems evolved? What is the structure and function of the kidney? What is the structure & function of the nephron? What causes the movement of water out of the filtrate? - Increasing salt concentration within the kidney

Figure 44.15 How the human kidney concentrates urine 300 100 400 600 900 1200 700 200 Active transport Passive transport OUTER MEDULLA INNER MEDULLA CORTEX Osmolarity of interstitial fluid (mosm/L)

Figure 44.15 How the human kidney concentrates urine Nacl 300 100 400 600 900 1200 700 200 Active transport Passive transport OUTER MEDULLA INNER MEDULLA CORTEX Osmolarity of interstitial fluid (mosm/L)

Figure 44.15 How the human kidney concentrates urine Nacl 300 100 400 600 900 1200 700 200 Active transport Passive transport OUTER MEDULLA INNER MEDULLA CORTEX Urea Osmolarity of interstitial fluid (mosm/L)

Chapter 44: Osmoregulation and Excretion What is osmoregulation? What is excretion? What is the difference between an osmoregulator & an osmoconformer? What is the biggest issue for land animals? What are the different nitrogenous waste products that animals excrete? What are the 4 main functions of excretory systems? How have excretory systems evolved? What is the structure and function of the kidney? What is the structure & function of the nephron? What causes the movement of water out of the filtrate? How is blood osmolarity regulation? - ADH - RAAS

Figure 44.16 Hormonal control of the kidney by negative feedback circuits Osmoreceptors in hypothalamus Drinking reduces blood osmolarity to set point Increased Na+ and H2O reab- sorption in distal tubules Homeostasis: Blood pressure, volume STIMULUS: The juxtaglomerular apparatus (JGA) responds to low blood volume or blood pressure (such as due to dehydration or loss of blood) H2O reab- sorption helps prevent further osmolarity increase The release of ADH is triggered when osmo- receptor cells in the hypothalamus detect an increase in the osmolarity of the blood Blood osmolarity Hypothalamus ADH Pituitary gland Increased permeability Thirst Aldosterone Adrenal gland Angiotensin II Angiotensinogen Renin production Collecting duct Distal tubule Arteriole constriction JGA Antidiuretic hormone (ADH) enhances fluid retention by making the kidneys reclaim more water. The renin-angiotensin-aldosterone system (RAAS) leads to an increase in blood volume and pressure. (a) (b)