Bio 12 Unit O: Excretory System Excretor:

Standards: I can explain the overall function of the urinary system I can outline the major organs and their function in the urinary system I can explain how urine production contributes to homeostasis

NO ADVANCED!THAT MEANS YOU NEED TO KNOW EVERYTHING!!

Excretory System: AKA: the __________________ system (how you make pee!)

TWO FUNCTIONS OF THE EXCRETORY SYSTEM: _______________________________: the control of the gain and loss of water and dissolved solutes _______________________________: the disposal of metabolic wastes

Osmoregulation:Compared to our aquatic relatives, land animals need to be very aware of our ________________ intake/output

Land animals ____________ water by drinking and eating ____________ water by evaporation and waste disposal

Their ____________________, behavioral adaptations, and waterproof skin help to conserve water (VERY important!)

CONNECTION:Do we need to drink eight glasses of water each day?

Water lost in thermoregulation can cause _______________________________ problems

Is it true you can “drown” from drinking too much water?? YES!! BUT…It's very, very rare – you’d need to drink many, many litres of water in a very short

amount of time. Its called ______________________________: too much water in our blood, dilutes the

salts/solutes to the point where the blood becomes hypotonic to the body’s cell causing them to swell (NOT good – especially in the brain!!) can be fatal!!

_________________ is usually an adequate guide to water intake – usually by the time you’re thirsty you are already dehydrated!

Animals must dispose of __________________________ wastes Nitrogenous wastes are the toxic _____________________ from the breakdown of _________________ ________________________ is poisonous but soluble and is easily disposed of by animals _____________________ is less toxic and easier to store Some land animals save water by excreting ______________ ____________ - virtually dry waste Urea and uric acid take ___________________ to produce

The liver has _____ functions:1) Produces ______________ from ammonia2) ___________________: converts alcohol fats (which are stored

in the liver leads to a fatty liver – NOT good!) 3) Produces ___________: emulsifier of fats, stored in the gall

bladder4) Produces __________ ______________ _______________ and

lipoproteins (EX. Albumin- regulating osmotic pressure; fibrinogen/prothrombin – clotting)

5) Adjusts the ___________ _____________ level: glucose glycogen based on pancreatic hormones (insulin & glucagon)

6) Removes _________ ____________ ___________ ___________ from the blood, send the hemoglobin to the bone marrow and the rest is converted into bile

The _________________ has a strategic location in the body between the intestines and the heart Alcohol consumption can damage the liver

Liver function can be impaired by excessive alcohol consumption (converts alcohol fats creating a _________liver) or ______________ (inflammation of parts of liver, which can lead to liver _____________: parts or all of liver stop working)

The excretory system plays several major roles in __________________ The excretory system expels ______________ and regulates water and ion balance _______________, the functional units of the kidneys extract a __________________ from the blood

and refine it to ________________ Urine leaves the kidneys via ________________ is stored in the urinary ____________________, and is

expelled through the _________________

HepaticPor talvein

Kidneys

Intestines

Liver

Overview: The key processes of the excretory system are filtration, reabsorption, secretion, and excretion In __________________ blood pressure forces water and many small solutes into the nephron (occurs

in ___________________ ________________ in the _____________________)

Figure 25.9A–D D Detailed structure of a nephron

2 _____ __ ______ with capillary network

Branch ofrenal vein

Arteriolefromglomerulus

Arteriolefrom renalartery

Bowman’s capsule

_______________

Fromanothernephron

Capillaries

3 _______ tubule

1 _______ tubuleGlomerulus

Renal medulla

Renal cortex

Torenalpelvis

Collectingduct

Nephrontubule

Renal vein

Renal artery

C Orientation of a nephron within the kidney

Bowman’scapsule

B The kidney

Ureter

Renal pelvis

Renal medulla

Renal cortex

Kidney

A The excretory system

Urethra

Urinary bladder

Ureter

Renal artery and vein

Inferiorvena cava

Aorta

In __________________________ valuable solutes are reclaimed from the filtrate (occurs through the rest of the nephron: in the PCT, LoH, DCT & CD)

In ____________________excess H+ and toxins are added to the filtrate (occurs in PCT & DCT) The product of all of the above processes is urine which is _____________________

From blood to filtrate to urine: A closer look Nutrients, salt, and water are reabsorbed from the _____________and _______________tubules

Blood pH is regulated by the ______________________ of H+ and __________________________ of HCO3

– There is a network of blood capillaries (_________

_____________) that are located over the Loop of Henle which reabsorb many nutrients and salts

High_________ concentration in the ________________ promotes reabsorption of water in the Loop of Henle

Nephron tubule

Interstitial fluidCapillary

UrineH2O, other small molecules

LOOP OF HENLE DETAILS!! ____________________ loop is only permeable to _________ (osmosis) ___________________ loop in only permeable to ____________ (actively pumped) Best to imagine it happening backwards with ascending first (pump out salt) and then descending (water follows

passively by osmosis)

Overview: reabsorption and secretion in a nephron

Reabsorption

Secretion

Filtrate composition H2O

NaCI HCO3

H Urea Glucose Amino acids Some drugs

Medulla

Urine (to renal pelvis)

H2O

H2O

UreaNaCI

NaCI

NaCILoop ofHenle

Collectingduct

K+ H+

H2OHCO3

NaCI

Cortex

H+Somedrugsand poisons

Nutrients H2O

H2OHCO3

NaCl

Distal tubuleProximal tubuleBowman’scapsule

Blood

Collecting Duct: reabsorbs_________________ under __________________ control; regulates how concentrated the urine is, in response to blood osmolarityHORMONE:Antidiuretic hormone (______): regulates the amount of water the kidneys excrete by controlling the # of ___________________ in the collecting duct

ADH production is inhibited by ______________ consumption

CONNECTION Kidney dialysis can be a lifesaver by compensating for kidney failure

A dialysis machine removes wastes from the blood and maintains its solute concentration