Bio 102 - Lesson 20 Osmoregulation & Excretion

osmosis

movement of water across a selectively permeable membrane

osmoregulation

regulation of solute concentration and water balance by a cell or an organism

osmolarity

number of solute particle per 1L of solvent

osmolarity contributes to ________

homeostasis of blood pressure and blood volume

what two ways can animals maintain water balance?

osmoconformer & osmoregulator

osmoconformer

animal thats “iso” with its environment (expands less energy)

osmoregulation

animal that controls its internal osmolarity independent of the external environment

osmoregulation expands _________

more energy

ammonia

toxic molecule that is formed as a biproduct when proteins or nucleic acids break down

excretion

process of a body disposing of nitrogenous metabolites and other waste products

terrestrial animals gotta convert ammonia to other _________

nitrogenous compounds like urea or uric acid

both urea and ureic acid need an _____________

investment of energy to produce

urea requires less energy to make but needs _______

more water

uric acid requires more energy to make but needs ________

less water

water enter the body through

drinking, eating, and metabolism

blood pressure drives solutes and solvents in bloodstream to be filtered through _________

excretory tubule

excretory tubule

internal tubes that filter waste from body fluids

filtrate

fluid extracted from the body by the excretory system

kidney

excretory organs in vertebrates where blood filtrate is formed and made into urine

ureter

tube that transports urine from kidney to the urinary bladder

urinary bladder

stores urine before it is excreted as waste

renal cortex

outer region of kidney

renal medulla

inner region of kidney

how is blood supplied to the kidney

renal artery

tubules in the _______ and ______ cary and process filtrate from blood

cortex, medulla

almost all filrate fluid is reabsorbed into bloodstream and exits through ______

renal vein

where is urine collected?

renal pelvis

renal pelvis

funnel-shaped chamber in kidney that collects urine from tubules

nephron

excretory tubule of the vertebrate kidney

a ball of capillaries called the __________ is surrounded by a receptacle ________

glomerulus, bowmans capsule

Bowmans capsule leads to ______ which leads to _______

proximal tubule, U-shaped loop of henle

loop of henle goes to renal medulla then back to renal cortex an finally into ________

distal tubule

what are the three district steps of urine prodcution

filtration, secretion, reabsorption

filtration

• BP forces water+small molecules through capillary walls in glomerulus (glamerous)

• blood+plasma too big so stay in capillaries

• smaller molecules exit glamerous into Bowmans Campsule

secretion

• H+ ions, drugs/poisons are secreted from bloodstream into filtrate

reabsorption

• Body takes back useful stuff (salt, glucose)

• Water follows out by osmosis

• Loop of Henle: more water + salt leave

• Distal tubule: even more water + urea leave

• Final urine = mostly water (about 95%)