homeostasis AND the urinary system (add in things written in class ! + p 8 on)

Homeostasis

maintenance of a constant internal environment within the body

what conditions within the body must be kept at near constants

• body temp (skin, blood vessels)

• water balance (kidneys)

• blood glucose conc (pancreas and livers - insulin)

• co2 conc

stimulus

change in the internal or external environment

response

action taken to return conditions to normal

What is the internal environment in human

consists of tissue fluid, which surrounds every cell in the human body

one way liver contributes to homeostasis

Absorption of glucose or release of glucose or heat generation

state one way lungs contribute to homeostasis

excretion of water and co2 or release of heat

one way kidneys contributes to homeostais

excretion/reabsorption of water

excretion/reabsorption of salts

Diffusion

spreading out of molecules from a region of high concentration to a region of low concentration

Osmosis

movement of water molecules across a selectively permeable membrane from a region of high water concentration to a region of low water concentration

Active transport

use of energy to move molecules across biological membranes against a concentration gradient, i.e. from low concentrations to high concentrations

one reason why homeostasis important?

maintain body temperature at a constant level so enzymes can work at optimum rate

Benefits of homeostasis

• allows organism to function properly

• allows slight changes in the internal environments

• allow cells to maintain constant conditions (incl the most suitable condition)

  • if temp rises above 37 degrees, enzymes become denature, slowing reactions down

what do receptors do

detect change

what do effectors do

carry out response

negative feedback

where each response reverses the original change

excretion

removal of waste products of metabolism from the body

what role does the excretory system play in homeostasis

regulating body temp (skin)

maintaining fluid balance (kidneys)

what key role does the urinary system play

regulates water balance and removing nitrogenous waste

labels in the urinary system

two kidneys, two ureters, bladder and urethra

function of kidney

filter the blood to remove waste products and regulate water and salt balance

function of ureters

carry urine from the kidneys to the bladder

function of bladder

stores urine until its ready to be released

urethra

carries urine from bladder to outside of body

functions of kidney

• excretion (removal of waste products of metabolsim)

• osmoregulation (control of water and salt conc in body)

• ph control (help maintain blood ph at 7.4)

how, briefly, do the kidneys work

• filter the blood and reabsorbing the materials it needs thru the renal vein

• waste materials form urine

• reabsorbed materials are useful and absorbed into the blood

nephrons

structure in kidney that filters blood and produces urine