excretion

  • Selective reabsorption

  • Ultrafiltration

  • Parts of kidney

  • Parts of uretra 

  • Parts of urethra

  • Concentration of urine 

  • Deamination 

Stuff ms said will be in quiz

–—----------------------------------

Stuff i need to know

  • Functions of organs in excretory system 

  • Amino acid stuff 

    • Structure

    • Components 

  • The lists of stuff 

    • Components

    • Cellular waste 

    • Factors

  • Do past papers (old and new) 

  • Sme

  • That vid

  • Quizlet 


Excretion is the process of removing toxic materials and waste products of metabolism and substances of excess requirements in the body 

Or js say Excretion is the removal of the waste substances of metabolic reactions


Kidneys excrete urea and excess water and ions in the body through urine 


Components of urine: urea, excess water, excess ions

-made by ultrafiltration and selective absorption 


UREA: Toxic to body in high concentrations and must be excreted 



Parts:

  1. Kidney- blood is filtered here to remove waste and form urine 

  2. Ureter- tubes which connects and transports urine from kidneys to the bladder

  3. Urinary Bladder- where urine is stored before it is excreted 

  4. Urethra-tube where urine flows out of the body 

  5. Aorta- delivers oxyfen rich blood from heart to lungs

  6. Renal vein- carries filtered blood from kidney to heart

  7. Renal artery- supplies oxygen-rich blood to kidneys for filtration 

  8. Vena cava- deoxygenated blood returned from body to heart 




Nephron

-part of nebulla

-millions produced

-filter blood 

-separating waste 

-returning substances needed back into blood stream 


3 parts of nephron:

-medulla

-glomerulus

-bowmans capsule 


Ultrafiltration 

High blood pressure inside of glomerulus which forces out smaller molecules from the blood into the bowman’s capsule 

Waste substances are: excess water, salt, urea, ions 


Selective reabsorption:

The process in the kidney where the nephron reabsorbs only the molecules the body needs back into the bloodstream.

Nephron reabsorbs: all of the glucose, some ions, and most water


UREA IS NOT REABSORBED 


-Whatever is left from filtrate forms urine

Components of urine: urea, excess water, excess ions

-made by ultrafiltration and selective absorption 


LIVER:


Assimilation: digested food molecules are converted to other molecules that the body will use (takes place in the liver)


Deamination: excess amino acids that are not needed by the body to make proteins that cannot be stored in the body are broken down by deamination. Deamination is the removal of of the nitrogen-containing parts of amino acids to form urea 


Deamination chemical formula:


4 parts of amino acids are 

-carbon

-hydrogen

-COH

-R group


Urea is formed in the liver from excess amino acids 


Xtra bs:


Cellular waste:

Heat, water, salts, co2, urea

If not released it will lead to death


Factors affecting volume and concentration of urine:

  • Water intake (more water more urine)

  • Temperature (less urine bc loss of bodily fluids due to sweating and urine becomes concentrated)

  • Exercise (increase in urine volume

Urine formation:

Urea transported from liver to kidney, excess waste urea and excess ions combine with excess water to form urine