Biology Chapter 13 (Excretion and Hormones) Flashcards
Name the 5 major waste products produced by your cells.
. Carbon dioxide
. Water
. Salts (Minerals)
. Urea
. Heat
What is Excretion?
The removal of toxic materials, waste products and excess materials.
What is one waste product that is not excreted in the body?
Faeces
What is Egestion?
The removal of undigested food
What is Urea?
A nitrogen waste derived from breaking down excess protein and amino acids.
How is the circulatory system connected to the excretory system?
The circulatory system transports metabolic wastes from body cells to various excretory organs.
How does the skin help with the removal of wastes?
. Through sweat from sweat glands.
. We have 2 to 5 million sweat glands.
What is deamination of Amino acids?
The removal of nitrogen-containing part of amino acids to form urea.
How is urine formed?
When the filtered Urea is diluted with water.
What vessel transports Urine from kidney to Bladder?
The ureter.
What is Nephron?
The filter inside the kidneys.
What is the bladder?
A bag that stores urine coming from the kisney.
What is the bladder?
A bag that stores urine coming from the kidney.
What is the vessel that carries the Urine out of the body?
The urethra
Function of the sphincter in the bladder?
It keeps the bladder closed until you go to the toilet.
What are the 4 parts of the kidney?
. Cortex
. Medulla
. Pelvis
. Ureter
What is the Cortex of the liver?
The outer-layer jampacked with filters called nephrons.
What is the Medulla of the liver?
The middle layer which has the tubes carrying filtered wastes to the center of the kidney.
What is the Pelvis of the liver?
Area where all the collecting ducts come together and connect with ureter.
What is the Ureter of the liver?
Transports urine to the bladder.
Function of the Renal artery?
Brings blood containing waste products to the kidney.
Funtion of Renal Vein?
Takes blood away from the kidneys
Function of Convoluted Tubules?
Reabsorption of useful substances happens here; including glucose, most water and some salts.
Function of Bowman’s capsule?
This is where filtration takes place.
Function of Collecting Duct?
Collects urine from nephrons and transports it to the pelvis.
What is Glomerulus?
A ball of capillaries inside the Bowman’s Capsule.
What causes kidney failure?
Traumatic injury, Drugs/Toxins, Infections, High blood pressure, and Diabetes.
What is Kidney failure?
A low rate of filtration caused by the nephrons not working properly in both kidneys.
How is Kidney Failure treated?
Dialysis, Kidney transplant
What is Kidney dialysis?
This is the process of removing wastes and excess fluid from the blood using an artificial kidney machine that filters or washes the blood.
How is kidney dialysis performed?
i) Blood is collected form a vein in the arm and passes along a tube that is semi-permeable.
ii) The Dialysis solution on the other side has to urea and so the urea from the blood diffuses into the solution.
iii) Treatment is required 3 times a week, each lasting 5 hours.
Advantages of the Dialysis Machine?
. Constant medical attention
. Saves lives
. More readily available than transplants.
Disadvantages of Dialysis machine?
. Repeated use daily
. After some years levels can be hard to maintain
. Must follow a strict healthy diet.
Where can a kidney transplant come from?
A donor who is a relative or from someone who has died in the hospital and has given permission for their kidneys to be used.
Where is a transplant kidney placed and why?
In the groin as the original kidneys are not taken out.
Advantages of kidney transplant.
. Sustain life without Dialysis
. Feels better physically
. Diet is less limited
. Don’t see yourself as chronically ill
Disadvantages of Kidney transplant.
. A borrowed kidney will last 9 years without shutting down
. Need immuno-suppressants for life
. Surgery risks (Infection and bleeding)
. Tissue rejection
. Finding a suitable donor (long wait list)
What is Homeostasis?
Involves maintaining a constant environment in the body.
What aspects of our body does Homeostasis cover?
. Tempature
. Water
. Carbon dioxide
. Blood sugar
. Oxygen
Why is Homeostasis inportant?
. Enzyme activity
. Cell size
. Independance form external conditions
How is Enzyme activity affected by Homeostasis?
Enzymes operate over a specific range of conditions; by maintaining the temperature and pH level.
How is Cell size affected by Homeostasis?
Changes in the water potential of the blood will affect the amount of water in the tissue fluids and cells.
How is dependance of external conditions affected by Homeostasis?
Animals with a constant internal environment can maintain a constant level of activity regardless of their environment
Parts of the body involved in Homeostasis.
. Kidneys (Regulate water and minerals)
. Skin (Regulates body temperature)
. Liver & Pancreas (Regulates blood glucose level.
What is Negative feedback?
A self regulating mechanism needed by organisms to maintain their internal enviroment.
How does Negative feedback work?
It works by initiating corrective mechanisms whenever the internal environment deviates from its normal or acceptable level.
At what temperature do the Enzymes in our body work best at?
37 degrees Celcious
What are the receptors linked to thermoregulation?
The Hypothalamus located in the brain.
What happens when skin temperature is too high?
i) Hair on the skin lies flat
ii) Sweating starts
iii) Blood is diverted close to the surface of the skin
What happens to the skin when the temperature is too low?
i) Hair on the skin stand up
ii) Sweating stops
iii) Shivering starts, so that muscles respire more
iv) Blood is diverted from the surface of the skin (Less heat loss through radiation)
What is the term for Arterioles opening?
Vasodilatation
What is the term for Arterioles closing?
Vasoconstriction
