1) List 3 functions of the excretory system.
2) Explain the term homeostasis.
3) Identify 3 nitrogenous wastes. How are they produced?
4) Differentiate between excretion and elimination.
5) Describe the role of the liver in each of the following: detoxification, bile excretion, urea formation.
6) List the function of each component of the urinary system: kidney, ureters, urinary bladder, urethra.
7) Label the diarams of the kidney and nephron.
8) Give the functin of each part of the nephron.
9) Explain the formation of urine.
10) Why are the lungs also considered to be organs of excretion?
11) What substances are excreted from the lungs?
12) Describe the structure and functions of the two layers of the skin? epidermis and dermis.
13) Describe the two skin glands: sebaceous and sweat glands.
14) List the four main functions of the skin.
15) How is the skin involved in homeostasis?
16) Label the skin diagram.
is the condition of a stable internal environment in an organism.
(glossary of terms)
3) Three nitrogenous
wastes are ammonia, urea, and uric acid. They are formed by the breakdown
of amino acids.
is the removal of unabsorbed and undigested food from the digestive
tract in the form of feces. Excretion is the removal of metabolic
wastes. Since unabsorbed and undigested food never enter the body
cells they are not metabolic wastes.
5) The liver
purifies or detoxifies the blood of harmful or toxic substances.
Any harmful or toxic substances are excreted and the blood put back into
the blood stream.
The bile is produced in the liver and travels to the gall bladder to be excreted.
When excess amino acids are injested, the liver must breakdown these. This produces an amino group (NH2) which is converted into ammonia (NH3) which is converted to urea.
filter metabolic wastes and other substances from the blood, producing
Ureters are two tubes that carry urine to the urinary bladder.
Urinary bladder is the temporary storage place for urine until it is excreted.
is a tube that carries urine from the urinary bladder to outside the body.
7) Be able to label fig 12-7 page 201, it appeared on my test.
9) The formation
of urine ocurrs in the nephrons in two stages, filtration and reabsorption.
Filtration occurs while the blood is flowing through the glomerulus within
Bowman's capsule. Reabsorption brings back all the vital nutrients
to the blood stream such as glucose, amino acids, and salt ions.
10) The lungs
are considered excretory organs because they remove metabolic wastes, specifically
carbon dioxide and water.
from the lungs are carbon dioxide and water.
12) Epidermis is the upper layer of the skin. It is composed of layers of tightly packed epithelial cells. These cells grow rapidly underneath and push existing cells out to the top where they receive less nutrition and die. We call this dead skin. They produce a waterproofing protein called keratin.
Dermis lies below the epidermis and is made up of elastic connective
tissue. It is a thick layer that supports the skin and binds it to
the underlying muscle and bone.
13) Sebaceous glands produce oily secretions that keep the skin and hair soft and provide a protective coating.
consist of tiny coiled tubes that open to the surface of the skin through
hole called pores. Sweat is secreted from here to cool the body off.
14) The functions of the skin are:
15) The skin
is involved in homeostasis by regulating the body temperature. The
mechanisms by which the body maintains a constant temperature are a good
example of homeostatic control. These mechanisms include the constriction
of blood vessels in the skin when it cold and expand when it is hot.
This controls the amount of sweat lost. This is an example of homeostatic
16) Be able to label the skin diagram fig. 12-8 page 203, this also was a question on my grade 11 biology test.
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