Download URINE FORMATION- occurs in the nephron: Molecules are

Urinary System Concept Map
After this introductory lesson to the urinary system you and will create a concept map as an
overview of the system. A list of terms is given that you must incorporate into your assignment
but feel free to add terms as needed. You will be required to write in words on the connecting
lines, the relationship that exists between the two concepts that you linked together. A single
concept can have many other concepts linked to it. Be sure to write down the relationship on the
line for full marks. Refer to the rubric on the back of this handout for marking guidelines and to
make sure you’ve fulfilled all the criteria.
The terms that must be included are:
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excretion
kidneys
metabolic wastes
nitrogenous wastes
ammonia
urea
creatinine
renal vein
renal artery
ureter
urinary bladder
urethra
urine
Urinary System Concept Map Marking Details
Exceeds Expectations (5)
Concept map is laid out
nicely on the chart paper.
Format/Organization Terms are arranged into
groups radiating off the
centre concept.
Content
Detail
Presentation
Total: 20 marks
Meets Expectations (3)
Concept map is scattered
across the chart paper.
Terms are arranged into
groups but may not radiate
off the centre concept.
Unsatisfactory (1)
Concept map is scattered
across the chart paper with
no apparent relations.
Terms are not arranged into
groups.
Two or more of the
vocabulary terms are
missing in the concept
map. Two or more of the
relationships linking the
concepts have not been
labeled.
All the relationships
Two or more of the
between the vocabulary
relationships between the
terms are correctly labeled. vocabulary terms are
All the terms are grouped incorrectly labeled. Two
correctly.
or more terms are grouped
incorrectly.
Five or more of the
vocabulary terms are
missing in the concept
map. Five or more of the
relationships linking the
concepts have not been
labeled.
Five or more of the
relationships between the
vocabulary terms are
incorrectly labeled. Five or
more terms are grouped
incorrectly.
All group members
participate in the 2-minute
presentation. Clear
explanation of the
reasoning behind the
grouping of vocabulary
terms on the concept map.
Not all group members
participate in the 2-minute
presentation. Explanation
of the reasoning behind the
grouping of vocabulary
terms on the concept map
is unclear or vague.
All the vocabulary terms
are included in the concept
map. All the relationships
linking the concepts have
been labeled.
Not all group members
participate in the 2-minute
presentation. Clear
explanation of the
reasoning behind the
grouping of vocabulary
terms on the concept map.
URINE FORMATION- occurs in the nephron: Molecules are exchanged between
blood vessels and nephrons. Specifically between the glomerulus and
peritubular capillary network that surrounds the nephron
1. PRESSURE FILTRATION:
The AFFERENT ARTERIOLE supplies the glomerulus with blood. Blood pressure
in the GLOMERULUS forces SMALL MOLECULES such as nitrogenous wastes, H2O,
nutrients (glucose, amino acids, vitamins) ions salts into BOWMAN'S CAPSULE.
Large, non-filterable molecules are unable to pass out of the blood vessels such as
blood cells, platelets, and proteins. These remain in the blood and leave the
glomerulus via the EFFERENT ARTERIOLE. “E for Exit” The small, filterable
molecules that are forced into Bowman's capsule form Glomerular FILTRATE.
2.SELECTIVE REABSORPTION AT THE PROXIMAL CONVOLUTED TUBULE
If the kidneys only did pressure filtration, we would quickly die from water
and nutrient loss. Once the glomerular filtrate is made, the next task of the
kidneys is to reabsorb molecules in the filtrate that the body cannot afford to
lose. Molecules needed by the body include water, nutrients, and some salts The
process of “SELECTIVE reabsorption” is called “selective” because there are
CARRIER MOLECULES that determine what is reabsorbed and what passes
through the tubule; This is done by ACTIVE transport (except for the water, which
is reabsorbed by OSMOSIS). The molecules that are reabsorbed move from the
proximal convoluted tubule to the peritubular capillary network back into the
blood. This is very efficient. Every minute about 1200 mL of blood enters the
kidneys and 1199 mL of that blood leaves. About 250 ml become glomerular
filtrate - most of which is quickly reabsorbed into the blood. Only about 1 mL
becomes urine. Most of the glomerular filtrate gets reabsorbed!!
WHAT GETS REABSORBED?: most H2O, nutrients (glucose, amino acids, vitamin C,
potassium ions…) some salts (NaCl)
A balanced salt concentration in the blood must be maintained. The process of
selective reabsorption ensures this by actively reabsorbing sodium ions while
chloride ions follow passively. The reabsorption of salt by the blood causes the
blood to be hypotonic to the filtrate which attracts water from the filtrate and
causes water from the filtrate to enter the blood! (again, a water-retaining
mechanism).
WHAT DOES NOT GET REABSORBED and therefore SECRETED?: some H2O, wastes,
excess salts. Non-reabsorbed material continues through Loop of Henle.
REABSORTION/SECREATION IN THE LOOP OF HENLE/DISTAL CONVOLUTED
TUBULE
Glomerular fluid is now called Tubular fluid as it enters the LOOP OF HENLE and,
eventually, the distal convoluted tubule. The primary role of Loop of Henle and
distal convoluted tubule is REABSORPTION OF WATER. Over 99% of the water in
original filtrate is reabsorbed by the nephron during urine formation. Much of this
reabsorption is done by OSMOSIS at the Loop of Henle. This CONCENTRATES THE
URINE, making it HYPERTONIC to plasma or blood. The ascending loop of Henle is
IMPERMEABLE to water, therefore, the hypertonic filtrate does not absorb water
from the capillary network! Also, the loop of Henle secretes NaCl into the
surrounding tissue (the renal medulla) to ensure that the neighbouring tissue is
hypertonic to the filtrate. By doing this, the loop of Henle creates an osmotic
gradient.
Na+ ions are actively reabsorbed as their uptake is associated with water
retention (remember, the body does not want to lose or waste water!)
3.
TUBULAR EXCRETION (=TUBULAR SECRETION
Although urine formation occurs primarily by selective reabsorption, tubular
secretion, is also involved. This is an ACTIVE PROCESS by which wastes that were
too big to be filtered out by the earlier process can be added to the tubular fluid
so that they can be excreted in the urine.
Tubular excretion occurs along the distal convoluted tubule: Actively secreted
substances include some chemicals such as penicillin, histamine H+ ions, NH3 fluid
now enters the collecting duct. It is a good thing that the filtrate is HYPOTONIC at
this stage SO THAT H2O PASSIVELY DIFFUSES OUT OF COLLECTING DUCT AND
STAYS IN THE BODY. The tubular fluid, which we can now “OFFICIALLY” call URINE
passes from the collecting duct into the pelvis of kidney, and enters the ureter for
transport to the bladder.
Hypotonic=solution having a lower concentration of solute than another solution, hence
exerting less osmotic pressure than that solution, pertaining to a solution that causes cells to
swell
Hypertonic=solution that increases the degree of osmotic pressure on a semipermeable
membrane, pertaining to a solution that causes cells to shrink
Isotonic=equivalence in osmotic pressure. Specifically used in reference to a solution whose
osmotic pressure is equal to that of a body fluid, such as blood plasma or tears, to which the
solution is compared.
****Read the article and answer the questions below: Information from the article will help
you in your amazing kidney game!
1. The ______________________________supplies the glomerulus with blood?
2. What forces small molecules out of the blood and into the glomerulus?
3. If a molecule is big what happens to it in the blood vessel?
4. What things are contained in glomerular filtrate?
5. Why does material taken out of the blood that is now called glomerular filtrate have to be
put back into the blood?
6. Where does most of the water and glucose from the blood get reabsorbed?
7. What is the primary job of the loop of Henle?
8. How does the loop of Henle do its job?
9. Tubular excretion occurs at WHICH part of the nephron?
10. What is the purpose of tubular excretion?
11. What is it that allows filtration to take place?
12. Do glucose and water enter the filtrate?
Partner 1: ________________________Partner 2: _______________________
The Amazing Kidney Race
After you have answered the question you will use the reading and your notes to create a game.
You probably all remember playing snakes and ladders as kids. Now it’s your chance to create
your own board game using the incredible organ the kidney as your inspiration. You will design
a board game that incorporates the structure and function of the kidney and nephron into the
game. Be creative in the design of your board and your playing pieces! The focus should be on
the path a molecule will take as it travels through the kidney and nephron. You must also create
5 possible scenarios where the movement of the players is either halted or accelerated. On the
back of this handout you are given the rubric detailing assignment of marks. Be sure that your
board game satisfies all the criteria listed. As a guideline, the following items must be addressed
in your board game:
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What are the three main regions of the kidney?
What are the main structures of the nephron?
What are the functions of these structures?
What would happen if some of the structures of the kidney or nephron were not
functioning properly?
On the day you hand in your project I will need:
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Your game board
The playing pieces
A copy of the rules for the game
A detailed description of the 5 scenarios that players will possibly encounter in the game.
Partner 1: __________________________________________
Responsibilities/Input:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Partner 2: __________________________________________
Responsibilities/Input:
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Name____________________
The Amazing Kidney Race Marking Details
Exceeds Expectations (5)
All the components of the
assignment are submitted
(game board, playing pieces,
copy of the rules, 5
Format/Organization
scenarios). Game board is
easy to read and laid out in a
clear and concise manner.
Content
Detail
Creativity/Quality
Meets Expectations (3)
One component of the
assignment is not submitted.
Game board is easy to read
and laid out in a clear and
concise manner.
Unsatisfactory (1)
More than one component of
the assignment is not
submitted. Game board is
difficult to read and laid out in
a confusing manner.
The game board, playing
The game board, playing
The game board, playing
pieces and scenarios
pieces and scenarios fail to pieces and scenarios fail to
incorporate all the questions incorporate one of the
incorporate 2 or more of the
that need to be addressed.
questions that needs to be
questions that need to be
The structure and function of addressed. The structure and addressed. The structure and
the kidney and nephron are function of the kidney and function of the kidney and
the underlying concepts in nephron are the underlying nephron are not the underlying
the design and rules of the concepts in the design and concepts in the design and
game.
rules of the game.
rules of the game.
The scenarios, rules and
The scenarios, rules and
The scenarios, rules and game
game board correctly answer game board incorrectly
board incorrectly answer 2 or
the questions dealing with answer one of the questions more of the questions dealing
the structure and function of dealing with the structure
with the structure and function
the kidney and nephron.
and function of the kidney of the kidney and nephron.
The path the players take
and nephron. The path the The path the players take
during the game follows a players take during the game during the game does not
logical sequence and clearly follows a logical sequence follow a logical sequence and
relates back to lesson
and minimally relates back is not related to lesson content.
content.
to lesson content.
Assignment is presented in
an original manner. Content
is effectively incorporated
into the presentation.
Quality of work is evident.
Total: 20 marks
Assignment is presented in
an original manner. Content
is ineffectively incorporated
into the presentation.
Quality of work is evident.
Assignment lacks originality.
Content is not incorporated into
the presentation. Quality of
work is not evident.