Transcript Kidney Homeostasis

Kidney Homeostasis
By: Marion Paxton and Rosanna Parise
Agenda:
Introduction
 Expectations
 Lesson Sequence
 Assessment and Evaluation
 Activity/Student Lab
 Student Misconceptions
 Demo
 Practical Applications
 Resources

Introduction: The Kidney

Main function: to filter the blood to
remove waste products and to adjust salt
concentrations in the blood

Associated with the excretion of cellular
wastes (urea, uric acid, creatinine)
The Kidney Cont’d

Composed of 3
sections:
◦ Outer cortex
◦ Medulla
◦ Inner pelvis
Kidney Cont’d

In the cortex and medulla, there are
about 1,000,000 nephrons – these act as
filters and are composed of:
◦
◦
◦
◦
◦
◦
Bowman’s capsule
The glomerulus
Proximal tubule
The loop of Henle
Distal tubule
Collecting duct
Picture of the nephron on next slide
The Kidney Nephron
The Kidney Cont’d

Please go to the following interactive site
to learn more about the kidney:
http://www.biologymad.com/resources/kidney.swf
The Kidney Cont’d

Homeostatic mechanisms are in place to
control the levels of water and
electrolytes in the blood

One very important hormone involved in
this is called Antidiuretic Hormone
(ADH)
Expectations

The following are a list of expectations that will be covered through studying Kidney
Homeostasis:

E1.1 assess on the basis of findings from a case study, the effects on the human body of
taking chemical substances to enhance performance or improve health (e.g. the risks and
benefits of taking large quantities of vitamins or amino acids; the effects on the human
body of substances that people use to cope with stress)

E2.2 plan and construct a model to illustrate the essential components of the homeostatic
process (e.g. create a flow chart that illustrates representative feedback mechanisms in
living things)

E2.3 plan and conduct an investigation to study a feedback system (e.g., stimulus response
loop)

E3.1 describe the anatomy and physiology of the endocrine, excretory, and nervous
systems, and explain how these systems interact to maintain homeostasis

E3.3 describe the homeostatic processes involved in maintaining water, ionic, thermal, and
acid–base equilibrium, and explain how these processes help body systems respond to
both a change in environment and the effects of medical treatments (e.g., the role of
feedback mechanisms in water balance or thermoregulation, how the buffering system of
blood maintains the body’s pH balance, the effect of medical treatments on the endocrine
system, the effect of chemotherapy on homeostasis)
Lesson Sequence

Lesson 1: Kidney Structure and Function

Lesson 2: The Nephron: Filtration and Reabsorption

Lesson 3: Homeostasis: Feedback Mechanisms

Lesson 4: Lab: The Physiological Effects of Coffee

Lesson 5: Kidney Transplant Article and Case Study
Lesson 1: Introduction to the Kidney:
Structure and Function

KWL Chart – have students fill in KW now and L
after lesson 5 (self assessment)
Intro Video:
 http://www.youtube.com/watch?v=qxb2_d9ilEw


Group work:
◦ Provide students with basic diagram – have them fill
in the name of each structure
◦ Then, they will complete a T chart on the structure
and function of the following: kidney, renal veins,
renal arteries, urinary bladder, urethra
Lesson 2: The Kidney Nephron:
Filtration and Re-absorption

Teacher demo on passive transport

Youtube video:


http://www.youtube.com/watch?v=glu0dzK4dbU
Interactive Site

http://www.biologymad.com/resources/kidney.swf
• Role play exercise where students are the filtrate and
classroom desks are arranged as the nephron
• Worksheet
Lesson 2: The Kidney Nephron:
Filtration and Re-absorption
Lesson 3:
Homeostasis: Feedback Mechanisms

Introduce hormone ADH

Students investigate ADH feedback loop
(next slide)

They come up with a way to demonstrate
how ADH works to their peers
Lesson 3:
Homeostasis: Feedback Mechanisms
Lesson 4: Lab
The Physiological Effects of Coffee

For this lab, students will design an
experiment that allows them to
investigate one physiological effect of
consuming coffee (e.g. Effects on blood
pressure, urine output, etc.)

Refer to Word document
for a more detailed description
of this lab
Lesson 5:
Kidney Transplant Article and Case Study

Students use an anticipation guide to read an article
about kidney transplants in Canada.

4 corners strategy used to discuss opinions

A class debate about a kidney transplant case study:
Article: “Kidney transplants in Canada: unequal
access”
http://www.cmaj.ca/content/175/5/489.full

Peer and self assessment
Assessment and Evaluation

Lesson 1: KWL Chart – diagnostic and form of
self assessment

Lesson 2: Nephron Worksheet

Lesson 3:

Lesson 4: Lab Report

Lesson 5: Anticipation guide; peer and selfassessment
Student Difficulties

Difficulty:
◦ Students may have difficulty understanding how and why
different substances enter and leave the kidney tubule.

Rectification
◦ Have students watch the youtube video on the function
of the nephron and allow students to use the interactive
website to see where different substances enter and
leave the nephron.
◦ Youtube video:
 http://www.youtube.com/watch?v=glu0dzK4dbU
◦ Interactive website:
 http://www.biologymad.com/resources/kidney.swf
**Note: Refer to summary handout for other rectifications.**
Student Difficulties cont’d

Difficulty:
◦ Some students may have trouble understanding the
feedback mechanism involved in controlling urine
output.

Rectification
◦ Use a flow chart to help students visualize the
feedback mechanism.
◦ Group weaker students with stronger students
during the problem solving activity.
Demonstration

Passive Transport Lab
◦ Students will observe passive transport of a
substance across a membrane
Practical Applications

Effects of steroid use on kidney functioning

Kidney transplants, dialysis and organ
harvesting

Effects of alcohol and caffeine on kidney
homeostasis

Chronic renal diseases
Internet Websites


This video shows how the kidney nephron
functions in great detail.
http://www.youtube.com/watch?v=glu0dzK4
dbU
This is an interactive website that illustrates
how different substances move through the
kidney nephron and how ADH affects the
concentration of urine.
 http://www.biologymad.com/resources/kidne
y.swf

Internet Websites Cont’d
Article “Kidney Transplants in Canada: unequal
access”. This article highlights some of the kidney
transplants problems in Canada i.e. patients dying on
waiting lists, transplants being ineffective if a patient
waits more than 2 years and organ donation rates by
region.
 http://www.cmaj.ca/content/175/5/489.full

This website contains a free downloadable lesson
plan for conducting a class debate on kidney
transplants. All references are British but the lesson
plan can be easily modified for Canadian students.
 http://www.triplescience.org.uk/search/Resource30619.aspx

Internet Websites Cont’d
A great place to access background information on the
kidney:
 http://knight.noblehs.sad60.k12.me.us/content/exploringLife/text/chapter32/con
cept32.2.html


This textbook contains 'The Physiological Effects of Coffee
Lab'. It explains the kidney functions and structure in detail,
describes the role of ADH, and contains a weblink that talks
about the process of hemodialysis. The textbook has a
complimentary website
Blake, Leesa. McGraw-Hill Ryerson Biology 12. Toronto:
McGraw-Hill Ryerson, 2002.
The textbook has a complimentary website:
 www.mcgrawhill.ca/links/biology12
