This document provides information and guidelines about writing a report on homeostasis. It includes definitions of homeostasis, descriptions of the key components and mechanisms involved in maintaining homeostasis, examples of disruptions to homeostasis, and the adaptive advantages of homeostasis. Students are instructed to research and write a report that describes the purpose, components, and mechanism of a homeostatic control system, explains how balance is reestablished following a disruption, discusses the system's adaptive advantage, and analyzes an example of how a disruption could occur. The document also provides guidance on including citations and creating a bibliography to avoid plagiarism.
Insulin and glucagon help maintain blood sugar levels. Glucagon helps prevent blood sugar from dropping, while insulin stops it from rising too high. Insulin and glucagon work together in a balance and play a vital role in regulating a person's blood sugar levels. Glucagon breaks down glycogen to glucose in the liver.
organic biologically active compounds of different chemical nature that are produced by the endocrine glands, enter directly into blood and accomplish humoral regulation of the metabolism of compounds and functions on the organism level.
Qu’est-ce que l’hypoglycémie – l’hyperglycémie – l’acidocétose et comment intervenir? Quoi faire quand l’enfant diabétique fait de la fièvre ou une gastro-entérite? Exemples des mises en situations.
Insulin and glucagon help maintain blood sugar levels. Glucagon helps prevent blood sugar from dropping, while insulin stops it from rising too high. Insulin and glucagon work together in a balance and play a vital role in regulating a person's blood sugar levels. Glucagon breaks down glycogen to glucose in the liver.
organic biologically active compounds of different chemical nature that are produced by the endocrine glands, enter directly into blood and accomplish humoral regulation of the metabolism of compounds and functions on the organism level.
Qu’est-ce que l’hypoglycémie – l’hyperglycémie – l’acidocétose et comment intervenir? Quoi faire quand l’enfant diabétique fait de la fièvre ou une gastro-entérite? Exemples des mises en situations.
Why is the gut our second brain? Robert-J M BrummerValio
Robert-J M Brummer MD PhD
Professor of Gastroenterology and Clinical Nutrition, director Nutrition-Gut-Brain Interactions Research Centre
Pro-Vice-Chancellor, Örebro University, Sweden
Helsinki, June 15, 2016
2. Achievement Standard
Demonstrate comprehensive understanding involves linking biological ideas about maintaining a stable internal environment in an animal. This
includes at least one of:
a discussion of the significance of the control system in terms of its adaptive advantage
an explanation of the biochemical and/or biophysical processes underpinning the mechanism (such as equilibrium reactions, changes in
membrane permeability, metabolic pathways)
an analysis of a specific example of how external and/or internal environmental influences result in a breakdown of the control system.
A control system that maintains a stable internal environment (homeostatic system) refers to those that regulate:
body temperature
blood pressure
osmotic balance
level of blood glucose
levels and balance of respiratory gases in tissues.
The biological ideas related to the control system includes the:
purpose of the system
components of the system
mechanism of the system (how it responds to the normal range of environmental fluctuations, interaction and feedback mechanisms
between parts of the system)
potential effect of disruption to the system by internal or external influences.
Environmental influences that result in a breakdown of the control system may be external influences such as extreme environment conditions,
disease or infection, drugs or toxins, or internal influences such as genetic conditions or metabolic disorders.
3. Topic Outline
There are three parts to this assessment:
1. Classroom teaching/learning – Introduction to Homeostasis
2. Student research – Completed at HOME or in STUDY using google doc
template, MUST BE finished by 25/8, printed and brought into class on
Monday 25/8. (you can share useful websites but MUST complete the main
points on your own)
3. Report – in class under test conditions with the use of your printed out
research google doc information you will write a report based on a scenario
to do with thermoregulation.
NOTE:
Resubmissions are for minor omissions with no extra time for further research or
teaching and for those on the boarder of grade boundaries only.
6. Homeostasis
Homeostasis - body’s ability to maintain a constant internal
environment.
Required for proper functioning of the body because the enzymes
that control all metabolic activity essential for life, are very
sensitive to changes in their environment.
Thus constant state must be maintained in spite of changing the
external environment.
7. Balancing Act I
The following factors need to be kept in balance:
Body temperature
Water (osmotic pressure)
Blood sugar
Carbon dioxide concentration
Oxygen concentration
pH
Mineral salts
10. What do you know?
Cut and paste the worksheet
provided to match up the
explanation and the organ
responsible
Then draw an arrow to where on
the body the organs are found
12. Negative Feedback
When a condition in the body changes from the norm, a message is sent to a control center
(usually the brain).
The Control centers then instructs effectors, such as glands and muscles, to send a response that
reverses the change.
Works in the opposite direction to the stimulus hence negative feedback and is process by which
homeostasis takes place.
13. Adaptive Advantage
Organisms can adapt to the changing environments and therefore occupy
new/different niches, hence reducing competition
The more advanced an animal’s regulatory systems, the greater its chance of
survival with a changing environment = survival of organism
If metabolic processes can continue despite a fluctuating environment, an
organism is able to inhabit a wider range of habitats and reproduce more
successfully to maintain its population. = survival of species
16. Example 1: Regulation of Blood Sugar Levels
Purpose of the system
Ensures body has sufficient energy (glucose is turned into energy via respiration)
The amount of ATP demanded will fluctuate, and therefore the body regulates the availability
of glucose to maximise its energy making potential.
Too much or too little glucose can damage the retina and brain cells
Components of the system
Pancreas
Islets of Langerhans (pancreatic tissue) contain alpha and beta cells, which secrete the hormones
glucagon and insulin
Adrenal Gland
Secretes adrenalin and cortisol
Liver
Cell membranes
18. Mechanism of the system (how it responds to the normal
range of environmental fluctuations, interaction and
feedback mechanisms between parts of the system)
Normally:
When you eat, glucose goes into your bloodstream and signals the
pancreas to release insulin. This helps the glucose move into the
cells and gives them needed energy.
Low Blood Sugar:
Alpha cells detect low blood glucose and respond by secreting the
hormone glucagon.
Glucagon tells the body and liver cells to break down glycogen to
glucose (glycogenolysis)
Glucose is then released into the blood stream and transported
around the body to where it is required.
A process called gluconeogenesis also takes place in the liver and
this makes new glucose molecules from molecules other than
carbohydrates, for use in the body.
Lipolysis also contributes to increasing the blood glucose level. By
the breakdown of fat (adipose tissue) from body stores into glucose.
19. High Blood Glucose:
Beta cells detect high blood glucose levels and secrete the
hormone insulin.
Cell membranes respond to insulin by becoming more
permeable to glucose, thus glucose is absorbed into the
body cells.
The liver also converts glucose to glycogen
(glycogenesis).
Insulin stimulates the conversion of glucose to fat in
adipose tissue (lipogenesis).
Insulin also converts excess glucose into protein via protein
synthesis.
25. Potential effect of disruption to the system by internal or external influences.
Factors that Affect Glucose Levels:
Alcohol - prevents your body from being able to control your blood sugar as
well as it should. When you drink your liver, pancreas and kidneys are
inhibited from processing blood sugar properly.
Exercise – lowers blood sugars
Diet – increased carbohydrates increases levels of glucose in the body
Time of day – glucose levels increase prior to waking – dawn effect
Sickness and Ill health – increases glucose levels
BMI – body mass index – heavier you are the slower the body processes
glucose
Diabetes – pancreas doesn’t make insulin or body doesn’t process insulin
sufficiently to reduce glucose levels in the blood
26. Effects of disruption to Glucose Levels:
Hyperglycemia
Higher than the normal blood Glucose eg above 110 mg/dL
Overly or excessively thirsty.
urinating more often than usual.
tired, and losing weight without trying.
yeast or fungal infections.
Late symptoms of prolonged, elevated blood sugar levels are blurred vision and possibly numbness in your fingers and
toes.
Severely high levels of blood sugar may cause confusion or a coma
Hyperglycemia
glucose falls below 72 mg/dl
Shakiness, anxiety, nervousness
Palpitations, tachycardia
Sweating, feeling of warmth
Pallor, coldness, clamminess
Dilated pupils (mydriasis)
•.
27. Adaptive advantage of being able to regulate glucose levels:
Increases animals chances of survival as more efficient bodies and more energy results in a fitter
organism
Our body’s primary source of energy is glucose. All of our cells use it, and when there is not enough
glucose available, our body shuts down in a similar way that a car engine stops when the gasoline tank is
empty.
When glucose is properly utilized, our cells produce energy efficiently and our bodies work like a well
oiled machine!
Enables animals to maintain bodies during feast and famine situations
Excess glucose can be stored as fat for later use
Fat can be turned into glucose for use when food is scarce
30. Example 2: Osmoregulation
Water is continually being lost from the body in a variety of ways, sweat and urine. When water is lost
from any of the body fluids, dissolved solutes become more concentrated and water is less
concentrated - this creates high osmotic pressure. When water content increases and solutes are less
concentrated this creates low osmotic pressure.
Changes in osmotic pressure will stimulate responses in the body to ensure water levels are maintained
in optimum amounts.
Purpose of the system
Body relies upon a constant fluid level to ensure metabolic reactions within cells can proceed
Gases, nutrients, ions, hormones and wastes are carried in body fluids
Components of the system
Hypothalamus
Kidneys
Nerves
Pituitary Gland
31. Mechanism of the system (how it responds to the normal range of environmental fluctuations,
interaction and feedback mechanisms between parts of the system)
32.
33.
34. Potential effect of disruption to the system by internal or external influences.
Hyponatremia
too much water
potentially fatal disturbance in brain functions
Marathon runners are susceptible to water intoxication if they drink too much while running.
Dehydration
People who ignore thirst during exercise, or who do not drink fluids properly while working out, often become
dehydrated because of a physical lack of replacement fluids.
Another example of dehydration can occur when temperature become too high
Blood thickens and becomes harder to pump around the body
Body over heats as cannot cool itself by sweating and heat stroke can occur
Adaptive advantage of being able to regulate water levels:
Can survive in range of temperatures and water levels increases chances of survival and niche differentiation
38. Thermoregulation – The Basics
Temperature is regulated by the
hypothalamus via the blood
Body temperature is affected by the
external environment, amount of exercise
(respiring muscles create more heat), BMI,
illness, hydration
Changes in blood temperature result in a
NEGATIVE FEEDBACK RESPONSE
40. Too Hot?
Nervous impulses send messages:
to the sweat glands which start to
sweat in order to lower the body
temperature through evaporation,
blood vessels dilate to lose heat
through conduction
breathing rate increases (brings
more cooler air into body)
Muscles relax lowering skin hairs
letting more air flow across skin to
lose heat by convection and
evaporation
No shivering
41. Too Hot?
If this is ineffective at cooling the body goes into a HYPERTHERMIC STATE
Resulting in heat exhaustion 37’C – 39’C
Resulting in heat stroke over 39’C
Often dehydration also occurs at the same time
Signs:
Red skin, sweating, fever, diorientation
Treatment:
Cooling blood and constricting blood vessels by submersing body in ice water
Stretch body out to increase surface area in contact with cool air
Move into shade
Remove clothing
42. Too Cold? Nervous impulses send messages:
to the sweat glands which stop any sweating
blood vessels constrict to prevent the loss of heat
through conduction
Blood circulates near core and away from extremities
breathing rate decreases
Glands secrete adrenaline and thyroxin to increase
metabolic rate
metabolic rate increases (reactions usually create
heat)
Muscles shiver – respiration creates heat and friction
Muscles contract to make hairs stand up and trap warm
air against the skin
43. Too Cold?
If this is ineffective at heating the body goes into a HYPOTHERMIC STATE
When core body temperature drops below 35’C
Metabolic activity slows
Signs:
Shivering, skin looks blue (especially lips)
Slowing of heart rate, breathing rate, blood pressure decreases
Confusion, difficulty walking
Frost bite, chill blains
Treatment
Shelter, more dry clothing, warm drinks – not alcohol
Hot water bottle
45. Internal Assessment Requirements
a description of the purpose and components of this homeostatic control system, which may
include annotated diagrams or models
an explanation of the mechanism of this control system, i.e. how and why it responds to the
normal range of environmental fluctuations, the interaction and feedback mechanisms between
parts of the system
How they work together
an explanation of how balance is re-established following the potential effect of one specific
disruption to this control system by internal or external influences in the scenario below (Student
Resource A), e.g. extreme environmental conditions, disease or infection, drugs or toxins, genetic
conditions, or metabolic disorders.
a discussion of the significance of this control system in terms of its adaptive advantage
an explanation of the biochemical and/or biophysical processes underpinning the mechanism of
this control system, e.g. equilibrium reactions, changes in membrane permeability, metabolic
pathways
an analysis of a specific example of how external and/or internal environmental influences, e.g.
extreme environmental conditions, disease or infection, drugs or toxins, genetic conditions, or
metabolic disorders, may result in a breakdown of this control system.
46. Bibliography
A bibliography is an alphabetical list of all sources
you consult or use for projects, reports, research,
etc., including–
books
magazines
newspapers
CD-ROMs
websites
interviews
encyclopaedias
video clips
images (pictures)
47. Why do we need a bibliography?
To acknowledge our sources
show where we found the information
To give our readers information to
identify and consult our sources
To make sure our information is accurate
To show academic honesty
48. Cheating
This is called plagiarism (using another person’s words, pictures
or ideas without giving them credit).
To avoid plagiarism, we give credit to our sources by citing
them in our bibliography.
49. Paraphrasing
Learn to borrow from a source without plagiarizing.
A paraphrase is...
your own rendition of essential information and ideas expressed by someone
else, presented in a new form.
one legitimate way (when accompanied by accurate documentation) to borrow
from a source.
a more detailed restatement than a summary, which focuses concisely on a single
main idea.
Paraphrasing is a valuable skill because...
it is better than quoting information from an undistinguished passage.
it helps you control the temptation to quote too much.
the mental process required for successful paraphrasing helps you to grasp the
full meaning of the original.
50. 6 Steps to Effective Paraphrasing
1. Reread the original passage until you understand its full meaning.
2. Set the original aside, and write your paraphrase on a note card.
3. Jot down a few words below your paraphrase to remind you later how you envision using this material. At the
top of the note card, write a key word or phrase to indicate the subject of your paraphrase.
4. Check your rendition with the original to make sure that your version accurately expresses all the essential
information in a new form.
5. Use quotation marks to identify any unique term or phraseology you have borrowed exactly from the source.
6. Record the source (including the page) on your note card so that you can credit it easily if you decide to
incorporate the material into your paper.
51. Example of Paraphrasing
The original passage:
Students frequently overuse direct quotation in taking notes, and as a result they overuse quotations in the
final [research] paper. Probably only about 10% of your final manuscript should appear as directly quoted
matter. Therefore, you should strive to limit the amount of exact transcribing of source materials while
taking notes. Lester, James D. Writing Research Papers. 2nd ed. (1976): 46-47.
A legitimate paraphrase:
In research papers students often quote excessively, failing to keep quoted material down to a desirable
level. Since the problem usually originates during note taking, it is essential to minimize the material
recorded verbatim (Lester 46-47).
An acceptable summary:
Students should take just a few notes in direct quotation from sources to help minimize the amount of
quoted material in a research paper (Lester 46-47).
A plagiarized version:
Students often use too many direct quotations when they take notes, resulting in too many of them in the
final research paper. In fact, probably only about 10% of the final copy should consist of directly quoted
material. So it is important to limit the amount of source material copied while taking notes.
52. Exercises
Directions: On a separate piece of paper, write a paraphrase of each of the following
passages. Try not to look back at the original passage.
1. "The Antarctic is the vast source of cold on our planet, just as the sun is the source of our
heat, and it exerts tremendous control on our climate," [Jacques] Cousteau told the camera.
"The cold ocean water around Antarctica flows north to mix with warmer water from the
tropics, and its upwellings help to cool both the surface water and our atmosphere. Yet the
fragility of this regulating system is now threatened by human activity." From "Captain
Cousteau," Audubon (May 1990):17.
2. The twenties were the years when drinking was against the law, and the law was a bad
joke because everyone knew of a local bar where liquor could be had. They were the years
when organized crime ruled the cities, and the police seemed powerless to do anything
against it. Classical music was forgotten while jazz spread throughout the land, and men like
Bix Beiderbecke, Louis Armstrong, and Count Basie became the heroes of the young. The
flapper was born in the twenties, and with her bobbed hair and short skirts, she symbolized,
perhaps more than anyone or anything else, America's break with the past. From Kathleen
Yancey, English 102 Supplemental Guide (1989): 25.
53. 3. Of the more than 1000 bicycling deaths each year, three-fourths are caused by head injuries. Half of those
killed are school-age children. One study concluded that wearing a bike helmet can reduce the risk of head
injury by 85 percent. In an accident, a bike helmet absorbs the shock and cushions the head. From "Bike
Helmets: Unused Lifesavers," Consumer Reports (May 1990): 348.
4. Matisse is the best painter ever at putting the viewer at the scene. He's the most realistic of all modern
artists, if you admit the feel of the breeze as necessary to a landscape and the smell of oranges as essential
to a still life. "The Casbah Gate" depicts the well-known gateway Bab el Aassa, which pierces the southern
wall of the city near the sultan's palace. With scrubby coats of ivory, aqua, blue, and rose delicately fenced
by the liveliest gray outline in art history, Matisse gets the essence of a Tangier afternoon, including the
subtle presence of the bowaab, the sentry who sits and surveys those who pass through the gate. From Peter
Plagens, "Bright Lights." Newsweek (26 March 1990): 50.
5. While the Sears Tower is arguably the greatest achievement in skyscraper engineering so far, it's unlikely
that architects and engineers have abandoned the quest for the world's tallest building. The question is: Just
how high can a building go? Structural engineer William LeMessurier has designed a skyscraper nearly one-
half mile high, twice as tall as the Sears Tower. And architect Robert Sobel claims that existing technology
could produce a 500-story building. From Ron Bachman, "Reaching for the Sky." Dial (May 1990): 15.
54.
55.
56. Now What?
Now you have a basic understanding of Homeostasis and have seen two examples of the type
of information you need to find and explain.
Next you need to go to the wiki and complete the rest of the pre learning activities, while
you do these you need to be filling in the research table in google docs
Any questions not completed after completing the wiki prelearning you will need to go and
find the answers to on your own
Print off the completed google table and bring it to class
Use your notes to complete the report write up based on a scenario on thermoregulation
