Download homeostasis - Mr. Shanks` Class

HOMEOSTASIS
T.A. Blakelock High School
Grade 12 Preparation Biology
\
Student:______________________ Date:___________________
Teacher:______________________ Room:__________________
Period:_________
UNIT 4 HOMEOSTASIS
I. INTRODUCTION
A. Definition – a process of maintaining a constant ____________________ environment
despite changes in the____________________ environment
B. Feedback Loop
1.
a feedback loop is any system in which part of an _____________ of the system
2.
eg. Ecosystems
is connected back into one of its _____________.
in an ecosystem in which weasels ___________ mice we have a feedback loop
if the weasels eat more mice then there are __________ mice to eat which will result in fewer weasels over time
if there are fewer weasels, there will be _________ mice  more food for weasels and more weasels
3. eg. thermostat
Cool room
3.
Warm room
Parts of a feedback loop
a.
_________________
- part that detects the difference
a.
_________________
- part that detects & manages the response
b.
_________________
- part that effects a change
c.
_________________
- the effect of the regulator change
5. ___________________ feedback – a system that is activated to restore the original condition
6. ___________________ a system which is designed to amplify a small effect
eg keep room at 20oC
eg. contractions at childbirth
C. Thermoregulation in humans – maintaining the body at 37oC regardless of outside conditions
too high
Body temperature
too low
-the blood passes through the ___________________ arteries in the neck on the way to the hypothalamus in the ___________
if this blood is cooled, you feel cool and if this blood is warm, you feel warm
eg. a scarf keeps the neck warm & so you feel_____________
eg. when you are hot, a wet cloth around the neck makes you feel ____________________________
II) HORMONES & THE ENDOCRINE SYSTEM
Hormones  chemicals released by cells in__________________ of the body
that affect cells in______________________ of the body
_______________
-__________________________
-these secrete hormones directly into the _________________
_______________ - __________________________
-hormones go to ___________ cell
______________________
-these are cells with receptors for the hormones
-a hormone may have ___________ specific target cell
or it may target _______________ cell
Steroid hormones
[see next page]
Protein hormones
[see next page]
The Master Gland – the Pituitary Gland
[pg 392 and pg 424]
- the pituitary gland is located under the _______________________,
the area of the _____________ associated with homeostasis
- there are two _______________ of the pituitary,
the ____________________lobe stores & releases hormones
the ____________________lobe produces many hormones
HORMONE
Anterior lobe
thyroid stimulating
hormone
[TSH]
adrenocortiotropic
hormone
[ACTH]
somatotropin [STH]
or growth hormone [hGH]
follicle stimulating
hormone
[FSH]
lutenizing hormone
[LH]
prolactin [PRL]
Posterior lobe
Oxytocin [OCT]
antidiuretic hormone
[ADH]
TARGET
PRIMARY FUNCTION
Parathyroid
parathyroid hormone
[PTH]
Adrenal Cortex
glucocorticoids (eg
Cortisol)
mineralocorticoids
(Aldosterone)
gonadocorticoids
Adrenal Medulla
Epinephrine
Norepinephrine
Pancreas
Insulin
Glucagon
Ovaries
Estrogen
Progesterone
Testes
Testosterone
Notes
B. Steroid hormones
1.
3.
4.
2.
5.
6.
7.
8.
9.
C. Protein hormones
4.
1.
3.
5.
2.
6.
7.
E. Blood glucose control
1. Levels
the goal is to maintain the level of blood glucose within a _______________________
if there is too__________________ blood glucose,
the body cells will not be able to get enough in and so will be ___________________
if there is too __________________blood glucose
the body cells will not be able to get enough in and so will be ___________________
2. Hormones
the hormones __________________ and __________________ are the major controllers
the hormones __________________ and __________________plus __________________
are also involved in control at a minor level
3. Details of Feedback Loop
4. Insulin’s effects
[see diagram on next page]
3. Major hormones affecting blood glucose
high
blood glucose
low
INSULIN ACTIONS
(directed towards reducing blood glucose levels)
CONSEQUENCES OF A LACK OF INSULIN
stimulates ___________________________
into cells thus reducing blood glucose
hyperglycemia - glucose ___________________ cells
and the osmotic effect of glucose leads to damage to
eyes & kidneys
stimulates ____________________________
by increasing cell amino acid transport
________________________________ is broken
down to release amino acids which are used to make
glucose - leads to muscle wasting
_____________________ liver gluconeogenesis (i.e.
the production of glucose from non- carbohydrate
sources like protein and fats
______________________ are broken down to convert
lipid to glucose [lipolysis]
diabetic ketoacidosis - breakdown in fat cells leads
inhibits ______________________ breakdown
to production of free _______________ and
___________________________bodies.
Can lead to coma and death.
inhibits _____________________________
breakdown and stimulates glycogen synthesis
5. Diabetes – the ____________ of blood glucose homeostasis
1. Type I Diabetes
a. person fails to produce sufficient ______________________
b. insulin must be _____________________to the system
2. Type II Diabetes
a. the pancreas produces insulin but body cells do not _____________
b. the body then produces ___________________ insulin
c. eventually, beta-cells _____________ and ______ more insulin is made
d. to prevent this, a person MUST manage their ____________________
e. Blood sugar control: Can diet help?
1. Avoid sugar and foods high in ____________.
6. Bedtime snack that offers ____________.
2. Eat mostly ______________ carbohydrates.
7. ________ daily.
3. Emphasize foods high in dietary ____________.
8. Keep _____________ intake low.
4. Keep your diet low in ________.
9. Keep ____________ intake low.
5. Eat more ____________ meals evenly throughout
the day.
6. Short term changes in Blood sugar
a. blood glucose is regulated over time by _____________________ & _______________________
but sometimes the body needs a sudden burst of blood glucose
b. these responses are called ____________________ responses and they elevate blood glucose
only, there is no hormone that lowers blood glucose in these responses
c. because this is ___________________________ a feedback loop stress can continue
and problems will result [pg 389 Table 2]
d. stress responses
Stress sensed by brain
Hypothalamus responds
Short term
Long term
_______________________
stimulate
releases ACTH to stimulate
Adrenal gland
Adrenal gland
______________
_
_________________
Epinephrine &
nor-epinephrine
released
Glucocorticoids
released
Glycogen
___________
Amino acids
_______________________
Fats
______________________
Fatty acids
______________________
Blood glucose
Blood glucose
The glycemic index (GI)
a numerical system of measuring how much of a rise in circulating ____________ a carbohydrate triggers
the _________________ the number, the greater the blood sugar response.
Food type
Food type
GI
roasted peanuts
milk chocolate
skim milk
white rice
GI
french fries
baked potato
potato chips
dates
fresh pineapple
Blood glucose over time for different conditions.
B
L
O
O
D
B
C
D
G
L
U
C
O
S
E
A
0
1
2
3
4
5
TIME
A- _______________ response because blood glucose stays within a ______________________
B. ___________________ response because blood glucose does respond to hormones,
but is __________ to do so
C. ____________________ response / _______________ insulin because blood glucose
is falling _____________________
D. _____________________ response / Insulin at ____________ because blood glucose
does fall ______________________
The hunger hormone: Ghrelin
Cells in the _________________ secrete ghrelin.
The hormone ghrelin stimulates _________________.
Insulin and leptin __________________ appetite.
The rise in blood sugar following a meal causes an increase in _______________.
The rise in insulin depresses ghrelin and so the desire to eat more is ____________.
People with lower insulin levels suppress ghrelin ____________
and so are hungrier ___________ often.
Fat cells secrete ________________ which decreases ghrelin levels.
Basically having __________ body fat signals the body to accumulate ____________ extra fat.
Eating the same amount of calories of _______________ as of carbohydrate results
in less ______________ of ghrelin.
This means that a diet high in fat leaves you _______________!
Not all __________________ are equal at suppressing ghrelin.
Drinks sweetened with _________________ suppress ghrelin 50% as much
as those sweetened with ______________.
People who drink _________________ drinks are more likely to choose _______________ foods to
accompany them and ghrelin may be involved in this.
When people diet, their ghrelin levels ________________ as the body tries to replace lost calories.
Surprisingly, people with naturally high blood levels of ghrelin tend to be ________________ than those
with lower levels.
People who are obese tend to have less _________________ ghrelin levels, so that eating does not
reduce their desire to eat more.
A lack of __________________ has been shown to alter people’s eating habits.
Just two nights of getting only 4 hours of sleep increased ghrelin levels by almost __________.
Researchers are working on ___________ to reduce ghrelin levels as possible ‘diet pills’.
III] KIDNEY and WASTE EXCRETION
A] Macronutrients & wastes
1. Carbohydrates
a. formula is [______________]n
b.
break down into __________ and ____________ which are exhaled
2. Lipids
a. formula involves ____, ____ and a few ______
b.
converted to ______________ or pyruvate
& breakdown into ______ and _________
exhaled
3. Proteins
a. formula involves_____, _____, _____ and ______
b.
breakdown into __________________ and then amino group is removed
before converted to _______________,
________________
which breakdown into ____________ and ____________
c.
the -_______ or amino group is a problem
it is ______________
d. amine wastes are combined with ____________ as follows to form _________
-NH2
+
-NH2
+ CO2
_________ + ________ + CO2
O
//
H2N – C – NH2
______________
B] Goals of the kidney
1. filter as much blood as possible – ______________ per minute
2. conserve the ______________ and ________________ in the blood
3. retain ________________ in the body
4. retain as much _________________ as possible
5. eliminate the _____________ and other ______________ from the blood
6. be able to _____________ system to account for _________________ in dietary water, proteins,
minerals
C] The parts of the system
Diagram 1 Urinary system & Kidney parts
D] Parts of the nephron
Diagram 2
E] Concept of Countercurrent System
1. the countercurrent system is similar to an uncontrolled ______________feedback loop
2. it depends on the fact that as ___________________ is pulled out of the decending arm of the Loop of
Henle by the ______________________, the concentration of the remaining solution changes
A Loop of Henle is at _____________________
No __________________ or
___________________ is occuring
B Ascending arm is pumping out _______________
300 mol/L
The _____________________ tissue surrounding the
Nephron now has a _____________sodium concentration
than the nephron
300 mol/L
C The higher concentration of sodium outside the
Nephron descending arm causes _______________
to diffuse out of the ___________________ arm of
the nephron.
D. As water diffuses out of the descending arm, the
concentration of sodium remaining _______________
300 mol/L
This means that sodium pumping by the ascending
arm creates a ____________________gradient
outside the nephron
300 mol/L
4. This countercurrent eventually builds up to a maximum level of ______________ mol/L
Complete countercurrent set-up for the human nephron.
F. The value of the counter current system
1. Most of the water will be removed at the ______________________
2. More water will be removed at the ___________________
3. The counter current system is designed to recover additional water from
the __________________________
4. It does this by creating a _____________________________ in the tissues outside the
collecting duct
and then water will move from the area of _____________ concentration
in the _________________ to an area of low water concentration in the interstitial fluids.
G. Achieving the goals of the kidney
1. Filtering
a. The blood from the _______________ enters the glomerulus
under ___________ pressure.
b. All ___________________ molecules and cells stay in the blood,
all ___________________ molecules pass through.
c. The Bowman’s capsule therefore receives __________________ +
_________________ molecules now called _____________.
d. The NaCl concentration is _____________ umol/L.
[because ________ is also pumped out of the nephron here]
2. Retaining glucose and amino acids
a. The cells in the ____________________________actively transport glucose &
amino acids out of urine.
b. ________ follows these molecules out of urine due to the concentration gradient.
c. The NaCl concentration of the urine is ________ _______ umol/L.
2. Retaining sodium
a. Pumps in the _______________ arm of the Loop of Henle pump out NaCl.
b. Due to the ______________system this means that the level of NaCl rises to as
high as _____________ umol/L in the urine and surrounding tissue.
c. By the top of the ascending arm, there is _________ umol/L in the urine.
d. Sodium / potassium pumps in the __________________________ and the
_________________________ will pump additional sodium out of the urine.
3. Retaining water
a. About ____________% of the water leaves the urine in the proximal tubule
due to glucose & amino acid gradients.
b. _______ % of the water leaves the urine in the descending arm
due to the sodium gradient.
c. 0-10 % water leaves the urine in the _______________________
due to the sodium gradient
d. Remember  water can never be ____________________
it only moves due to a _______________________ gradient
4. Removing urea and wastes from the body
a. The urea is dissolved in the __________________ and therefore enters through the
Bowman’s capsule.
b. Some additional wastes are added at the distal tubule by ____________.
c. In cases of severe dehydration, the urea ____________ out of the urine
d. _____________ moves out of the urine due to the [gradient]
5. Controlling the system over a range of conditions..........._____________________
hormone notes will come from student presentations
IV] THE NERVOUS SYTEM
1. The Nerve Cell
NAME
FUNCTION
1
DENDRITES
2
BODY OF CELL
3
NUCLEUS
4
SCHWANN CELLS
5
NODES OF RANVIER
6
AXON
7
AXON TERMINAL
8
TERMINAL BOUTON
9
AXON HILLOCK
2. How Neurons Work
Na/K
pump
Na+ gate
K+ gate
inside of neuron
outside of neuron
1. The Na/K pump
- pumps 2 _____ in and 3 _____ out of the neuron
2. The K+ gate
- allows K+ to ________________ move out of neuron
3. The Na+ gate
- usually these are ____________________________,
and so only allows some _______ to move back into neuron
4. The result
- there are more ________ ions outside of neuron which gives it
a ________ charge outside
- because there are _____ ions equally inside and out, the inside of the
neuron now has a ___________ charge after some of the Na+ ions
have moved outside
- the net result is a _________ mV negative charge inside the neuron compared
to outside
3. PROPAGATING SIGNAL ALONG NEURON
A. Resting potential
B. Stimulus
C. Propagating signal
D. Further propagation of signal
4. ACTION POTENTIAL
+40 mV
C
0 mV
MILLISECONDS
B
-70 mV
A
D
A
E
A. RESTING POTENTIAL
- the Na/K pumps are ________________
- Na+ gates are ____________________
B. DEPOLARIZING
- the Na/K pumps are ______________
- the Na+ gates are ________________
C. REPOLARIZING
- the Na/K pumps are _______________
- the Na+ gates are _________________
D. HYPERPOLARIZATION - the Na/K pumps are ________________
- the Na+ gates are _________________
- extra _______ ions are pumped out, making a larger electrical difference
E. REFRACTORY PERIOD - the time during which the neuron____________ respond to a new signal
F. THRESHHOLD VALUES - a neuron is either ON or OFF, there are ________________ signals
- a stronger stimulus results in the sending of________________ signals
5. SALTATORY CONDUCTION - in mylenated cells
A. RESTING POTENTIAL
B. STIMULUS
C. PROPAGATING THE SIGNAL
D. FURTHER PROPAGATION OF SIGNAL
6. PROPAGATING A SIGNAL ACROSS A SYNAPSE
synaptic cleft
2
7
axon
dendrite
4
1
3
4
5
6
2
1. INCOMING ELECTRICAL SIGNAL
2. CALCIUM CHANNELS
-arrives at the _________________ end of the synapse
-are triggered to _______________ and let Ca2+ ions ___________the axon
3. PRE-SYNAPTIC VESICLES-the Ca2+ causes pre-synaptic vesicles to move to the ______ of the axon
4. NEUROTRANSMITTER
-the pre-synaptic vesicles release _______________ [acetylcholine] into the synaptic cleft [space]
5.
RECEPTORS
-the neurotransmitter________________ to receptors in the dendrite
6.
OUTGOING ELECTRICAL SIGNAL
-the neurotransmitter / receptor complex [N/R complex]______________________
an electrical signal in the dendrite
7.
ENZYME
- an enzyme [acetylcholinesterase] is released from the dendrite to get rid of ________________
and stop the N / R complex from initiating another ___________________________
7. NEUROTRANSMITTERS
NEUROTRANSMITTER
LOCATION
FUNCTION
ACETYL CHOLINE
SEROTONIN
NOREPINEPHRINE
BETA-ENDORPHINS &
ENKEPHALINS
DOPAMINE
GLYCINE & GABA
GLUTAMATE
Anatomy of The Brain
The brain is the organ that controls the conscious (and most unconscious) aspects of the central nervous
system.
It acts as the control centre of the body and it is the seat of consciousness. Understanding the brain helps
us understand how we think and, ultimately, who we are.
Philosophies of the Brain
There are various philosophies that have been put forward to describe the importance of the brain in
relation to the human consciousness, and that extremely difficult concept to define, the soul.
Where do you think the human soul lies? Is it separate from the body or part of it?
Some Psychological Perspectives
Structuralist
The viewpoint that consciousness arises exclusively from the components of the brain, meaning that there
is no consciousness, per se, but that your experience is simply a collection of the reaction of many different
neurons interacting with one another to create the experience of ‘consciousness’.
Functionalist
The viewpoint that consciousness is not as important as what the brain does(its functions), and that
consciousness arises as product of these functions.
Gestalt
Consciousness is a product of the entire activity of the brain, an cannot be broken down into smaller parts,
as the mind often attempts to make order where the is none as it sees the ‘big picture’.
Behaviourism
Consciousness is too complex a problem to attempt to understand through its parts, so the only thing that
can be reliably studied is the behavior of the subject and any conclusions regarding consciousness should
be avoided.
Let’s look at the actual structure of the brain, and what scientists have been able to identify about the
functions of the parts of the brain.
Additional Notes:
V] THE HEALTHY IMMUNE SYSTEM
A. Non-specific Mechanical Defenses
1a. In order to cause disease, microorganisms must first ________________ the body in some way.
b. The __________________protects us from surface pathogens.
2a. Tears, saliva and mucus help ________________________ pathogens
b. and contain mild______________________ (bacteria-killing) chemicals.
c. If pathogens enter through the air way they are trapped in a layer of___________________
They may be removed through the continuous, wave-like motion of ____________________
moving dirty mucus up to where it can be _____________,
____________or ________________
B. Non-specific Innate Immune Responses
1a. several types of ____________________ (white blood cells) that attack and eliminate
anything they recognize as _______________________
b. ________________________ will engulf or eat the invading cells
c.
____________ surround invading cells & release ___________ that destroy the invader & themselves
2. ________________ causes more fluid in an area which allows the entry of other immune cells
and chemicals into the infected area and helps _________________ the infection
3. _____________ raises body temperature over 40oC which is less favorable to ___________ replication
4. ___________________ (a chemical released by a virus-infected cell),
signals neighboring cells to produce _________________________ substances
5. _____________________ (a cascade of 20 anti-infective proteins) released when the first protein in
the cascade contacts the cell wall of certain bacteria and fungi
a. the complement may surround and _________________ an invader
b. the complement may ___________________ the cell membrane of the invader
c. the complement may ____________ the invader and _________________ a macrophage
C. Specific Immune Responses
1. Cell-mediated immunity by ______________
a. They are called ‘T cells’ because they mature in the _______, high in the chest behind the breastbone.
b. The process starts when a _________________ engulfs the invader
and processes an ___________ [a specific surface component of the pathogen, usually a protein].
c. The macrophage displays the antigen fragments combined with a Major Histocompatibility Complex
[______] on the macrophage _________________
antigen
d. A receptor on a circulating, resting ____________ recognizes the antigen-protein complex & binds to it.
e. The binding process causes the helper T cell to activate the cytotoxic T cell [or ________________l]
so that it can attack and destroy the ____________ The killer T cell does ____ attack the pathogen.
f. The helper T cell also releases _______________ which attract other T cells and B cells
g. The body also releases ____________________ that will calm the body
and shut off the immune response.
2. Humoral response – B cells
a. B cells are ______________________ that grow to maturity in the ____________________
b. B cells produce ____________________ that circulate in the blood and lymph streams
and attach to foreign _____________ to mark them for ________________ by other immune cells.
c. Antibodies are _______________ with the same basic Y shape but with a special region that is
____________________ to target a given antigen.
d. The variety of antibodies is very large. Different antibodies are destined for different purposes.
i] Some _________ the foreign invaders to make them attractive to the circulating scavenger cells,
_________________, that will engulf an unwelcome microbe.
ii] Some antibodies _______________ with antigens and activate a cascade of nine proteins,
known as __________________, that have been circulating in inactive form in the blood.
Complement helps _________________ foreign invaders and remove them from the body.
ii] Still other types of antibodies block ________________ from entering cells.
e. The final group of B cells are the ____________ cells that retain the information about the geometry of
an antigen so that on a subsequent exposure, the body will ‘recognize’ the invader
f. Activation of B cells to make antibody
The B cell uses one of its _______________________ to bind to its matching antigen,
which the B cell ________________________
The B cell then displays a piece of the antigen, bound to a MHC protein,
on its cell _________________________
This whole complex then binds to an activated ___________________________
This binding process stimulates the transformation of the B cell
into an_________________________-secreting plasma cell.
D. PROBLEMS IN THE IMMUNE SYSTEM
1. ALLERGIES
a. a foreign_________________ is recognized as an invader and the body responds to its presence
b. basophil cells [WBC] release ____________________
c. histamine makes capillaries more _________________ to allow WBC to leave & find invaders
d. as an indirect result tissues ________________l – this may be annoying or even life threatening
2. AUTOIMMUNE DISEASES
a. the self / non-self system breaks down & __________ antigens are treated as ____________
b. this is usually the result of an injury to specific cells and does ______ affect ______ self proteins
c. or it is possible that a few _____________________ attack your cells
and ________________________________ fail to control them
d. either way, when the suppressor T cells do not control ____________ --> autoimmune disease
e. eg. type I diabetes – your own killer T cells attack your beta cells in the Islets of Langerhans
multiple sclerosis – you attack your own myelin sheath cells
3. Leptin effect on immune system
a. ______________ cells secrete leptin
b. Leptin suppresses the _________________ response
c. People with more body fat secrete _____________ leptin
d. Therefore, people with more body fat have a ___________________________ immune system
e. These people will heal more ___________________ after surgery
F. PASSIVE & ACTIVE IMMUNITY
1. Passive immunity
a. direct passage of ____________________ into a person
b. _____________________ passes antibodies into baby from the mother
c. _________________________ passes transfer factor – protein that helps
T cells & B cells recognize _____________________
d. a __________________________ shot is a shot of antibodies
2. Active Immunity
a. this is when something is _________ into the body to trigger a T cell and B cell response
b. what is injected? -__________ pathogens
- ____________ of a pathogen
- _______________ pathogens eg. cowpox for smallpox
- ___________________ of the pathogen
c. problem – what if the pathogen changes its______________?