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Transcript
Human Systems
Let’s talk digestion
Pick a digestive organ from the bowl.
List 5 amazing facts about your assigned
organ.
Full length digestive system
• Include all parts involved in digestion
• Write the functions of each part that pertains
to digestion
• List the macromolecules we eat with the
molecules we get from them.
• What enzymes work where and on what
Why do we need to digest food?
• To get the nutrients needed for our body to
function by making it small enough to pass
through our cell membranes.
– Major events of digestion:
•
•
•
•
Ingestion
Digestion
Absorption
Transport
Making molecules your own
• Most of the foods you eat are composed of plant
or animal cells.
• When we digest foods we break them down into
their smallest components (by way of hydrolysis).
• These components then can be reassembled into
larger molecules that are useful to our bodies.
Molecules we eat to get the
molecules we need
Molecule type
Molecular form ingested
Molecular form after
digestion
Protein
Protein
Amino acids
Lipids
Triglycerides
Glycerol & fatty acids
Carbohydrates
Polysaccharides, disaccharides,
monosaccharide
Monosaccharide
Nucleic acids
DNA, RNA
Nucleotides
The roles of enzymes during digestion
• You have certain enzymes for specific food types.
– They act as catalysts for reactions
• They help a reaction proceed at high rates in lower
temperatures.
• Below are some examples of digestive enzymes
Enzyme type  Salivary amylase
Pepsin (a protease)
Pancreatic lipase
Source
Salivary glands
Stomach cells
Pancreas cells
Substrate
Amylose (starch)
Proteins
Lipids
Products
Maltose & glucose
Amino acids
Glycerol & fatty acids
Optimum pH
Neutral (pH 7)
Acidic (pH 3)
Neutral (pH 7)
Digestive system (alimentary canal)
Alimentary canal
consists of:
•Mouth
•Oesophagus (esophagus)
•Stomach
•Small intestine
•Large intestine (colon)
•rectum
Oesophagus (esophagus)
• Food is first chewed by the mouth with the help of saliva
which carries amylase enzymes and is then swallowed
down the oesophagus.
Food travels down the
oesophagus by a
sequential series of
smooth muscle
contractions: peristalsis
Stomach
• Food is held here for a period of ~2hrs.
• This is so gastric juices have a chance to mix the food.
– pepsin is most effective in lower pH’s so the hydrochloric acid not only
breaks down food, & kills bacteria, but provides an environment for
pepsin to be active. This is initial stages of protein digestion.
Helps breakdown proteins
Mucus lines the inside of the stomach to prevent damage that
may be causes by the hydrochloric acid
Small Intestine
• When food finishes in the stomach it is
deposited into the 1st part of the small
intestine called: duodenum
Final stages of
digestion of lipids,
carbohydrates,
proteins, & nucleic
acids, plus absorption
of nutrients.
Trypsin (a protease), lipase, &
bicarbonate
Pancreas, Liver, & Gall bladder
• Liver:
– makes & secretes bile to emulsify fats. The bile is sent to
the duodenum.
– Stores excess glucose in the form of glycogen.
• Pancreas:
– secretes digestive juices (pancreatic lipase, amylase, and
protease) in the duodenum.
• Gall Bladder:
– holds the bile until sent to the duodenum. Regulates the
release of the bile.
Villi of the small intestine
Why is your small intestine infested with villi?
Function of villi
• Location of absorption of molecules
– All but the fatty acids are absorbed into
the capillaries.
– Fatty acids are absorbed into the lacteal.
• Lacteal is a vessel that is part of the lymphatic system
• Villi are thin for easy absorption & has an abundance of
capillaries and lymph vessels.
• All absorbed molecules are taken to body cells by the
circulatory system
• Nutrient molecule can be used for energy (glucose) or as a
component to build a larger molecule (amino acids).
– The process of building a bigger molecule is called:
assimilation
Large intestine (colon)
• After the absorption of nutrients is finished in the
small intestine; what is left moves through to the
large intestine along with the water.
• Main function: water absorption
• Home of bacteria Escherichia coli
– We provide food, water, & warm environment & they
provide us with vitamin K & maintain a healthy
environment for us.
• Anything left is eliminated as solid waste through
the anus
Where does the breakdown of food end
& the absorption of nutrients begin?
• While food is still being broken down in the
duodenum, it begins to be absorbed by the
lower part of the small intestine.
• By the time food is in the colon, it is no longer
being digested, but water is still being
absorbed.
Absorption vs Assimilation
• Absorption occurs when the food enters the body as
the food molecules pass through a layer of cells and
into the bodies tissues. This occurs in the small
intestine which has many villi that are specialized for
absorption.
• Assimilation occurs when the food molecules becomes
part of the bodies tissue. This is where small molecules
are built up to form larger molecules.
– EX: amino acids = proteins OR nucleic acids = DNA or RNA
What’s the difference between
the digestive system & the
excretory system?
Excretory- filters excess salts, water, &
nitrogenous waste out of the blood stream.
Digestive- breaks down & absorbs nutrients from
food.
Good things to eat for a good
digestive system
FIBER, FOLIC ACID, & CALCIUM
Fiber
• Fiber is not digested by our body. It helps us not
be constipated, helps lower cholesterol & glucose
levels
– There are 2 types:
• Soluble-dissolves in water & becomes gel-like; helps lower
cholesterol by lowering low-density lipoprotein, or "bad,"
cholesterol levels & glucose levels by slowing the absorption
of sugar.
– Apples, oats, citrus fruits, peas, beans…
• Insoluble- does not dissolve in water; promotes movement
of material through digestive system
– Whole-wheat flour, wheat bran, nuts, and vegetables
How much fiber do you need?
• How much fiber do you need each day? The Institute of
Medicine, which provides science-based advice on
matters of medicine and health, gives the following
daily recommendations for adults:
Men
Women
Age 50 or younger
38 grams
25 grams
Age 51 or older
30 grams
21 grams
Institute of Medicine, 2012
Folic acid
(a type of vitamin B)
• Key for growth and metabolism
• It aids in rapid cell division (which occurs in the
stomach lining)
• Folic acid supplements are standard for pregnant
women and women who plan to become
pregnant.
– lower the risk of preeclampsia and early labor.
– Reduces the risk for devastating birth defects of a
baby’s brain and spine -- spina bifida and anencephaly
-- by 50% to 70%.
How much folic acid do you need?
Category
Folate (Folic Acid)
Recommended Dietary Allowance
(RDA)
For children under 1, only an
adequate intake (AI) is available
The recommended dietary
allowance (RDA) includes the
folic acid you get from both the
food you eat and any
supplements you take.
0-6 months
65 micrograms/day
7-12 months
Adequate Intake (AI)
80 mcg/day
1-3 years
4-8 years
9-13 years
14 years and up
Adequate Intake (AI)
150 mcg/day
200 mcg/day
300 mcg/day
400 mcg/day
Pregnant women
600 mcg/day
Breastfeeding
women
500 mcg/day
How Do Essential Fatty Acids Aid the Body?
Fish, leafy vegetables, sunflower seeds, canola oil, walnuts…
• Essential fatty acids (omega 3 and 6) assist in the
development and function of the brain and nervous
system, and they help regulate proper thyroid and adrenal
activity. They play a role in thinning your blood, which can
prevent blood clots that lead to heart attacks and stroke.
They also possess natural anti-inflammatory qualities that
can relieve symptoms of both arthritis and other
autoimmune system diseases.
• Essential fatty acids regulate blood pressure, immune
responses and liver function, as well as help with blood
clotting and breaking down cholesterol. They also help you
look good, as a diet low in these fatty acids has been shown
to create skin problems, including eczema, dandruff, split
nails and brittle hair.
Calcium
• Helps promote good teeth & bones.
Calcium Requirements
SCHOOL AGE CHILDREN AGES 4 TO 8 REQUIRE 1,000 MG
OF CALCIUM PER DAY.
AS CHILDREN REACH PUBERTY, A TIME OF INCREASED
GROWTH AND DEVELOPMENT, FROM AGE 9 TO 18,
CALCIUM REQUIREMENTS INCREASE TO 1,300 MG EACH
DAY.
DURING ADULTHOOD, AGES 19 TO 50, CALCIUM
REQUIREMENTS DROP BACK TO 1,000 MG EACH DAY.
ADULTS OVER THE AGE OF 50 REQUIRE 1,200 MG OF
CALCIUM PER DAY.
Digestive Disorders
Celiac disease: the body's immune system is triggered by gluten in food.
Antibodies attack the intestinal lining, damaging, flattening, or destroying the
tiny hair-like projections (villi) in the small intestine. Damaged villi can't
effectively absorb nutrients through the intestinal wall. As a result, fats, proteins,
vitamins, and minerals get passed through the stool. Over time, this can lead to
malnutrition.
Lactose Intolerance- body is lacking the enzyme (lactase) to break
down the sugar in milk or other dairy products.
Constipation: Best avoided through regular exercise and a diet high in fiber
from whole grains, fruits, and vegetables. To older folks, who tend to get
constipated more frequently: Be sure you're hydrating properly and aware of any
medications that might be causing the holdup.
A challenge….an inexpensive
colon check up.
Eat a half cup of corn and record the date and time of
consumption.
Keep an eye out for the corn to come out in your bowel
movement.
While you are looking at your feces, observe the color, shape,
density and frequency.
Checking your “poop”
IDEAL
Density:
Color:
sinks
Black-coffee brown
Eat more fiber
Eat fewer processed foods
Shape:
Rounded, small pieces
Frequency:
Less than once per day
floats/sinks slowly
coffee-with-cream
floats
yellowish brown
Eat less fiber
Lower your stress level
size & shape of your colon
1-3 times/day
diarrhea
3+ times/day
What about other organisms?
Gastrovascular
Cavity
Mouth and anus are the
same opening
Food is moistened and stored in the crop.
Most of the digestion occurs.
Gizzard pulverizes food
Circulatory System
Pumps your blood!!!
The Human Heart
“Pumps Your Blood”
Valves close to
prevent backflow
venules
arterioles
Closing of the valves
produces the “lub dub”
sound of you heart
Why is the muscle thicker at the left ventricle?
Where would you suppose the
highest blood pressure is and
why?
The aorta because this is the
first place blood travels from
the heart pumping it out.
Where would you suppose the
lowest blood pressure is and
why?
Veins- this is the last area blood
travels before entering the heart
again. They have valves to prevent
back flow
There are 2 separate circulations:
-pulmonary
-systemic
Arteries carry
blood away
from the heart
“Pumps Your Blood”
Each side has
2 chambers
Each side has
2 valves
Atrioventricular valve
(mitral valve)
Semilunar valve
(pulmonary valve)
Atrioventricular valve
(Tricuspid valve)
Semilunar valve
(aortic valve)
Oxygenated
blood flows into
the left side
from the lungs
What blood vessel supplies the
heart muscle with blood?
Control of your heart rate
• Hearts are made of muscle tissue; cardiac
muscle.
– Contracts & relaxes = myogenic muscle
contraction
• Mass of tissue in the right atrium known as
the sinoatrial node (SA node)- initiates the
heartbeat
– Acts as a pacemaker by sending electrical
signals for the artrias to contract (aka
stimulate the myogenic contraction)
• 2nd mass is known as the atrioventricular node
(AV node)
– On a 0.1 second delay from the SA node in
which it sends a signal for both ventricles to
contract.
What happens during exercise?
• Increased demand for oxygen so heart beat
speeds up.
• Also an increased build up of CO2 in the
bloodstream.
• The medulla chemically senses the rise of CO2
– sends signal through the cardiac nerve to the SA
node to increase your heart rate
– Later sends another signal to decrease heart rate
through the vagus nerve
Adrenaline
• Chemical that is able to influence your heart
rate.
• High stress times and times of excitement
triggers the adrenal glands to release
adrenaline into your bloodstream.
• The SA node “fires” more frequently causing
an increase in your heart rate.
The different blood vessels
Arteries- take blood away from heart
thick walled
internal pressure is high
Veins- return blood from capillaries
to the heart
thin walled
internal pressure is low
have internal valves
Valves close to
prevent backflow
Capillaries- thin walled (fits one cell at a time)
all exchanges occur here
internal pressure low
IDENTIFYING BLOOD VESSELS
Artery
Capillary
Vein
Diameter
Larger than 10µm
Around 10µm
Variable but much
larger than 10µm
Relative thickness
of wall & diameter
of lumen
Relatively thick wall
& narrow lumen
Extremely thin wall
Relatively thin wall
with variable but
often wide lumen
Number of layers in
wall
3 layers
1 layer
3 layers
How present are
muscles & elastic
fibers in the wall
Abundant
None
Small amounts
Valves present or
not
None
None
Present in many
veins
Components of blood
leucocytes
erythrocytes
WHAT IS TRANSPORTED BY OUR BLOOD?
NUTRIENTS
OXYGEN
CARBON DIOXIDE
HORMONES
ANTIBODIES
UREA
HEAT
WHAT IS IN OUR PLASMA?
• 90% water
• Salts in the form of dissolved ions (aka blood
electrolytes)
– The concentration of these ions maintains osmotic
balance of the blood.
• Human blood pH 7.4
– Plasma proteins- act as a buffer against pH
change, help maintain osmotic balance,
contributes to blood’s thickness (viscosity)
The cardiac cycle
when the heart refills with blood
when the ventricles contract
Get
Worksheet
Cardiac Cycle Questions & Answers
Questions
Answers
Deduce when blood is being pumped from the
atrium to the ventricle. Give start & end times.
0 seconds to 0.1 seconds
Deduce when the ventricle starts to contract
0.10 seconds
The atrioventricular valve is the valve b/w the
atrium & the ventricle. State when the
atrioventricular valve closes.
0.1 seconds ( atrial pressure falls
below ventricular pressure)
The semilunar valve is the valve b/w the ventricle
& the artery. State when the semilunar valve
opens.
0.15 seconds (ventricular pressure
rises above arterial pressure)
Deduce when the semilunar valve closes.
0.4 seconds (ventricular pressure
falls below arterial pressure)
Deduce when blood is being pumped from the
0.15 seconds to 0.4 seconds
ventricle to the artery. Give both start & end times.
Deduce when the volume of blood in the ventricle
is at a maximum & at a minimum
0.1 seconds maximum (just before
the SL valve opens)
0.4 seconds minimum (at the end
of ventricular systole/contraction)
Atherosclerosis
CORONARY
OCCLUSION
HEADING
TO THE
HEART
MUSCLE
LDL
You are now going to diagram the
circulatory system!!!!
Things to include:
-Heart in detail
4 chambers
valves
veins & arteries
-lungs & upper of lower body
-arteries
-arterioles
-veins
-venuoles
-capillaries
-make your diagram a circuit
-indicate by color the deoxygenated
and oxygenated blood
You will do a presentation
showing & naming the parts.
Everyone in your group will talk.
Pump, pump, pumps your blood.
The right atrium's where the process
begins,
Where the C02 blood enters the heart
Through the tricuspid valve to the right
ventricle
The pulmonary artery and lungs.
Once inside the lungs it dumps its
carbon dioxide
And picks up its oxygen supply
Then it's back to the heart through the
pulmonary vein
Through the atrium and left ventricle."
"Pump, pump, pumps your blood.
"The aortic valve’s where the
blood leaves the heart
Then it's channeled to the rest of the
bod
The arteries, arterioles, and capillaries
too
Bring the oxygenated blood to the cells
The tissues and the cells trade off waste
and CO2
Which is carried through the venules
and the veins
Through the larger vena cava to the
atrium and lungs
And we're back to where we started in
the heart.
Pump, pump, pump, pumps your blood
RESPIRATORY SYSTEM
GAS EXCHANGE
Anatomy of
the respiratory
system
Our lungs act together with
our heart & blood vessels
Overview of our respiratory system
• Aerobic cell respiration
Process of delivering oxygen to our cells and releasing CO2
-chemical bonds in a glucose molecule are broken to release energy.
Energy is then stored as ATP.
-Process requires O2 & the C molecules in glucose are given off as a CO2
molecule
• Ventilation
Breathing in air to our lungs and releasing CO2 into the air from our lungs
-oxygen diffuses from the lungs to the bloodstream by way of the alveoli &
capillaries. CO2 diffuses the same way in reverse.
Why do we need a ventilation
system for gas exchange? Why can’t
we just take in oxygen by diffusion
through our cells?
Our bodies are too thick. Only the cells exposed to
the outside would participate in the gas exchange.
Also, it ensures that the concentration of gases
within the lungs encourages the diffusion of each
gas in a direction that’s beneficial to our bodies.
Gas exchange within the alveoli
There are ~300 million
alveoli in each of our
lungs.
Where does the blood
come from prior to
entering the lungs?
Right ventricle
Diffusion of oxygen and carbon dioxide occurs simultaneously as long
as you keep breathing; it replenishes the gases in the alveolus by
keeping the concentration gradients
Structure & Function of the Alveoli
• The round shape provides a large
surface area for the gasses to
diffuse
• The thinness (single cell) of each
alveoli as well as the capillary
beds surrounding the alveoli
allows for quick & efficient
diffusion
• Moist inner lining (surfactants) of
the alveolus allows the alveoli not
to stick to each other & tear
causing scar tissue.
– Premature babies have not
developed the surfactant & need to
be on a ventilator.
MECHANISM FOR BREATHING
What muscles are
involved in
breathing?
Diaphragm
Abdomen
Intercostal (surrounds
the rib cage)
Breathing is based on the inverse relationship between pressure & volume.
- an increase in volume will lead to a decrease in pressure (& vice versa).
Action in Ventilation
Inspiration/Inhaling
Diaphragm
Ribcage
Volume & Pressure
changes
Moves downwards & flattens
Moves upwards & outwards
Volume in thorax increases & pressure
decreases
Expiration/Exhaling
Diaphragm
Moves upwards and becomes more domed
Ribcage
Volume & Pressure
changes
Moves downwards & inwards
Volume in thorax decreases & pressure
increases
Muscle Movement of the ribcage
Inspiration/Inhaling
External Intercostal Muscles
contract, pulling the ribcage
upwards and outwards
Internal Intercostal Muscles
relax and are pulled back into
their elongated state
Expiration/Exhaling
External Intercostal Muscles
relax and are pulled back into
their elongated state.
Internal Intercostal Muscles
contract, pulling the ribcage
inwards and downwards
Lung Cancer
Some causes:
-smoking
87% of lung cancer is caused by smoking & 3% is from passive smoking
(secondhand smoke)
-Air Pollution
5% of lung cancer is caused by air pollution
-Others
Radon gas- a radioactive gas that leaks out of certain rocks such as
granite. It accumulates in badly ventilated buildings
Asbestos
Draw the pathway that an oxygen
molecule travels starting with going in
through the nose and ending with being
delivered at a cell in your big toe.
LIST AS MANY PARTS AS POSSIBLE
What about other animals?
Aquatic
Bony Fish
It is a bit more difficult
for gas exchange than for
land animals. Why?
Density & O2 availability
Blood flows in the direction opposite to the movement of water past the gills.
As blood moves through a gill capillary it becomes more and more loaded with oxygen
but it simultaneously encounters water with ever higher oxygen concentrations because
the water is just beginning its passage over the gills.