Transcript Long Small intestine - Mr Leitch`s Science

Biology 1.5
“Mammals as Consumers”
Bio1.5 Life processes related to
a mammal as a consumer
Part One:
Processing Food
(physical and chemical digestion, absorption,
assimilation, egestion)
Here we begin our journey along
the alimentary canal¹ from mouth to
anus
The Buccal Cavity
(mouth + teeth)
¹ aka: digestive system, gut
Tooth Types
• Incisors
– biting & cutting food
• Canines
– tearing meat
– piercing & holding prey
• Premolars
– chewing, grinding soft food
• Molars
– chewing, grinding hard
food
Pre Molar or Molar?
Premolars: Bicuspid
(two cusps)
Molars: Quadrate (humans, some other
spp) Four cusps are arranged in a
rectangle; there may be a fifth.
Hypsodont: There is a lot of enamel and dentine above
the gumline and the top of the pulp. This kind of molar is
found in mammals that wear their teeth a lot, eg horse.
Parts of a Tooth
cement
Functions of Tooth Parts
• Enamel – covers crown, hardest
substance in body, made of calcium
phosphate
• Dentine – underneath enamel, harder
than bone
• Pulp cavity – nerves & blood vessels run
through this
• Cement – covers root, holds tooth in jaw
• Crown – part of tooth above gum
• Root – part of tooth in jaw (molars have
more roots than incisors)
How Many Teeth Do You Have?
• In humans, the first set (20
milk teeth) appear from age
six months to two and a half
years. The permanent
dentition replaces these from
the sixth year onwards, the
wisdom teeth (third molars)
sometimes not appearing until
the age of 25 or 30.
• Adults have 32 teeth: two
incisors, one canine (eye
tooth), two premolars, and
three molars on each side of
each jaw.
Dental Formula
“method of recording number and types of teeth in mammal jaws”
Lower Jaw
Upper Jaw
Upper
Lower
i2
2
c 1 pm 2
1
2
m3
3
x2 = 16
x2 = 16
total = 32
Animal Dental Formula
Example Dental Formulae
Carnivores
• Cat
3.1.3.1
3.1.2.1
• Dog
3.1.4.2
3.1.4.3
Omnivores
• Pig
3.1.4.3
3.1.4.3
• Human
2.1.2.3
2.1.2.3
Herbivores
• Cow
0.0.3.3
4.0.3.3
• Horse
3.1.3/4.3
3.1.3.3
• Rabbit
2.0.3.3
1.0.2.3
• Sheep
0.0.3.3
3.0.3.3
Herbivore Teeth - Sheep
• Sharp lower incisors
– Cutting grass
• Bony pad
– For incisors to cut against
• Gap – diastema
– Clear food, protrude
tongue to grasp grass
• Molars
– Grinding plant material
Diastema
• + eyes face forward
– Watch for predators
Carnivore Teeth - Dog
• Sharp incisors
– Biting meat
• Long pointy canines
– Piercing, holding, tearing
prey
• Teeth right along jaw
– Chewing meat
• Overlapping teeth
– “Scissor like” to chop meat
• Jagged molars
– Cutting & grinding meat
• + eyes face front
– Focus on prey
*Root Canal
• (endodontic treatment) -- procedure in which the
diseased nerve (also called the pulp or inside
core) of a heavily decayed or damaged tooth is
removed and the central pulp space of the tooth
is filled and sealed with dental cement.
http://www.ahealthyme.com/topic/dentalterms
*Knocked out teeth
• Avulsion: injury in which a body structure
is forcibly detached
• What do you do? See:
http://www.nlm.nih.gov/medlineplus/ency/a
rticle/000058.htm
*Shark teeth
• Sit in scissor like rows
• Next tooth always ready to erupt
• 1000s shed over lifetime (some species
lose 35,000!)
F
Pharynx
A
Tongue
G
Larynx
H
Oesophagus
B
Liver
C
Gall Bladder
D
Large Intestine (colon)
Rectum
Stomach
I
E
J
Pancreas
K
Small intestine
(ileum)
L
Anus
Digestion
“The breakdown of food into molecules small
enough to be absorbed into the blood”
• Physical Digestion: Mechanical
breakdown of food – chewing (mastication),
churning of food by stomach.
• Chemical Digestion: Enzymes + bile
chemically break food down.
What are physical and chemical digestion and why are both
needed for the efficient digestion of food?
• Physical digestion occurs when food is broken down
into smaller pieces by the teeth or the muscle action of
the stomach wall.
• Chemical digestion is similar in that it results in food
being broken down into smaller pieces, but is different
in that it involves the use of enzymes to break the
chemical bonds holding the food molecules together.
• Both types of digestion are required because physical
digestion breaks up the larger pieces of food first, thus
increasing the surface area available for the enzymes
in chemical digestion to work on. This increases the
overall efficiency of the digestive process.
Mouth
• Digestion starts here: food taken in:
ingestion
• Food chewed into smaller pieces
(physical digestion)
• Saliva moistens and lubricates the
food making it easier to swallow
• Saliva contains salivary amylase (an
enzyme) which chemically breaks
starch down to glucose* (chemical
digestion)
• Salivary amylase is made by salivary
glands, works at a pH of 7 and is a
carbohydrase type of enzyme
• Tongue forms food into a ball shaped
“bolus” and is swallowed
* Actually maltose (which
is converted to glucose in
the epithelium of the villi
in the small intestine)
Oesophagus
• Food pushed to stomach by wave of
muscular contraction behind the food this
is called peristalsis
(7s for food to get from mouth to stomach)
Oesophageal Peristalsis
http://www.nature.com/gimo/contents/pt1/fig_tab/gimo13_V1.
Oesophagus – Barrett’s Syndrome
Stomach
• Large muscular bag, churns and mixes food. Food
becomes a soupy mix called chyme, Food stored for
~4 hours
• Acid (HCl) activates pepsin a protease enzyme
(enzymes that break protein down to amino acids),
produced by stomach wall, work best at pH of 2
• Acid in stomach kills bacteria in food.
• Water, alcohol and some food absorbed into blood
here
• Gastric Juice: A thin, virtually colourless acidic fluid
secreted by the stomach glands and active in
promoting digestion (pepsin + HCl)
! Churning = physical digestion
! Pepsin action = chemical digestion
*Why doesn’t your stomach
digest itself?
• Mucous stops the stomach digesting itself
• Pepsin secreted as pepsinogen from
stomach wall (inactive) only active when it
touches the stomach acid.
*Haggis
• Made of sheep's
or calf's heart,
lungs, liver
minced with
oatmeal onions
and boiled in the
animal's stomach
*Stomach Gurgles
aka borborygmi
http://www.youtube.com/watch?v=VgoZbf6Jm5M&featu
Causes:
1 In stomach / upper small intestine as muscles contract
to move food and gastric / digestive juices along
(normal!)
– Intestinal housecleaning?
– Happens most several hours after eating – this is why stomach growling
is associated with hunger.
2 Can also happen when incomplete digestion of food
causes gas (eg in lactose intolerance, coeliac disease
(gluten))
3 Caused by disease … include carcinoid neoplasm and
celiac sprue.
http://en.wikipedia.org/wiki/Kuru_%28disease%29
Small Intestine - Ileum
• Bile is added (breaks down fat, neutralises stomach
acid so other enzymes can work also gives faeces
their brown colour)
• Pancreatic enzymes added (break down proteins,
carbohydrates)
• Soluble food passes across small intestine wall into
blood: absorption
• Villi (finger-like projections increase surface area for
absorption)
• Surrounded by rings of muscle which ensure
peristalsis continues, forcing food along
• 7 metres long, 2.5-3 cm wide
Villi
Structure
~ 1mm long
Thin surface layer (epithelium) – food absorbed quickly
Dense network of blood capillaries – to absorb food quickly
(and transport to body cells)
Fatty acids & glycerol may reform to fats in the intestine
lining, these may be absorbed by the lacteal pass to the
‘lymphatic system’ and eventually end up in blood.
Main Function
• Villi (and micro villi) increase small intestine surface
area
–
This improves effectiveness of nutrient absorption into capillaries
Video Clips
• Small Intestine Endoscopy:
http://www.youtube.com/watch?v=Ln09qihUi3g
• Worm in Small Intestine:
http://www.youtube.com/watch?v=EXuoOWb8b
Gg
• Tapeworm Segment:
http://www.youtube.com/watch?v=3uk_aCZxmW
Y&feature=related
• Roundworm in cat intestine
http://www.youtube.com/watch?v=dB0cL3PcYZI
&feature=related
Peristalsis in horse intestine
Villi
*Extra Guts For Experts
Small Intestine
Size and Area
• The small intestine in an adult human measures on
average about 5 metres (16 feet), with a normal
range of 3 - 7 metres; it can measure around 50%
longer at autopsy because of muscle relaxation after
death. It is approximately 2.5-3 cm in diameter.
• CALCULATE THE AREA (use 5m & 2.75cm)
Area = circumference x length
= pi x d x l
= 3.141 x 2.75 x 500
= 4319cm2
= 0.43m2
(3.141 x 0.0275m x 5m)
Actual small intestine area…
• Although as a simple tube the length and
diameter of the small intestine would have
a surface area of only about 0.5m2 or
50cm2, the surface complexity of the inner
lining of the small intestine increase its
surface area by a factor of 500 to
approximately 200m2, or roughly the size
of a tennis court.
Small Intestine Parts
Parts of Small Intestine
• Duodenum 26 cm long. Breakdown of food, using enzymes.
• Jejunum 2.5 m. Absorption of food
• Ileum 3.5 m. Absorb vitamin B12 and bile salts and whatever
products of digestion were not absorbed by the jejunum.
* Cystic Fibrosis
• Inherited genetic disease – symptoms include
excess mucous production in lungs, gut
• Prevents pancreatic enzymes reaching small
intestine.
• SOLUTION?
– Coughing (lungs)
– Oral enzymes (gut)
• SOURCE?
– Pigs
• more issues…
Pancreas
• Produces pancreatic juice which contains enzymes that
breakdown carbohydrates, fat, proteins. These are secreted
into the duodenum part of the small intestine where they have
their action
• Pancreatic juice includes:
•
•
•
Lipases (break down fat to fatty acids and
glycerol – this is possible because bile has
already emulsified the fat and raised pH to
a level where lipase can work.
Amylase (breaks starch down to glucose)
Protease (breaks protein down to amino
acids)
• Pancreatic duct: tube connecting pancreas
to duodenum
• Also: produces hormones such as insulin
which controls blood sugar levels.
Sweetbreads (on mushroom risotto)
Sweetbreads also = thymus, testis…
Gall Bladder
• Stores the bile made in the liver (max = 50mL)
• Bile leaves via bile duct and enters small
intestine at the duodenum
What does bile do?
– Bile is the only non enzyme involved in chemical
digestion
– Bile is an alkaline solution, it raises pH of chyme
leaving stomach to ph of 8 in the small intestine
• Pancreatic juice contains the enzymes lipase, amlyase,
protease – these work best at a pH of 8
– Bile contains salts which emulsify fats
• Emulsification: break down into small droplets
• This increases surface area so that:
– Lipases work more effectively to break fat into fatty acids and
glycerol AND THEREFORE:
– Rate of absorption in small intestine will be faster
Basic Emulsion Experiment
1 Fill a clean, empty bottle with water.
2 Add some oil to the bottle of water and screw the lid firmly in
place. Shake the bottle vigorously so that the oil and water
form a cloudy mixture.
3 Leave the bottle to stand for a while. Observe how the oil
separates from the water and floats to the surface.
4 Add a few drops of dish soap to the bottle. Shake it up
again.
5 Leave the bottle to stand for a while. Notice that the oil and
water no longer separate but remain mixed. The oil has
broken up into droplets that are held in the water by the
emulsifying action of the soap.
Video: Science Experiment How Bile Emulsifies Fat
http://www.youtube.com/watch?v=VQrtYap84zA&feature=player_detailpage
What does Bile do?
Do This:
•
Mix a little oil + vinegar in a test tube. Observe.
•
Add a small pinch of mustard, mix. Observe.
Results Copy title then copy & complete below:
1. Oil and vinegar d_______ mix
2. The mustard emulsified the oil (this means it spread
the o____ through the v_____)
3. Bile e_____ oil and fat in the s____ i_________. This
helps d_________ by breaking lipids like f__ and
o____ into smaller pieces so that the enzyme l______
can work more effectively as it has more s_______
a_____ to work on.
!Why does the gut have
different regions / sections?
• Why not just have one big sack where
everything is digested in the one place?
Large Intestine - Colon
• Water & minerals
absorbed, pass into blood
• Surrounded by rings of
muscle which ensure
peristalsis continues,
forcing remaining insoluble
food to rectum
• 1.5 metres long, 6 cm wide
From Greys Anatomy pub. 1918
Appendix
• No CLEAR function in
humans
• BUT some suggestion
that the appendix may
harbour and protect
bacteria that are
beneficial in the function
of the large intestine
• In some herbivores
bacteria in the appendix
break down cellulose
• About 10cm long 7-8mm
wide
Appendix
Rectum
• Temporary storage for faeces.
• When full the nervous system triggers
need to defecate.
Anus
• Function: expelling
faeces (egestion or
defecation)
Liver
• Assimilation: Food molecules
packaged & stored for use in cells
(energy, growth, repair)
• Produces bile (helps breaks down fat
& is stored in gall bladder)
• Breaks down toxins (eg alcohol)
! The only internal human organ
capable of natural regeneration of lost
tissue; as little as 25% of a liver can
regenerate into a whole liver
*How long does it take for a
damaged liver to repair itself?
• The liver is a unique organ. It is the only organ in the body that is able to
regenerate... that is completely repair the damage. With most organs, such
as the heart, the damaged tissue is replaced with scar, like on the skin. The
liver, however, is able to replace damaged tissue with new cells. An extreme
example is a patient who suffers an overdose from Tylenol. In this example
up to 50 - 60 percent of the liver cells may be killed within 3 - 4 days.
However, if no other complications arise, the patient's liver will repair
completely, and a liver biopsy after 30 days will appear completely normal
with no signs of damage and no scar. However, the long-term complications
of liver disease occur when regeneration is either incomplete or prevented
by progressive development of scar tissue within the liver. This occurs when
the damaging agent such as a virus, a drug, alcohol, etc., continues to attack
the liver and prevents complete regeneration. Once scar tissue has
developed it is very difficult to reverse that process. Severe scarring of the
liver is the condition known as cirrhosis. The development of cirrhosis
indicates late stage liver disease and is usually followed by the onset of
complications.
A liver riddled with multiple secondary cancer deposits
Digestion Terms Summary
What
Where
How
Ingestion
Mouth
Food taken into body
Digestion
Gut
Absorption
Stomach (a
little), Small
Intestine
(most)
Food broken into pieces small
enough to be absorbed into the
blood
Food molecules cross gut wall into
the blood for transportation to
body cells (via circulatory system)
Assimilation Liver
Food molecules enter cells and are
used for energy, growth, repair
Egestion
Undigested food (+ bacteria) leaves
the body as faeces
Anus
Enzymes
•
•
•
•
•
are chemicals
are protein
are not living
don’t eat
speed up chemical reactions (eg digestion
by breaking chemical bonds between
molecules)
They don’t look like this
They look like this
Pepsin
Visual Summary of Enzyme Action
Tabular Summary of Enzyme Action
Group of enzyme
Carbohydrases
Proteases
Lipases
Proteases
Example
Site of production
Substrate
Products
Optimum pH
Amylase
Salivary
Gland /
Pancreas
Starch
Glucose
7
Stomach
Wall
Protein
Pancreas
Lipids
Glycerol +
Fatty Acids
8
Pancreas
Proteins
Amino Acids
8
Pepsin
Lipase
Trypsin +
Chymotry
psin
(*or maltose,
later converted
to glucose)
Amino acids
2
(*actually peptides
which are later
digested to amino
acids by trypsin)
* What does xenical do?
* Read: http://biology.about.com/library/organs/bldigestpan2.htm
Enzymes and optimum pH
pH affects how different enzymes function, each
digestive enzyme has an optimum pH that it works
best at.
Outside of this their effectiveness is less. At extreme
pH their 3D shape is changed (denaturated) and they
can no longer bind to food particles and break them up
• explain how pH affects the functioning of an enzyme
• elaborate upon why different foods are digested in
different parts of the gut.
Enzymes are not alive therefore they can’t be killed
Enzymes and their location
• Because enzymes have different optimum
pHs they must be located in separate regions
of the gut therefore the food they digest is
also digested in different locations
– Eg salivary amylase digest starch to glucose in
the mouth (optimum pH:7 which matches the
neutral pH of the mouth). Amylase is denatured in
stomach acid this is a pH of 2 which is the
optimum pH for pepsin to digest protein.
*Kiwifruit vs Agar
Task: Place a slice of kiwifruit on some agar. Leave it for 10min.
Observe.
Copy & Complete:
Kiwifruit vs Agar
Observations before:
Observations after:
Inferences:
A method to test our inferences:
*Q: Why Won’t Pineapple and JellO Be Friends?
• A: If Jell-O™ ads and 1950s cookbooks are to be
believed, you can mix almost anything with gelatin and
have it come out tasty. Ham? Absolutely. Carrots? Sure
thing. Tomato soup? M’m, m’m, good.
• The only ingredient that seems to be taboo is the one
that actually sounds delicious: fresh pineapple.
Unfortunately, the tropical treat works like kryptonite on
Jell-O because it contains an enzyme called bromelain,
which prevents gelatin from forming into a solid. But fret
not, fruit salad and mold fans: canned pineapple doesn’t
contain bromelain. The canning process heats the
pineapple to a temperature sufficient to break the
enzyme down, making it oh-so Jell-O friendly.
Source: http://blogcritics.org/tastes/article/q-why-wont-pineapple-and-jell/
So, what’s Bromelain??? http://en.wikipedia.org/wiki/Bromelain
Digesting Starch Experiment
• Did salivary amylase break down the
starch to glucose?
• What was the evidence?
• How do we know the saliva didn’t contain
glucose?
• Why did we leave the tube for 20min?
Comparing Guts of Different Consumers
Herbivores
Koala
Goat
Carnivores
Vampire bat
Wolf
Omnivore - Pig
Herbivore Gut Features
•
•
•
•
•
•
•
(not including features of teeth)
Salivary carbohydrate enzymes – begins chemical digestion
in mouth (head start required to get max nutrients out of low
nutrient diet)
Extensive chewing – breaks open tough plant cells &
increase surface area of food to aid chemical digestion (both to
get max nutrients out of low nutrient diet). May rechew (cud in
cows)
Weak stomach acid – diet low in protein (don’t need to
activate much pepsin)
Large stomach – to hold max amount of low nutrient food.
Slow gut transit time – to allow for maximum time to digest
difficult to digest food & absorb all nutrients in the low nutrient
food
Long Small intestine – large surface area to absorb max
nutrients out of low nutrient food (and allow max chance of full
chemical digestion)
Long large intestine - Use bacteria to breakdown indigestible
fibre in the large intestine
Specialised Herbivores
Humans can’t digest cellulose (sugar in plant cell walls = fibre) as lack enzyme cellulase.
Herbivores lack cellulase too BUT may have bacteria in their gut which have cellulase.
The bacteria break cellulose down to glucose using some for themselves the remainder
can be used by the herbivore.
Hindgut Digestion/Fermentation eg rabbit, horse, rhino, rodents
Bacteria found in caecum / appendix – this is AFTER the small
intestine (where absorption occurs) so rabbits will have to eat their
faeces in order to get the glucose provided by the bacteria (they
may eat faeces anyway to allow for more digestion / absorption of
http://www.youtube.com/watch?v=maWXVKI-gq4
nutrients).
Copraphagy = eating faeces http://www.merricks.com/digestion.html#lgintest
http://www.youtube.com/watch?v=8lqk7igz9L4&feature=related
Foregut Digestion/Fermentation aka ruminant
eg cow, sheep, goat
Simple Version: Cellulose digesting bacteria
found in a four chambered stomach. These break
down cellulose to glucose which is absorbed in
the small intestine.
Even with these bacteria cellulose is difficult to
digest and a long small intestine is necessary.
* More detail
Food softened in first two stomach
compartments (by bacterial action). Bacteria
break down cellulose to glucose (absorbed
in small intestine) Regurgitates this food
(cud), rechews to further break down plant
matter and stimulate digestion
(ruminating).In third compartment water and
minerals are absorbed. In fourth food is
digested in a similar way to in humans
** Even more detail
The four parts of the stomach are rumen, reticulum, omasum, and abomasum. In the
first two chambers, the rumen and the reticulum, the food is mixed with saliva and
separates into layers of solid and liquid material. Solids clump together to form the cud
or bolus.
The cud is then regurgitated, chewed slowly to completely mix it with saliva and to break
down the particle size. Fibre, especially cellulose and hemi-cellulose, is primarily broken
down into volatile fatty acids in these chambers by microbes (Cellulomonas spp.).
Protein and some other carbohydrates are also fermented.
Even though the rumen and reticulum have different names they represent the same
functional space as food can move back and forth between them. Together these
chambers are called the reticulorumen. The degraded digesta, which is now in the lower
liquid part of the reticulorumen, then passes into the next chamber, the omasum, where
water and many of the inorganic mineral elements are absorbed into the blood stream.
After this the food is moved to the true stomach, the abomasum. The abomasum is the
direct equivalent of the stomach in humans, and food is digested here in much the same
way.
Want MORE detail? Go to: http://en.wikipedia.org/wiki/Ruminant
* Extra For Experts
• Compare the efficacy of hindgut and foregut digesters
http://en.wikipedia.org/wiki/Hindgut_fermentation
• Compare the caecal and faecal pellets of rabbits
http://en.wikipedia.org/wiki/Rabbit#Diet_and_eating_habits
Carnivore Gut Features
(not including features of teeth)
• Strong stomach acid – to activate pepsin (to digest
meat)
• No extensive chewing – meat easy to digest
(chewing not needed to increase food surface area,
swallow in bulk allows you to compete with other
carnivores for max food)
• Small stomach – but rapidly expands to engorge food
(carnivores may irregularly get food)
• Short small intestine – meat nutrient rich (only a
short small intestine is needed to absorb the nutrients
required)
• Short large intestine (colon) - No further digestion /
absorption of food (also lack cellulose digesting
bacteria here)
• Fast transit time – meat nutrient rich, easy to digest
(long time not required to digest and absorb meat)
Omnivore Features
The human system is closer to that of a primate, who has a
slightly longer large intestine and shorter small intestine. But
both share attributes of both systems:
•
•
•
•
Salivary enzymes (to start digesting carbs) herbivore trait.
Strong stomach acid (to digest meat), carnivore trait.
Short large intestine carnivore trait.
Fast transit time carnivore trait.
Bio1.5 Life processes related to
a mammal as a consumer
Part Two:
Circulation
(transport of products of digestion within the body)
Circulation System Notes
• Organ system consisting of heart (pump),
vessels (veins, arteries, arterioles, capillaries)
• Transports:
– Oxygen (from lungs) to the cells that need it for
respiration (to produce energy)
– Glucose (from small intestine) to the cells that
need it for respiration (to produce energy)
– Other molecules (food, hormones) that have
been packaged by the liver
– Wastes such as carbon dioxide to the lungs for
exhalation
*Basic
Circulation
Plan
*Detailed
Circulation
Plan
*Heart Exterior
http://wikieducator.org/The_Anatomy_and_Physiology_of_Animals/Heart_Worksheet
*Heart Interior
*Heart Interior (v2)
*Components of Blood
Red Blood Cells
• Disc shaped, no nucleus
• Haemoglobin pigment binds to oxygen weakly (oxygen released in tissue where
oxygen is low)
• Life span: 4 months (dies, broken down, iron stored in liver)
• Made in bone marrow (ribs / breast bone)
White Blood Cells
• Also called leucocytes
• Some engulf / eat / destroy bacteria at infection sites or in blood
• Other produce antibody to inactivate pathogens
• Made in red marrow of bones
Platelets
• Help clot blood to stop bleeding at wounds
• Made when pieces of cytoplasm bud off larger cells
Plasma
• Liquid part of blood, straw coloured
• Carries dissolved substances (salts, + products of digestion: amino acids, glucose, +
wastes (urea, CO2) + hormones (eg adrenalin)
• Carries plasma proteins (for clotting), antibodies (for protection against pathogens)
Blood Loss*
Four classes:
• Class I Hemorrhage involves up to 15% of blood volume. There is typically no
change in vital signs.
• Class II Hemorrhage involves 15-30% of total blood volume. A patient is often
tachycardic (rapid heart beat). The body attempts to compensate with peripheral
vasoconstriction. Skin may start to look pale and be cool to the touch. The patient
may exhibit slight changes in behaviour. Saline solution is all that is typically
required. Blood transfusion is not typically required.
ABL about here (33%). ABL = allowable blood loss
• Class III Hemorrhage involves loss of 30-40% of circulating blood volume. The
patient's blood pressure drops, the heart rate increases, shock, capillary refill
worsens, and the mental status worsens. Saline solution and blood transfusion are
usually necessary.
• Class IV Hemorrhage involves loss of >40% of circulating blood volume. The limit of
the body's compensation is reached and aggressive resuscitation is required to
prevent death.
Blood*
• How much & how much can I lose?
– Allowable blood loss calculator^ (amount you can lose
before you need a transfusion) and estimate of total
volume: http://www.manuelsweb.com/blood_loss.htm
• NB: The hematocrit (Ht or HCT) or packed cell
volume (PCV) or erythrocyte volume fraction
(EVF) is the volume percentage (%) of red blood
cells in blood. It is normally about 45% for men and
40% for women.
• ^ who would need to know this? Why?
Bio1.5 Life processes related to
a mammal as a consumer
Part Three:
Respiration
(use of food at the cell level)
From Ass. Specification: Structure includes lungs
but structures in lungs not needed…
Respiratory System
• Organ system (lungs etc) that its function is
– exchanging gases with the environment OR
– to get oxygen into the body and remove carbon
dioxide.
– NOT: breathing (not enough detail)
– NOR using O2 to release energy from food (that’s
respiration)
Remember….!
• Respiration is NOT breathing
• Breathing is inhalation/exhalation of air
• Gas exchange diffuses oxygen into the
blood and carbon dioxide out of the blood
• Circulation delivers oxygen and glucose
to the cells (for cell respiration) and takes
carbon dioxide away
(EASIER) Respiration
(ATP!)
(ATP!)
(nb: respiratory enzymes speed up the
process of respiration)
What is so important about ATP?
• The ATP molecules provide the energy
needed for all other cellular processes.
• This energy is essential as it is used to join
small molecules together to make larger ones
(metabolism). It enables muscle cells to
contract so that mammals can move. It is
necessary for the active transport of
chemicals. If these processes were not to
happen the animal would not survive, as it
would be unable to move, feed, grow or
repair itself.
What is so important about
ATP? (more detail)
• When the last bond in ATP is broken
energy is released – this is the energy that
fuels cellular processes
• This results in
ADP + a
phosphate ion
(respiration
‘recharges’ this
back to ATP
(HARDER) Respiration
“the process by which energy is released from food”
• Cellular respiration involves the breakdown of glucose molecules.
Respiratory enzymes convert glucose into carbon dioxide and water, and
capture the energy released in the process in ATP molecules.
• The ATP molecules provide the energy needed for all other cellular
processes.
• This energy is essential as it is used to join small molecules together to
make larger ones (metabolism). It enables muscle cells to contract so that
mammals can move. It is necessary for the active transport of chemicals. If
these processes were not to happen the animal would not survive, as it
would be unable to move, feed, grow or repair itself.
• Respiration also produces the heat that keeps the body of warm blooded
animals above environmental temperature.
Aerobic Respiration (requires oxygen)
Glucose reacts with oxygen to produce carbon dioxide and energy (in the form
of a chemical called ATP)
O2 + C6H12O6  CO2 + H2O + energy(ATP)
Oxygen + Glucose  Carbon dioxide + Water + energy(ATP)
Anaerobic Respiration (in absence of oxygen)
Glucose breaks down without the use of oxygen. This produces only a small
amount of energy.
Glucose  pyruvic acid + energy (ATP)
EXTRA FOR EXPERTS:
The pyruvic acid is used up in aerobic respiration so that the whole process,
may look like this:
Glucose  pyruvic acid + energy(ATP)  CO2 + H2O + energy(ATP)
In yeast fermentation occurs under these conditions and produces alcohol
instead of pyruvic acid.
Are Potatoes Alive?
Evidence for Cellular Respiration
O2 + C6H12O6  CO2 + H2O + energy(ATP)
What could we detect to prove a potato is alive
and is respiring?
Detecting Respiration
O2 + C6H12O6  CO2 + H2O + energy(ATP)
CO2 + H2O  H2CO3
Bio1.5 Life processes related to
a mammal as a consumer
Part Four:
Linking
(relate processing of food, circulation and respiration to
each other and to the overall survival of the
mammal)
What are the links between:
• Digestion & Circulation?
• Digestion & Respiration?
• Circulation & Respiration?
• How do each help a mammal survive?
Expts & Extra Activities
Digestive System Problems
Choose one of the problems from
below.
• Indigestion
• Peptic ulcers
• Constipation
• Diarrhoea
• Tracheoesophageal fistula
• Barret’s syndrome
• Inflammatory bowel disease
• Celiac disease
• Irritable bowel disease
Write a paragraph to
give an account of:
• The symptoms
• The cause(s)
• The treatment
Include a labelled
diagram.
Possible Expts
• Weet bix challenge
• Starch digestion in mouth – Roberts
• Pepsin activity (LifeStudy) (2013 – dil the pepsin
(or order clear stuff, conc the egg)
• Small intestine absorbance
•
•
•
•
Fat digestion (roberts) need to order lipase
Bile (ppt)
Bile (LifeScience) using mustard
Dissections