Download The Digestive System

NUTRIENT ABSORPTION
How many different
systems do you see?
Digestive-Breaks
down and absorbs
nutrients
1.
2. Respiratoryabsorbs oxygen
3. Circulatory –
transports nutrients
C6H12O6 + 6O2
glucose + oxygen
6 CO2 + 6H2O + 36 ATP
carbon dioxide + water + energy
1. Where does the glucose come from?
Food
2. Where does the oxygen come from?
Breathing
3. What are the final products of cellular respiration?
CO2, H2O, ATP
4. In which organelle does this take place in our cells?
Mitochondria
Nutrient Absorption- DIGESTIVE
Types of digestive
Filter feeder
systems:
Digestive cavity:
Digestive tract:
1 opening
2 openings
(Gastrovascular cavity)
Description of system
Aquatic animals that
Digestive chamber with
strain tiny floating
food entering and waste
organisms from water
exiting through one
2 openings: mouth,
anus.
opening.
Picture of system
Jellyfish, Sea Anemone,
Examples
Sponges
Snails, oysters, squid, octopus,
Corals, Portuguese Man-of- starfish, sand dollar, crayfish,
War, Planaria (flatworm)
spiders, crabs, butterflies,
humans
Function of The Digestive System

The function of the
digestive system is to help
convert foods into simpler
molecules that can be
absorbed and used by
the cells of the body;
eliminates waste.
The Digestive System (aka. Alimentary
Canal) Includes:
Mouth
2.
Pharynx
3.
Esophagus
4.
Stomach
5.
Small Intestine
6.
Large Intestine/Colon
7.
Rectum
8.
(Accessory organs:
salivary glands, liver,
gallbladder, pancreas)
1.
The Mouth

Teeth
Cutting, tearing, and crushing food into small fragments.
 Begins the process of mechanical digestion or physical
breakdown.


Saliva
Secreted by the salivary glands.
 Helps moisten the food and make it easier to chew.
 Contains amylase, a digestive enzyme that begins the
breakdown of carbohydrates.
 Begins the process of chemical digestion, where chemicals
breakdown the large pieces into smaller pieces.

The Esophagus




Bolus – Chewed clump of
food.
From the throat, the bolus
passes through the esophagus,
or food tube, into the stomach.
Food travels through the
esophagus to the stomach by
smooth muscle contractions
(wave-like) called peristalsis.
The epiglottis (small flap
covering the trachea)
separates the food from air
when swallowing
The Stomach


Food from the esophagus empties into
a large
muscular sac called the stomach.
The stomach continues the mechanical and chemical
digestion of food.
Mechanical: Stomach muscles contract to churn and mix
stomach fluids and food, gradually producing a mixture
known as chyme.
 Chemical:

1.
2.
3.
Gastric glands release mucous to protect the stomach wall
Gastric glands produce hydrochloric acid and pepsin, which
begins the complex process of protein digestion.
Amylase is denatured by the stomach acid so carbohydrate
breakdown does not occur in the stomach.
The Small Intestine

Most of the chemical
digestion and beginning
absorption of the food
you eat occurs in the small
intestines.
The Small Intestine

Divided into three parts:
1.
2.
3.
Duodenum
Jejunum
Ileum
Together average about
6 meters (19.7 ft) long.

Duodenum



The first of three parts of
the small intestine.
It is where almost all of the
digestive enzymes enter the
intestine.
The pancreas and the liver
release digestive enzymes
and fluids to help with
digestion in the small
intestine.
Absorption in the Small Intestine

By the time chyme enters the
jejenum and the ileum parts of
the small intestine, much of the
chemical digestion has been
completed.
 Chyme
is now a rich mixture of
medium and small nutrient
molecules.
Absorption in the Small Intestine

The small intestine is
specially adapted for
absorption of nutrients.
 The
folded surfaces of the
small intestine are covered
with fingerlike projections
called villi.
 Villi increases the surface
area for absorption of
nutrients
Absorption of Nutrients in the
Small Intestine


Nutrients are absorbed
through the wall of the
small intestine directly
into the capillaries (blood)
by the process of
diffusion.
Diffusion – movement of
substances from an area
of high concentration to
an area of low
concentration
Absorption in the Small Intestine

By the time food is ready to leave the small
intestine, it is basically nutrient-free.
 The
complex organic molecules have been digested
and absorbed, leaving only water, cellulose, and other
undigestible substances behind.
The Large Intestine




When the chyme leaves the
small intestine, it enters the
large
intestine, or colon.
Primary Function: Remove water from the undigested
material that is left.
The concentrated waste material (feces) that
remains after the water has been removed passes
through the rectum and is eliminated from the body.
http://www.youtube.com/watch?v=Z7xKYNz9AS0
Click on picture
Accessory Structures of Digestion
1.
2.
3.
4.
Pancreas
Liver
Gallbladder
Salivary
Glands
Pancreas


Located just behind
the stomach.
Gland that serves three
important functions:
1.
2.
3.
Produces insulin that regulate blood sugar levels.
Produces enzymes that break down carbohydrates,
proteins, lipids, and nucleic acids.
Produces sodium bicarbonate, a base that neutralizes
stomach acid so that these enzymes can be effective.
Liver


Assisting the pancreas is the
liver, a large organ located just
above and to the right of the
stomach.
Produces bile; to help digest fats
 Bile
acts like a detergent, dissolving and dispersing the
droplets of fat found in fatty foods.
 Makes it possible for enzymes to reach the smaller fat
molecules and break them down.
 Bile is stored in a small, pouch-like organ called the gall
bladder.
Gallbladder



https://www.youtube.com/watch?v=TkREXrY4CZc
(dr. oz)
A pouch like organ that stores the bile
The bile is brought to the small intestine by the bile
duct
20 million ppl get gallstones, small hard mineral
deposits due to excess cholesterol buildup
Salivary Glands

There are 3 salivary glands:
1.
2.
3.
Parotid gland – largest of the salivary glands that
secretes saliva to assist with chewing and swallowing;
located in the cheek area inferior to the ear
Submandibular gland – secretes amylase to help
breakdown starches in the mouth; located below and
inferior to the parotid gland
Sublingual gland – secretes mucous that helps coat
the food being swallowed; located in front of the
submandibular gland on the floor of the mouth
Digestive System
Levels of Organization
Epithelial cells, Liver cell, stomach cell,
pancreatic cell, etc….
epithelium, villi, smooth muscle
Mouth, esophagus, stomach, small & large intestines,
etc…
digestive
A. SALIVARY GLANDS
B. MOUTH
C. ESOPHAGUS
D. STOMACH
F. LARGE
INTESTINE
H. ANUS
E. SMALL
INTESTINE
G. RECTUM
Digestive System Disorders

Peptic Ulcer
 Hole
in the stomach wall
 Most peptic ulcers are caused by bacteria and most
can be cured by antibiotics.

Diarrhea or Constipation
 If
not enough water is absorbed by the large intestine,
diarrhea occurs.
 If too much water is absorbed from the undigested
materials, constipation occurs.

http://www.youtube.com/watch?v=cdijh32NiLs
(constipation)
NUTRIENT ABSORPTIONC I R C U L AT O R Y
T H E C I R C U L AT O R Y S Y S T E M
-ALSO CALLED CARDIOVASCULAR
SYSTEM
CONSISTS OF THE
HEART, SERIES OF
BLOOD VESSELS ,
AND THE BLOOD
EVOLUTIONARY TRENDS OF THE CIRCULATORY
Complex
SYSTEM Simple
Types of circulatory
Diffusion through skin/cells
Open circulatory
Closed circulatory
system
system
system:
Blood is not contained in
Blood is contained within a
Organisms are thin and most of their
a network of blood
network of blood vessels
cells are close to the external
vessels
Description of
system:
environment so materials can pass
easily in to and out of their bodies
Picture of
system:
Examples
Flatworms
Insects, crustaceans,
Squid, octopus, Mammals,
snails, oysters
humans
FUNCTIONS OF THE CIRCULATORY SYSTEM
• Main Functions:
1.Transports O2 & nutrients
(sugars, amino acids,
hormones) to the cells
2.Removes wastes from cells
•
Also, works with the immune
system to protect body against
disease causing pathogens
PARTS OF THE BLOOD
• Plasma – thick, yellowish liquid, mostly water, in
which blood cells are suspended
• Red blood cells (erythrocytes)
– Transport O2 to body/ remove CO2
– Red in color due to the hemoglobin
(iron containing protein)
– Produced in red bone marrow,
average life span of 120 days,
destroyed by spleen later
• White blood cells (leukocytes)
– Guard against infection
– Some work with the immune system to
produce antibodies
Platelets: cell fragments
a. Stick to broken blood vessels
b. Helps body heal wounds by forming clots
WHEN YOU GET CUT WHY DOES THE BLEEDING
EVENTUALLY STOP?
• You have plasma proteins
and cell fragments called
platelets.
• When there is a broken
blood vessel, platelets start
to accumulate at the site
and release clotting factors.
These factors form a web
(like the pic. to the right)
of filaments that stops the
bleeding.
BLOOD VESSELS
Adults have over 60,000 miles of vessels in their bodies
The blood volume in our bodies = 8% of our total weight
130lbs = 10.4 lbs of blood!
THREE TYPES OF BLOOD VESSELS- Arteries,
Veins, and Capillaries
1. Arteries
o Large vessels that
carry blood AWAY
from the heart to the
tissues of the body
o Except for the
pulmonary arteries, all
arteries carry
oxygen-rich blood.
2. Veins
Large vessels that return blood TO the heart.
– Have valves to keep blood from flowing
backwards
– Carrying oxygen-poor blood
VALVES ARE ALSO IN THE VEINS
Prevent backflow and push blood against gravity to the
heart(systemic circulation). One way flow.
Leaky valves in extremities can cause blood to
“pool”=varicose veins
Treatment=
• Sclerotherapy (medicine
injected into vein)
• Vein stripping
3. Capillaries
~Smallest blood vessel; site of gas exchange: brings
nutrients and oxygen to the tissues and absorbs
carbon dioxide and waste products
~The walls of capillaries are only one cell thick, and
most are so narrow that blood cells must pass
through them in single file.
THE HEART: SOME FACTS
• Hollow organ about the
size of your clenched fist.
• Contracts on average 72
times per minute.
• Pumps about 70 mL of
blood with each
contraction.
The Heart
1. Heart – muscular organ
 4 chambers
 Pumps blood from heart
to lungs
& back to heart, to
tissues
throughout body
2. Pericardium- outer covering of the heart;
provides protection for heart.
 Myocardium – Heart’s muscular wall that
contracts to pump blood out of the heart.
3. Septum: muscular wall in heart
 Separates right side from left
side
 Keeps O2 poor & O2 rich
blood from mixing
4. Atria – 2 upper chambers
 Receive blood from body
(right) or lungs (left) &
pump blood into ventricles
5. Ventricles – 2 lower chambers
 Pump blood out of heart to
lungs
(right) or aorta (left)
The Heart
2 chambers: fish
3 chambers:
amphibians, most
reptiles
4 chambers: birds,
mammals.
The 4 chambered
heart is more
efficient because
the oxygenated
and
deoxygenated
blood are never
mixed.
NATURAL PACEMAKER- “SETS THE PACE”
• Sinoatrial node (SA node) –
– found in the upper part of
the right atrium of the heart
– a specialized bundle of
neurons that act as the heart's
natural pacemaker
– the SA node "fires" at regular
intervals to cause the heart of
beat with a rhythm of about
60 to 70 bpm(healthy, resting).
Artificial Pacemaker
A medical device placed under your skin near heart which uses electrical impulses,
delivered by electrodes contacting the heart muscles, to regulate the beating of the
heart if you have arithemias
TWO PATHS OF CIRCULATION
How the Heart Works…..
• Systemic-blood circulates from the heart to
the body and back to the heart
• Pulmonary-blood circulates from the heart
to the lungs and back to the heart
CIRCULATION THROUGH THE BODY
The heart functions as two
separate pumps:
1. Right Side - Pumps
oxygen-poor blood to
the lungs.
o
Known as pulmonary
circulation
2. Left Side - Pumps
oxygen-rich blood to
the rest of the body.
o Known as systemic
circulation
PATHWAY OF BLOOD FLOW THROUGH THE HEART
1.
Blood enters the heart through
the right (3) and left (9) atria.
2.
As the heart contracts, blood
flows into the ventricles (5, 11).
3.
Then out from the ventricles to
either the body or the lungs.
• Valves – Flaps of connective tissue
that prevents blood from flowing
backwards.
– Exist between the atria and
ventricles.
– Also exist at the end of the
ventricles.
HEART BEATS & BLOOD PRESSURE
• Normal heart sound
– Lub-Dub – “lub” is the bicuspid and tricuspid valve
closing and the “dub” is the semilunar valves
closing
• Blood pressure is the force of the blood on the walls
of the arteries. (Systolic over Diastolic)
– Diastole – period of time when the heart-atriafills with blood (relaxation)
– Systole – the contraction of the ventricles
 Normal blood pressure is 110/70
CIRCULATORY SYSTEM DISEASES
1. Leukemia: bone marrow produces abnormal
WBCs. At first, leukemia cells function normally. In
time, there are too many & they crowd out normal
WBCs, RBCs & platelets.
2. Hemophilia: an inherited disorder. Afflicted
persons cannot produce clotting factors, which causes
people w/ hemophilia to bleed for longer periods of
time than people whose produce clotting factors. The
main problem w/ hemophilia is internal bleeding, mainly
into muscles & joints.
CIRCULATORY SYSTEM DISEASES
• 3. Atherosclerosis- “plaque” (fat) build up on
the inner walls of arteries.
• 4. Arteriosclerosis: arteries become hard &
brittle because calcium is deposited in their
walls. Vessels become thickened & lose
elasticity. Blood pressure increases & blood
clots may form
• 5. Stroke: blood clot blocks artery or a blood
vessel breaks, interrupting blood flow to an
area of the brain. Brain cells begin to die &
abilities controlled by that area of the brain
are lost.
6. ANEURYSMS
• A ballooned bulge in a blood vessel caused by disease or weakening of
vessel wall.
– Usually found in artery at base of brain or in the aorta
– If these rupture then will lead to hemorrhaging and death
Circulatory System
Red & white blood cells
Blood, Blood vessels (smooth muscle)
heart
circulatory
INTERACTIONS AMONG SYSTEMS TO ACHIEVE NUTRIENT
ABSORPTION
Nutrients are obtained from food that
the digestive system has broken down.
The respiratory system obtains oxygen
from the atmosphere. These nutrients
are transported by the circulatory
system to cell of the body for
absorption.
Cellular Respiration - the process by
which cells get energy from the
breakdown of glucose in the presence
of oxygen

Takes place in the mitochondria
 External
Respiration - The process
of gas exchange between the
lungs and the environment.


Release carbon dioxide
Uptake of oxygen
C6H12O6 + 6O2
glucose + oxygen
6 CO2 + 6H2O + 36 ATP
carbon dioxide + water + energy
1. Where does the glucose come from?
Food
2. Where does the oxygen come from?
Breathing
3. What are the final products of cellular
respiration?
CO2, H2O, ATP
4. In which organelle does this take place in our
cells?
Mitochondria
Simple
Types of
Diffusion
respiratory
through
system:
Complex
Gills
Tracheal tubes
Book lungs
Lungs
skin/cells
Structures
of system:
Adaptation
to land or
Water
Water
Terrestrial, land
Terrestrial, land
land
water?
Examples
Terrestrial,
Sponges, corals,
Fish, crayfish,
jellyfish,
lobsters, crabs
planarian,
earthworm
Insects
Spiders
Mammals,
humans
 To
bring about the exchange of
oxygen and carbon dioxide
between the blood, the air, and
tissues.
 Diaphragm – Large, flat muscle at
the bottom of the chest cavity
that helps with breathing.
 Inhaling
(Breathing in)
 Ribs rise, diaphragm contracts,
fills chest cavity.
 Exhaling (Breathing out)
 Passive event
 Ribs lower, diaphragm relaxes,
empties chest cavity.

http://www.youtube.com/watch?v=HiT621PrrO0
 https://www.youtube.com/watch?v=2RZjDl
-2_24
1.
2.
3.
4.
Nose (Nasal
cavity)
Pharynx
(Throat)
Larynx (Voice
Box)
Trachea(Windpipe)
Glottis
2. Epiglottis
1.
5.
6.
Bronchi-Rt.—
Lft.
Lungs-Rt.(3
lobes)—
Lft.(2Lobes)
Bronchioles
2. Alveoli-lined
w/cappillaries=d
iffusion
1.
7.
Diaphragm
 Where


air enters and exits the body
Nose hairs – trap dust and unwanted particles
Nasal chamber – warms and moistens air before it
enters the respiratory system
 Air
moves through the nose
to a tube at the back of the
mouth called the pharynx,
or throat.
 Pharynx - Serves as a
passageway for both air and
food.
 Located
between the pharynx
and top of trachea.
 Contains two highly elastic
ligaments known as the vocal
cords.


When muscles pull the vocal
cords together, the air moving
between them causes the cords
to vibrate and produce sounds.
Your ability to speak, shout, and
sing comes from these tissues.

Air moves from the
pharynx into the trachea,
to the lungs. Opening of
trachea is called glottis.

A flap of tissue called the
epiglottis covers the
entrance to the trachea
(glottis) when you swallow


The glottis is covered by
epiglottis and prevents
choking.
Lined with cartilage rings, cilia
Cilia in the trachea.
 From
the larynx, air passes
through the trachea into two large
passageways in the chest cavity
called bronchi.

Each bronchus leads into one of the
lungs.
 The
large bronchus subdivides into
smaller bronchi, which lead to
even smaller passageways called
bronchioles.

Surrounded by smooth muscle
enabling the nervous system to
regulate the size of the air
passageways.
 The
bronchioles continue to
subdivide until they reach a
series of dead ends—millions
of tiny air sacs called alveoli.




Grouped in little clusters, like
bunches of grapes.
A delicate network of thinwalled capillaries surrounds
each alveolus.
This is where gas exchange
occurs because blood
(capillaries) and air are side by
side.
O2 is put into the blood and
C02 is removed from the blood
 Each
healthy lung contains
about 150 million alveoli !

Provides for an enormous surface area for gas exchange.
 Oxygen

Dissolves in the moisture on the inner surface of the
alveoli and then diffuses across the thin-walled
capillaries into the blood.
 Carbon

Dioxide in the Bloodstream
Diffuses in the opposite direction, across the membrane
of an alveolus and into the air within it.
 You
have some voluntary control
over breathing.
 The medulla oblongata in the
brain also monitors carbon
dioxide levels in the blood.


It forces you to breathe even if you
are trying to hold your breathe.
As the CO2 levels rise, nerve
impulses from the brain cause the
diaphragm to contract, bringing air
into the lungs.
Respiratory System
Levels of Organization
lung cell
alveoli
mouth, nose, trachea, bronchi, bronchioles,
diaphragm
respiratory
 After
food is
broken
down/digested,
what system do
the molecules
diffuse to?
 After
you take
a breath, in to
what system
does the
oxygen diffuse
to?
 The
upper respiratory tract
can usually filter out dust and
foreign particles that could
damage the lungs.
 Tobacco smoke contains
nicotine, carbon monoxide,
and tar all of which paralyze
the cilia. With no working
cilia these particles stick to
and enter the lungs.
 Smoking can cause chronic
bronchitis, emphysema, and
lung cancer.
 Destroys
alveoli and the damage is irreversible