Download Human Digestive System

INTRODUCTION
TO BODY
STRUCTURE
BODY ORGANIZATION
1.
The levels of organization of the body:
cells- individual unit
tissues- Similar cells that work together to perform a
common function.
organs- Combination of 2 or more tissues that
work together to perform a common
function
organ system- Group of organs that work together to
perform a specific function.
BODY ORGANIZATION
Maintaining homeostasis requires:
1.
2.
3.
4.
5.
Body’s organs functioning together.
Temperature regulation (endotherms)
Adjusting metabolism
Detecting and responding to stimuli
Maintaining water and mineral balances
Integumentary
System
Consists of:
Skin, Hair,
& Nails
Skin
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The largest organ in your body. Yes, skin
is an organ.
Functions of the Skin
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Protective barrier against pathogens
Prevents water loss
Offers body protection
Regulates body temperature through sweating
Four Tissues of the
Integumentary System
•Epithelial- covers body surfaces
•Connective- provides support and
protection
•Muscle – body movement
•Nerve- forms body’s communication
network
3 layers of skin
1. Epidermis: Top layer
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Constantly makes new skin cells to replace dead
ones
Contains keratin, which as a waterproof barrier
Also contains melanin, a brown pigment that
helps protect you from UV rays. (This is why
people tan)
3 layers of skin
2. Dermis: The 2nd layer of skin
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Contains hair follicles (each follicle contains 1
hair)
Contains the sebaceous glands which produce
an oil called sebum. This lubricates the skin and
hair.
Contains sweat glands. These release water and
some wastes to cool the body and maintain
homeostasis
3 layers of skin
3. Subcutaneous tissue: The 3rd layer
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Composed of fat cells
This is used for insulation and an energy supply
SKIN LAYER DIAGRAM
EPIDERMIS
SEBACEOUS
DERMIS
GLAND
SUBCUTANEOUS
TISSUE
HAIR FOLLICLE
SWEAT GLAND
SKELETAL SYSTEM
Functions of the skeleton:
1.
2.
3.
Support the body
Provide protection for the
internal organs
Enables movement
SKELETAL SYSTEM
There are 206 bones in the skeleton.
The skeleton is divided into 2 parts:
1.
axial- includes the skull, spine, ribs, and
sternum
2. appendicular- includes shoulders, arms,
hips, and legs
SKELETAL SYSTEM
Bone is made of hard compact bone
surrounding porous bone.
BONE MARROW
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RED – makes all blood cells for body (RBC,
WBC, & platelets)
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YELLOW = stores fat tissue
SKELETAL SYSTEM
Early in development, the skeleton is
made mostly of hyaline cartilage.
Bones hardens as calcium, phosphate
and other mineral deposits build up.
Osteoblasts make bone tissue.
Bones thicken and elongate as
development continues.
SKELETAL SYSTEM
JOINT = where 2 bones meet.
Three types of joints:
1.
Immovable
permits little or no movement.
ex. skull joined by sutures.
2.
Slightly moveable
ex. Spine and ribs
3.
Freely moveable joints
(see table 2 p. 854)
ex. knee
SKELETAL SYSTEM
1.
Ligament: Connects bone to bone
2.
Tendon: Connects muscle to bone
Osteogenesis Imperfecta
MUSCULAR SYSTEM
Functions Include:
 Movement in body
 Generate Heat for Body Temperature
MUSCLES
Involuntary muscles – not under conscious control.
1. Smooth muscles – line internal organs
& blood vessels.
a. Function of smooth muscle is to
contract.
b. Smooth muscle contractions are
slow.
MUSCLE
2. Cardiac muscle – heart muscle.
Adapted to conduct electrical
impulse.
MUSCLE
Voluntary muscles – under conscious
control skeletal system.
3. Skeletal muscles – attached
to the bones & skeletal system.
a. Majority of muscles are skeletal
b. Contractions are short & strong
MUSCLE
Page skeletal muscle structure
1. Skeletal muscle are made up of
bundles of muscle fibers.
2. Each muscle fiber is made up of
myofibrils.
MUSCLE
3. Myofibrils are made up of smaller
proteins filaments.
a. Myofibrils are striated or divided
into sections called sarcomeres
which are the functional units of the
muscle
MUSCLE
4. Two types of filaments
a. Thick filaments are made up
myosin.
b. Thin filaments are made up of
actin.
MUSCLES
Sliding Filament Theory
1. during contractions, actin filaments
move towards one another from the
pulls of myosin heads
Muscle Fiber

Muscle
contractions
take a lot of
ATP therefore
they must
have plenty of
mitochondria
to supply the
power.

Tendons connect
bone to muscle.
Muscular Dystrophy
Human Excretory
System
Human Excretory System
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Excretion is the removal of metabolic
wastes from the body, including toxic
chemicals, excess water, carbon dioxide
and salts.
Excretory Organs
Skin
 Lungs
 Kidneys
https://www.youtube.com/watch?v=EhnRhfFLyOg
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Human Urinary System
Diagram
Nephron
Kidney
Kidney
Ureter
Urinary
Bladder
Urethra
Urinary system
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The urinary system, consisting of the
kidneys, ureters, urinary bladder and
urethra, is responsible for eliminating the
majority of metabolic wastes from the body
The functional unit of the kidney is the
nephron. Each nephron is made of a cupshaped portion called Bowman’s capsule,
tubules and a network of capillaries
Inside the Kidney
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Blood pressure within a knot of capillaries (called the
glomerulus) increases, causing most of the fluid of the
blood to enter Bowman’s capsule
This fluid is called filtrate.
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As the filtrate passes through the tubule portion of the
nephron, materials needed by the body are reabsorbed and
the remainder of the filtrate becomes urine
Proper functioning of the kidney is essential to maintaining
homeostatsis in the body
Warm-Up

Write down in correct sequence all the
organs (at least 5) through which their
food passes as it travels along the
digestive tract. Then try to list any glands
or organs that are found along the
digestive tract, but through which food
does not pass.
DIGESTION ANIMATIONS
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https://www.youtube.com/watch?v=bo2Ape
8JHqA
https://www.youtube.com/watch?v=08VyJO
EcDos
https://www.youtube.com/watch?v=Mq9fW
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Cool Facts
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Your intestines will grow to at least 25 feet as an adult.
Be glad you're not a full-grown horse their coiled-up
intestines are 89 feet long!
Food sloshing in the stomach can last 3-4 hours
It takes 3 hours for food to move through the intestine
Food drying up and hanging out in the large intestine
can last 18 hours to 2 days!
Americans eat over 2 billion pounds of chocolate a year.
In your lifetime, your digestive system may handle about
50 tons!!
Human Digestive
System
Structures

The GastrointestinaI tract (GI), also called the
alimentary canal is the system of organs that
take in food, digest it to extract nutrients and
expels the waste. These organs are the mouth,
pharynx, esophagus, stomach, small intestine
and large intestine.
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Major Functions:
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Ingestion
Digestion
Absorption
Defecation or Excretion
Following the Trail
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The process begins in the mouth.
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Chewing initiates mechanical breakdown of food
and is followed by secretion of saliva, which
moistens and lubricates food for swallowing.
Saliva also contains amylases (enzymes), which
start the chemical breakdown of carbohydrates.
The swallowing reflex begins in the pharynx
and initiates rhythmic waves of smooth muscle
contractions called peristalsis.
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Peristaltic contractions transport food to the
stomach and allow a person to swallow even if
he/she are upside down.
Human Digestive System
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Digestion is the ability to process food in the body into a form
that can be absorbed and used or excreted.
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Digestion involves three principle processes:
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Mechanical digestion: takes place in the mouth, your
teeth chew the food
Chemical digestion: using chemicals to digest/ break
down food, this takes place in your mouth and stomach
where acid and enzymes mix with the food.
Absorption: pulling nutrients out of the food, occurs in
the small intestine
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Accessory organs: Organs that help with
digestion but are not part of the digestive
tract. These organs are the tongue,
salivary glands, liver, gall bladder, and
pancreas.
Human Digestive System
Diagram
Mouth
Pharynx
Esophagus
Liver
Stomach
Large Intestine
Small Intestine
Villi
Following the Trail II
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The stomach contains an extra layer of
muscle that aids in mechanically
mixing and churning food into a
semiliquid form called “chyme.”
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Chemical digestion begins with proteins
through the action of hydrochloric acid (HCl)
and the enzyme, pepsin.
Only water and a few substances, such as
aspirin and alcohol, are absorbed by the
lining of the stomach.
Following the Trail III
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As food enters the small intestine secretions from
the liver, gall bladder and pancreas are added .
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The small intestine completes digestion
of food materials by absorbing nutrients
into the blood stream
The lining of the small intestine
consists of tiny folds or fingerlike
projections, called villi, which, in turn,
are covered by microvilli which increase
surface area
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The villi contain capillaries and lymphatic
vessels for the absorption of nutrients
Microvilli have brush border enzymes to
hydrolyze lactose and sucrose.
Cross-Section of small
intestine
Villi
Microvilli
 The
large intestine does not
contain villi and it plays no
role in digestion
Only water and vitamin K are
absorbed from the large intestine
 Undigested or unabsorbed food is
eliminated through the rectum and
then anus.
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Nutrition
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Food materials are broken down to usable nutrients and
absorbed into the bloodstream.
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They are used by the body for metabolism, building and repair
Some nutrients are stored within the body
Nutrients include carbohydrates, proteins, lipids, vitamins,
minerals and water.
Carbohydrates
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Must be broken down into monosaccharides
Body’s main source of energy.
Nutrition II
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Proteins
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Broken down to amino acids
Supply the raw materials for growth and repair.
The body requires 20 amino acids, 10 of which it cannot
make and must obtain
Lipids are reduced to fatty acids and glycerol
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They are used to make steroid hormones, cell
membranes
Store energy
 Nucleic
acids are reduced to nucleotides.
 DNA and RNA
 The genetic material of all cells.
Where does each nutrient get
broken down?
CarbDigestion
Mouth,
Throat,
Esophagus
Stomach
Small
Intestine
Protein
Digestion
Nucleic Acid
Digestion
Fat
Digestion
Polysacch.
Into
Disacch.
Polypepties DNA, RNA
into smaller into
proteins
nucleotides
Disacch.
Small
Into
proteins
Monosacch. into amino
acids
Nucleotides
into nitrogen
base, sugar
and phospate
Fat into
glycerol,
fatty acids
and
glycerides
What enzymes break down
each nutrient?
Protein
Carb Digestion Digestion
Nucleic Acid
Digestion
Salivary
amylase
Peptidases
Nucleotidases
(amino acids
are connected
by “peptide”
bonds)
(nucleotides
are building
block of DNA
and RNA)
(amylose is
starch, a
polysacch)
Fat Digestion
Bile salts and
Lipase
(fats are made
of lipids)
Nutrition III
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Vitamins are organic molecules that aid in
the regulation of body processes
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Vitamin C: healthy teeth, gums and blood
vessels; improves iron absorption and
resistance to infection
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Vitamin K: for normal blood clotting and
synthesis of proteins found in plasma, bone, and
kidneys
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Water
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Required for metabolism and chemical reactions
within the body
Transport of substances around the body
Regulation of body temperature. Approximately
two-thirds of the body weight is water.