Transcript Aliya

What is it made up of?
Skin, hair, nails, and
sweat and oil glands
What does it do?
1. protects against
infections and injuries
2. protects against
ultraviolet radiation
3. provides a gateway into
the nervous system
4. maintains body heat
Standards?
None
1. Protects against infections and injuries.
The skin, the largest part of the
system, is made of two sections.
The epidermis is the thin layer at
the top. Cells at the bottom of
the epidermis divide quickly and
move to the top.
As the cells die, they become
filled with keratin, a tough
protein. These dead cells form
a tough, waterproof barrier.
The skin also prevents infections and injuries
because the epidermis does not have any blood
vessels.
Because of this, a small scratch will not cause
bleeding and expose the bloodstream to germs.
Hair, another part of the integumentary system,
also prevents infections and injuries by keeping
particles from entering the nose, ears, or eyes
(eyelashes).
2. Protects against ultraviolet radiation.
The second part of the skin is the
dermis, which is much thicker than the
epidermis. (In the picture, it is both the
dermis and hypodermis.)
Cells within the dermis, called
melanocytes, produce a dark brown
pigment (melanin). This pigment protects
the body from sunburn and skin cancer.
That is why dark skinned people like
African Americans do not sunburn easily
and have lower rates of skin cancer than
people of European descent.
Hair also protects against radiation by
shielding the head from the sun. Hair is
maintained by the sebaceous glands in the
dermis, which secrete an oil that maintains
each hair.
3. Provides a gateway into the nervous system.
The dermis contains pain, heat, cold, and pressure receptors that
transmit messages about the environment to the nervous system.
4. Maintains body heat.
On cold days, the blood vessels in the dermis
contract to conserve heat.
On hot days, they widen to bring blood to the
surface of the skin and increase heat loss.
The dermis also contains sweat glands that
make a watery secretion called sweat. When
sweat evaporates from the skin on a hot day, it
takes heat away.
The skin also provides insulation because it has
a layer of fat in the deepest part of the dermis.
REAL LIFE SITUATION
You decided a few months ago to grow your hair out to shoulder
length. But recently you’ve begun to notice that your hair has
become dry and split.
You ask your sister, who also has long hair, how she keeps her
hair from splitting or becoming too dry. She doesn’t really know
either, but she explains that she brushes her hair every morning
and every night for twenty minutes.
Why does brushing help her hair?
REAL LIFE SITUATION
You have learned that the sebaceous glands in the dermis
maintain individual hair strands.
The sebaceous glands produce oils that keep hair glossy and
healthy. However, as hair grows longer, the oils have to be
spread out over the entire hair.
Otherwise the ends of the hair will become dry and split.
As your hair grew out, you didn’t realize that you needed to
brush it more often to spread out the sebaceous oils.
What is it made up of?
Specialized cells
called neurons
Standards?
What does it do?
1. controls body
functions
2. responds to
internal and
external changes
b. how the nervous system mediates communication between
different parts of the body and the body’s interactions with the
environment
d. Functions of the nervous system and the role of neurons in
transmitting electrochemical impulses
e. Role of sensory neurons, interneurons, and motor neurons in
sensation, thought, and response.
The Neuron
The dendrites, the branches on the body of the neuron, are the
“ears” of the neuron. They receive messages from other neurons.
The axon, the long section of the neuron, is the “mouth”. It tells
other neurons about what its dendrites have received, by sending an
electrochemical message that other neurons’ dendrites will
receive.
Standard D
Functions of the nervous system and the role of neurons in
transmitting electrochemical impulses
The nervous system
controls body functions
and responds to the
environment by relaying
messages between neurons.
As an electrical current
from another neuron or a
change in the environment
moves across a neuron’s
membrane, it is
transferred across the
membrane in a domino
effect.
Eventually the ions of the electrical current reach the axon.
The impulse travels down the axon to where it branches out into an axon
terminal. Axon terminals are either connected to a cell that is not a
neuron, or are very close to a dendrite of another neuron. The axon
terminal uses chemicals called neurotransmitters to send the impulse to a
cell or another neuron.
The place where the axon terminal can send on an impulse is called a
synapse. In the image above, the synapses are the highlighted gold parts.
Standard E
Role of sensory neurons, interneurons, and motor
neurons in sensation, thought, and response.
There are 3 different types of neurons.
Sensory Neurons are found in the sensory
organs— the nose, eyes, ears, tongue, and
skin. They carry impulses about changes in
the environment to the brain or spinal
cord
?!!
Interneurons are found in the brain and
spinal cord. They are a bridge between
sensation and response. They receive
impulses from the sensory neurons and
send the appropriate impulse to motor
neurons.
Motor Neurons are found in muscles and
glands. They receive impulses from the
brain or spinal cord and prompt the
muscles to move the body. (More in the
Muscular System)
Standard B
How the nervous system mediates communication
between different parts of the body and the body’s
interactions with the environment
The nervous system is divided into two parts that work together
to transmit messages from sense organs to the brain/spinal
cord and then to the muscles.
This circular method is known as a “reflex arc”. (Standard C)
The central nervous
system is the brain and
spinal cord. The neurons
in the central nervous
system are mainly
interneurons.
The central nervous
system analyzes and
processes information
from sensory and motor
neurons.
The spinal cord only
handles rapid reflexes
that must happen very
quickly. The brain takes
care of all thinking.
The peripheral nervous
system is made up of the
nerves and ganglia
(groups of neuron cell
bodies) that are not in
the brain or spinal
cord. The neurons in
the peripheral nervous
system are mainly
motor and sensory
neurons. The sensory
division transmits
impulses to and the
motor division receives
impulses from the
central nervous
system.
REAL LIFE SITUATION
It’s 7 A.M. on a Monday morning. As you blearily stumble into the
kitchen, you hear the intolerably cheerful humming of your
mother as she packs lunches for you and your siblings before
rushing off to work.
The sharp ding of the toaster goes off a few feet away. “Would
you grab the toast?” your mother calls from the kitchen table.
But when you reach for the two pieces of bread, you stumble
forward and the side of your hand brushes against the hot
surface of the toaster.
Before you even feel the pain, you yelp and pull your hand away.
As your pinky suddenly throbs with pain, you quickly put it in your
mouth to cool it.
What happened?
REAL LIFE SITUATION
First, the pain and heat sensory neurons in your finger detected
the heat of the toaster (the stimulus) and sent an
electrochemical impulse to the central nervous system.
Because the danger of the toaster was great, this impulse was
processed directly by the spinal cord.
The interneurons in the spinal cord sent an impulse to the motor
neurons of your arm and chest muscles to pull away from the
toaster.
You did not feel the pain of the burn at first because the spinal
cord cannot analyze information like the brain.
However, when an impulse was sent to the brain, AFTER the
danger had been taken care of, you felt the pain.
The interneurons in your brain “decided” that the best way to
stop the pain was to put your hand in your mouth.
What is it made up of?
bones and cartilage
What does it do?
1. supports the body
2. protects internal
organs from injury
3. allows movement
4. stores mineral
reserves
Standards?
None
5. provides a place where
blood cells can be
made
The Bone
Bones are made of several layers.
The outer layer is a tough tissue called
the periosteum. Blood vessels must pass
through the periosteum to carry
nutrients and oxygen to the bone.
Next is a layer of compact bone. Through
the compact bone, tiny channels called
Haversian canals contain nerves and
blood vessels.
Another kind of bone, less dense than
compact bone, is spongy bone. It is found
at the ends of long bones and in the
middle of short bones. Spongy bone “adds
strength to bone without adding mass” (p.
922, Prentice Hall Biology). Where force
is regularly applied to the end of bones,
spongy bone is organized into a strong,
supportive structure.
A bone also has a cavity in its center. The
cavity is filled with a tissue called bone
marrow. The function of marrow will be
discussed later.
1. Supports the body.
The bones of your body hold up your body like
the walls of a building. Everything in the
human body is supported by and built around
the skeleton.
2. Protects internal organs from injury.
Some bones are designed to protect a
certain vital organ. Three good
examples are the pelvis (protects the
reproductive organs) the ribs (act as a
cage around the heart and lungs), and
the skull (protects the brain).
The combined strength of the
periosteum, compact bone, and spongy
bone keeps the body’s most important
organs from most injuries.
Deposits of calcium salts in bones are
essential in giving bones strength.
3. Allows movement.
Despite the strength and protection that the skeleton gives the body, it
still allows free movement. This is because the places where bones
attach to each other, called joints, are often movable.
Joints can be immovable (the bones in the skull are fused), slightly
movable (the joints between adjacent vertebra allow restricted
movement), or freely movable (four different types).
Pivot Joint—elbow
Ball-and-Socket Joint—
Lets one bone pivot shoulder
around the other
Permits circular
movement
Hinge Joint—knees
Permits back and
forth movement
Saddle Joint—hands
Bones can slide
over each other
The ends of bones in freely movable joints have cartilage to stop chafing.
A joint capsule around the joint helps the bone stay together and move.
Bands of connective tissue called ligaments hold the bones together. The
capsule also produces synovial fluid, which lubricates the joint.
Some freely movable joints, like the knee, have small bags of synovial fluid
called bursae. Bursae reduce friction and absorb shock.
4. Stores mineral reserves.
Bones are made up of cells called osteocytes.
Osteocytes deposit and regulate calcium salts in
the bone. Calcium can be removed from the bone if
the bloodstream’s calcium level is too low. (Other
than strengthening bones, calcium also helps
blood clot and ensures proper muscle and nerve
function.
5. Provides a place where blood cells can be made
The cavity in a bone contains marrow, a soft
tissue that produces red and some white blood
cells.
There are 2 kinds of marrow: red & yellow
Red marrow is found in spongy bone, the ends of
long bones, and in the ribs, vertebrae, sternum,
and pelvis. It makes all red blood cells, white
blood cells, and platelets.
Yellow marrow is found in most bones, especially
the shafts of long bones. Yellow marrow is
mostly fat, and it is used as an energy reserve. If
the body loses a large amount of blood, yellow
marrow can be changed into red marrow.
How a Broken Bone is Fixed
As discussed previously, a bone is made up of cells called osteocytes,
whose main job is to maintain the bone. But what happens when a bone is
broken?
First of all, the damaged bone is removed by cells called osteoclasts.
Osteoclasts tidy the damaged site to create a clean working area.
Then, cells called osteoblasts create new bone tissue through a slow
process that can take months. Osteoblasts are also the bones that fused
bones and changed cartilage into bone while you were a child.
REAL LIFE SITUATION
Your Aunt Georgia, aged 57, fractured her hip and ribs recently
after tripping down a staircase.
You asked your doctor why a small fall caused such a bad injury.
He said that Aunt Georgia is probably suffering from
osteoporosis, a gradual weakening of the bones as they lose
density. He also said that osteoporosis affects people after the
age of 30, when bone tissue replacement slows.
However, he warned you that it is hard to prevent osteoporosis
after your mid-twenties.
It’s easiest to increase bone density now, as a teenager, by eating
healthy foods (especially milk and dairy) and exercising
regularly.
Why did he advise these two solutions?
REAL LIFE SITUATION
1. A healthy diet, especially milkbased foods, is important to
preventing osteoporosis early
because it contains a lot of
calcium. Calcium salts strengthen
bones and provide density.
Osteoporosis occurs because
osteocytes cannot replace
calcium salts efficiently.
You can also take calcium pills to
make sure that you have enough.
2. Exercise at a young age prevents
osteoporosis because applying force
to bones actually strengthens them.
For example, the leg bones of a
runner will be dense and strong
because of the constant pounding on
them. The spongy bone at the end of
his leg bones is arranged to support
the compact bone.
Note that exercises like weightlifting
do not prevent osteoporosis because
they do not apply force to the bones.
What is it made up
of?
skeletal, smooth,
and cardiac
muscle tissue
What does it do?
1. moves bones,
pumps blood, etc.
Standards?
h. Students know the cellular and molecular basis of muscle
contraction, including the roles of actin, myosin, Ca+2, and ATP.
Muscle Tissue
There are 3 different types of muscle
tissue.
Skeletal muscle is attached to bones. It
moves bones and its movement is voluntary
and controlled by the central nervous
system.
Skeletal muscle cells are large and
appear to make stripes, or striations.
Smooth muscle is found in hollow organs
like the stomach and blood vessels. It
moves food through the digestive tract and
blood through blood vessels. This
movement is involuntary. Most smooth
muscles do not need nerves to contract.
Instead, impulses travel directly between
muscle cells.
Cardiac muscle is found in the heart. It is
striated like skeletal muscle, but its
movement is involuntary like smooth
muscle. It pumps blood through the heart.
Standard H
Students know the cellular and molecular basis of
muscle contraction, including the roles of actin, myosin,
Ca+2, and ATP.
The striations in a skeletal muscle
are made up of alternating thick
and thin filaments.
The thick filament with the branches is formed by a protein called myosin.
The thin filament is made of a protein called actin.
For a muscle to contract, each myosin fiber attaches to an actin fiber and
uses energy from ATP to pull.
Standard H (continued)
Students know the cellular and molecular basis of
muscle contraction, including the roles of actin, myosin,
Ca+2, and ATP.
When motor neurons in the muscle
receive an impulse from the central
nervous system, acetylcholine is
released.
Acetylcholine makes the muscle
release calcium ions (CA2+) .
The calcium ions make the myosin fiber
bind to the actin fiber. This is called a
cross-bridge.
The cell in which the contraction is
taking place burns ATP through
cellular respiration to make energy.
The energy is used to bend the crossbridge and pull the ends of the muscle
cell together.
As each cell in a muscle shortens, the
entire muscle contracts. Click on the
animation at left to see this.
When the motor neurons stop producing acetylcholine and CA2+ stops
being made, the myosin fiber will release the actin fiber and the
contraction will stop.
REAL LIFE SITUATION
You wake up with a start, suddenly remembering the morning soccer
practice you now have on Saturday mornings. You roll over and stare
at the time. It’s already 6:45, and you only have 15 minutes to get to
practice.
While hurriedly brushing your teeth, you briefly consider eating
breakfast and risking the wrath of your coach. Nah, you think to
yourself. I’m not that hungry anyway.
You get to the field just in time for practice, and you run up to join your
friend Taylor.
Later on in practice, you notice that Taylor is sprinting every drill and
working harder than anyone else. But the fact doesn’t seem very
important you, because your legs and stomach are in excruciating pain.
Your abs and hamstrings feel like they’re knotted tightly, and you can
barely run.
Ten minutes later, both you and Taylor are on the bench watching your
teammates. Taylor is complaining of an intense burning in the thighs.
What happened?
REAL LIFE SITUATION
Your problem came from your lack of food. When a muscle cell does
not have enough ATP, it remains in constantly contracted because the
calcium ions are forcing the myosin fiber to pull on the actin fiber.
This causes severe muscle cramps known as muscle fatigue.
When your body ran out of ATP, your leg muscles could not relax and
you began to feel a very painful cramp.
Taylor’s problem, however, came from the sudden increase in exercise.
By pushing his muscles beyond their endurance, Taylor put himself in a
state of oxygen debt.
Taylor’s body was not efficient enough to supply his muscles with
enough oxygen. So his muscles needed another way to make energy
without oxygen—fermentation.
In fermentation, lactic acid is produced as a waste product, and builds
up in the muscle. This caused the burning Taylor felt.
What is it
made up of?
the heart, a
network
blood
vessels, and
blood
What does it do?
1. delivers oxygen and to
cells within the body
2. transports oxygenpoor blood back to the
heart to receive more
oxygen
Standards?
a. how the complementary activity of major body systems provides
cells with oxygen and nutrients and removes toxic waste
products such as carbon dioxide.
Blood
For a cell to make energy, it needs two things: ATP and oxygen.
In the human body, blood is the fluid that provides oxygen and
food to every cell.
Blood is about 55% plasma, a brownish liquid that is essentially water with
dissolved gases, salts, nutrients, waste products, and plasma proteins.
There are 3 kinds of plasma proteins: globulins (transport substances and
fight infection), albumins (transport substances and control blood
pressure & volume), and fibrinogen (clots blood).
The remaining 45% of blood consists of red blood cells, white blood cells,
& platelets.
Red blood cells are the most common
blood cell. They are released into the
bloodstream without nuclei.
Instead, they are filled with an ironproducing protein called hemoglobin that
transports oxygen.
White blood cells are less common
than red blood cells. Their job is to
attack and consume foreign
substances like viruses.
Different types of white blood cells
have different ways of destroying
foreign cells.
Blood
Platelets and Clotting
Platelets are very small fragments of cytoplasm. Their key function is to
clot blood whenever a blood vessel breaks.
When a blood vessel breaks, platelets
in the bloodstream become sticky and
accumulate around the break.
The platelets release proteins called
clotting factors. These begin a
complicated series of reactions that
ends with the plasma protein
fibrinogen being converted into sticky
fibrins.
These fibers hold the wound together
until it heals.
Standard A
how the complementary activity of major body systems
provides cells with oxygen and nutrients and removes toxic
waste products such as carbon dioxide.
1. Transporting oxygen to Cells
heart
The circulatory system
provides oxygen to cells
within the body by using
the heart to pump
oxygen-rich blood
through arteries and
arterioles (smaller
arteries). Arteries are
blood vessels that take
blood from the heart to
the body/lungs.
Blood is then taken
through capillaries,
which are extremely tiny
blood vessels, which
supply cells with oxygen.
artery
arteriole
capillary
Standard A (cont.)
1. Replenishing Blood with Oxygen
capillary
venule
vein
heart
After depleting the oxygen in
the blood, cells produce
carbon dioxide as a waste
product.
The blood in the capillaries
take this oxygen-poor blood
and the carbon dioxide in it to
venules and then larger
veins. Venules and veins are
blood vessels that transport
blood back to the heart.
In the heart, the oxygen-poor
blood is pumped into the
lungs, where it releases the
carbon dioxide and receives
oxygen.
Then the oxygen-rich blood
goes back to the heart and is
pumped through the body,
starting the process over
again.
Standard A (cont.)
The Heart
The heart is the most important part of the
human body.
Pulmonary Circulation
(Right Side of the heart to the Lungs)
The heart receives oxygen-poor
blood from the superior and inferior
vena cava. The superior vena cava
brings the blood from the upper
part of the body, the inferior from
the lower part.
The oxygen-poor blood is put into the
right atrium, one of the 4 chambers
in the heart.
Then it is pumped into the right
ventricle.
The tricuspid valve keeps blood from
flowing back into the right atrium.
Then the blood is pumped into the
NOTE: The pulmonary arteries are
lungs by the pulmonary arteries.
called arteries even though they
The pulmonary valve keeps the blood
carry oxygen-poor blood. This is
from flowing back into the right
because they take blood away from the
ventricle.
heart.
Standard A (cont.)
The Heart
The heart is the most important part of the
human body.
Systemic Circulation
(Left Side of the heart to the Body)
The lungs replenish the blood with
oxygen. Then it sends the oxygenrich blood back to the heart
through the pulmonary veins.
NOTE: The pulmonary veins are
called veins although they carry
oxygen-rich blood. This is because
they take blood to the heart.
The oxygen-rich blood enters the
left atrium. Then it is pumped into
the left ventricle. The mitral valve
keeps the blood from flowing back
into the left atrium.
From the left ventricle the blood is pumped into the aorta, a huge
artery that carries all oxygen-rich blood from the heart.
What is it
made up of?
a network
of vessels,
the thymus,
and the
spleen
What does it do?
1. Returns lost fluid to
the bloodstream
2. Protects against
disease
3. Absorbs nutrients
Standards?
None
4. Destroy damaged red
blood cells and
platelets
1. Returns lost fluid to the bloodstream
The lymphatic system is closely linked with the circulatory system.
When blood moves through the body, more than 3 liters of fluid
leak from blood vessels into the rest of the body per day.
The lymphatic system makes the circulatory system more efficient
by collecting the lost fluid, known as lymph, and moving it back into
the bloodstream.
There are several different
vessels in the lymphatic system.
Lymphatic capillaries are the
first vessels to collect lymph
from tissue.
bloodstream
Then the lymph moves into
larger vessels, and eventually
into ducts. Ducts return the
lymph to the bloodstream
through two holes in the
superior vena cava.
lymphatic vessels
lymphatic ducts
2. Protects against disease
Lymph vessels are lined with small knobs called
lymph nodes. Lymph nodes remove bacteria and
microorganisms from lymph. When lymph nodes
become filled with bacteria, they swell up.
Swollen tonsils are a good example of this.
Lymph nodes also contain lymphocytes, which
protect the body from disease.
A certain kind of lymphocyte called a T cell
matures in the thymus gland, another part of the
lymphatic system.
3. Absorbs nutrients
Blood needs to supply cells
with food as well as oxygen.
The lymphatic system supplies
the necessary nutrients.
Lymph vessels near the
intestines absorb nutrients
and carry them into the
bloodstream.
4. Destroy damaged red blood cells and platelets
The Spleen
The spleen is the largest organ
in the lymphatic system.
It is a mass of lymphatic tissue
that destroys damaged blood
cells and platelets.
Blood cells that are too old
are sent to the spleen to be
broken down.
What is it made up of?
the nose, pharynx, larynx, trachea, bronchi, and
lungs
What does it do?
1. supplies blood
with oxygen
Standards?
2. removes carbon
dioxide from the
blood
a. how the complementary activity of major body systems provides
cells with oxygen and nutrients and removes toxic waste
products such as carbon dioxide.
Standard A
how the complementary activity of major body systems
provides cells with oxygen and nutrients and removes
toxic waste products such as carbon dioxide.
The Need for Air
For a cell to make energy, it needs two things: ATP and oxygen. It
produces water and carbon dioxide as waste products.
In the human body, the respiratory system’s function is to take in
oxygen and let out carbon dioxide.
Breathing
When a person takes a breath, the flat
muscle below the lungs (the diaphragm)
contracts and increases the lungs’ volume.
Air rushes into the vacuum of the expanded
lungs.
When the diaphragm relaxes, the air in the
lungs is squeezed out as their volume
decreases.
Standard A (cont.)
Breathing
When a person inhales, air enters
through either the nose or mouth.
It moves into the throat, or
pharynx, which both air and food
pass through.
Since lung tissue is very delicate,
nostril hairs and mucus in the
pharynx filter out particles.
Air is moved from the pharynx into
the windpipe, or trachea.
Food is prevented from entering
the trachea because a piece of
cartilage (the epiglottis) covers
the opening when you swallow.
Located at the top of the trachea
is the larynx, which is made of 2
elastic bands of tissue called
vocal cords. As air passes
through the larynx, a person can
speak.
Next the air passes through one of
the 2 air passages that lead to the
lungs (bronchi).
Standard A (cont.)
Inside the Lungs
Each bronchus separates into
smaller bronchi, and then into
even smaller bronchioles.
The bronchioles divide until they
come to a dead-end—millions of
minuscule air sacs (alveoli).
Each alveolus is connected to a
fragile network of capillaries.
As you inhale, air is brought into each
alveolus. The oxygen in the air
diffuses across the alveolus’
membrane and the capillary’s thin
wall.
At the same time, the carbon dioxide in
the blood diffuses into the alveolus.
When this exchange occurs and the
lungs are filled with carbon dioxide,
the diaphragm relaxes and the
carbon dioxide is exhaled.
What is it made
up of?
the mouth,
pharynx,
esophagus,
stomach, small
intestine, and
large intestine.
The salivary
glands, pancreas,
and liver add
secretions.
What does it do?
1. converts food into
molecules that cells
can use
Standards?
a. how the complementary activity of major body systems provides
cells with oxygen and nutrients and removes toxic waste
products such as carbon dioxide.
f. the individual functions and sites of secretion of digestive
enzymes (amylases, proteases, nucleases, lipases), stomach acid,
and bile salts.
The Need for Food
For a cell to make energy, it needs two things: ATP and oxygen. The
job of the digestive system is to ingest food and break it down into
sugars that cells can convert into ATP.
However, food is not needed only for its sugars. There are many
other materials in food that the body needs.
Water—needed to replenish
fluids like blood and lymph,
and to replace urine and
sweat
Fats—needed for
protection,
insulation, and
stored energy.
Also help absorb
fat-soluble
vitamins
Carbohydrates—
breads and fruit
contain sugar used
for cellular
respiration, and
fiber that helps with
digestion
Proteins—
meat, eggs,
and beans
are needed
for skin,
muscle,
enzymes, and
amino acids
The Difference between Vitamins and Minerals
Vitamins—are organic materials that
interact with enzymes to regulate
body processes. Some are created
within the body and some must be
ingested.
Vitamin C (found in oranges and
tomatoes) maintains cartilage, bone,
and gums and helps heal wounds.
Vitamin D (found in eggs and made by
the skin when exposed to sunlight)
promotes bone growth.
Minerals—are inorganic materials
that are used to a variety of different
purposes. Usually they are needed in
smaller quantities than vitamins.
Calcium (found in dairy) is essential
for healthy bones and teeth.
Iron (found in leafy vegetables) is
needed for hemoglobin in red blood
cells.
Standard A & F
how the complementary activity of major body systems
provides cells with nutrients &
the individual functions and sites of secretion of digestive
enzymes (amylases, proteases, nucleases, lipases), stomach
acid, and bile salts
Beginning the Digestive Process
The mouth—ingestion begins when a
person puts food into his/her mouth.
Teeth , whose surfaces of enamel are
much harder than bone, physically
tear and crush the food to pieces.
As the teeth grind the food, the
salivary glands at the bottom of the
mouth secrete saliva, a thick fluid.
Saliva contains amylase, an enzyme
that breaks down starch into sugar.
Saliva also contains an enzyme called
lysozyme that breaks down the cell
walls of bacteria that are in food.
This protects the body from infection.
Standard A & F (cont.)
Getting to the Stomach
After being chewed and broken down,
the tongue and throat muscles make
the person swallow. The food moves
into the esophagus, a long tube that
leads to the stomach.
As discussed previously, the epiglottis
blocks food from entering the
trachea.
The food is forced down the epiglottis
by involuntary muscle contractions.
Inside the Stomach
The stomach is a large sac lined with
smooth muscle. The muscles around
the stomach let it churn and mix the
food, helping with the physical
digestion of food.
Standard A & F (cont.)
Chemical Digestion in the Stomach
The stomach is lined with millions of
gastric glands that release fluids
into the stomach.
Mucus protects the stomach wall
from damage.
Hydrochloric acid makes the food in
the stomach very acidic, and activates
an enzyme called pepsin.
Pepsin and hydrochloric acid work
together to break down proteins into
smaller pieces.
The combination of chemical and physical digestion in the stomach
breaks food into a mixture called chyme.
About an hour after ingestion, the pyloric valve between the stomach
and small intestine, opens to slowly allow chyme to enter the small
intestine.
Standard A & F (cont.)
The Duodenum
The duodenum is the first of
the three parts of the small
intestine.
Inside the duodenum,
enzymes and fluids from the
liver and pancreas digest
the chyme further.
The pancreas produces
amylase, protease, and
lipase, which neutralize the
stomach acid and also break
down starch, proteins, and
fat.
The liver produces bile, a
fluid filled with lipids and
salts. Bile dissolves fats so
that they can be broken
down.
Bile is stored in the gall
bladder, a small organ
beneath the liver.
Standard A & F (cont.)
The Jejunum and Ileum (Small Intestine
The jejunum and ileum are the second
and third parts of the small intestine.
the cells in the walls of the jejunum
and ileum rapidly absorb nutrient
molecules from the chyme.
These nutrients are absorbed by
either capillaries or lymph vessels.
This allows the nutrients to be
transported by the circulatory
system to all cells in the body.
The Large Intestine
The large intestine absorbs the
materials that remain after the small
intestine has finished absorbing
nutrients. The large intestine’s job is
to remove water from the undigested
material.
Water is absorbed by the large
intestine’s lining. The remaining
material passes through the rectum
and is removed from the body.
What is it made
up of?
the skin, lungs,
liver, and kidneys
What does it do?
1. removes carbon dioxide
2. removes excess water
Standards?
a. how the complementary activity of major body systems provides cells
with oxygen and nutrients and removes toxic waste products such as
carbon dioxide.
g. the homeostatic role of the kidneys in the removal of nitrogenous
wastes and the role of the liver in blood detoxification and glucose
balance.
Standard A
how the complementary activity of major body systems
removes toxic waste products such as carbon dioxide
The Lungs
As discussed in the respiratory
system, the lungs remove carbon
dioxide from the blood and use
exhalation to release it from the
body.
The Skin
As discussed in the integumentary
system, sweat glands in the dermis
release water to cool off.
Standard G
the homeostatic role of the kidneys in the removal of
nitrogenous wastes and the role of the liver in blood
detoxification and glucose balance.
The Kidneys
The kidneys are small, saclike organs that filter
out blood.
Blood enters the kidney through the renal artery.
As the blood passes through it, wastes and excess
water are collected. Filtered blood exits
through the renal vein.
The independent units in the kidney that
perform this function are called nephrons.
Each nephron has an arteriole and venule
attached to it by capillaries.
As blood flows through the nephron from
arteriole to venule, it filters out urea, water,
glucose, salts, and some vitamins.
A tube called the ureter carries these
wastes, now called urine, to the urinary
bladder.
The bladder releases the urine through a
tube called the urethra.
Standard G (cont)
Maintaining Homeostasis
Homeostasis is the stability of the
internal body. The kidneys maintain
homeostasis by controlling their
activities based on the composition of
the blood.
For example, when you drink a lot of
water, the kidneys sense the
increased concentration of water in
the blood.
To compensate for this change, they
remove more water from the system.
Excess water is sent to the bladder,
resulting in increased urination.
The blood, however, retains the same
level of water concentration.
What is it made
up of?
glands and the
hormones they
produce
What does it do?
1. broadcast messages
throughout the body
Standards?
c. how feedback loops in the endocrine system regulates conditions in
the body.
i. how hormones (including digestive, reproductive, osmoregulatory)
provide internal feedback mechanisms for homeostasis at the cellular
level and in whole organisms.
Hormones & Glands
Hormones are chemicals that pass
through the bloodstream to deliver
messages.
Hormones bind to chemical receptors
on specific cells. If a cell has a
chemical receptor for a particular
hormone, it is a target cell for that
hormone.
Hormones are released from organs
called glands. Exocrine glands
release hormones through small
tubes, called ducts.
Ducts let a gland release a hormone
in a very specific place.
Examples of exocrine glands include
sweat glands and tear ducts.
However, endocrine glands affect a
larger area of the body because they
release their hormones directly into
the bloodstream.
The endocrine system deals with this
type of gland.
Examples of Endocrine Glands & Their Hormones
The pineal gland releases melatonin, which
involves cyclic activities like sleeping.
The pituitary gland’s hormones monitor
other glands.
The thyroid releases thyroxine, which
speeds or slows metabolism.
The parathyroid glands regulate the
amount of calcium in blood.
The adrenal gland produces epinephrine and
norepinephrine, which reduce stress.
The pancreas produces insulin and
glucagon, which regulate blood sugar.
The testis and ovary produce sex hormones
that will be discussed more in the
reproductive system.
Standard I & C
how hormones (including digestive, reproductive,
osmoregulatory) provide internal feedback mechanisms for
homeostasis at the cellular level and in whole organisms.
When a gland (often the pituitary gland, which
regulates the functions of others) senses a
change in the body, it releases hormones that
work to maintain homeostasis.
For example, when you are exercising, your body
loses water through sweat. This makes the
concentration of other materials in your blood
rise. When the hypothalamus (a part of the
brain that controls the pituitary gland) senses
this, it signals the pituitary gland to slow the
kidneys’ removal of water.
When you drink a lot of water, the
concentration of water in the blood increases.
The hypothalamus senses this and tells the
pituitary gland to stop producing hormones.
The kidneys begin to act normally again, and
remove the excess water from the body.
What is it made
up of?
Male: testes,
scrotum,
epididymis, vas
deferens,
urethra, penis
Female: ovaries,
the Fallopian
tubes, uterus,
vagina
Standards?
None
What does it do?
1. Male: develop
sperm and
deliver it to
the female
body
2. Female:
produce eggs
and provide a
safe
environment
for a fetus
The Male Reproductive System
Males fertilize a female
egg cell with smaller
cells called sperm.
Sperm are produced within the testes in
hundreds of tiny tubes.
The testes are kept outside of the body in the
scrotum so that the temperature will be cool
enough to make sperm.
Sperm cells are moved to a structure behind the
testes called the epididymis, where they mature.
Some sperm cells are moved from the epididymis
to the vas deferens, a tube that eventually
merges with the urethra, the tube that carries
urine to the end of the penis.
Sperm cells are nourished by a fluid produced by the
reproductive glands: the seminal vesicles, the prostate
gland, and the bulbourethral gland.
The fluid is called seminal fluid, and the mixture of sperm
and seminal fluid is known as semen.
The Female Reproductive System
Females have egg cells called ova (singular
ovum) that mature into a fetus if fertilized.
Every woman is born with all
of her ova, which are stored
in the ovaries.
About every month, an
immature egg cell goes
through meiosis and
produces one large gamete
and three polar bodies that
soon disintegrate.
After the egg cell is mature,
it is pushed into a Fallopian
tube and begins to travel
downward.
The cell can be fertilized as
it passes through the tube
into the uterus.
If the cell is fertilized when it reaches the uterus, it attaches the
wall and begins to form a fetus. If not, it is swept out of the body
through the vagina in a process called menstruation.
What is it made
up of?
skin, red bone
marrow, lymph
nodes, and
lymphocytes
What does it do?
1. protects the body from
infection
Standards?
As a basis for understanding the human immune
response:
a. the role of the skin in providing nonspecific
defenses against infection.
b. the role of antibodies in the body's response to
infection.
c. how vaccination protects an individual from
infectious diseases.
d. the important differences between bacteria and
viruses with respect to their requirements for
growth and replication, the body's primary
defenses against bacterial and viral infections,
and effective treatments of these infections.
e. why an individual with a compromised immune system (for example, a
person with AIDS) may be unable to fight off and survive infections
by microorganisms that are usually benign.
f. the roles of phagocytes, B-lymphocytes, and T-lymphocytes.
D. the important differences between bacteria and
viruses with respect to their requirements for growth
and replication, the body's primary defenses against
bacterial and viral infections, and effective
treatments of these infections.
Bacteria—one-celled organisms. Most
are harmless, but some are dangerous.
Bacteria can reproduce on their own,
and can live on a non-living host.
The body fights bacteria with
phagocytes and antibodies.
Treatment can include vaccines, and
antibiotics which prevent bacteria from
functioning.
However, antibiotics cannot be used to
regularly because bacteria will rapidly
become resistant to the drug.
Viruses—a section of DNA or RNA
covered by a coat of proteins,
much smaller than bacteria.
Viruses must invade a living host
cell to reproduce.
The body fights viral infections
with antibodies, phagocytes, and
T cells.
Treatment can include vaccines &
antiviral medications (prevent
viruses from entering cells)
a. the role of the skin in providing nonspecific
defenses against infection.
The easiest and most efficient way to protect against
infection is to keep pathogens out of the body.
The skin provides the best nonspecific defense against
infection.
(A nonspecific defense is a protection system that guards
against all infections, like a wall.
Specific defenses are like police that track down
pathogens that have entered the body.)
First of all, the top layer of the skin
is made of dead skin cells filled with
the tough protein keratin.
Very little passes through this
strong barrier.
Most pathogens can only enter when
the skin is cut.
Skin oils and sweat are also
nonspecific defenses because they
create acids that kill many bacteria.
Other nonspecific defenses are mucus, nose hairs and cilia (trap
pathogens) and stomach acid (destroys them). Many secretions like tears
and sweat also contain lysozyme, which breaks down bacteria’s cell walls.
f. the roles of phagocytes, B-lymphocytes, and T-lymphocytes.
A phagocyte is a white blood
cell that engulfs foreign
materials in the blood.
Macrophages are very large
phagocytes.
Millions of Blymphocytes develop
early in life, and each
one has a d formula for
making a different
antibody (see next slide).
There are 2 type of T-lymphocytes
Helper T-cells control B-cells’
production of antibodies.
Killer T-cells rupture foreign cells by
forcing proteins through their cell
membranes.
b. the role of antibodies in the body's response to infection.
When the body is infected
with a pathogen, the natural
immune response begins.
Helper T-cells aid B-cells in
becoming an antibodyproducing plasma cell.
The proteins bind to the
bacterium/virus. The clumps
of antibodies around the
pathogen help other cells
find and destroy it.
The plasma cell then
produces lots of antibody
proteins.
C. how vaccination protects an individual from infectious diseases.
A vaccine is a method of exposing the body to a disease so it
can build up an immunity to it with little risk.
A weakened pathogen is injected into the body, and makes
the immune system produce millions of white blood cells
that can fight it.
If the actual pathogen ever enters the body, the
necessary information will be there to fight it efficiently.
E. why an individual with a compromised immune system (for
example, a person with AIDS) may be unable to fight off and
survive infections by microorganisms.
AIDS is caused by HIV (human immunodeficiency virus).
When the virus enters the bloodstream, it binds to the receptors of
helper T-cells, which help other lymphocytes respond to infection.
The body produces antibodies against the HIV virus. However, since
the virus is already inside the cells of the immune system, the
antibodies almost never are able to bind to it.