Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

The Human Body

Integumentary, Muscular, Skeletal, Respiratory, Blood & Immune
by

Miss Schwinge

on 3 September 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of The Human Body

The Human Body
Integumentary System
Skeletal System
Muscular System
The

integumentary system
(made up of
skin, hair and nails
), serves as the body's
first defense against infection and injury, helps to regulate body temperature, removes waste products from the body, and provides protection against ultraviolet (UV) radiation from the sun.
The skin is made up of two main layers:

1.) the epidermis
2.) the dermis
Beneath the dermis is a layer of fat (the
hypodermis
) and loose connective tissue that helps
insulate the body
Skin is
the largest organ in the human body.
It also has an acidic pH value (anywhere between 4.5-7) to
help prevent bacteria and foreign material from growing on it
. Babies have a pH skin value closer to 7, but it decreases as you get older.
The
inner layer
is made up of
living cells
, and constantly go through constant rapid cell division. This produces
new cells
, which
push older cells to the surface of the skin
and creates a
tough, flexible, waterproof covering on the surface of the skin.
The epidermis also contains
melanocytes,
which produce
melanin
: a
dark brown pigment.
Melanin helps
protect the skin from damage by absorbing UV rays
from the sun. Although most people have roughly
the same number of melanocytes
in their skin, differences in skin color are caused by the
different amount of melanin the melanocytes produce
, and where these cells are distributed.
The
more melanin
you have in your skin, the
tanner
you look. People with fair skin have less melanin in their skin to begin with, but
some of their melanocytes make more melanin when exposed to the sun
. So instead of easily getting an even suntan, they sometimes get
freckles
.
The
dermis
lies
beneath
the epidermis, and contains
blood vessels, nerve endings, sensory receptors, smooth muscle, sweat glands, and hair fibers.
The skin interacts with other body parts to maintain
homeostasis
(internal stability) by helping to regulate body temperature.
When the body needs to
conserve heat
on a cold day, the blood vessels in the dermis
narrow
, helping them lower heat loss.

On hot days, the blood vessels
widen,
bringing heat from the
body's core to the skin
and increasing heat loss.
Hair covers almost every exposed surface of the body. Hair on the head protects the scalp from
UV light from the sun and provides insulation from the cold.

Eyelashes, and hairs in the nostrils and outer ear canals prevent
dirt and other particles from entering
the body.
Nails cover and protect fingers and toes, and are made from the
same thing as hair
(keratin). Due
to their more frequent use, fingernails
grow around

4 times faster

than toenails.
Despite what some horror movies may say, a skeleton cannot move on its own.

Movement
is the function of the
muscular system.
More than
40%
of the mass of the average human body is
muscle
Muscle tissue is found
everywhere in the body
, not just beneath the skin. There are
3 types
of muscle tissue:
1.) skeletal
2.) smooth
3.) cardiac

Each type of muscle is
specialized
for specific function in the body
1.) Skeletal Muscle
Skeletal muscles
are usually attached to

bones
(hence their name).

They are responsible for
voluntary movements
, like typing on a keyboard, dancing, or winking.
When viewed under a microscope, skeletal muscle has alternating
light and dark bands called striations.
This is why skeletal muscles are also called
striated muscles.
Skeletal muscle cells are
large,
have
many nuclei
, and
vary in length
.
2.) Smooth Muscle
Smooth muscles
are usually
not under voluntary control.

They are
spindle shaped, have only one nucleus
, and are
not striated
.
They
move food through your digestive tract,

control the way

blood flows through your circulatory system,

and decrease the size of the

pupils of your eyes in bright light.
3.) Cardiac Muscle
Cardiac muscle
is found in only one place:
the heart.
Cardiac muscle is
striated like skeletal muscle
, but its cells are
smaller.
It is
similar to smooth muscle
because it is also
not under voluntary control.
Muscle Contraction
Most skeletal
muscles
work in
opposing pairs.

When one muscle
contracts,
the other
relaxes
. The
muscle fibers

in skeletal muscles are made up of

smaller structures

called
myofibrils
Each myofibril is made up of
even smaller
structures called
filaments.
The
thick
filaments contain a protein called
myosin
.
The
thin
filaments are made up mainly of a protein called
actin.
A muscle
contracts

when the

thin filaments

in the muscle fiber
slide over the thick filaments.
Skeletal muscles
generate force
and
produce movement
by
contracting,
or pulling on body parts.
Individual muscles can only pull in

one direction

(no, not these guys -->) but yet we can manage to bend and extend things like our legs. How?
Skeletal muscles are joined to bones by tough
connective tissues
called
tendons
. Tendons are attached in such a way that they
pull on the bones
and make them work like levers.
Our body is kept together through hugs!
To retain their shape, all organisms need some type of
structural support.
The human skeleton is composed of a type of
connective tissue called bone.

Bones
and other connective tissues, such as cartilage and ligaments,
form the skeletal system.
The skeleton
supports the body, protects internal organs, provides for movement, stores mineral reserves,
and provides a site for

blood cell formation.
It easy to think of bones as non-living. After all, many of the mass of bone is made of mineral salts. However,
bones are living tissue.
Bones are a solid network

of
living cells and protein fibers
that are surrounded by deposits of

calcium salts.
Structure of bones
Bones are surrounded by a
tough layer of connective tissue
called the
periosteum
Blood vessels that
pass through
the periosteum carry
oxygen
and
nutrients
to the bone.
Beneath the periosteum is a thick layer of
compact bone
. Although compact bone is dense,
it is not solid.
A less dense tissue known as
spongy bone
is found inside the
outer layer
of compact bone. Even though it is called spongy, it's actually
quite strong
.
Within bones are
cavities
that contain a
soft tissue
called
bone marrow.
There are
2 types

of marrow:


1.) yellow
2.) red

Yellow marrow
is made up mostly of
fat cells,
and
red marrow
produces
red blood cells,
some kinds of
white blood cells,
and
cell fragments
called
platelets.
The skeleton of an
embryo
is composed almost entirely of a type of connective tissue called
cartilage.
Cartilage does
not contain blood vessels.
Because of this, it must rely on the
diffusion of nutrients
from the tiny blood vessels in surrounding tissues.
In adults, cartilage is found in parts of the body that are
flexible,
such as the
tip of the nose, external ears, and where the ribs are attached to the sternum.
Types of Joints
A place where
one bone attaches to another
bone is called a
joint.
Ligaments
are what
hold bones together
in a joint, and they are attached to the
membranes
that surround bones.
Respiratory System
Blood
carries
oxygen from the lungs

to the body's

tissues,
and carries
carbon dioxide
(a waste product) in the
opposite direction.

This is known as

gas exchange,

and is the

main function of the respiratory system.
The
respiratory system
consists of the
nose, pharynx, larynx, trachea, bronchi, and lungs.
The air that makes it
past the nostrils
moves through the
nose
to a tube at the back of the mouth called the
pharynx, or throat.
The
pharynx
serves as a
passageway
for both
air and food.
Then the air moves from the pharynx
into the trachea
, or
windpipe
. A
flap of tissue
called the
epiglottis

covers the
entrance to the trachea
when you
swallow.
The
respiratory passageways
allow air to
pass directly
into some of the most
delicate tissues
in the body.
To keep the lung tissue
healthy,
air entering the respiratory system must be
warmed, moistened and filtered.
Large dust particles get
trapped by the hairs
lining the entrance to the
nasal cavity.
At the
top of the trachea
is the
larynx.
The
larynx
contains two
highly elastic folds of tissue

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 (such as words).
From the larynx, air passes into the lungs
through the trachea
, where it branches into
two large passageways
in the chest cavity called the

bronchi.
These then divide into
increasingly smaller branches
called
bronchioles.
Breathing

is the
movement of air into and out of the lungs
. There are
no muscles
connected to the lungs, instead, the force that drives air into the lungs is just ordinary

air pressure.
The lungs are
sealed in two sacs
inside the chest cavity. At the
bottom
of the cavity is a
large, flat muscle
known as the
diaphragm.
When you
breathe in (inhale)
, the diaphragm
contracts
and the rib cage
rises up
. This
expands the volume of the chest cavity.
Most of the time,
breathing out (exhaling)
is a
passive event.
When the rib cage lowers and the
diaphragm muscle relaxes,
air
rushes out of the lungs.
Healthy lungs vs. smoker's lungs
The smallest bronchioles end in a
cluster of air sacs,

collectively called
alveoli.
Alveoli
are the
primary site for gas exchange
in the respiratory system.
Blood and the Lymphatic System
Just like the plumbing system in your home carries water through a series of pipes to different parts of a house,
the circulatory system carries blood through a series of blood vessels to different parts of the body
Blood
is a type of
connective tissue
containing both
dissolved substances and specialized cells.
Blood

collects

oxygen from the lungs, nutrients from the digestive tract, and waste products from tissues.
The human body contains
4 to 6 liters of blood
, which is about
8%
of the
total body mass.

About
45%

of the volume of
blood
consists of
cells,

which are suspended in the
other 55%: a straw colored fluid
called

plasma.

Plasma
is about
90% water
and
10% dissolved gases, salts, nutrients, enzymes, hormones, waste products and proteins.
The
cellular portion
of blood consists of

red blood cells, white blood cells, and platelets.
Red blood cells transport oxygen, white blood cells perform a variety of protective functions, and platelets help in the clotting process.




Platelets
are actually
fragments of cells
derived from larger cells in
red bone marrow.
The
most numerous cells
in the blood are the
red blood cells.
They
transport oxygen
, and get their color from
hemoglobin.
Hemoglobin
is the
iron containing protein
that binds to
oxygen in the lungs
and
transports it to tissues
throughout the body.
Red blood cells
are shaped like disks that are thinner in the center than along the edges. They are
produced from cells in red bone marrow,
and
circulate for an average of 120 days

before they are
worn out
from squeezing through narrow capillaries.
White blood cells do not contain hemoglobin.
They are
much less common than red cells
, which outnumber them almost
1000 to 1
. They can live for
days, months, or even years depending on health.
White blood cells
are the
"army"
of the
circulatory system.
They
guard against infection, fight parasites and attack bacteria.
There are
many different types
of
white blood cells,
and they perform a wide variety of important functions.
Some protect the body
by acting as
phagocytes, or "eating cells,"
that
engulf and digest bacteria
and other disease causing microbes.
Some react to foreign substances by
releasing chemicals known as histamines
. These chemicals
increase blood flow to the affected area
, producing
redness and swelling
that are often associated with
allergies.
Other
white blood cells
, known as
lymphocytes,
are involved in the

immune response.

Blood is essential to life
, so when we hurt ourselves and lose this vital fluid it can be a problem. Luckily our body has a way to

slow bleeding and begin healing.
Blood clotting
is made possible by
plasma proteins and cell fragments called platelets
that are formed from certain
large cells in red bone marrow
breaking into
many pieces.
When
platelets
come into contact with the
edges of a broken blood vessel,
their surfaces become very
sticky
, and a
cluster of platelets
develop
around the wound.
The Immune System
and Immune System Disorders
With
pathogens (disease causing agents)
all around us, it may seem like a miracle that you're not sick all the time. For that you can thank your
immune system, a series of defenses that guard against disease.
The
immune system recognizes, attacks, destroys, and "remembers" each type of pathogen that enters the body.
It does this by
producing specialized cells
that
inactivate
pathogens.
The
function of the immune system
is to
fight infection through the production of cells that inactivate foreign substances or cells.
This process is called

immunity.
The immune system includes
2
general categories of
defense mechanisms

against infection:
1.) Nonspecific
2.) Specific
Nonspecific defenses
guard against infections by
keeping most things out of the body.

They do
not discriminate
between one threat and another .
Your body's
most important nonspecific defense is the skin.
The importance of skin as a barrier against infection becomes obvious as soon as the skin is broken.
Pathogens can also enter your body through your
mouth and nose. Mucus in your nose and throat
help
trap
these pathogens, and
cilia that line your nose and throat
help
push pathogens away
from your
lungs. Stomach acid and digestive enzymes
destroy many
pathogens that make their way to your stomach.
If pathogens do manage to enter your body, they may
multiply quickly, releasing toxins
into your tissues. When this happens, the
inflammatory response (a second line of defense)
is activated.
If a pathogen is able to
get past
the body's nonspecific defenses, the
immune response is to attack the particular disease causing agent.

A substance that

triggers this response
is known as an
antigen
. Viruses, bacteria, and other pathogens may serve as antigens.
The
cells
of the immune system that recognize
specific antigens are B lymphocytes (B cells) and T lymphocytes (T cells).

B cells
provide immunity against antigens and pathogens
in the body fluids.
When a pathogen invades the body, its antigens are
recognized
by some of the

body's B cells
. These B cells

grow and divide rapidly,
producing large numbers of plasma cells.
Once the body has been
exposed to a pathogen,
millions of memory

B cells remain capable of producing antibodies specific to that pathogen
; which
greatly reduces

the chance that the disease could develop a second time.
Unfortunately they also make the acceptance of organ transplants difficult.
The
injection of a weakened form of a pathogen
to
produce immunity
is known as a
vaccination.

Active immunity
is the type of immunity produced by the body's reaction to a

vaccine.
Immune System Disorders
Although the immune system defends the body from a wide range of pathogens, sometimes disorders occur
in the immune system itself.

These disorders include:
1.) allergies
2.) autoimmune diseases
3.) immunodeficiency diseases
The
most common overreactions
of the immune system to antigens are known as
allergies.

Some allergic reactions can create a dangerous condition called asthma.
Asthma is a chronic respiratory disease
in which the
air passages become narrower than usual
; resulting in wheezing, coughing, and difficulty breathing.

When the immune system makes a mistake and
attacks the body's own cells
, it produces an
autoimmune disease.

Some examples of autoimmune diseases include
Type 1 diabetes, rheumatoid arthritis, and multiple sclerosis (MS).

Immunodeficiency diseases
occur when either the
immune system fails to develop normally, or a viral infection destroys a normally healthy immune system.

An example of this second type of immunodeficiency disease

is
AIDS (acquired immune deficiency syndrome).

HIV (human immune deficiency virus) evades the defenses of the immune system, and attacks key cells in the immune system
which leaves the body with
no defenses

against other pathogens.

Although HIV is a deadly disease, it is not easily transmitted and you
cannot catch it through casual contact.

HIV can only be transmitted through the exchange of:
1.) blood
2.) semen
3.) vaginal secretions
4.) breast milk

Blood helps
regulate internal environment factors,
such as
body temperature
. Also, components in blood help
fight infections
, and can even
form clots to repair damaged blood vessels.

B lymphocytes produce antibodies. Antibodies
are essential to
fighting infection,
and help
produce immunity
to many diseases.







T lymphocytes help fight tumors and viruses.

Specific defenses track down harmful pathogens that have managed to break through the body's nonspecific defenses.
When that happens,
pathogens can enter your body

and multiply. As they grow, this can cause the
symptoms of an infection
.

The
inflammatory response

is a

nonspecific defense

reaction

to

tissue damage
caused by injury or infection
.
T cells

provide a defense against
abnormal cells and pathogens inside living cells (cell-mediated immunity).
They are also the body's way of fighting against its

own cells

when they have become

cancerous or infected.
Plasma cells release antibodies. Antibodies

are proteins that
recognize and bind to antigens
.
The antibodies are carried into the bloodstream to attack the pathogen that is causing the infection.

When allergy causing antigens enter the body, they
activate a particular type of cell called mast cells,
which then

release

chemicals known as
histamines.

The epidermis has two layers. The
outside of the epidermis

(the part that comes in contact with the environment) is made up of
dead cells
.
...But sometimes we can't even see our freckles!
Smooth muscles are found in the

walls of hollow structures,

such as your

stomach, blood vessels, and intestines.
The
joint

functions as a
fixed point
the lever moves around.

Usually, there are
several muscles
surrounding each joint that pull in
different directions.
Depending on its type of movement, a joint is classified as
immovable
(like where your the bones in the skull meet),
slightly movable

(like the bones between our vertebrae), or
freely movable.
For
each kind of pathogen
, the immune system produces cells that are
specific
to that pathogen.
Antibodies
Antigen
Full transcript