The Human Body
Body Organization
• Organ Systems – groups of organs in the body
that work together to form a specific task
• Homeostasis – the maintenance of a constant
internal state in a changing environment
THE INTEGUMENTARY
SYSTEM
skin, hair, and nails
Functions of the Skin
• Protects you by keeping water in the body and foreign
substances out
• Sense of touch
• Helps regulate body temperature with sweat glands
• Gets rid of waste
• Largest organ of the body
Layers of the Skin
• Epidermis
• very thin top layer of the skin
• most epidermal cells are dead
• Dermis
• lies beneath the epidermis
• contains many other
small structures
• Subcutaneous Fat
• bottom layer
Parts of the Skin
• Hair follicle – where hair grows
• Sweat gland – releases sweat, which
regulates the body and gets rid of
waste
• Oil gland – releases oil, which keeps
hair flexible and makes the skin
waterproof
• Blood vessels – transport blood to the
skin; regulate body temperature
Other Parts
of the Skin
• Hair & Nails
• both grow from the base of a follicle or root
• only living cells are at the base and push old cells up
• provide protection and hair helps regulate body temperature
About the Skin
• Melanin
• chemical that determines color of the skin
• a lot of melanin = darker skin
• helps protect against UV radiation from the sun
• Skin Cancer
• abnormal growth of skin cells
• can develop from prolonged exposure to UV
radiation
Structure & Movement
The Musculoskeletal System
Kinds of Muscle
• Smooth Muscle
• found in the digestive tract and walls of blood vessels
• involuntary (not under your control)
• Cardiac Muscle
• found only in the heart
• involuntary (not under your control)
• Skeletal Muscle
• attached to your bones and allows you to move
• can be involuntary or voluntary (you control the
movement)
Tendons
• Tendons
• connective tissue that attaches muscles to bones
• when the muscle contracts, the bones are pulled up
• Ex. contracting your bicep makes your arm move upward
Muscle Fatigue
• Lactic Acid
• chemical produced by muscle cells during respiration
• if muscles are worked too hard too quickly lactic acid can
build up, this causes the muscles to burn or ache
Function of Skeletal System
• Protection
• ex. ribs protect heart, skull protects brain
• Storage
• store minerals and fat
• Movement
• muscles pull on bones to make them move
• Blood cell formation
• marrow inside the bones makes blood cells
Bone Structure
• Compact Bone
• dense and rigid structure
• no pores or open spaces
• stores minerals (calcium and
phosphorus)
• Spongy Bone
• many open spaces
• provides strength and support
Bone Structure
• Cartilage
• soft, flexible tissue usually replaced by bone
• also found on the ends of bones to ease friction
and absorb shock
• Marrow
• soft tissue inside bone
• red marrow produces blood cells
• yellow marrow is found in long bones
and stores fat
Joints
- a place where two or more bones meet
- held together by ligaments- connective tissue that
connects bone to bone.
• Three kinds of joints:
• Gliding Joint
- bones gliding over one another (ex. wrist, vertebrae)
• Ball-and-Socket Joint
- allows movement in all directions (ex. shoulder, hip)
• Hinge Joint
- allows for bending at right angles (ex. knees, elbows)
Skeletal System
Injuries & Disorders
• Sprain
• when a ligament is stretched too far or torn
• Osteoporosis
• bones become less dense and weak due to age or
poor diet
• Arthritis
• swelling or stiffening of the joints
Communication & Control
The Nervous & Endocrine Systems
The Nervous System
• The nervous system acts as the body’s central
command post.
• It detects , processes, and responds to
information in the body
• Communication occurs using electrical impulses.
Neurons
• The basic unit of the nervous system is the Neurona specialized nerve cell that transfers messages in the form of
electrical impulses.
• Three parts of a neuron:
• cell body – normal cell structure
• dendrite – branch-like structures
used to receive impulses
• axon – long, tail-like structure
covered in a myelin sheath (fat)
used to send impulses
Information Collection & Delivery
• Sensory Neurons – gather information about
what
is happening in and around the body
• Motor Neurons – send impulses from the
central nervous system to other systems of the
body
• Nerve – collection of axons bundled together
with blood vessels and connective tissue
Peripheral Nervous System
(PNS)
• Peripheral Nervous System (PNS)
• all of the parts of the nervous system except the brain and
spinal cord
• uses specialized structures call nerves to carry information
between parts of the body
Central Nervous System (CNS)
• Central Nervous System (CNS)
• receives messages from the
peripheral nervous system and
responds by sending
messages to the motor neurons
• made up of the brain and spinal cord
The Brain
• Main control center of the nervous system
• Three main parts of the brain:
• Cerebrum
• Cerebellum
• Medulla
Cerebrum
• largest part of the brain
• where you think and carry most
memories
• location of all your senses
• divided into two hemispheres
• right side controls left side of the
body, and vice versa
Parts of the Brain
Cerebellum
• second-largest part of the
brain
• located beneath the back of
the cerebrum
• processes sensory
information from muscles
and joints (i.e. balance)
Parts of the Brain
Medulla
• part of the brain that
connects to the spinal cord
• controls involuntary things
like breathing, heart rate,
blood pressure, and body
temperature
Parts of the Brain
Spinal Cord
• made of bundles of neurons that
pass impulses to and from the
brain
• surrounded by the vertebrae
(protective bones of the spine)
• sensory neurons  spinal cord 
brain  spinal cord  motor
neurons
The Endocrine System
pituitary, thyroid, gonads
• a collection of glands
that secrete hormones
into the body that
regulate growth,
development, and
homeostasis
Function
Hormones
• chemical messengers released by an endocrine gland and
carried through the blood to different parts of the body
• ex. adrenaline - released when you are scared, angry, or
excited to increase your heart rate and breathing
• Pituitary gland
• “master gland” that controls other
endocrine glands
• located in the brain
• makes human growth hormone (HGH)
• Thyroid gland
• controls how you use energy
(metabolism)
• in the neck
• Parathyroid gland
• regulates calcium levels in the blood
• behind the thyroid gland
Endocrine Glands
• Thymus gland
• regulates the immune system
to help fight disease
• behind the heart
• Adrenal glands
• produces adrenalin to help
the body respond to danger
• sit atop the kidneys
• Pancreas
• regulates blood sugar levels
by secreting insulin
Endocrine Glands
• Ovaries (female)
• produce estrogen to aid in
female reproduction
• released during puberty
• Testes (male)
• produce testosterone to aid
in male reproduction
• released during puberty
Endocrine Glands
• Diabetes
• the pancreas does not make insulin properly so the body
cannot regulate blood sugar levels
• patients must take insulin injections
• Hormone Imbalances
• Thyroid – controls metabolism, so this can lead to obesity
• Pituitary – controls growth, so this can lead to stunted
growth or being abnormally tall
Diseases & Disorders
The Respiratory System
lungs, bronchi, diaphragm
• The exchange of oxygen and carbon dioxide between
living cells and their environment
• Includes breathing and cellular respiration
• The respiratory system is a group of organs that take in
oxygen and release carbon dioxide
Respiration
• Nose
• air enters and exits through the nose
• hairs and mucus in the nose trap dirt and particles
• Pharynx (Throat)
• splits into two tubes – the esophagus (leads to the stomach) and
the trachea (leads to the lungs)
• a tiny flap called the epiglottis covers the trachea to prevent food
from going into the lungs when swallowed
• Larynx
• location of the vocal cords – two muscles stretched over the
trachea that vibrate when air passes through them
Upper Respiratory System
• Trachea
• also known as the windpipe
• Bronchus
• the trachea splits into two separate bronchi,
going to each lung
• the bronchi split further into smaller tubes
bronchioles
one
called
• Alveoli
• tiny air sacs located at the ends of each
bronchiole
• Covered in blood vessels so gas exchange
can take place
Lower Respiratory System
• the diaphragm is a dome-shaped muscle underneath your
lungs
• when it pushes downward you inhale, when it pushes
upward you exhale
• spasm of the diaphragm gives
you
hiccups
Breathing
• Asthma
• swelling and narrowing on the bronchioles
• makes breathing more difficult
• Emphysema
• damage to the alveoli
• trouble getting oxygen to the body
• Lung cancer
• can be caused by smoking
Respiratory Disorders
The Circulatory System
heart, blood, arteries & veins
• moves blood throughout the body
• carries nutrients to your cells
• removes waste from your cells
• carries chemicals through your body
• regulates body temperature
Functions
• Made of cardiac muscle
• Right side of the heart
pumps oxygen-poor
blood to the lungs
• Left side pumps oxygenrich blood to the body
Four chambers separated by valves:
Upper = atriums (right and left)
Lower = ventricles (right and left)
Heart
Path of Blood
• Three types of blood vessels:
• Artery
• Carries blood AWAY from the heart
• Vein
• Carries blood TO the heart
• Capillary
• Tiny blood vessels that allow for gas and waste exchange
between the blood and cells
Blood Vessels
• Two types of circulation
• Pulmonary Circulation –
between the heart and lungs
• Pulmonary artery – carries blood
from heart to lungs
• Pulmonary vein – carries blood
from lungs to heart
• Systemic Circulation – between
the heart and body
• Aorta – carries blood from heart to
body
• Superior/Inferior Vena Cava –
carries blood from body to heart
Circulation
Diseases & Disorders of
the Circulatory System
• Atherosclerosis
• build up of cholesterol in blood vessels
• clogs pathways and blood flow becomes
blocked
• Heart Attacks
• arteries going to the heart itself
become blocked
• heart muscle cells die
• Fluid that carries nutrients, waste, and gases throughout
the body
• Made up of four parts:
•
•
•
•
plasma
red blood cells
platelets
white blood cells
Blood
Plasma
Red Blood Cells
• Fluid part of the blood
• Most of what blood is
made of
• A mixture of water,
minerals, nutrients,
sugars, proteins, and
other substances
• Hemoglobin in your red
blood cells helps carry
oxygen to your body.
• All other parts of the
blood are found within
plasma
Parts of the Blood
Platelets
White Blood Cells
• Pieces of larger cells
floating among blood cells
• Destroy pathogens (bacteria
and viruses) that attack your
body
• Release chemicals that form
a net at damaged vessel to
stop blood flow and clot
• Some release antibodies
which identify and destroy
pathogens
Parts of the Blood
• Refers to the types of chemicals (antigens) you have on
the surface of your red blood cells
•
•
•
•
Type A = A antigens
Type B = B antigens
Type AB = both antigens
Type O = neither antigen
Can Receive
From
Can
Donate To
A
A, O
A, AB
B
B, O
B, AB
All types
AB only
O only
All types
AB
O
Blood Types
Universal Receptor = Type AB
Universal Donor = Type O
The Digestive System
stomach, liver, intestines
• organs that break down food to be used by the body
• Mechanical Digestion – breaking, crushing,
mashing of food particles
• Chemical Digestion – large molecules are broken
down into specific nutrients
Function
Teeth
• chew and mash food
beginning mechanical
digestion
• hardest substances in the
body
Saliva
• liquid made in the salivary
glands of the mouth
• contain enzymes that begins
the chemical
digestion of food
Digestion in the Mouth
• long, straight tube
connecting the throat
and stomach
• squeezes food down to
the stomach using
muscle contractions
called peristalsis
Esophagus
• muscular, saclike organ
where food continues to
get broken down
mechanically and
chemically
• releases small amount of
enzymes and acid to
break down food
• slowly releases the soupy
mixture, now called
chyme, into the small
intestine
The Stomach
• located between the stomach and small intestine
• released enzymes into the small intestine to continues digestion
• also releases hormones to regular blood sugar levels
Pancreas
Liver
Gallbladder
• located beside and above
the stomach on the right
side
• produces bile to help break
down fats
• also breaks down toxins
Helper Organs
• small, green, saclike organ
located
behind the liver
• stores the bile
• Small Intestine
• muscular tube that is about 6 meters long
• inside is covered in small projections
called villi where nutrients are absorbed
• Large Intestine (Colon)
• stores and compacts undigested material
by absorbing water
• feces (poop) are stored in the rectum and
eliminated through the anus
Small & Large Intestine
•
•
•
•
•
•
•
•
•
Mouth
Esophagus
Stomach
Pancreas
Liver
Gallbladder
Small Intestine
Large Intestine
Rectum
What to Know
• Essential needs for human development:
• Carbohydrates – give energy
• Examples: fruits, vegetables, grains
• Proteins – build muscle
• Examples: meat, dairy, beans
• Fats – protect body
• Examples: oils, nuts, lard
• Vitamins & Minerals
• Examples: zinc, calcium, potassium, vitamin A, vitamin C
Nutrition
• calories = how much energy is contained in food
• determined by using a calorimeter – food is burned to see
how much heat (energy) is released
Calories
The Excretory System
kidneys, urinary bladder
• removal of waste materials from the body
• Parts of the Excretory System:
• skin – sweating
• lungs – exhaling
• kidneys – urine
Function
• a pair of organs that constantly
clean the blood
• inside each kidney are about
one million nephrons
• Nephrons - microscopic filters
that remove harmful substances
from the blood, including urea
• Urea - a nitrogen-based substance
that is formed when cells use
protein for energy
Kidneys
• renal artery brings blood
into each kidney
• tiny blood vessels bring
blood to the nephrons
• blood gets filtered
• cleaned blood exits kidneys
through a renal vein
• waste material leaves
nephrons as urine
How Kidneys Work
• urine leaves the kidneys
through tubes called
ureters
• ureters lead to the urinary
bladder where urine is
stored
• it will eventually leave the
body through a tube called
the urethra
Exiting the Body
• Urinary Tract Infection (UTI)
• bacteria gets into the urinary tract (urethra, bladder, ureters)
and cause pain
• Kidney disease
• damage to nephrons prohibits normal filtering of the blood
• a machine must be used to filter the blood, called a dialysis
machine
Kidney Diseases & Disorders
• salts and other waste
build up in the kidneys
and make a hard stonelike substance that
interferes with urination
• can be passed naturally
or must be removed
surgically
Kidney Stones
The Immune System
disease, T & B cells, antibodies
Noninfectious
Infectious
• cannot be spread from
one individual to another
• can be spread from one
individual to another
• can be caused by
genetics, habits (ex.
smoking), poor diet
• ex. cancer, heart disease
Disease
• caused by pathogens (virus
or organism that causes
disease)
• some organisms that cause
disease: bacteria, fungi,
protists, worms
• Ways Pathogens Get Transferred:
•
•
•
•
•
Air
Contaminated objects (ex. doorknobs, keyboards)
Person to person
Animals (ex. dogs, ticks)
Food and water (ex. meat)
Pathogen Pathways
• List some ways pathogens can be spread from
one individual to another.
BELLWORK
Viruses
• Microscopic
• can be spread from one
individual to another
• need the cells of living things to reproduce, therefore
are not considered a living thing themselves
• Are treated with Vaccines.
Bacteria
• Some bacteria are pathogens
• Some bacteria that normally live in the body cause illness
only when the person's immune system is weakened.
• They can enter the body through a cut, in the air, or on food.
After they are in the body, they reproduce and cause disease.
• Some can:
• make people sick by damaging tissue.
• cause illness by releasing toxins.
• Antibiotics are medicines that stop the growth and
reproduction of bacteria
The Immune System
• Function
• cells and tissues that recognize and attack foreign
substances in the body
• Parts of the Immune System
• Macrophages
• T-cells
• B-cells
• If pathogens get past your first line of defenses (skin, oil,
mucus) your body will respond to destroy them.
• Macrophage
• engulf and destroy the virus
• engulf and destroy cells infected by the virus
• display viral antigens (substances that
stimulate an immune response)
• Helper T-Cells
• recognize the viral antigen and begin two responses:
• T-Cell Response
• B-Cell Response
Responding to a Virus
T-Cell Response
B-Cell Response
• activation of killer T-cells
• recognize antigens on
infected body cells
• kills the cells so they
cannot replicate
• activation of B-cells
• b-cells divide and create
anitbodies (proteins that
attach to specific antigens)
• antibodies cause viruses to
clump together and become
marked for destruction
Immune Responses
• normal B-cells create antibodies against a pathogen
within two weeks
• some B-cells become memory B-cells, which means the
next time your body encounters that pathogen your Bcells “remember” how to create the antibodies for it and
you will be protected within 3 or 4 days
Memory B-Cells
• Allergy
• an overreaction to a harmless or common substance by the
immune system
• Autoimmune Diseases
• diseases in which the immune system
mistakes body cells for pathogens and
attacks them
• ex. rheumatoid arthritis, multiple sclerosis, lupus
Challenging the Immune System
• Human Immunodeficiency Virus (HIV)
• causes acquired immune deficiency syndrome (AIDS)
• infects the cells of the immune system, specifically the
helper T-cells, and destroys them
• killer T-cells and B-cells do not get activated,
therefore the body cannot defend itself
against the virus or any other pathogens
• Most people die from other diseases that
their body could not fend off
HIV/AIDS
The Reproductive System
ovaries, testes, egg, sperm
• Testes – sperm is produced here
• Epididymis – sperm is stored here
• Vas Deferens – sperm leave the
testes through these tubes
• Prostate Gland – other fluids are
added here to make semen
• Urethra – semen leaves the body
through this tube out the penis
Male Reproductive System
• Ovaries – eggs are
produced here
• Fallopian Tubes – eggs
travel down these to get
to the uterus
• Uterus – fertilized eggs
attach here and this is
where the fetus develops
Female Reproductive System
• beginning at puberty eggs are
released from the ovary once
a month to be fertilized
• the uterus begins to prepare
for pregnancy by building up
blood vessels in the uterine
walls
• if the egg does not become
fertilized the uterus will
release the egg along with the
all the uterine lining through
the vagina
Menstruation
• An egg becomes fertilized when a sperm
enters the egg cell. The fertilized egg is
now called a zygote.
• The zygote begins to divide into many cells and implants
itself into the uterine wall. It is now called an embryo.
Fertilization
• The placenta gives the
embryo nutrients and picks
up any waste products.
• It is attached to the
placenta by the umbilical
cord.
• The embryo develops
inside a sac called the
amnion which is filled
with amniotic fluid.
Pregnancy