The Skeletal and Muscular Systems
1. Provide the body
with shape and
support
2. Allow for motion
3. Produce red blood
cells
4. Produce immune
response cells
Skeletons and Muscles In Other Animals
•
Animals tend to be divided into those with
skeletons and those without (jellies, sea anemones,
etc.).
•
The ones with skeletons are divided into external
(insects, crabs, clams, etc.) and internal
(amphibians, reptiles, birds, and mammals).
•
External skeletons must be shed as the animal
grows.
•
Starfish use a water pressure system for movement.
Bone Structure and Function
• Bones are made of calcium rich cells
called osteocytes, which surround tiny
canals that carry nutrients to the cells.
• Within this system of cells and canals,
in the long bones of the leg, are
hundreds of thousands of small spaces
where red marrow can be found. It is in
this marrow that red blood cells and B
and T cells (immune system) are made.
Bone Structure and Function
Joints
1. Fixed—the skull is an example
2. Ball and Socket—rotates in all
directions—shoulder and hip are
examples
3. Hinge—creates a back and forth
motion—knees and elbows are
examples.
Muscle Structure and Function
•
Muscle is a long thread like tissue compose
of thin fibers tightly compacted.
•
These fibers are made of two proteins called
actin and myosin.
•
These fibers slide past one another when
muscles contract.
Muscle Structure and Function
continued…
• A nerve response causes calcium
ions to flow, which causes the
actin to contract, or come
together around the myosin
fibers.
• This response causes the entire
muscle to contract.
Muscle Types
1. Skeletal—voluntary movement of
striated muscle. Allows for body
movement.
2. Smooth—involuntary movement—
movement of internal organs.
3. Cardiac—striated but involuntary—
heart muscle.
Muscles of Human Body
Tissues Necessary for Movement
1. Bone—gives body structure and support
2. Muscle—specialized tissue that contracts to
give bones movement.
3. Cartilage—lines joints and gives protection.
4. Ligaments— tissue surrounds bone and holds
it together.
5. Tendons—tissue connecting muscle to bone.
Muscle—Bone Interaction
• Muscles are attached to bones by
tendons.
• Muscles work in pairs. One extends
while its opposite flexes.
• Flexing is contracting, or pulling the
muscle together.
• Extending is relaxing the muscle which
allows it to stretch out.
Muscle and Bone Facts
•
Cartilage, ligaments, and tendons do not contain
blood vessels, and therefore can not repair
themselves.
•
Muscle and bone can repair themselves if torn or
broken.
•
Muscles always pull, they never push.
•
80% of our body weight is bone.
•
The average person makes 2,000,000 red blood
cells in bone marrow per second.
•
The femur is the largest bone.
•
The inner ear is the smallest bone.
Immune System Function
• The function of the
immune system is
to identify and
destroy disease
causing bacteria and
other foreign
substances (called
pathogens).
Immune Systems in Other
Animals
• Bacteria fight invaders by simply
mutating. They are so simple that
mutations occur regularly and have
profound effects.
• Sharks seem to be immune to cancer,
for reasons we have not yet figured
out.
How the Immune System Works
• White blood cells (called pathogens)
identify foreign proteins called antigens.
• Antibodies (proteins that attach to
antigens) match up to antigens and attach
to them.
• This allows macrophages (cell eating
molecules) to consume the antigens.
Attack Lymphocytes
1. B Cells-cells produced by red bone marrow that
attack antigens. They contain the antibody proteins
on their outer cell membrane.
2. T Cells—cells also produced in red bone marrow.
They also attach to antigens and help destroy it.
3. Suppressor T Cells—specialized T cells that
regulate how strong the immune response is.
4. Cytotoxic T cells—specialized T cells that are
specific to destroying cancer cells.
Macrophages and Lymph
• Macrophages—specialized white
blood cells that destroy antigens.
•
They are stored in lymph glands.
• Lymph is the fluid that contains
macrophages.
•
It flows through the body and past lymph
nodes where antigens are collected and
destroyed.
Protect Yourself!
First Lines of Defense
1. Skin—prevents most bacteria and
viruses from entering the body.
2. Hair—traps bacteria in the nose.
3. Acidic chemicals in mucus from the
nose, saliva from the mouth, and tears
from the eyes.
Second Lines of Defense
1. Histamines—chemicals released when
something foreign enters the body. They
increase blood flow, which brings more white
blood cells to the area of invasion.
2. White Cells (lymphocytes)—they engulf the
invaders and destroy them.
3. Temperature—A rise in body temperature
helps destroy foreign substances as well.
Immune System Facts
• There is a specific antibody created for every antigen
(foreign invader).
• When lymphocytes attack an antigen, they create memory
cells which recognize the invading bacteria. If the same
invader enters your body again, the response is immediate.
Therefore, you can’t get sick from the same bacteria twice.
• The spleen holds blood, filters out and destroys dead red
blood cells, and helps B cells make antigens.
• AIDS is a virus that attacks the immune response by
preventing T and B cells from destroying antigens.
Circulatory System Function
• To transport oxygen and nutrients to
body cells, and to remove carbon
dioxide and waste molecules.
Circulation In Other Animals
•
Simple animals like insects and spiders have open
circulatory systems in which the nutrients and
waste simply flow throughout the body.
•
Fish have a two-chambered heart (oxygenated and
deoxygenated blood mixes) , while amphibian’
heart is three-chambered.
•
Humans have a four-chambered heart which allows
for complete separation of oxygenated and
deoxygenated blood.
Blood
• The human body contains 5 to 6 liters
of blood (or 7-8% of body weight.)
• Each blood cell lives approximately 4
months.
• Blood contains red cells (carry oxygen),
white cells (fight foreign substances),
platelets (for clotting), and plasma
(55%) (basically water, proteins and
minerals).
Blood Vessels
1. Arteries—thick walled, they carry
blood away from the heart.
2. Veins—thin walled, they carry blood
toward the heart.
3. Capillaries—very thin and
microscopic in size, they allow blood
cells single file to exchange gases and
nutrients with cells around the body.
The Heart
• The heart is a hollow muscle that
contracts at regular intervals to
pump blood throughout the body.
• It has four chambers separated from
each other by valves that open and
close in one direction only. This
way, oxygen rich blood never mixes
with deoxygenated blood.
The Mammal and Bird Heart
The Complex Human Heart
Blood Pressure
• Blood Pressure is what is created
when the heart contracts and forces
blood through the arteries to the
body.
• Normal pressure is 120/80.
• High blood pressure can be a result
of the narrowing and hardening of
blood vessels as one ages.
Circulatory Facts
1. The heart is approximately the size of a
fist.
2. It pumps 2,000 gallons of blood per day.
3. It takes 20 seconds for one blood cell to
completely circulate through the body.
4. There are 8 million blood cells being
produced every minute.
5. The heart beats 3 billion times in an
average lifetime.
Respiratory System Function
• To get oxygen to
all the cells of the
body and to
remove carbon
dioxide from all
of the cells in the
body.
Respiration In Other Animals
•
Simple animals like spiders and insects have
modified gill or trachea system that allows for gas
exchange.
•
Marine animals such as shrimp and lobster, along
with fish have gills (smaller surface area).
•
Amphibians have gills to begin life and then lungs
as adults.
•
Reptiles, birds, and mammals all have lungs.
Nose, Mouth, and Nasal Cavity
• Air, containing oxygen, enters the
nose or mouth and is moistened.
• Moisture is present because oxygen
and carbon dioxide dissolve in water.
• Nasal hairs filter out foreign
substances.
Pharynx and Larynx
• The pharynx is the opening to the
digestive system.
•
Sound is created (voice box).
•
Long, stringy tissue vibrates when we talk, producing
sound.
• The larynx is opening to the lungs.
• The epiglottis covers the larynx when
food is swallowed.
Trachea
• The trachea is the passageway to the
lungs.
•
It is made of rings of cartilage.
•
These rings keep the trachea from collapsing or
expanding when the body moves.
•
It is lined with tiny hairs that filter out foreign
substances.
Bronchi
• The trachea branches into two small
tubes that lead to lungs.
•
These tubes are called the bronchi.
•
Air passes through the bronchi into the
lungs.
Lungs and Alveoli
•
The lungs are to sack-like structures at the ends of the
bronchi.
•
They contain thousands of small air sacs called
alveoli.
•
These small air sacs create a large surface area so that
more gases can be absorbed and released.
•
Capillaries attach to each alveoli.
•
Oxygen is taken into the blood and carbon dioxide is
released.
Respiratory System
The Diaphragm
•
The diaphragm is a large flat muscle under the lungs
that separates the chest from the abdominal cavity.
•
When this muscle contracts. It is pulled down. This
lowers the pressure and causes the lungs to expand
and fill with oxygenated air.
•
The diaphragm then relaxes and pushes up, This
raises the pressure and forces deoxygenated air out of
the lungs.
•
This process goes on 10 to 18 times per minute.
Breathing
The Control of Breathing
• Breathing is controlled by the amount of
carbon dioxide in the blood.
• Carbon dioxide breaks down to form
carbonic acid in the blood.
• When the nerves connected the blood
vessels detect a certain acid level, then
the brain sends a signal to the diaphragm
to breathe.
Respiratory Facts
Five liters of blood filter through the
lungs every minute.
1.
2. Eight liters of air through the lungs
per minute.
3. The surface area of the lungs equals
the size of a tennis court.
Digestive System
• The purpose of the
digestive system is to
breakdown food into
simpler molecules
(glucose, fats and
proteins) that can be
absorbed into blood
and used by the cells.
Digestion In Other Animals
•
Simple animals like jellies have a two way
digestive system (food comes in and food goes out
the same opening.
•
More complex animals have a one-way digestive
system (food goes in one opening and out
another—it flows only one direction).
•
Some animals filter food particles from the water
(tube worms) and some simply absorb it into their
bodies (flat worms).
Mouth and Salivary Glands
• Food is broken down by chewing in the
mouth.
• The salivary glands then begin to digest
the food.
• The salivary glands also produce
moisture.
• The tongue has taste buds.
Pharynx and Esophagus
• The pharynx is the passageway for food
to the esophagus.
• The esophagus is the passageway to the
stomach. It passes the heart, between the
lungs, and through the chest to the
abdomen.
•
It is surrounded by circular muscles that contract
in rhythm to push food down to the stomach.
•
Peristalsis
The Stomach
•
The stomach is where the major breakdown of
food occurs.
•
Pepsin (breakdown of protein), mucus
(lubrication), hydrochloric acid (carbohydrate
breakdown), lipase and bile (fat breakdown) are
chemicals produced by the liver and pancreas.
•
These chemicals break the food down so it my
pass to large intestine.
•
pH of 1.5
Liver and Pancreas
• Liver--the largest gland in the body. It
produces bile (a chemical that breaks
down fats) and filters out old red blood
cells. The bile is produced and then
stored in the gall bladder until needed.
• Pancreas--produces lipase and other
enzymes. It produces insulin for
carrying glucose into the blood. It also
makes sodium bicarbonate to return the
digestive juices pH to 8.0.
Small Intestine
•
The digested food passes into the small intestines from the
stomach.
•
In the upper small intestine more sugar and fat breakdown
occur.
•
When the food passes into the lower small intestine more
protein and sugar breakdown occur.
•
The small intestines are between 20 and 25 feet in length.
•
The broken down sugars, fats, and proteins are absorbed
into capillaries surrounding the small intestine.
•
They are then carried throughout the body.
Large Intestine
• Remaining undigested food, water, and
cellulose (fiber) pass from the small intestine
into the large intestine (6 feet long).
• Water is picked up by capillaries and taken
where needed in the body, by the blood.
• The unused solid material (feces) then passes
the appendix (function unknown) and out of
the body through the rectum and anus.
Digestion Facts
• Helpful bacteria live in the mouth,
stomach, and colon (large intestine).
•
They keep fungus from growing, aid in
digestion, and help make important
vitamins.
• The average person eats 50 tons
(100,000 pounds) of food in a
lifetime.
The Excretory System
• The function of the
excretory system is
to remove waste
and return useful
materials to the
body.
• To maintain the
water balance in the
body.
Excretion In Other Animals
•
Earthworms have tiny tubes in each body segment
that exchange oxygen and carbon dioxide with the
air.
•
Grasshoppers have tiny tube structures in their
intestines for the same purpose.
•
Amphibians, reptiles, and birds solid and liquid
waste is mixed together.
•
Mammals have separate organs for liquid and for
solid waste.
Kidneys and Bladder
•
The kidneys remove waste and excess salts from
the blood.
•
Blood flows through the nephrons that are
surrounded by capillaries.
•
The waste materials flow out of blood and into the
kidneys, along with excess water.
•
This is called urine (urea, water, salts).
•
The urine is stored in the bladder and then leaves
the body through the urethra.
Others Organs Involved with Waste
1. Lungs expel carbon dioxide and water
droplets
2. Skin releases water, urea, and salts with
help from sweat glands.
3. Liver filters out excess amino acids and
dead red blood cells.
4. Large Intestine excretes salts, bile, and
undigested solid food matter.
Human Excretory System
Excretory Facts
1. Blood passes through the kidneys 300 times a
day.
2. Dialysis is an artificial way of filtering blood
when the kidneys no longer work efficiently.
3. All of your blood is cleaned in 45 minutes.
4. Urine is 70 times more concentrated in salts.
Water. And waste than blood.
The Nervous System
• The nervous system
controls all body
functions and
movements. It
interprets stimuli
from the outside
world.
• Neurons in the brain
Nervous Systems In Other
Animals
• Simple animals like insects and spiders have a few nerve
cells clumped together called ganglia that help control body
functions.
• Fish, amphibians, and reptiles have small, simple brains,
similar to the human cerebellum that controls body
functions. They have significantly fewer nerve endings, so
feel pain much less than humans.
• Mammals have more complex, and larger brains, but only
humans have developed language skills and the ability to
reason.
Human Nervous System
• The brain (approximately 3 lbs.) controls
movement, maintains homeostasis, and
controls reasoning and problem solving.
•
Spinal chord is the major pathway for
nervous impulses throughout the body.
•
Nerves are the pathways that carry the
nervous impulses to and from the brain and
body organs.
The Brain
• The brain is divided into three parts
• Cerebellum - controls balance and
movement
• Cerebrum - reasoning, language, and
problem-solving
• Medulla or brain stem - controls
involuntary movements like breathing
and heart beat
Other Parts of the Brain
• The brain also contains smaller areas:
• thalamus - a relay station for incoming
impulses
• hypothalamus - regulates homeostasis
• pituitary - a gland that makes growth
hormones and other chemicals
The Brain
Brain Function
•
The frontal lobe of the brain is where thinking
and reasoning take place.
•
The temporal lobes (sides of brain) control
hearing and speech.
•
The occipital lobe is in the rear of the brain
and controls vision.
•
The parietal lobe is on top of the brain and
controls sensations like taste and touch.
Brain Function
Brain Function continued…
• Senses enter our brain and must first
pass through the amygdala.
• This is a small area deep inside the
middle of the brain that controls
emotions.
• Because almost all sensations pass
through this juncture before they are
stored, most of our memories have
emotional attachments to them.
The Power of Smell
• The sense of smell
is the strongest
sense because it has
a direct path to the
cerebrum, as where
the other senses
must pass through
relay stations first.
Nerves
• There are two types of nerves; somatic,
which control muscle movement and
autonomic, which control internal organ
functions.
• Nerves are made of neurons.
•
Sensory neurons carry messages from ears, eyes,
nose, etc. to the brain.
•
Motor neurons carry messages to the muscles to
react to the incoming stimuli.
How a Neuron Works
1.
Neurons are composed of an axon (carries messages away from
the cell to the next cell, a dendrite (carries messages to the cell)
and a synapse (the “bridge” between axons and dendrites).
2.
Schwann cells are scattered between nerve cells to provide
nutrients to the nerve cells.
3.
Sodium ions build up outside of the nerve cell, while potassium
ions build up inside of the cell. This is accomplished by active
transport in the cells.
4.
When the nerve “fires” sodium ions flow into the cell and
potassium ions flow out. This flow of ions causes the nerve to fire
and send the necessary information to the brain or from the brain
to the muscles.
5.
A chemical called acetylcholine and the myelin sheath in the nerve
cell allows this process to occur very rapidly.
Nervous System Facts
1. 20% of a persons daily calories go to
brain functions.
2. The brain works better when the body
has plenty of water and glucose.
3. New information gets stored best when
the person talks.
4. The brain can only store approximately
eight new words, ideas, etc. at a time.
The Endocrine System
• The function of the
endocrine system is to
regulate growth,
metabolism, and
reproduction by
producing and
distributing hormones
(chemical that, in small
amounts, regulate body
activities).
Endocrine Systems In Other
Animals
• In general, only animals with well
developed nervous and circulatory
systems have endocrine systems
composed of glands that produce
hormones.
• Humans have over 50 different hormones
being produced.
Brain Glands
•
Thyroid gland—small gland in the neck that produces
thyroxin (controls the rate of metabolism).
•
Parathyroid—four small glands behind the thyroid gland
that regulate salt (calcium and potassium) production. Too
little can create muscle spasms and convulsions. Too much
can cause tumors.
•
Pituitary—A very small gland in the skull that produces
growth hormone, hormones that control ovary and testes
growth, and milk production in pregnant women.
Glands in the Chest
• Thymus—Stores and stimulates the
growth of lymphocytes.
• Pancreas—considered part of digestive
system it produces insulin.
• Adrenal Glands—on top of kidneys—
produces sex hormones and adrenaline
(secreted in emergencies it increases
heart rate and respiration.
Sex Glands
• Ovaries in women produce estrogen
which controls mammary gland
development, menstruation, and mood
changes.
• Testes in men produces progesterone
which stimulates growth of facial hair,
large larynx (Adam’s apple), and muscle
development.
Endocrine System
Endocrine Facts
1. The pineal gland secretes melatonin
which helps control sleep. It is affected
by light.
2. It takes two hours of wakefulness (and
light) to clear the system of melatonin.
Reproductive System
• To create more
individuals of the
species.
• To assure healthy
offspring by
creating variation in
DNA, due to
separate sexes.
Reproduction In Other Animals
•
Simple organisms like hydra and starfish can
simply divide (asexual) and develop whole new
organisms.
•
This is easier than finding a mate, mating, etc.
•
However, it does not provide variety of DNA,
which can be deadly to a population if the
environment changes rapidly.
•
Most animals have sexual reproduction, which
requires both male and female members.
Reproduction In Other Animals
continued…
•
External Fertilization occurs in many less
complex species. Water must be present. Higher
risk of eggs being eaten and of fertilization
occurring successfully. Must have many offspring.
•
Internal Fertilization More successful and better
protection for young. Must have separate sexes
(with the exception of hermaphrodites). Can have
fewer young safely.
Female Reproduction
•
Women are born with all of the eggs they will ever have.
•
The eggs remain in prophase I of meiosis in their ovaries until hormones
begin to be released on a monthly cycle.
•
After the hormone production begins (puberty) one egg is released each
month.
•
The egg travels to the uterus, through the oviduct and fallopian tube, and if
fertilized attaches itself to the uterine lining.
•
The ovaries alternate in releasing eggs.
•
The uterine lining fills with nutrient rich blood throughout the monthly
cycle.
•
When the fertilized egg attaches itself it will have nourishment to begin
development.
•
If no egg attaches (no fertilization) then the lining is shed and the blood
passes out of the body through the vagina.
Female Reproduction
Male Reproductive System
•
Sperm is produced in the
testis, outside of the
body; normal body
temperature is too high
for sperm to live.
•
The sperm leave the
testis and join with a
fluid produced in the
prostate gland that
allows them to “swim”.
•
Together the sperm and
fluid are called semen.
Embryo Development
• Once an egg has attached itself to the
lining of the uterus, it begins to divide
(called cleavage) and grow.
• It feeds on fat and protein in the lining.
• The umbilical cord feeds the developing
fetus until birth (approximately 9
months).
Reproduction Facts
• The average male produces
200,000,000 sperm per day.
• The average female is born with 500
eggs.