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Human Biology
Part 2
URINARY (RENAL)
SYSTEM
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This system consists of the KIDNEYS, URETERS, URETHRA, and
BLADDER.
Not many structures, but very important.
Functions:
Regulate electrolytes (K, Na, etc) in body
Regulate pH in blood
Regulate blood pressure
Regulate blood volume
Removing metabolic wastes (chemicals produces by chemical reactions in the
body are excreted). This is the least important of the kidney’s functions. You
can survive for a few weeks without excreting waste products in the urine, but
hour by hour, the other functions are more important.
LOCATION OF THE KIDNEYS
They are toward the back side of the body, partly protected by the lower border
of the ribcage.
UREA
 Urea is a waste product of amino acid metabolism. Remember,
proteins are made of amino acids, so when you break down
proteins, you break down amino acids, and the waste product left
over is urea. This is the main waste product in urine. Diuretics are
substances that make you excrete more urine. Alcohol, regular
coffee, and regular Coca-cola are diuretics.
 COLOR OF URINE
 When you urinate, it should be mostly clear with almost no yellow
color. The more yellow the urine is, the more dehydrated you are. If
the urine is very dark yellow, you are burning too much protein (as
in food deprivation).
PROBLEMS WITH THE
URINARY TRACT
 UTI (urinary tract infection) needs to be treated, or
infection can reach the kidney.
 UTI can be prevented by drinking lots of water,
blueberry or cranberry juice
 URETHRITIS = infection of the urethra
 CYSTITIS = infection of the urinary bladder
KIDNEY PROBLEMS
 Things can happen to the kidney: infection, excess
proteins, pH change, blood pressure drops, and can lead
to kidney failure.
 Treatment is DIALYSIS, which removes blood, sends it
through a filter, and returns it without the wastes. Done
three times a week. Ideally, need a kidney transplant
because the kidney has other functions as well.
 The brain, heart, and kidney are the only three organs in
the body that have to get oxygen to sustain life.
KIDNEY STONES
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These develop for unknown reasons.
Stones are made out of a variety of things: uric acid, calcium, etc.
They keep growing.
Kidney Stones cause blockage of the urethra, causing the kidney to
enlarge. As the kidney stretches, it causes excruciating pain in cycles of
hours. As pressure builds up around the stone, urine can pass, and the
kidney stone moves down the urethra slowly.
Symptomatic kidney stones are pea sized or larger (up to 1 ½ inches).
Treatment is ULTRASOUND: Put a powerful speaker on the outside
of the kidney, sends a shock wave which the tissues absorb, but the
stones shatter so the pieces can pass easier. To help prevent kidney
stones, drink enough fluid so your urine stays clear and light colored.
NERVOUS SYSTEM
 Parts of the Nervous System
 Central Nervous System (CNS): brain and spinal cord.
 Peripheral Nervous System (PNS): nerves of the body
 Before we talk about these parts, let’s talk about the
nerve cells.
 The brain has about a trillion nerve cells.
NEURONS
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All neurons do three things:
Receive a signal.
Transmit a signal to another location.
Stimulate another cell
 Another neuron  transmit signal
 Muscle  contraction
 Gland  secretion
 There are hundreds of different types of neurons, each one is
specialized for a particular task (e.g. sense light, smell, tell
muscles to contract, etc). They all share certain
characteristics.
MYELIN
 MYELIN SHEATH is a coating of lipids around certain types of
neurons. It is like the plastic coating around wires we use around the
house. It functions to transmit the signals faster. This is important
because in a fetus, the only fat in the body is on the myelin sheaths
of neurons. Therefore, excess vitamins A, D, E, and K will tend to
lodge there and interfere with nerve transmission.
 MULTIPLE SCLEROSIS is an autoimmune disease where the
sheaths of the neurons are destroyed, interfering with the neuron
functions in the CNS and brain. Starts to manifest in late teens and
early 20’s. It progresses to paralysis and sometimes death. There
are treatments, but no cure.
Nerve Regeneration
 In humans, axons outside the brain and spinal cord can
regenerate, but not those inside. After injury, axons in the
human central nervous system degenerate, resulting in
permanent loss of nervous function. This is not so in cold
water fish and amphibians, where axon regeneration in the
central nervous system does occur. So far, investigators have
identified several proteins that seem to be necessary to axon
regeneration in these central nervous system of these animals,
but it may be a long time before biochemistry can offer a way
to bring about axon regeneration in the human central
nervous system. It is possible though, that one day these
proteins will become drugs or that gene therapy might be used
to cause humans to produce the same proteins when such
injuries occur.
Nerve Regeneration
 In the meantime, some accident victims are trying other ways
to bring about a cure. In 1995, Christopher Reeve, best known
for his acting role as Superman, was thrown headfirst from his
horse, crushing the spinal cord just below the neck’s top two
vertebrae. Immediately, his brain lost almost all
communication with the portion of his body below the site of
damage and he could not move his arms and lags. Many
years later, Reeve could move his left index finger slightly and
could take tiny steps while being held up right in a pool. He
had sensation throughout his body and could feel his wife's
touch.
Nerve Regeneration
 Reeves improvement was not the result of cutting edge
drugs or gene therapy-- it was due to exercise. Read the
exercised as much as five hours per day, especially using
a recombinant bike outfitted with electrodes that made
his leg muscles contract and relax. The bike cost him
$16,000. It could cost less if commonly used by spinal
cord injury patients in their own homes. Reeves, who
was an activist for the disabled, was pleased that
insurance would pay for the bike about 50% of the time.
Nerve Regeneration
 It's possible that Reeves advances were the result of improved
strength in bone density, which led to stronger nerve signals.
Normally, nerve cells are constantly signaling one another, but
after a spinal cord injury, this signal ceases. Perhaps Reeves’
intensive exercise brought back some of the normal
communication between nerves. His physician is convinced
that his axons were regenerating. Reef was convinced that
stem cell therapy would one day allow him to be off his
ventilator and functioning normally; however, Reeve died in
2004. So far, researchers have shown that both embryonic
stem cells in bone marrow stem cells can differentiate into
neurons in the laboratory. Bone marrow stem cells apparently
can also become neurons when injected into the body.
CENTRAL NERVOUS
SYSTEM
 1. CENTRAL NERVOUS SYSTEM: The brain and
spinal cord
 THE BRAIN : ANATOMICAL REGIONS
BRAIN
 The brain is divided into parts. The largest portion is the
CEREBRUM, which makes up 80% of the brain. It’s
responsible for consciousness and all the complex behaviors,
sensations, etc. The cerebrum is divided into 2 halves called
CEREBRAL HEMISPHERES. In general, the left side
controls the right half of the body, and the right side of the
brain controls the left half of the body. These two halves of
the brain communicate with each other.
 Since the brain is so important, it is protected by the skull,
cerebrospinal fluid which cushions it, and meninges which are
membranes that surround the brain and only let certain
substances cross through to the brain.
BRAIN
 The brain is one of the few organs that can only use glucose to get
ATP as its energy source. Therefore, without some sugar in our
bloodstream, the brain will die. That’s one reason why proper
nutrition is so important.
 By the way, geniuses have the same size brain as everyone else; they
are just more efficient at forming synapses. We don’t use 10% of
our brains, we use 100%.
MENINGES
 These are tissues that cover the entire CNS. They have fluid
between them (CSF) and serve to protect and cushion the brain.
HYDROCEPHALUS
 Hydrocephalus is when the brain swells.
CEREBRAL SPINAL
FLUID
 CSF is similar to plasma because it is derived from
plasma.
 Allows the brain to float. The brain has the consistency
of Jell-O, and weighs three pounds. Its weight would
crush the inferior structures if it didn’t float.
 It cushions. In sudden movement, like riding a bike into
a tree, and hitting the head on the tree, the brain hits
inside the skull in the front, and then in recoil it hits the
back of the skull = closed head injury, not necessarily
with a fracture.
MENINGITIS
 Meningitis is an infection requiring a spinal tap for
diagnosis. This is when the meninges become infected. Can
be caused from virus (not that bad) or bacteria (can be fatal).
The main symptom is a headache, so when this occurs in an
infant, they can’t say where they hurt. So when an infant
presents with a high fever of 104˚ with no other symptoms,
they will usually test for meningitis, because if they miss it, it’s
fatal. The test is a SPINAL TAP, where a needle is inserted
in the low back below the level of the spinal cord. They draw
the CSF to look at. It it’s cloudy or bloody, it’s usually
meningitis.
HIGHER FUNCTIONS OF THE BRAIN
(control behavior and emotion)
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BEHAVIOR
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THE FRONTAL LOBE involved in planning and judgment. How
much time do you need to be ready for the test? Damage here causes
people to become docile and do what they are told. 1930’s when people
acted up, they did a pre-frontal lobotomy by going up the eyelid and
stirring up the brain. Stopped in 1960’s; we do it with drugs now.
There was a 16 year old rebel who shot himself in the head, but the
bullet went too far forward, and his personality improved! Riddlin
suppresses CNS in children, stimulates it in adults. In a criminal psych
ward, an inmate with a lobotomy got his hand caught in the electric
door, and while his hand was dangling half off, a nurse asked him if it
hurt, and he just calmly said, “Yes, quite a lot.” No emotion.
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Remember, when you kill a neuron, it does not regenerate; it’s gone
forever.
MEMORY
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You have different types of memories
MOTOR MEMORY is when you remember things by using your body
movements. Drummers and people who play other percussion instruments are
good at this. When someone asks you to spell a word and you have to say, “Wait
a minute” and you have to write it out, that’s because you learned the word with
motor memory.
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MEMORY OF EVENTS is when you remember people and events. This type
of memory is also used to convert short term memory into long term memory.
When you have to look up a phone number, and then forget it 5 minutes later,
that’s short term memory. Memorizing new material is accomplished in two
ways:
Repetition
Context
You can’t learn anything brand new; you have to add to what you already know,
by putting it into context.
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AMNESIA
 AMNESIA is not caused by a blow to the head; it has to be
damage deeper, like from a stroke. Also, a second blow
doesn’t cure the first one! Strokes and Alzheimer’s are most
likely to cause amnesia. Nemo’s fish friend, Dorothy, has
RETROGRADE AMNESIA, which is when a person cannot
remember anything new at all.
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You can get around amnesia by using motor memory. Give
an amnesiac a new puzzle; they’ll do it in 30 mins. The next
day, they don’t recognize the puzzle, but they do it in 20 mins,
the next day in 10. Therefore, they are learning by motor
memory. They can learn their route from home to the market
by repetition. But they can’t make a detour, and if anything
bumps them off track, they’ll be lost.
MEMORY
 No one can remember new things, so you need some
context; you need to associate the new thing with
something you are already familiar with. That’s why
pneumonics are good. If the word “cerebrum” is a
brand new word, it sounds like “Sir read broom”, which
are words you already know and can visualize. Think of
Harry Potter asking a wizard to read the strange words
on his new broom: “Sir read broom”, and the wizard
scratches his brain (cerebrum) as he tries to read the
words. Now it’s easy to remember because you can relate
it to something you already know and can picture.
FUN FACTS
 Bees tell other members of the hive where food is by doing a special
dance that relays distance and direction. Octopus have the ability to
sort out complex problems on their own
 A dolphin doesn’t need to see to catch a meal. It sends out sound
waves which bounce back and create a 3D ultrasound picture of it,
even in complete darkness. A dolphin’s brain in relation to its body
is larger than that of a chimpanzee or great ape.
 Dolphins are one of the most intelligent mammals; they've learned
to sleep using only half their brains. While one half rests, the other
remains alert and continues the respiratory process, without
interruptions.
 The brain of a roach is located in its body, and if by accident
(natural or human) it should lose its head, it can live up to nine days
completely decapitated. It dies from starvation.
SPINAL CORD
 Really, this is just a continuation of the brain. The
primary functions of the spinal cord are for simple
reflexes and to be a link between brain and body
 If a person has a spinal cord injury in their cervical
region, they could have quadriplegia (arms and legs
paralyzed).
 If a person has a spinal cord injury in their thoracic
region, they could have paraplegia (legs only)
THE EYE
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What did the right eye say to the left eye?
Between you and me, something smells!
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GLANDS OF THE EYE
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1. LACRIMAL GLANDS are the largest set. They are on the superior lateral
eyelid (overhead) and they produce tears, which have enzymes to kill bacteria
(which thrive in warm, moist conditions). The tears moisten and lubricate the
eye surface. They drain out into the LACRIMAL DUCT, which is seen as a
small hole in your lower inner eyelid.
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2. LACRIMAL CARUNCLE (“little meat”) is the spot on the medial corner
of the eye. It makes an oily secretion to lubricate the eye for the eyelids. When
the secretion dries, it is called “sand” in the eyes.
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3. CILLIARY GLANDS go to only the cilia. When clogged = STY.
PROBLEMS WITH THE
LENS
 PRESBYOPIA: (“old eyes”). Occurs around age 45-50.
With age, the lens loses flexibility. It stays in the position
for seeing far, so there is trouble focusing on things that
are near.
 CATARACTS: Clouds in the lens which can completely
cloud the eye. Treatment is to remove the lens and
replace it with a plastic one.
VISION PROBLEMS
 HYPEROPIA (far-sighted) eyes are too short; can’t see up
close
 MYOPIA (nearsighted) eyes are too long; can’t see far away.
 Normal eyes are perfect spheres.
 Myopic eyes are elongated (overhead projector is in focus, but
move it backward, gets fuzzy. Even badly nearsighted eyes are
only 1mm from normal. Treatments are glasses or Lasix,
which is laser surgery on cornea, when it’s shaved so it
focuses light farther back to reach the retina. Contact lenses
were invented by Leonardo da Vinci in 1508.
VISION PROBLEMS
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ASTIGMATISM
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Cornea has an irregular shape. Part of the field of view is out of focus.
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They eyeball changes shape until age 24.
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RETINAL DETACHMENT
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The retina separates from the underlying blood supply. Looses oxygen,
cells die. Usually caused by an injury like a baseball, punch, or airbag
to the eye. Treatment is lasering to spot-weld it back. Manifests as a
shimmering light. Needs immediate treatment. Those who are most
vulnerable are those who are nearsighted.
VISION PROBLEMS
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MACULAR DEGENERATION
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The size of the macula is the size of the printed letter “O” in 14 pt font.
When the macula degenerates, you lose a lot of sight. This is the most
common cause of blindness in the US.
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It’s due to bleeding in the eye, causing scar tissue. The retina does not
get enough oxygen, and the cells die. Macular degeneration allows
vision in the periphery, but they can’t read or drive.
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DIABETIC RETINOPATHY
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This is when the high sugar levels destroy the photoreceptors in the
retina. The blood vessels also swell and rupture and the clots block
vision. Some of this damage can be repaired by using a laser to
evaporate the blood clots, but any damage to the photoreceptors is
permanent. It can lead to blindness.
VISION PROBLEMS
 If a child is blind until age 4-5, and then you restore the sight,
he will still be blind because the brain doesn’t form properly.
With kids who have astigmatism or weak eye muscles, one eye
stops seeing (or sees double). The thalamus in the brain will
shut off all the signals from the bad eye.
 GLAUCOMA Too much aqueous humor  pressure on the
anterior chamber and retina  blindness. This form of
blindness is more common in third-world countries because
we have tests to detect it and treat it. The test measures how
much pressure there is here by seeing how easily the cornea is
deformed, either with air or direct pressure. How many of
you have had this test?
THE EAR
 The sensory functions of the ear include not only
hearing, but balance, too.
 1. OUTER EAR
 A. EXTERNAL AUDITORY CANAL.
 B. PINNA: The cartilage around your ear. The pinna
funnels sound in. If you cup your hands to your ears (do
it now), you’ll notice the sound of my voice is louder.
MIDDLE EAR
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2. MIDDLE EAR is an air filled space (overhead) with structures.
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A. TYMPANIC MEMBRANE (ear drum) vibrates in response to sound.
Attached to it are 3 bones called OSSICLES which are the smallest bones in the
body
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1) MALLEUS (hammer)
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2) INCUS (anvil)
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3) STAPES (stirrup).
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Together, these three bones are only one inch long. Their function is to transmit
sound vibrations. The malleus vibrates the incus, which vibrates the stapes.
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B. AUDITORY TUBE connects the middle ear to the nasopharynx, and is only
the thickness of a pencil lead. If this tube is closed, the ears feel plugged up. Its
function is to equalize the pressure of the middle ear and the outside air to allow
the bones to vibrate freely. Tubes are put in the tympanic membrane to drain
fluids in kids.
INNER EAR
 3. INNER EAR is a complex structure. The main structure
of the inner ear is the COCHLEA (“snail shell”). When the
stapes vibrates, it causes the fluid in the cochlea to vibrate,
which triggers HAIR CELLS which are mechanoreceptors
that sense vibrations and send the information to the brain.
This portion of the inner ear is responsible for hearing.
 SEMI-CIRCULAR CANALS are the portion of the inner ear
that is responsible for balance. There are three of them, and
they determine movement in three planes. Within each canal
is fluid and hair cells (mechanoreceptors), which connect to
nerves that go to the brain. When you move in one direction,
like sliding across the room, the fluid sloshes like a cup of
coffee, and it makes the hair cells move. Within the
endolymph here are
EAR PROBLEMS
 OTOLITHS (“ear rocks”) which are calcium deposits. When
you stand perfectly upright, these otoliths fall directly down
and bend the hairs on the lower cells. When you tip your
head to the side, they will stimulate the hairs on the opposite
side. These stimulate the nerves to tell you what position your
head is in. Therefore, the sense of balance uses
mechanoreceptors.
 VERTIGO (dizziness): Inflammation of the semi-circular
canals gives you a sense of motion when you’re not moving.
This can be debilitating. Sometimes only one canal is
affected, so you only get dizzy if you turn your head one way.
Hearing Loss
 It is easy to take the sense of hearing for granted. But in fact
many people eventually lose some or all of their ability of
hear. There are two broad categories of hearing loss:
conduction deafness and nerve deafness. In conduction
deafness, sound waves are not conducted to the cochlea by the
usual pathway: through the auditory canal to the tympanic
membrane, then via the the oval window to the fluid filled
cochlea. Instead, sound waves must travel through the bones
of the skull. In nerve deafness, sound waves should be
transmitted to the cochlea, but there is a problem with the
nervous structures associated with the hearing, such as the
hair cells of the spiral organ, the cochlear nerve, or even in the
auditory portions of the cerebral cortex.
Hearing Loss
 There are numerous causes of conduction deafness.
Anything that affects the ability of the tympanic
membrane to vibrate may result in hearing loss. For
example, ear wax can build up in the auditory canal, and
press on the membrane. Inserting objects into the ear
can damage the tympanic membrane.
 Some people develop conduction deafness as they get
older. This may result from arthritis in which the bones
of the middle year to use. The good news is that this
type of disorder is often correctable with surgery.
Hearing Loss
 Otitis media is an infection of the middle ear that can lead to
conduction deafness. It typically occurs when an upper
respiratory infection, such as a cold, leads to swelling of the
auditory two, creating a vacuum that pulls fluid into the
middle ear. The fluid provides an ideal environment for
bacteria or viruses, and the pressure it exerts causes symptoms
such as pain, ringing in the ears, and hearing loss. The loss is
usually incomplete, and rarely permanent. However, when
such hearing loss occurs in very young children, it can delay
their speech development. If the tympanic membrane
ruptures under pressure, it usually heals on its own in a matter
of weeks. If it does not rupture, fluid may linger in the
middle ear, and in some cases a tube must be surgically
inserted for drainage.
Hearing Loss
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Noise exposure is a common and usually preventable cause of nerve
deafness. Noise volume is measured in units called decibels. Any noise
above a level of 80 dB could result in damage to the hair cells of the
year. Eventually, the hair cells disappear completely. If listening to city
traffic for extended periods can damage hearing, it stands to reason that
frequent attendance at rock concerts, constantly playing a stereo loudly,
or using earphones at high volume is also damaging to hearing. The
first-hand of danger could be temporary hearing loss, a feeling of
fullness in the ears, muffled hearing, or ringing in the ears. If you have
any of these symptoms, modify your listening habits immediately to
prevent further damage. If exposure to noise is unavoidable, specially
designed noise reduction earmuffs are available, and it is also possible to
purchase earplugs made from a compressible, spongelike material at the
drugstore or sporting goods store. These earplugs are not the same as
those worn for swimming, and they should not be used interchangeably.
Hearing Loss
 Aside from loud music, noisy indoor or outdoor
equipment, such as a rug cleaning machine or a
chainsaw, is also troublesome. Even motorcycles and
recreational vehicles such as snowmobiles can contribute
to gradual loss of hearing. Exposure to intense sounds
of short duration, such as a burst of gunfire, can result in
an immediate hearing loss. Hunters may have a
significant hearing reduction in the ear opposite of the
shoulder where the gun is Kerry. The butt of the rifle
offers some protection to the year nearest the gun when
it is shot.
Hearing Loss
 Certain over-the-counter and prescription drugs have the
potential to cause nerve deafness when taken in
combination or excessive amounts. Such medications
include anti-inflammatory drugs such as aspirin,
ibuprofen, Tylenol, antibiotics, anticancer drugs,
quinine, and certain blood pressure medications.
Sometimes hearing is restored when a person stops
taking the medication, but in other cases the damage is
permanent.
Hearing Loss
 One uncommon cause of deafness is autoimmune inner
ear disease. This occurs when a person's immune system
turns against normal, healthy tissue. The person
experiences symptoms such as dizziness and ringing in
the ears in addition to hearing loss. Although it can be
treated with drugs that suppress the immune system, the
drugs themselves can have serious side effects, and may
only slow the disease.
Hearing Loss
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Hearing aids can help with partial hearing loss such as that caused by
chronic noise exposure, but they do so by amplifying sound waves
rather than restoring lost earring. Most amplify all sound waves equally,
which is why it may be difficult for someone wearing a hearing aid to
carry on a conversation in a noisy restaurant. Some of the newer and
more expensive hearing aids are programmable, so the level of
amplification can be adjusted depending on the noise level of one's
surroundings. Through the use of cochlear implants, there is hope
today for people who have little or no hearing due to cochlear damage.
A person with a cochlear implant wears a microphone picks up sounds
and sends them to a processor, which relays signals to a small receiver
implanted beneath the scalp. The receiver transmits signals through a
number of electrodes to the origin of the cochlear nerve. Cochlear
implants are not yet capable of producing all of these sounds of normal
hearing, but they do allow people who have them to understand speech
and perceive sounds such as alarms and telephones.
Hearing Loss
 Nova Hearing Aid:
http://video.yahoo.com/video/play?vid=1074768518&f
r=yfp-t-471
 Sudden Hearing Loss:
http://texasent.com/newtexasent/media/video/video_f
iles/Sudden_hearing_loss_2002_360X240.swf
 Deaf Baby with Hearing Aid:
http://video.yahoo.com/video/play?vid=421542&fr=yf
p-t-471
ENDOCRINE SYSTEM
 The endocrine system is all the organs of the body that are
endocrine glands.
 An endocrine gland secretes hormones.
 Hormones are substances that are secreted by one group of cells,
enter into the bloodstream, and travel to another group of cells
(organs) and have an affect there.
 Hormones regulate growth, reproduction, chemical balance, and
metabolism.
 The endocrine system is controlled directly by the pituitary gland.
 The pituitary gland is controlled by the hypothalamus in the brain.
 1. HYPOTHALAMUS
 This is located at the base of the brain (overhead). It secretes
hormones that affect the pituitary gland.
 2. PITUITARY GLAND produces many important hormones,
including:
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A. THYROID STIMULATING HORMONE (for metabolism rate)
B. GROWTH HORMONE: Overproduction results in giantism
C. URINE OUTPUT
D. CHILDBIRTH CONTRACTIONS
THYROID GLAND
 3. THYROID GLAND located inferior to Adam’s apple;
makes THYROID HORMONE. Thyroid hormone contains
iodine. If a person doesn’t eat enough iodine, they can’t make
thyroid hormone. The hypothalamus and pituitary gland will
release more hormones to stimulate the thyroid gland, but the
thyroid can’t respond, so it grows  GOITER. This is
usually caused by too little iodine in diet. That’s why salt is
iodized. Iodine is only found in seafood, so if salt wasn’t
iodized, a lot of people wouldn’t get enough iodine, and there
would be a lot of goiters. There are more problems with the
thyroid gland than any other organ.
PARATHYROID
GLANDS
 4. PARATHYROID GLANDS are 4 little glands
embedded in the thyroid gland. They make
PARATHYROID HORMONE  controls calcium
levels.
PANCREAS
 The pancreas makes many substances, including
digestive enzymes, insulin, and hormones. INSULIN
controls blood sugar levels. It takes sugar out of the
bloodstream and brings it into the cells. If there is not
enough insulin, the blood sugar level rises and can lead
to coma and death. This condition is called
DIABETES.
ADRENAL GLANDS
 6. ADRENAL GLANDS (“On top of the kidney”) They are
increased during all times of stress.
A. CORTISONE  reduces inflammation
B. ESTROGEN sex hormone produced by males and
females.
C. TESTOSTERONE produced by males and females.
The circus lady with a beard most likely has a
malfunctioning adrenal gland.
D. ADRENALIN (epinephrine). When you are spooked,
the neurons fire.
DANGERS OF
STEROIDS
 Steroids that weightlifters take are synthetic testosterone, and
they are taken in doses 100x larger than a prescription, so they
are dangerous. Although they increase muscle size, they
decrease the size of testicles and cause a low sperm count,
impotence, and sterility. They increase rage and aggression as
well. Other side effects are that they cause baldness, give
women hair on their face and chest, enlarge the breast of
males and decrease the breast in females, cause kidney and
liver disease, cancer, severe acne, high blood pressure and high
cholesterol, can stunt growth in those whose bones have not
finished growing yet, and they can shorten the life span by
several decades.
Melatonin
 Melatonin is one of the least understood hormones; it does
not cause dramatic changes in the body like many of the other
hormones. It is produced by the pineal gland of the brain and
is often referred to as the hormone of darkness because it is
secreted only at night and it is inhibited by light. Some people
refer to it as the werewolf hormone. It was this unique
pattern of secretion that provided clues to one of its major
functions: it supplies time of day information to the body.
Most of our cells are unable to assess the time of day and they
depend on a special center in the brain to keep time.
Melatonin
 One of the clearest effects of melatonin is the ability to reset
the body's internal clock for blind people or those suffering
from jet lag or in night shift workers. Melatonin administered
in the afternoon shifts the sleep cycle so that people wake up
and go to sleep earlier. Melatonin given in the morning
causes people to wake up and go to sleep later. This capability
of melatonin to shift the body's internal clock will likely find
increasing use in the future as travel for business and pleasure
become more international. It should also be especially useful
in sports where teams playing in international competitions
now have to override a week before an event in order for there
internal rhythms to shift naturally so they can play at their
best.
Melatonin
 Another timekeeping function of melatonin is its role in
orchestrating seasonal changes. For example, it plays a
major part in signaling the body of animals to hibernate.
In this capacity, it is believed that melatonin is
instrumental in causing tissues to shift into a state of
metabolic inactivity during hibernation. This capability
has led some researchers to propose that melatonin
might be able to induce a hibernation-like state and
donor organs prior to transplantation in order to prolong
their shelf life.
Melatonin
 In seasonally reproducing animals, melatonin plays a part in
directing the reproductive system to become inactive. Because
of this ability to regulate seasonal activities, there has been
interest in the role that melatonin might play in seasonal
affective disorder (SAD), which makes some people depressed
in the winter. The present evidence indicates that the short
days of winter cause excess melatonin to be produced in
individuals susceptible to this disorder. It appears that in
people with SAD, the melatonin system does not respond to
artificial lighting, while in unaffected people the system ceases
production of melatonin in response to artificial lighting.
Interestingly, in many people with SAD, special bright lights
that mimic sunlight are effective in shutting down the
melatonin and alleviating depression.
Melatonin
 Although melatonin is widely advertised as a sleep aid, there is
controversy among scientists about what role it plays in sleep it does
not appear to work like a sleeping pill that simply induces sleep,
rather it seems to produce a physiological bias toward sleep. As
people get older, the amount of melatonin they produce at night
decreases, while insomnia and other sleep problems increase.
Alzheimer's patients have less melatonin than normal. Fortunately, a
few studies have already shown that melatonin treatment can cause
significant improvements in the sleep quality of both elderly
insomniacs and Alzheimer's patients. If melatonin can be used to
reestablish more normal sleep patterns in Alzheimer's patients, it
should help delay their institutionalization and reduce the
psychological, physical, and monetary burden of this devastating
disease.
MALE REPRODUCTIVE SYSTEM
 1. THE AMAZING PENIS
 This organ can vary in size from 1” to 6” in seconds, while
maintaining the integrity of the blood vessels, nerves, and
lymphatics.
 Viagra is a medicine which allows vasodilatation (to
encourage a penile erection), but if you have heart disease, it
can give you a heart attack. Viagra can also cause vision
problems.

An erection squeezes the veins shut so the blood can’t leak
out. If Viagra (or anything else) causes an erection for longer
than four hours, the erection decreases the blood flow, and the
tissue is killed.
SCROTUM

2. SCROTUM
A. TESTICLES makes sperm.
B. VAS DEFERENS is the tube that the sperm goes into.
C. PROSTATE GLAND is where the vas deferens passes through.
D. SEMINAL FLUID is the liquid that carries the sperm. It is
made by the prostate gland.
E. SEMEN is the seminal fluid plus the sperm. The semen is then
dumped into the urethra during ejaculation. The urethra is
the same tube that excretes urine.

In order for sperm to be produced, the temperature has to be a few
degrees lower than normal (35˚C or 94˚F instead of 37˚C or 98˚F). To
insure a lower temperature, the testes are located outside of the body, in
the scrotum (outside of the pelvis). The temperature is maintained by
muscles that elevate and depress the testes.
PROBLEMS
 There is an opening in the groin area called the INGUINAL
CANAL. If you do heavy lifting, it increases the abdominal
pressure, and intestine gets pushed into it = INGUINAL HERNIA
(surgery). To check for hernia, feel scrotum, and cough. Should be a
little movement, but the testes should not move all the way up.

VASECTOMY is the #1 birth control method in the US. An
incision is made in back of the scrotum, cut out a piece of the vas
deferens. It is possible to reverse it, but it is assumed permanent.
Only 1 in a million grows back together in 5-10 years.
 Infertility
 The most frequent cause of infertility in males is low sperm count
and/or abnormal sperm. Disease, radiation, chemicals, high testes
temperature, and drug abuse can also contribute to this condition.
PROSTATE GLAND
 The urethra goes through the middle of the prostate, which
continues to grow throughout life. By the time men are older,
most of them have PROSTATIC HYPERTROPHY
(enlarged prostate). It can constrict the urethra, making it
hard to urinate. Needs surgery to open.

Prostate cancer affects 10% of the male population. To check
for cancer of the prostate, do a rectal exam. A finger is placed
in the rectum and the prostate can be palpated. It should be
part of a routine physical.

If the prostate needs to be removed, there are nerves that
might be severed that run along it, causing erectile
dysfunction.
FEMALE REPRODUCTIVE SYSTEM
 Consists of the following:
1. Ovaries
2. Fallopian Tubes
3. Uterus
4. Vagina
5. External genetalia
OVARIES
 These are about one inch around.
 OVARIAN CYCLE
 This is the process of egg development on a monthly basis.
 Eggs develop during fetal development. A woman is born
with all the eggs she will ever have; about half a million. At
puberty there is a change in hormones which causes
development of some of these eggs. The two hormones that
influence the development of female secondary sex
characteristics are estrogen and progesterone.
OVARIAN CYCLE
 The average ovarian cycle is 28 days.
 Day 1
 This is the first day of menstruation. The new eggs in the
ovary begin to develop.
 Day 14
 OVULATION.
 sperm live for 7-10 days. That means that you can have sex
during menstruation, and the sperm might live inside past
ovulation. There is no safe time to have unprotected sex.
Unprotected sex once a week = 90% chance of pregnancy.
 When the egg is released, it goes into the fallopian tube.
Infertility
 One of the most common causes of infertility in women is
STD (sexually transmitted disease). We’ll talk about that
later. Also, Fat is needed to have the menstrual cycle. Skinny
and athletic women may not menstruate.
 Women who have trouble conceiving take fertility pills, which
causes 100 eggs to develop, 4-5 of which may mature 
multiple births. Therefore, fertility pills frequently result in
multiple births.
 A diaphragm is a cup-like structure that a woman can insert
in the vagina to block the sperm from getting in. However,
it is not very effective because it requires significant skill.

IUD (intra-uterine device) is implanted in the uterus by a
doctor and prevents implantation. However, it can cause
infection.
Birth Control




Birth Control Pills are made of estrogen, so they inhibit the
development of the eggs, but the uterine lining still grows. You take
them for 3 weeks, and then take one week off to allow for menstruation.
They are 99% effective if taken properly. You have to be careful to take
the pill not only every day, but at the same time every day, to keep from
getting pregnant. Some of the new estrogen pills can cause a period
only every 3 months instead, but there are side effects: Birth control
pills can cause a heart attack Stop BCP 6-12 months before planning
conception, or there may be birth defects.
Implantable birth control = NORPLANT, etc (capsules of estrogen
surgically implanted under the skin of the arm), releases tiny amount of
estrogen continually.
Condoms are also 99% effective if used correctly; if not, only 85%
effective. Solution = put the woman in charge of the condom, and the
failure rate drops dramatically.
A Condom can rupture by applying hand lotion
ECTOPIC
PREGNANCIES
 The egg is normally fertilized in the fallopian tube, goes
down into the uterus and implants there. If it implants
in the fallopian tube = ECTOPIC PREGNANCY. This
is fatal to the mother and embryo, but nowadays there
are few deaths of the mother because it is very painful,
so she will go to the ER and they will do surgery. A
woman who goes into the ER with abdominal pain will
always get a pregnancy test.
STD
 Sperm swim out of the opening of the fallopian tube and
into the body cavity.
 That means any STD can also enter there, causing
PELVIC INFLAMMATORY DISEASE (PID), where it
spreads to all organs in the pelvis. This STD is
chronically extremely painful for the rest of the woman’s
life, and there is no cure and no treatment.
 The most common cause of infertility in women is STD.
The inflammation and scarring closes off the fallopian
tube.
TUBAL LIGATION
 TUBAL LIGATION is a method of birth control where
a piece of the fallopian tube is cut out, and there’s no
way for the sperm to reach the egg. It is more
complicated than a vasectomy, so it is done less often
than a vasectomy.
UTERUS
 The uterus consists of a BODY, CERVIX, and VAGINA. The
cervix is the neck of the uterus.
 PROBLEMS WITH THE UTERUS
 ENDOMETRIOSIS is a very strange condition. Pieces of the
uterus wall (endometrium) are supposed to fall down the vagina
during menstruation, but sometimes its cells go up the fallopian tube
and enter the body cavity. They can lodge anywhere; on top of the
lung, kidney, etc. These cells still respond to hormone changes,
grow, and break down and die, causing a lot of weird pain during
menstruation. It’s difficult to diagnose because the pain goes away
before the doctor appointment. The symptoms vary, depending on
the location. One lady had it on her lung and got a collapsed lung
every month. Treatment is to give hormones to prevent menses.
UTERUS PROBLEMS
 FIBROIDS
 These are benign tumors like scar tissue. They can get large and be
painful, especially during contraction of menses and pregnancy.
Fibroids are the most common reason for hysterectomy (surgical
removal of the uterus).
 HYSTERECTOMY comes from the Greek “hysteria”. It was
thought that only women get hysterical because they have a uterus.
Now we know that’s not true. They get hysterical because they have
ovaries! The surgery involves going through the abdominal wall, cut
the fallopian tubes, and yank the uterus out through the vagina.
FUN FACTS
 Be glad you’re not an octopus. They die after laying
their eggs or after mating. However, if you remove an
octopus's reproductive organs, it can live until a ripe old
age - albeit bored and without much company.
 Lions have sex every 15 minutes for an entire week.
However, this only occurs every two years.
 The pig has the longest orgasm; it can last up to 15
minutes.
FUN FACTS

Every human spent about half an hour as a single cell.
A fetus acquires fingerprints at the age of three months.

If we could breed like a rabbit, we could produce 6 babies a month!

The mammal with the largest number of births is the Tasmanian Devil, which
gives birth to about 50 tiny babies at a time.

The largest egg layer is the kiwi, whose egg is about 25 percent of it's total
weight! That would be like a human having a 30 pound baby.

The paradoxical frog tadpole is five times larger than its parents.

A giraffe gives birth standing up, so the baby has a 5 foot drop to the ground.
This stimulates breathing and helps the placenta to detach.
The Theory of Evolution
 The term theory in science is reserved for those ideas that
scientists have found to be all encompassing because
they are based on data collected in a number of different
fields. Evolution is a scientific theory. So is the cell
theory, which says that all organisms are composed
themselves, and so is the atomic theory, which says that
all matter is composed of atoms. No one argues that
schools should teach alternatives to the cell theory or the
atomic theory. Yet controversy reigns over the use of the
expression “the theory of evolution”.
The Theory of Evolution
 No wonder most scientists in our country are dismayed
when state legislatures or school boards rule that
teachers must put forward a variety of “theories” on the
origin of life, including one that runs contrary to the
massive data that supports the theory of evolution. An
organization in California called the Institution for
Creation Research advocates that students be taught an
“intelligent-design theory”, which says that DNA could
never have arisen in without involvement of an
intelligent agent, and that gaps in the fossil record mean
that species arose fully developed with no antecedents.
The Theory of Evolution
 Since our country forbids the mingling of church and state-- that is,
no purely religious ideas can be taught in the schools-- the advocates
for an intelligent design. Our careful not to mention the Bible or
any strictly religious ideas such as “God created the world in seven
days”. Still, teachers who have a solid scientific background do not
feel comfortable teaching and intelligent design theory because it
does not meet the test of a scientific theory. Science is based on
hypotheses that have been tested by observation and/or
experimentation. A scientific theory has stood the test of time-- that
is, no hypothesis that runs contrary to the theory have been
supported by observation and/or experimentation. On the contrary,
the theory of evolution is supported by data collected in such wide
ranging fields as development, anatomy, geology, and biochemistry.
The Theory of Evolution
 Polls consistently show that nearly half of all Americans
prefer to believe the Old Testament account of creation.
That is their right, but should schools be required to
teach and intelligent design?