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Anatomy
Male
Surface Anatomy
Male
ext genitalia
Penis
Foreskin
Scrotum
Skin
Female Surface Anatomy
Female ext genitalia
Mons
Vulva
Breasts
Skin
Urogenital System
Kidneys
Urinary Tract
Ureters
Bladder
Prostate
Urethra
Spermatic Duct
Testicles
Vas deferens
Ductus deferens
Seminal vesicles
Ejaculatory ducts
Female int genitalia
Uterus
Ovaries
Fallopian tubes
Vagina
Skeletal
System
Head
Skull
Orbits
Mandible
Cranium
Zygomatic arches
Cheek bones
Scapula
Colar bone
Ribs
Vertebral column
Cervical vertebrae
Atlas
Axis
Thoracic vertebrae
Lumbar verebrae
Sacral vertebrae
Sacrum
Coccyx
Pelvis
Hip bone
Legs
Femur
Tibia
Fibula
Feet
Tarsals
Metatarsals
Phalanges
Arms
Humerus
Radius
Ulna
Hands
Carpals
Metacarpals
Phalanges
Muscular System
Smooth muscle
Heart
Tongue
Muscles within arteries
Skeletal muscle
Facial muscles
Neck
Sternocleidomastoid
Chest
Pectoral muscles
Pecs
Diaphragm
Stomach
Abdominals
Abs
Rectus abdominis
External oblique
Internal oblique
Transversus abdominis
Shoulders
Deltoids
Delts
Arms
Biceps
Triceps
Forearms
Extensors
Flexors
Legs
Thigh muscles
Quadriceps
Quads
Lower leg muscles
Calves
Back
Trapezius
Traps
Latissimus dorsi
Lats
Erector spinae
muscles
Correct Posture
Cardiovascular System
Vessels
Heart
Respiratory
System
Mouth & Pharynx
Larynx
Lungs
Trachea
Diaphragm
Digestive System
Mouth & Pharynx
Esophagus & Stomach
Small intestine
Large intestine
Rectum & Anal canal
Liver
Gall bladder
Pancreas
Nervous System
Nerves
Spinal cord
Senses
Brain
Eyes
Ears
Nose
Tongue
Endocrine System
Pituitary gland
Thyroid gland
Parathyroid glands |
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Nervous
System
The internet of the human body. The nervous
system provides the fastest way for cells and tissues from all over
the body to communicate with each other, by sending electrical impulses
through a vast network of nerve fibers. It's composed of a central
nervous system (CNS), holding 99% of the body's neurons, and
a peripheral nervous system, holding the rest. The central nervous
system is composed of the brain and the spinal cord. The peripheral
nervous system is composed of many branching nerves, which reach
to every corner of the body.
A typical nerve is composed of a cell body,
around 10,000 highly branched receptive tentacles called dendrites (although some nerves have no dendrites at all), and a single long
thin tentacle called an axon or nerve
fiber, which branches possibly along its course and at its
ends. |
The dendrites contain receptors that respond
to various physical or chemical changes in its immediate vicinity.
When one of these receptors is activated, it causes charged ions
to travel across the cell's membrane, either by activating an
ionic pump or by opening channels though which ions can travel pulled
by their own magnetic charge. If enough of these receptors are activated,
together they will induce an action potential,
a significant difference in charge between the inside and outside
of a nerve cell. Once this action potential reaches a certain threshold,
a chain reaction is initiated that travels down the length of the
nerve's axon. This is an electrical nerve impulse. Once this
impulse reaches the end of an axon branch, it causes chemicals called neurotransmitters to be released from
the axon's branch. These neurotransmitters are the chemicals
that activate the receptors on the next neuron. This induces another
nerve impulse, which induces another and another, etc.

Participate in sports that require coordination
between different muscles and quick thinking. Activities like this
can train certain muscle groups to harmoniously work together to
produce smoother more coordinated movements. These activities will
also exercise the ability of your central nervous system to make
quick decisions or quick reactions. An improved coordination and
quick reaction time can help you prevent injury in your day to day
activities.
Anything good for the brain is good for the
nervous, so check out the brain user manual.

- Nerve impulses travel up to 250 miles per
hour.
- Some nerve cells are over a foot long.
- A nerve's axon can be 5000 to 10,000
times longer than the width of the nerve's cell body.
- For every 1 neuron traveling toward the CNS
(central nervous system), there are 10 neurons traveling away
from the CNS, and 200,000 neurons traveling within the CNS!
- Certain neurons in the brain are hit with
over 100,000 different synapses (the junction between an axon
branch of one neuron and the receiving surface of another neuron).
- One of the teams in a nation-wide improvisational
comedy act called Comedy Sports is named after the dendrites of
a neuron.
Brain
Eyes
Ears
Nose
Tongue

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