CENTRAL NERVOUS SYSTEM

Central nervous system
From Wikipedia, the free encyclopedia
Jump to: navigation, search

A diagram showing the CNS:1. Brain2. Central nervous system (brain and spinal cord)3. Spinal cord
The central nervous system (CNS) is the part of the nervous system that functions to coordinate the activity of all parts of the bodies of multicellular organisms. In vertebrates, the central nervous system is enclosed in the meninges. It contains the majority of the nervous system and consists of the brain (in vertebrates which have them), and the spinal cord. Together with the peripheral nervous system it has a fundamental role in the control of behavior. The CNS is contained within the dorsal cavity, with the brain in the cranial cavity and the spinal cord in the spinal cavity. The brain is protected by the skull, while the spinal cord is protected by the vertebrae.[1]
Contents[hide]
1 Function
2 Neuroanatomy
3 Evolution
4 Parts of the vertebrate CNS
5 See also
6 References
7 External links
//

[edit] Function
Main article: Brain Function
Since the strong theoretical influence of cybernetics in the fifties, the central nervous system is conceived as a system devoted to information processing, where an appropriate motor output is computed as a response to a sensory input. Yet, many threads of research suggest that motor activity exists well before the maturation of the sensory systems, and that then the senses only influence behavior without dictating it.

[edit] Neuroanatomy

Para-sagittal MRI of the head
Main article: Neuroanatomy
The telencephalon gives rise to the striatum (caudate nucleus and putamen), the hippocampus and the neocortex, its cavity becomes the lateral ventricles (first and second ventricles). The diencephalon give rise to the subthalamus, hypothalamus, thalamus and epithalamus, its cavity to the third ventricle. The mesencephalon gives rise to the tectum, pretectum, cerebral peduncle and its cavity develops into the mesencephalic duct or cerebral aqueduct. Finally, the rhombencephalon gives rise to the pons, the cerebellum and the medulla oblongata, its cavity becomes the fourth ventricle.
Centralnervoussystem
Brain
Prosencephalon
Telencephalon
Rhinencephalon, Amygdala, Hippocampus, Neocortex, Lateral ventricles
Diencephalon
Epithalamus, Thalamus, Hypothalamus, Subthalamus, Pituitary gland, Pineal gland, Third ventricle
Brain stem
Mesencephalon
Tectum, Cerebral peduncle, Pretectum, Mesencephalic duct
Rhombencephalon
Metencephalon
Pons, Cerebellum,
Myelencephalon
Medulla oblongata
Spinal cord

[edit] Evolution
Main article: Brain
Planarians, members of the phylum Platyhelminthes (flatworms), have the simplest, clearly defined delineation of a nervous system into a central nervous system (CNS) and a peripheral nervous system (PNS).[2] [3] Their primitive brain, consisting of 2 fused anterior ganglia, and longitudinal nerve cords form the CNS and the laterally projecting nerves form the PNS. A molecular study found that more than 95% of the 116 genes involved in the nervous system of planarians, which includes those related to the planarian CNS, also exist in humans.[4] Like planarians, vertebrates have a distinct CNS and PNS, though those of vertebrates display greater complexity.
The basic pattern of the CNS is highly conserved throughout the different species of vertebrates and during evolution. The major trend that can be observed is towards a progressive telencephalisation: while in the reptilian brain that region is only an appendix to the large olfactory bulb, it represents most of the volume of the mammalian CNS. In the human brain, the telencephalon covers most of the diencephalon and the mesencephalon. Indeed, the allometric study of brain size among different species shows a striking continuity from rats to whales, and allows us to complete the knowledge about the evolution of the CNS obtained through cranial endocasts.
Mammals – which appear in the fossil record after the first fishes, amphibians, and reptiles - are the only vertebrates to possess the evolutionarily recent, outermost part of the cerebral cortex known as the neocortex.[5]
The neocortex of monotremes (the duck-billed platypus and several species of spiny anteaters) as well as that of marsupials (such as kangaroos, koalas, opossums, wombats, Tasmanian devils, etc.) lack the convolutions - gyri and sulci - found in the neocortex of most placental mammals (eutherians).[6] Within placental mammals, the size and complexity of the neocortex increased over time. The area of the neocortex of mice is only about 1/100 that of monkeys, and that of monkeys is only about 1/10 that of humans.[5] In addition, rats lack convolutions in their neocortex (possibly also because they are small mammals), whereas the neocortex of cats has a moderate degree of convolutions, and that of humans exhibits quite extensive convolutions.[5]
See also: Encephalization, Neocortex, Archicortex

[edit] Parts of the vertebrate CNS
Main article: List of regions in the human brain
In addition to the structures seen to the right in table above, a vast number of structures are present in the adult brain.

MUSCULAR SYSTEM

The muscular system is the anatomical system of a species that allows it to move. The muscular system in vertebrates is controlled through the nervous system, although some muscles (such as the cardiac muscle) can be completely autonomous.There are three distinct types of muscles: skeletal muscles, cardiac or heart muscles, and smooth muscles.Muscles provide strength, posture balance, movement and muscles provide heat for the body to keep warm.

[edit] Skeletal muscle
Main article: Skeletal muscle
Skeletal muscle fibers are also multinucleated, with the cell's nuclei located just beneath the plasma membrane. The cell comprises a series of striped or striated, thread-like myofibrils. Within each myofibril there are protein filaments that are anchored by tendons. The fiber is one long continuous string-like structure. The smallest cross section of skeletal muscle is called a sarcomere which is the functional unit within the cell. It extends from one Z line to the next attached Z line. The individual sarcomere has alternating thick myosin and thin actin protein filaments. Myosin forms the center or middle of each M line. Thinner actin filaments form a zig zag pattern along the anchor points or Z line.
Upon stimulation by an action potential, skeletal muscles perform a coordinated contraction by shortening each sarcomere. The best proposed model for understanding contraction is the sliding filament model of muscle contraction. Actin and myosin fibers overlap in a contractile motion towards each other. Myosin filaments have club-shaped heads that project toward the actin filaments.
Larger structures along the myosin filament called myosin heads are used to provide attachment points on binding sites for the actin filaments. The myosin heads move in a coordinated style, they swivel toward the center of the sarcomere, detach and then reattach to the nearest active site of the actin filament. This is called a rachet type drive system. This process consumes large amounts of adenosine triphosphate (ATP).
Energy for this comes from ATP, the energy source of the cell. ATP binds to the cross bridges between myosin heads and actin filaments. The release of energy powers the swiveling of the myosin head. Muscles store little ATP and so must continuously recycle the discharged adenosine diphosphate molecule (ADP) into ATP rapidly. Muscle tissue also contains a stored supply of a fast acting recharge chemical, creatine phosphate which can assist initially producing the rapid regeneration of ADP into ATP.
Calcium ions are required for each cycle of the sarcomere. Calcium is released from the sarcoplasmic reticulum into the sarcomere when a muscle is stimulated to contract. This calcium uncovers the actin binding sites. When the muscle no longer needs to contract, the calcium ions are pumped from the sarcomere and back into storage in the sarcoplasmic reticulum.

[edit] Anatomy
Main article: Table of muscles of the human body
There are approximately 639 skeletal muscles in the human body.
The following are some major muscles[1] and their basic features:
Muscle
Origin
Insertion
Artery
Nerve
Action
Antagonist
gastrocnemius
femur
calcaneus
sural arteries
tibial nerve
plantarflexion, flexion of knee (minor)key
Tibialis anterior muscle
tibialis posterior
tibia, fibula
Foot
posterior tibial artery
tibial nerve
inversion of the foot, plantar flexion of the foot at the ankle
Tibialis anterior muscle
soleus
fibula, medial border of tibia
calcaneus
sural arteries
tibial nerve
plantarflexion
Tibialis anterior muscle
tibialis anterior
tibia
foot
anterior tibial artery
Fibular nerve
dorsiflex and invert the foot
Fibularis longus, Gastrocnemius, Soleus, Plantaris, Tibialis posterior
longus
fibula
Foot
fibular artery
Superficial fibular nerve
plantarflexion, eversion
Tibialis anterior muscle
brevis
fibula
Foot, eversion
peroneal artery
superficial peroneal nerve
gluteus maximus muscle
ilium, sacrum, sacrotuberous ligament
Gluteal tuberosity of the femur
gluteal arteries
inferior gluteal nerve
external rotation and extension of the hip joint
Iliacus, Psoas major, Psoas minor
biceps femoris
ischium, femur
fibula
inferior gluteal artery, popliteal artery
tibial nerve, common peroneal nerve
flexes and laterally rotates knee joint, extends hip joint
Quadriceps muscle
semitendinosus
ischium
tibia
inferior gluteal artery
sciatic
flex knee, extend hip joint
Quadriceps muscle
semimembranosus
ischium
tibia
profunda femoris, gluteal artery
sciatic nerve
Hip extension, Knee flexion
Quadriceps muscle
Iliopsoas
ilium
femur
medial femoral circumflex artery, iliolumbar artery
femoral nerve, lumbar nerves
flexion of hip
Gluteus maximus, posterior compartment of thigh
quadriceps femoriss
combined rectus femoris and vastus muscles
femoral artery
Femoral nerve
Knee extension; Hip flexion
Hamstring
adductor muscles of the hip
pubis
femur, tibia
obturator nerve
adduction of hip
levator scapulae
vertebral column
scapula
dorsal scapular artery
cervical nerve, dorsal scapular nerve
Elevates scapula, tilts its glenoid cavity inferiorly
trapezius
the rear of the skull, vertebral column
clavicle, scapula
cranial nerve XI, cervical nerves
retraction of scapula
Serratus anterior muscle
rectus abdominis
pubis
Costal cartilage of ribs 5-7, sternum
inferior epigastric artery
segmentally by thoraco-abdominal nerves
flexion of trunk/lumbar vertebrae
Erector spinae
transversus abdominis
ribs, ilium
pubic tubercle
lower intercostal nerves, iliohypogastric nerve and the ilioinguinal nerve
compress the ribs and viscera, thoracic and pelvic stability
Abdominal external oblique muscle
Lower 8 costae
Crista iliaca, ligamentum inguinale
lower 6 intercostal nerve, subcostal nerve
Rotates torso
Abdominal internal oblique muscle
Inguinal ligament, Iliac crest and the Lumbodorsal fascia
Linea alba, sternum and the inferior ribs.
Compresses abdomen and rotates vertebral column.
erector spinae
on the spines of the last four thoracic vertebræ
both the spines of the most cranial thoracic vertebrae and the cervical vertebrae
lateral sacral artery
posterior branch of spinal nerve
extends the vertebral column
Rectus abdominis muscle
pectoralis major
clavicle, sternum, costal cartilages
humerus
thoracoacromial trunk
lateral pectoral nerve and medial pectoral nerve
Clavicular head: flexes the humerusSternocostal head: extends the humerusAs a whole, adducts and medially rotates the humerus. It also draws the scapula anteriorly and inferiorly.
biceps brachii
scapula
radius
brachial artery
Musculocutaneous nerve
flexes elbow and supinates forearm
Triceps brachii muscle
triceps brachii
scapula and humerus
ulna
deep brachial artery
radial nerve
extends forearm, caput longum adducts shoulder
Biceps brachii muscle
brachialis
humerus
ulna
radial recurrent artery
musculocutaneous nerve
flexion at elbow joint
pronator teres
humerus, ulna
radius
ulnar artery and radial artery
median nerve
pronation of forearm, flexes elbow
Supinator muscle
brachioradialis
humerus
radius
radial recurrent artery
radial nerve
Flexion of forearm
rhomboids
nuchal ligaments, spinous processes of the C7 to T5 vertebrae
scapula
dorsal scapular artery
dorsal scapular nerve
Retracts the scapula and rotates it to depress the glenoid cavity. fixes the scapula to the thoracic wall.
Serratus anterior muscle
deltoid
clavicle, acromion, scapula
deltoid tuberosity of humerus
primarily posterior circumflex humeral artery
Axillary nerve
shoulder abduction, flexion and extension
Latissimus dorsi
latissimus dorsi
vertebral column, ilium and inferior 3 or 4 ribs
humerus
subscapular artery, dorsal scapular artery
thoracodorsal nerve
pulls the forelimb dorsally and caudally
deltoid, trapezius
Rotator cuff
scapula
humerus
lateral rotation, medial rotation, abduction

[edit] Aerobic and anaerobic muscle activity

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (July 2007)
At rest, the body produces the majority of its ATP aerobically in the mitochondria[2] without producing lactic acid or other fatiguing byproducts.[3] During exercise, the method of ATP production varies depending on the fitness of the individual as well as the duration, and intensity of exercise. At lower activity levels, when exercise continues for a long duration (several minutes or longer), energy is produced aerobically by combining oxygen with carbohydrates and fats stored in the body. Activity that is higher in intensity, with possible duration decreasing as intensity increases, ATP production can switch to anaerobic pathways, such as the use of the creatine phosphate and the phosphagen system or anaerobic glycolysis. Aerobic ATP production is biochemically much slower and can only be used for long-duration, low intensity exercise, but produces no fatiguing waste products that can not be removed immediately from sarcomere and body and results in a much greater number of ATP molecules per fat or carbohydrate molecule. Aerobic training allows the oxygen delivery system to be more efficient, allowing aerobic metabolism to being more quickly.[3] Anaerobic ATP production produces ATP much faster and allows near-maximal intensity exercise, but also produces significant amounts of lactic acid which render high intensity exercise unsustainable for greater than several minutes.[3] The phosphagen system is also anaerobic, allows for the highest levels of exercise intensity, but intramuscular stores of phosphocreatine are very limited and can only provide energy for exercises lasting up to ten seconds. Recovery is very quick, with full creatine stores regenerated within five minutes.[3]

[edit] Cardiac Muscle
Main article: Heart muscle
Heart muscles are distinct from skeletal muscles because the muscle fibers are laterally connected to each other. Furthermore, just as with smooth muscles, they are not controlling themselves. Heart muscles are controlled by the sinus node influenced by the autonomic nervous system.

[edit] Smooth muscle
Main article: Smooth muscle
Smooth muscles are controlled directly by the autonomic nervous system and are involuntary, meaning that they are incapable of being moved by conscious thought. Functions such as heart beat and lungs (which are capable of being willingly controlled, be it to a limited extent though) are involuntary muscles but are not smooth muscles.

[edit] Control of muscle contraction
Neuromuscular junctions are the focal point where a motor neuron attaches to a muscle. Acetylcholine, (a neurotransmitter used in skeletal muscle contraction) is released from the axon terminal of the nerve cell when an action potential reaches the microscopic junction, called a synapse. A group of chemical messengers cross the synapse and stimulate the formation of electrical changes, which are produced in the muscle cell when the acetylcholine binds to receptors on its surface. Calcium is released from its storage area in the cell's sarcoplasmic reticulum. An impulse from a nerve cell causes calcium release and brings about a single, short muscle contraction called a muscle twitch. If there is a problem at the neuromuscular junction, a very prolonged contraction may occur, tetanus. Also, a loss of function at the junction can produce paralysis.
Skeletal muscles are organized into hundreds of motor units, each of which involves a motor neuron, attached by a series of thin finger-like structures called axon terminals. These attach to and control discrete bundles of muscle fibers. A coordinated and fine tuned response to a specific circumstance will involve controlling the precise number of motor units used. While individual muscle units contract as a unit, the entire muscle can contract on a predetermined basis due to the structure of the motor unit. Motor unit coordination, balance, and control frequently come under the direction of the cerebellum of the brain. This allows for complex muscular coordination with little conscious effort, such as when one drives a car without thinking about the process.

HUMAN ANATOMY

HUMAN ANATOMY
Human anatomyFrom Wikipedia, the free encyclopediaJump to: navigation, search List of bones of the human skeletonHuman anatomy, which, with physiology and biochemistry, is a complementary basic medical science is primarily the scientific study of the morphology of the adult human body.[1] Anatomy is subdivided into gross anatomy and microscopic anatomy.[1] Gross anatomy (also called topographical anatomy, regional anatomy, or anthropotomy) is the study of anatomical structures that can be seen by unaided vision.[1] Microscopic anatomy is the study of minute anatomical structures assisted with microscopes, which includes histology (the study of the organization of tissues),[1] and cytology (the study of cells). Anatomy, physiology (the study of function) and biochemistry (the study of the chemistry of living structures) are complementary basic medical sciences which are usually taught together (or in tandem).In some of its facets human anatomy is closely related to embryology, comparative anatomy and comparative embryology,[1] through common roots in evolution; for example, much of the human body maintains the ancient segmental pattern that is present in all vertebrates with basic units being repeated, which is particularly obvious in the vertebral column and in the ribcage, and can be traced from very early embryos.The human body consists of biological systems, that consist of organs, that consist of tissues, that consist of cells and connective tissue.The history of anatomy has been characterized, over a long period of time, by a continually developing understanding of the functions of organs and structures in the body. Methods have also advanced dramatically, advancing from examination of animals through dissection of preserved cadavers (dead human bodies) to technologically complex techniques developed in the 20th century.Contents[hide]1 Study1.1 Regional groups1.2 Major organ systems2 Superficial anatomy3 Internal organs4 Brain5 See also6 References7 External links//[edit] StudyA full articulated human skeleton used in educationGenerally, medical students, dentists, physiotherapists, nurses, paramedics, radiographers, artists, and students of certain biological sciences, learn gross anatomy and microscopic anatomy from anatomical models, skeletons, textbooks, diagrams, photographs, lectures, and tutorials. The study of microscopic anatomy (or histology) can be aided by practical experience examining histological preparations (or slides) under a microscope; and in addition, medical and dental students generally also learn anatomy with practical experience of dissection and inspection of cadavers (dead human bodies). A thorough working knowledge of anatomy is required by all medical doctors, especially surgeons, and doctors working in some diagnostic specialities, such as histopathology and radiology.Human anatomy, physiology, and biochemistry are complementary basic medical sciences, which are generally taught to medical students in their first year at medical school. Human anatomy can be taught regionally or systemically;[1] that is, respectively, studying anatomy by bodily regions such as the head and chest, or studying by specific systems, such as the nervous or respiratory systems. The major anatomy textbook, Gray's Anatomy, has recently been reorganized from a systems format to a regional format,[2][3] in line with modern teaching methods.[edit] Regional groupsHead and neck — includes everything above the thoracic inletUpper limb — includes the hand, wrist, forearm, elbow, arm, and shoulder.Thorax — the region of the chest from the thoracic inlet to the thoracic diaphragm.Human abdomen to the pelvic brim or to the pelvic inlet.The back — the spine and its components, the vertebrae, sacrum, coccyx, and intervertebral disks .Pelvis and Perineum — the pelvis consists of everything from the pelvic inlet to the pelvic diaphragm. The perineum is the region between the sex organs and the anus.Lower limb — everything below the inguinal ligament, including the hip, the thigh, the knee, the leg, the ankle, and the foot.[edit] Major organ systemsCirculatory system: pumping and channeling blood to and from the body and lungs with heart, blood, and blood vessels.Digestive system: digestion and processing food with salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines, rectum, and anus.Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitary or pituitary gland, pineal body or pineal gland, thyroid, parathyroids, and adrenals or adrenal glandsIntegumentary system: skin, hair and nailsLymphatic system: structures involved in the transfer of lymph between tissues and the blood stream, the lymph and the nodes and vessels that transport it including the Immune system: defending against disease-causing agents with leukocytes, tonsils, adenoids, thymus, and spleenMusculoskeletal system: movement with muscles and human skeleton (structural support and protection with bones, cartilage, ligaments, and tendons).Nervous system: collecting, transferring and processing information with brain, spinal cord, peripheral nerves, and nervesReproductive system: the sex organs; in the female; ovaries, fallopian tubes, uterus, vagina, mammary glands, and in the male; testes, vas deferens, seminal vesicles, prostate, and penis.Respiratory system: the organs used for breathing, the pharynx, larynx, trachea, bronchi, lungs, and diaphragm.Urinary system: kidneys, ureters, bladder and urethra involved in fluid balance, electrolyte balance and excretion of urine.[edit] Superficial anatomySuperficial anatomy of female and male humanSuperficial anatomy or surface anatomy is important in human anatomy being the study of anatomical landmarks that can be readily identified from the contours or other reference points on the surface of the body.[1] With knowledge of superficial anatomy, physicians gauge the position and anatomy of the associated deeper structures.Common names of well known parts of the human body, from top to bottom:Head — Forehead — Jaw — Cheek — ChinNeck — ShouldersArm — Elbow — Wrist — Hand — Fingers — ThumbSpine — Chest — RibcageAbdomen — GroinHip — Buttocks — Leg — Thigh — Knee — Calf — Heel — Ankle — Foot — ToesThe eye, ear, nose, mouth, teeth, tongue, throat, adam's apple, breast, penis, scrotum, clitoris, vulva, navel are visible too.[edit] Internal organsCommon names of internal organs (in alphabetical order) :Adrenals — Appendix — Bladder — Brain — Eyes — Gall bladder — Heart — Intestines — Kidney — Liver — Lungs — Esophagus — Ovaries — Pancreas — Parathyroids — Pituitary — Prostate — Spleen — Stomach — Testicles — Thymus — Thyroid — Uterus — Veins[edit] BrainMain article: Human brainAmygdala — Brain stem — Cerebellum — Cerebral cortex — Limbic system — medulla — midbrain — pons

MICROSCOPES

A microscope (from the Greek: μικρός, mikrós, "small" and σκοπεῖν, skopeîn, "to look" or "see") is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. The science of investigating small objects using such an instrument is called microscopy. The term microscopic means minute or very small, not visible with the eye unless aided by a microscope.

History

Microscopes trace their history back almost 1200 years with Abbas Ibn Firnas's corrective lenses,[1] and it was Ibn al-Haytham's Book of Optics — written between 1011 and 1021 — that laid the foundation for optical research on the magnifying glass. Also, a device called the reading stone by an unknown inventor (thought to be Ibn Firnas) magnified text when laid on top of reading materials.[2]
The first true microscope was made around 1595 in Middelburg, The Netherlands.[3] Three different eyeglass makers have been given credit for the invention: Hans Lippershey (who also developed the first real telescope); Hans Janssen; and his son, Zacharias. The coining of the name "microscope" has been credited to Giovanni Faber, who gave that name to Galileo Galilei's compound microscope in 1625.[4] (Galileo had called it the "occhiolino" or "little eye".)
The most common type of microscope—and the first to be invented—is the optical microscope. This is an optical instrument containing one or more lenses that produce an enlarged image of an object placed in the focal plane of the lens(es). There are, however, many other microscope designs.

Types
Several types of microscops
Several types of microscopes
"Microscopes" can largely be separated into three classes: optical theory microscopes (Light microscope), electron microscopes (e.g.,TEM), and scanning probe microscopes (SPM).
Optical theory microscopes are microscopes which function through the optical theory of lenses in order to magnify the image generated by the passage of a wave through the sample. The waves used are either electromagnetic (in optical microscopes) or electron beams (in electron microscopes). The types are the Compound Light, Stereo, and the electron microscope.
[edit] Optical microscopes
Main article: Optical microscope
Optical microscopes, through their use of visible wavelengths of light, are the simplest and hence most widely used type of microscope.
Optical microscopes typically use refractive glass and occasionally of plastic or quartz, to focus light into the eye or another light detector. Mirror-based optical microscopes operate in the same manner. Typical magnification of a light microscope, assuming visible range light, is up to 1500x with a theoretical resolution limit of around 0.2 micrometres or 200 nanometers. Specialized techniques (e.g., scanning confocal microscopy) may exceed this magnification but the resolution is diffraction limited. Using shorter wavelengths of light, such as the ultraviolet, is one way to improve the spatial resolution of the microscope as are techniques such as Near-field scanning optical microscope.

A stereo microscope is often used for lower-power magnification on large subjects.
Various wavelengths of light, including those beyond the visible range, are sometimes used for special purposes. Ultraviolet light is used to enable the resolution of smaller features as well as to image samples that are transparent to the eye. Near infrared light is used to image circuitry embedded in bonded silicon devices as silicon is transparent in this region. Many wavelengths of light, ranging from the ultraviolet to the visible are used to excite fluorescence emission from objects for viewing by eye or with sensitive cameras.
phase contrast microscope:Phase contrast microscopy is an optical microscopy illumination technique in which small phase shifts in the light passing through a transparent specimen are converted into amplitude or contrast changes in the image.
A phase contrast microscope does not require staining to view the slide. This microscope made it possible to study the cell cycle.The Digital microscope appeared a few years ago, using optics and a charge-coupled device (CCD) camera to output a digital image to a monitor. This technology invented by Hirox offers a much higher depth of field and working distance as well as increased flexibility of inspection for large sized objects (NDT, skin, paintings) in a broad range of applications.

[edit] Electron Microscopes
Main article: Electron microscope
Three major variants of electron microscopes exist:
Scanning electron microscope (SEM): looks at the surface of bulk objects by scanning the surface with a fine electron beam and measuring reflection. May also be used for spectroscopy.
Transmission electron microscope (TEM): passes electrons completely through the sample, analogous to basic optical microscopy. This requires careful sample preparation, since electrons are scattered so strongly by most materials.This is a scientific device that allows people to see objects that could normally not be seen by the naked or unaided eye.
Scanning Tunneling Microscope (STM): is a powerful technique for viewing surfaces at the atomic level.
The SEM, TEM, STM are included in the scanning probe microscopy.

[edit] Established types of scanning probe microscopy
AFM, atomic force microscopy
Contact AFM
Non-contact AFM
Dynamic contact AFM
Tapping AFM
BEEM, ballistic electron emission microscopy
EFM, electrostatic force microscope
ESTM electrochemical scanning tunneling microscope
FMM, force modulation microscopy
KPFM, kelvin probe force microscopy
MFM, magnetic force microscopy
MRFM, magnetic resonance force microscopy
NSOM, near-field scanning optical microscopy (or SNOM, scanning near-field optical microscopy)
PFM, Piezo Force Microscopy
PSTM, photon scanning tunneling microscopy
PTMS, photothermal microspectroscopy/microscopy
SAP, scanning atom probe [5]
SECM, scanning electrochemical microscopy
SCM, scanning capacitance microscopy
SGM, scanning gate microscopy
SICM, scanning ion-conductance microscopy
SPSM spin polarized scanning tunneling microscopy
SThM, scanning thermal microscopy[2]
STM, scanning tunneling microscopy
SVM, scanning voltage microscopy
SHPM, scanning Hall probe microscopy
SSM, Scanning SQUID microscope
Of these techniques AFM and STM are the most commonly used followed by MFM and SNOM/NSOM.

[edit] Other microscopes
Scanning acoustic microscopes use sound waves to measure variations in acoustic impedance. Similar to Sonar in principle, they are used for such jobs as detecting defects in the subsurfaces of materials including those found in integrated circuits.

[edit] See also

Different microscopes

Wikimedia Commons has media related to: Microscopes
Acronyms in microscopy
Angular resolution
Bright field microscopy
Condensed Matter Physics
Confocal microscopy
Dark field microscopy
Digital microscope
Electron Microscope
Fluorescence interference contrast microscopy
Fluorescence microscope
Microscope image processing
Microscopy
Optical Microscope
Intel Play
Phase contrast microscopy
Microscope slide
Telescope
Timeline of microscope technology
X-ray microscope
Microscopy laboratory in: A Study Guide to the Science of Botany at Wikibooks
Laser capture microdissection

[edit] References
^ Ajram, K. (1992). The miracle of Islamic science. Knowledge House Publishers. pp. Appendix B. ISBN 0-911119-43-4.
^ [1] Timeline - History of Microscopes
^ Microscopes: Time Line
^ Stephen Jay Gould(2000). The Lying Stones of Marrakech, ch.2 "The Sharp-Eyed Lynx, Outfoxed by Nature". London: Jonathon Cape. ISBN 0224050443
^ Morita, Seizo. Roadmap of Scanning Probe Microscopy. 3 January 2007