Difference between revisions of "Arm"
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An '''arm''' is a particular upper [[limb]] appendage having varying usage and strength within the animal kingdom. In humans it is made up of three distinct [[bone]]s: | An '''arm''' is a particular upper [[limb]] appendage having varying usage and strength within the animal kingdom. In humans it is made up of three distinct [[bone]]s: | ||
| − | * Humerus: ( | + | * Humerus: (upper arm) |
| − | * Radius: ( | + | * Radius: (outer bone of the forearm, when supinated) |
| − | * Ulna: ( | + | * Ulna: (inner bone of the forearm, when supinated) |
| + | |||
| + | The hands have these bones: | ||
| + | * Carpals: ("wrist bones," | ||
| + | * Metacarpals: (longer bones in the "palm") | ||
| + | * Phalanges: (s. phalanx; two in the pollex, or thumb; three four the remaing four fingers) | ||
| + | |||
| + | The upper region of the arm has the following muscles: | ||
| + | * Deltoid ("shoulder", anterior, lateral, and posterior sections) | ||
| + | * Biceps brachii (the front, two heads) | ||
| + | * Triceps brachii (the back, three heads) | ||
| + | |||
| + | The forearm has these muscles: | ||
| + | * Brachioradialis (connects | ||
| + | * Supinator (turns forearm up) | ||
| + | * Pronator quadratus (turns forearm down) | ||
| + | * Flexor carpi radialis (flexes forearm) | ||
| + | * Flexor digitorum superficialis (flexes fingers) | ||
| + | * Flexor pollicis longus (flexes thumb) | ||
| + | * Extensor carpi radialis longus and brevis (straightens forearm) | ||
| + | * Extensor carpi ulnarus (straightens forearm) | ||
| + | * Extensor digitorum (straightens fingers) | ||
| + | |||
| + | Also, the hands have many muscles for fine control of the fingers. | ||
== Sources == | == Sources == | ||
Revision as of 02:23, December 13, 2009
An arm is a particular upper limb appendage having varying usage and strength within the animal kingdom. In humans it is made up of three distinct bones:
- Humerus: (upper arm)
- Radius: (outer bone of the forearm, when supinated)
- Ulna: (inner bone of the forearm, when supinated)
The hands have these bones:
- Carpals: ("wrist bones,"
- Metacarpals: (longer bones in the "palm")
- Phalanges: (s. phalanx; two in the pollex, or thumb; three four the remaing four fingers)
The upper region of the arm has the following muscles:
- Deltoid ("shoulder", anterior, lateral, and posterior sections)
- Biceps brachii (the front, two heads)
- Triceps brachii (the back, three heads)
The forearm has these muscles:
- Brachioradialis (connects
- Supinator (turns forearm up)
- Pronator quadratus (turns forearm down)
- Flexor carpi radialis (flexes forearm)
- Flexor digitorum superficialis (flexes fingers)
- Flexor pollicis longus (flexes thumb)
- Extensor carpi radialis longus and brevis (straightens forearm)
- Extensor carpi ulnarus (straightens forearm)
- Extensor digitorum (straightens fingers)
Also, the hands have many muscles for fine control of the fingers.