Forelimb: Difference between revisions

Latest revision as of 11:00, 15 February 2025

Anatomy of the Forelimb[edit]

The forelimb is a crucial anatomical structure in many vertebrates, including humans. It is primarily involved in locomotion, manipulation of the environment, and various other functions depending on the species. In humans, the forelimb is commonly referred to as the arm, which includes the shoulder, upper arm, forearm, and hand.

Structure[edit]

The forelimb consists of several key components:

Shoulder Girdle: This includes the scapula (shoulder blade) and the clavicle (collarbone). These bones connect the forelimb to the axial skeleton and provide attachment points for muscles.

Upper Arm: The main bone of the upper arm is the humerus. It articulates with the scapula at the shoulder joint and with the bones of the forearm at the elbow joint.

Forearm: The forearm contains two bones, the radius and the ulna. These bones allow for the rotation of the forearm, enabling pronation and supination.

Hand: The hand is composed of the carpals (wrist bones), metacarpals (bones of the hand), and phalanges (finger bones). The intricate structure of the hand allows for a wide range of movements and dexterity.

Function[edit]

The forelimb serves several functions:

Locomotion: In quadrupeds, the forelimbs are essential for movement. In humans, they are primarily used for balance and support during activities such as climbing.

Manipulation: The human hand is highly specialized for grasping and manipulating objects, a key factor in the development of tool use and fine motor skills.

Sensation: The forelimb, particularly the hand, is rich in sensory receptors, allowing for detailed perception of the environment.

Evolution[edit]

The evolution of the forelimb has been a significant factor in the adaptation of various species to their environments. In tetrapods, the forelimbs have evolved from the pectoral fins of lobe-finned fish. This transition involved changes in bone structure and function, allowing for the development of limbs capable of supporting weight on land.

In humans, the forelimb has evolved to prioritize dexterity and manipulation over locomotion, leading to the development of the opposable thumb and increased manual dexterity.

Related Pages[edit]

@@ Line 1: / Line 1: @@
-'''Forelimb'''
+== Anatomy of the Forelimb ==
-The '''forelimb''' is the anterior limb (arm, leg, or similar appendage) on an animal's body. In quadrupeds, it is one of the front pair of walking appendages. There are three main parts of the forelimb: the upper arm, forearm, and hand (or paw, hoof, or wing).
-== Anatomy of the Forelimb ==
+The [[forelimb]] is a crucial anatomical structure in many vertebrates, including humans. It is primarily involved in [[locomotion]], manipulation of the environment, and various other functions depending on the species. In humans, the forelimb is commonly referred to as the [[arm]], which includes the [[shoulder]], [[upper arm]], [[forearm]], and [[hand]].
-The forelimb is made up of several key components, including the [[humerus]], [[radius]], [[ulna]], and various smaller structures such as the [[carpal bones]], [[metacarpal bones]], and [[phalanges]].
+[[File:Handskelett_MK1888.png|thumb|right|Diagram of the human hand skeleton]]
-=== Humerus ===
+=== Structure ===
-The [[humerus]] is the bone of the upper arm or forelimb forming joints at the shoulder and the elbow.
+The forelimb consists of several key components:
-=== Radius and Ulna ===
+* '''Shoulder Girdle''': This includes the [[scapula]] (shoulder blade) and the [[clavicle]] (collarbone). These bones connect the forelimb to the [[axial skeleton]] and provide attachment points for muscles.
-The [[radius]] and [[ulna]] are the two long bones located in the forearm that extend from the elbow to the wrist.
+* '''Upper Arm''': The main bone of the upper arm is the [[humerus]]. It articulates with the scapula at the [[shoulder joint]] and with the bones of the forearm at the [[elbow joint]].
-=== Carpal Bones ===
+* '''Forearm''': The forearm contains two bones, the [[radius]] and the [[ulna]]. These bones allow for the rotation of the forearm, enabling [[pronation]] and [[supination]].
-The [[carpal bones]] are the eight small bones that make up the wrist (or carpus) that connects the hand to the forearm.
+* '''Hand''': The hand is composed of the [[carpals]] (wrist bones), [[metacarpals]] (bones of the hand), and [[phalanges]] (finger bones). The intricate structure of the hand allows for a wide range of movements and dexterity.
-=== Metacarpal Bones ===
+=== Function ===
-The [[metacarpal bones]] are the five long bones in the hand, located between the carpal bones of the wrist and the phalanges of the fingers.
+The forelimb serves several functions:
-=== Phalanges ===
+* '''Locomotion''': In quadrupeds, the forelimbs are essential for movement. In humans, they are primarily used for balance and support during activities such as climbing.
-The [[phalanges]] are the bones that make up the fingers of the hand and the toes of the foot. There are 56 phalanges in the human body, with fourteen on each hand and foot.
+* '''Manipulation''': The human hand is highly specialized for grasping and manipulating objects, a key factor in the development of [[tool use]] and [[fine motor skills]].
-== Function of the Forelimb ==
+* '''Sensation''': The forelimb, particularly the hand, is rich in [[sensory receptors]], allowing for detailed perception of the environment.
-The forelimb plays a crucial role in locomotion, allowing an animal to move about and interact with its environment. It also serves a variety of specialized functions depending on the species, such as grasping objects, digging, or flying.
+=== Evolution ===
-== Evolution of the Forelimb ==
+The evolution of the forelimb has been a significant factor in the adaptation of various species to their environments. In [[tetrapods]], the forelimbs have evolved from the [[pectoral fins]] of [[lobe-finned fish]]. This transition involved changes in bone structure and function, allowing for the development of limbs capable of supporting weight on land.
-The structure of the forelimb has evolved over millions of years to suit the needs of different species. For example, the forelimbs of a bird have evolved into wings, while those of a whale have become flippers.
+In humans, the forelimb has evolved to prioritize dexterity and manipulation over locomotion, leading to the development of the [[opposable thumb]] and increased [[manual dexterity]].
-== See Also ==
+== Related Pages ==
-* [[Hindlimb]]
+* [[Humerus]]
-* [[Limb development]]
+* [[Radius (bone)]]
-* [[Limb (anatomy)]]
+* [[Ulna]]
+* [[Scapula]]
+* [[Clavicle]]
+* [[Hand]]
+* [[Shoulder joint]]
 [[Category:Anatomy]]
-[[Category:Zoology]]
+[[Category:Musculoskeletal system]]
-[[Category:Veterinary medicine]]
-{{stub}}