Saddle Joint | |
---|---|
Details | |
Identifiers | |
Latin | articulatio sellaris |
TA98 | A03.0.00.048 |
TA2 | 1560 |
FMA | 75298 |
Anatomical terminology |
A saddle joint (sellar joint, [1] [2] articulation by reciprocal reception[ citation needed ]) is a type of synovial joint in which the opposing surfaces are reciprocally concave and convex. It is found in the thumb, the thorax, the middle ear, and the heel.
In a saddle joint, one bone surface is concave while another is convex. [3] [4] This creates significant stability. [3]
The movements of saddle joints are similar to those of the condyloid joint and include flexion, extension, adduction, abduction, and circumduction. [1] However, axial rotation is not allowed. Saddle joints are said to be biaxial, [5] allowing movement in the sagittal and frontal planes. [2]
Examples of saddle joints in the human body include the carpometacarpal joint of the thumb, [6] [7] the sternoclavicular joint of the thorax, [8] the incudomalleolar joint of the middle ear, [9] and the calcaneocuboid joint of the heel. [2]
The term "saddle" arises because the concave-convex bone interaction is compared to a horse rider riding a horse, with both bone surfaces being saddle-shaped. [2] [3] The saddle joint is also known as the sellar joint. [1] [2]
In vertebrate anatomy, ribs are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax. In some animals, especially snakes, ribs may provide support and protection for the entire body.
In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or five metacarpal bones and the series of joints between these bones, thus referred to as wrist joints. This region also includes the carpal tunnel, the anatomical snuff box, bracelet lines, the flexor retinaculum, and the extensor retinaculum.
The quadriceps femoris muscle is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large fleshy mass which covers the front and sides of the femur. The name derives from Latin four-headed muscle of the femur.
In human anatomy, the dorsalis pedis artery is a blood vessel of the lower limb. It arises from the anterior tibial artery, and ends at the first intermetatarsal space. It carries oxygenated blood to the dorsal side of the foot. It is useful for taking a pulse. It is also at risk during anaesthesia of the deep peroneal nerve.
The facial artery is a branch of the external carotid artery that supplies structures of the superficial face.
The olecranon, is a large, thick, curved bony eminence of the ulna, a long bone in the forearm that projects behind the elbow. It forms the most pointed portion of the elbow and is opposite to the cubital fossa or elbow pit. The olecranon serves as a lever for the extensor muscles that straighten the elbow joint.
The flexor pollicis brevis is a muscle in the hand that flexes the thumb. It is one of three thenar muscles. It has both a superficial part and a deep part.
The supratrochlear nerve is a branch of the frontal nerve, itself a branch of the ophthalmic nerve (CN V1) from the trigeminal nerve (CN V). It provides sensory innervation to the skin of the forehead and the upper eyelid.
The mylohyoid nerve is a mixed nerve of the head. It is a branch of the inferior alveolar nerve. It supplies the mylohyoid muscle, and the anterior belly of the digastric muscle. It may also supply mandibular (lower) molar teeth, requiring local anaesthesia for some oral procedures.
The intercostal space (ICS) is the anatomic space between two ribs. Since there are 12 ribs on each side, there are 11 intercostal spaces, each numbered for the rib superior to it.
The retromandibular vein is a major vein of the face.
The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles and it has openings for blood vessels. From its borders, the mastoid part articulates with two other bones.
The tympanic nerve is a branch of the glossopharyngeal nerve found near the ear. It gives sensation to the middle ear, the Eustachian tube, the parotid gland, and mastoid air cells. It gives parasympathetic to supply to the parotid gland via the otic ganglion and the auriculotemporal nerve.
The mandibular fossa, also known as the glenoid fossa in some dental literature, is the depression in the temporal bone that articulates with the mandible.
Thoracic splanchnic nerves are splanchnic nerves that arise from the sympathetic trunk in the thorax and travel inferiorly to provide sympathetic supply to the abdomen. The nerves contain preganglionic sympathetic fibers and general visceral afferent fibers.
Beneath the neck of the radius, on the medial side, is an eminence, the radial tuberosity; its surface is divided into:
The sternocostal joints, also known as sternochondral joints or costosternal articulations, are synovial plane joints of the costal cartilages of the true ribs with the sternum. The only exception is the first rib, which has a synchondrosis joint since the cartilage is directly united with the sternum. The sternocostal joints are important for thoracic wall mobility.
The supraglenoid tubercle is a region of the scapula from which the long head of the biceps brachii muscle originates. It is a small, rough projection superior to the glenoid cavity near the base of the coracoid process. The term supraglenoid is from the Latin supra, meaning above, and glenoid, meaning socket or cavity.
The radial styloid process is a projection of bone on the lateral surface of the distal radius bone.
The styloid process of the ulna is a bony prominence found at distal end of the ulna in the forearm.
This article incorporates text in the public domain from page 286 of the 20th edition of Gray's Anatomy (1918)