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Pivot joint

At a pivot joint    , a rounded portion of a bone is enclosed within a ring formed partially by the articulation with another bone and partially by a ligament (see [link] a ). The bone rotates within this ring. Since the rotation is around a single axis, pivot joints are functionally classified as a uniaxial diarthrosis type of joint. An example of a pivot joint is the atlantoaxial joint, found between the C1 (atlas) and C2 (axis) vertebrae. Here, the upward projecting dens of the axis articulates with the inner aspect of the atlas, where it is held in place by a ligament. Rotation at this joint allows you to turn your head from side to side. A second pivot joint is found at the proximal radioulnar joint    . Here, the head of the radius is largely encircled by a ligament that holds it in place as it articulates with the radial notch of the ulna. Rotation of the radius allows for forearm movements.

Hinge joint

In a hinge joint    , the convex end of one bone articulates with the concave end of the adjoining bone (see [link] b ). This type of joint allows only for bending and straightening motions along a single axis, and thus hinge joints are functionally classified as uniaxial joints. A good example is the elbow joint, with the articulation between the trochlea of the humerus and the trochlear notch of the ulna. Other hinge joints of the body include the knee, ankle, and interphalangeal joints between the phalanx bones of the fingers and toes.

Condyloid joint

At a condyloid joint    (ellipsoid joint), the shallow depression at the end of one bone articulates with a rounded structure from an adjacent bone or bones (see [link] e ). The knuckle (metacarpophalangeal) joints of the hand between the distal end of a metacarpal bone and the proximal phalanx bone are condyloid joints. Another example is the radiocarpal joint of the wrist, between the shallow depression at the distal end of the radius bone and the rounded scaphoid, lunate, and triquetrum carpal bones. In this case, the articulation area has a more oval (elliptical) shape. Functionally, condyloid joints are biaxial joints that allow for two planes of movement. One movement involves the bending and straightening of the fingers or the anterior-posterior movements of the hand. The second movement is a side-to-side movement, which allows you to spread your fingers apart and bring them together, or to move your hand in a medial-going or lateral-going direction.

Saddle joint

At a saddle joint    , both of the articulating surfaces for the bones have a saddle shape, which is concave in one direction and convex in the other (see [link] c ). This allows the two bones to fit together like a rider sitting on a saddle. Saddle joints are functionally classified as biaxial joints. The primary example is the first carpometacarpal joint, between the trapezium (a carpal bone) and the first metacarpal bone at the base of the thumb. This joint provides the thumb the ability to move away from the palm of the hand along two planes. Thus, the thumb can move within the same plane as the palm of the hand, or it can jut out anteriorly, perpendicular to the palm. This movement of the first carpometacarpal joint is what gives humans their distinctive “opposable” thumbs. The sternoclavicular joint is also classified as a saddle joint.

Questions & Answers

how many classes of drugs do we have?
Jesse Reply
site of fracture in the kneel
holuwahseun Reply
what is pelvis
Aisha Reply
Complex of bones that connect the trunk and the legs,supports and balance the trunk.
Orpha
What is d most heaviest organ in d body
Abraham Reply
Liver
Akasi
The skin
Akasi
skin
Divya
why skin?
Sam
liver
Anne
water
Mehdi
Heart
Biplob
the brain
lehumo
skin
Emma
skin
jessica
largest internal organ is the liver
jessica
liver is the heaviest organ
Eyyammeh
the liver is the heaviest organs
Khh
What is the meaning? What does it entails to? What are the works of Arthropologists?
Orpha Reply
bones of appendicular skeleton
hemalatha Reply
Fore limbs, hind limbs, pectoral and pelvic girdle
Abraham
Functions of the thoracic cage
Fereh Reply
protect all the organs and tissues from any impact or injury
Javier
It protects the heart other tissues in the chest region
Abraham
why sickle cell carrier people don't get malaria
Boakye Reply
Bcos mosquitoes are not attracted by their blood due to poor oxygen
Abraham
What is the amniotic fluid
bollywood Reply
amniotic fluid is the fluid that is inside the uterus with the baby.
Fati
shielded
Varun
This fluid serves as a cushion for the growing fetus but also serves to facilitate the exchange of nutrients, water, and biochemical products between mother and fetus.
Anne
it also reduces friction during birth as it wets the birth canal during delivery
steve
Amniotic fluid can be taken out by inserting needle to detect birth abnormalities as the foetus cells are present in amniotic fluid. This process is known as amniocentesis.
Biplav
structure of heart and it's function (10 mark )
Priyanka Reply
not possible
Abraham
What is the best book on physiology?
cesar Reply
describe varicocele
malulu
what do you mean by peritoneum
Siba Reply
It is thick covering surrounding the abdomen
Awais
r8
how to become good in Anatomy and physiology
malulu
hi
Milkah
hlo
Wani
What are is the last solution to abdomen pain in pregnant women
Umoru
no it is in kidney
Tantray
Kk
Umoru
structure of heart and it's function
Priyanka
Serous membrane lining the cavity of the abdomen
bollywood
it is four lobs structure and it is triangular in shaped. it 's function pumping the blood
ABDULLAH
explain root of lungs
ABDULLAH
Glomerular pressure -capsule pressure -colloid osmosis pressure
malulu Reply
how to describe mechanism of micturition
malulu
spleen is important?
AKASH Reply
helpful in destruction of rbc
It is imp in storing blood and destruction of microbes and harmful particles
Awais
ty sir
AKASH
K
Umoru
what are the sources of glucose in the body
malulu
describe mechanism of micturition
malulu
Pancreatic hormones with function
mami Reply
Insulin, which helps to regulate our blood sugar levels.
Bb
glucagon which is antagonistic to insulin increase the blood glucose level,. Somatostatin help to regulate the levels of both insulin and glucagon
Ashish
thnks for helping
nimco
thanks
Narendra
what is a lymph node.?
AKASH
lymph nodes are small kidney shaped organs of the lymphatic system.
Trishauna
there are several hundred lymph nodes found mostly throughout the thorax and abdomen of the body with the highest concentrations in the auxiliary (armpit) and inguinal groin regions.
Trishauna

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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