help with 2 aassgn due in 24 hours
Anatomy
Skeletal System
Mrs. Shields
Appendicular skeleton
Total of 126 bones
Consists of the upper and lower extremities, the pectoral girdle and the pelvic girdle
Functionally it is involved in locomotion (lower limbs) of the axial skeleton and manipulation of objects in the environment (upper limbs)
Unlike the axial skeleton, the appendicular skeleton is unfused, allowing for a much greater range of motion
Upper extremities and pectoral girdle
Clavicle (2)
Collar bone
Medial end articulates with manubrium
Lateral end joins with superior part of scapula to help form the shoulder
Scapulae (2)
Shoulder blades
Acromion: superior, lateral projection that articulates with the clavicle
Coracoid process: “Crow’s Beak” acts as an anchor point for several muscles
Glenoid cavity/fossa: depression into which the head of the humerus fits, forming the shoulder joint
Humerus (2)
Long bone in the upper arm which runs from the shoulder to the elbow
Head: Ball-like superior end
Condyles: curved protuberance at the end of a bone forming part of an articulation
Located on inferior end
Articulate with radius and ulna to form the elbow joint
Epicondyles: rounded eminence on a bone that lies upon a condyle and act as attachment points for ligaments
medial epicondyle of the humerus
protects the ulnar nerve
lateral epicondyle of the humerus
Smaller of the two
Ulna (2)
Medial of the two forearm bones
Superior end is called the olecranon process; the elbow
Radius (2)
Lateral of the two forearm bones
Shorter and smaller than the ulna
Carpals (16)
Wrist bones
Consist of 8 per hand
Metacarpals (10)
Bones of the hand just beyond the carpals
Consist of 5 per hand
Phalanges (28)
Bones of the fingers
Consist of 14 per hand
Each finger consists of 3 phalanges
Each thumb consists of 2 phalanges
Not individually named, rather, referred to as proximal, medial, and distal
Fingers are referred to by number starting with the index finger
Lower Extremities
Lower extremities and pelvic girdle
Os coxae (2)
Hip bones; make up the pelvic girdle
Also known as innominate bone, pelvic bone or coxal bone
Composed of 3 parts
Ilium: broad superior portion
Iliac crest: upper rim of the ilium
Ischium: inferior portion of the os coxae
forms the lower and back part
Pubis: inferior, anterior segment of the os coxae
Also called pubic bone
Acetabulum: cup-like area into which the head of the femur fits to form the hip joint
Pubic symphysis: cartilaginous joint that sits between and joins left and right superior rami of the pubic bones
Located in front of and below the urinary bladder
Can be moved roughly 2 mm and with 1 degree rotation; increases for women at the time of childbirth
Femur (2)
Large bone of the upper leg
Strongest bone in the body
Longest bone in the body
Femoral head: superior end of the femur
Fits into the acetabulum to form the hip joint
Supported by the femoral neck
Most common area for hip fractures
Condyles: articulate with lower leg bones to form knee joint
Epicondyles: point of attachment for ligaments in the knee joint
Medial and lateral
Patella (2)
Commonly referred to as kneecap
Considered a sesamoid bone due to its formation within the tendon of the femoral muscles
Roughly triangular in shape, with the apex of the patella facing downwards
Tibia (2)
Shin bone
Medial bone of the lower leg
Tibial crest is a pronounced ridge on the anterior margin “Furniture locator”
Medial malleolus
Projection on the distal end of the tibia
While not an actual ankle bone, many consider this the “inside ankle bone”
Fibula (2)
Lateral bone of the lower leg
Smaller than tibia
Lateral malleolus
Distal end of the fibula
Like the medial malleolus, it is known as the “outer ankle bone” but isn’t actually a bone in itself
Tarsals (14)
Actual ankle bones
7 per foot
Include calcaneous (heel bone)
Metatarsals (10)
Bones of the foot itself
5 per foot
Phalanges (28)
Bones of the toes
Equal to the phalanges of the hands (3 per toe, 2 per big toe)
Arthrology
Arthro = joints or articulations, -ology = study of
Articulation: point of union between two bones, or cartilage and a bone
All bones, except the hyoid bone, articulate with other bones
Three types of articulations
Synarthroses
Immovable articulations
At these joints, movement is not intended
Example?
Cranial sutures: point at which bones of the cranium come together
Coronal suture: between the frontal and parietal bones
Lambdoid suture: between the parietal and occipital bones and continuous with the occipitomastoid suture
Occipitomastoid suture: between the occipital and temporal bones and continuous with the lambdoid suture
Squamosal suture: between the parietal and the temporal bone
Frontal suture / Metopic suture: between the two frontal bones, prior to the fusion of the two into a single bone
Sagittal suture: along the midline, between parietal bones
Fontanel
Space between the bones of the skull in an infant or fetus, where ossification is not complete and the sutures not fully formed
Allow for rapid stretching and deformation of the neurocranium as the brain expands faster than the surrounding bone can grow
Posterior fontanel is triangle-shaped. It lies at the junction between the sagittal suture and lambdoid suture
Anterior fontanel is a diamond-shaped membrane-filled space located between the two frontal and two parietal bones of the developing fetal skull
Two smaller fontanelles are located on each side of the head
Sphenoidal or anterolateral fontanelle (between the sphenoid, parietal, temporal, and frontal bones)
Mastoid or posterolateral fontanelle (between the temporal, occipital, and parietal bones)
During birth, fontanelles enable the bony plates of the skull to flex, allowing the child's head to pass through the birth canal
Posterior fontanelle generally closes 2 to 3 months after birth
Sphenoidal fontanelle is the next to close around 6 months after birth
Mastoid fontanelle closes next from 6 to 18 months after birth
Anterior fontanelle is generally the last to close between 18–24 months
Another example of a synarthroses joint
Sternocostal joint: point at which the ribs attach to the sternum
Amphiarthroses
Slightly movable articulations
Allow a small amount of movement at the joint
Usually a small piece of cartilage which separates the two bones
Examples ?
Pubic symphysis
Sacroiliac articulation: point where sacrum meets the two os coxae
Intervertebral joints: area between the bodies of the vertebrae
Movement here is necessary for twisting and bending
Diarthroses
Freely moveable articulations
Allow significant movement; sometimes in only one direction, sometimes in several
As opposed to other types of joints, diarthroses contain a capsule surrounding the joint
Joint cavity: lined with smooth, connective tissue membrane called synovial membrane
Secretes synovial fluid to lubricate the joint, reducing friction
Layers of articular cartilage cover the ends of bones forming the joint
Examples
Shoulder: ball and socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body
Elbow: hinge joint which allows the forearm and hand to be moved towards and away from the body
Wrist: condyloid joint (also called condylar, ellipsoidal, or bicondylar) which permits movement in two planes, allowing flexion, extension, adduction, abduction, and circumduction