Skeletal System Flashcards
Two types of skeleton
Axial - Central bones, protects organs and supports stability.
Appendicular - Limbs, enables movement, provides stability and execution of regular tasks.
How many bones in Axial & list the main bones
80 bones.
Bones that form the skull, laryngeal skeleton, vertebral column, and thoracic cage.
How many bones in Appendicular & list the main bones
126 bones.
Bones that form the arms, hands, feet, and legs (limbs).
Total bones in the human body
206.
Functions of the Skeletal System
Supports movement, balance, and provides structure.
Long bones
Cylinder-like shape, longer than it is wide. Primary function is leverage.
Short bones
Cube-like shape, approximately equal in length, width, and thickness. They provide stability and support while allowing for some motion.
Irregular bones
Complex shape, primary function is to protect internal organs.
Flat bones
Thin and curved, the points of attachment for muscle and also protectors of internal organs.
Sesamoid
Small and round, embedded in tendons. They protect tendons from compressive forces.
Epiphysis
The ends of the long bone.
Diaphysis
The shaft of the long bone.
Articular Cartilage
Padding for the epiphysis.
Periosteum
Membrane that covers the long bone.
Medullary Cavity
The hollow space filled with bone marrow within the long bone.
Red bone marrow
Produces blood cells from the bone.
Yellow bone marrow
Acts as storage for fat.
Compact bone tissue
Wall of the diaphysis.
Spongy bone tissue
Cancellous part of the epiphysis.
Pivot Joint
Uniaxial joint, allows for rotational movement.
Ex). C1-C2 vertebrae articulation
Hinge Joint
Uniaxial joint, allows flexion/extension movements.
Ex). Knee
Condyloid Joint
Biaxial Joint, allows flexion/extension, abduction/adduction, and circumduction movements.
Ex). Knuckles
Saddle Joint
Ditch like bone with allows curving but not rotation. Biaxial Joint, allows flexion/extension, abduction/adduction, and circumduction movements.
Ex). First joint of the thumb
Plane Joint
Multiaxial Joint, allows inversion and eversion of foot or flexion, extension, and lateral flexion of the vertebral column.
Ex). Internal foot joints
Ball-and-socket
Multiaxial joint, allows flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation of movements
Ex). Shoulder and hip joints
Flexion/Extension
Flexion is basically flexing
Extension is folding back in
Abduction/Adduction/Circumduction
Adduction - Moves the limb laterally away from the midline of the body.
Abduction - Brings the limb toward the body or across the midline.
Circumduction - Movement of a body region in a circular manner, in which one end of the body region being moved stays relatively stationary while the other end describes a circle.
Rotation
Rotation can occur within the vertebral column, at a pivot joint, or at a ball-and-socket joint.
Medial (Internal) Rotation - Movement that brings the anterior surface of the limb toward the midline of the body.
Lateral (External) Rotation - Rotation of the limb so that the anterior surface moves away from the midline.
Supination/Pronation
Pronation is the motion that moves the forearm from the supinated position to the pronated (palm backward) position.
Supination is the opposite motion, in which rotation of the radius returns the bones to their parallel positions and moves the palm to the anterior facing (palms upwards) position.
It helps to remember that supination is the motion you use when scooping up soup with a spoon.
Dorsiflexion/Plantar Flexion
Dorsiflexion and plantar flexion are movements at the ankle joint, which is a hinge joint.
Dorsiflexion - Lifting the front of the foot, so that the top of the foot moves toward the anterior leg.
Plantar flexion - Lifting the heel of the foot from the ground or pointing the toes downward.
Inversion/Eversion
Inversion is the turning of the foot to angle the bottom of the foot toward the midline.
Eversion turns the bottom of the foot away from the midline.
Protraction/Retraction
These are anterior-posterior movements of the scapula or mandible.
Protraction of the scapula occurs when the shoulder is moved forward, as when pushing against something or throwing a ball.
Retraction is the opposite motion, with the scapula being pulled posteriorly and medially, toward the vertebral column.
Depression/Elevation
Downward (Depression) and upward (Elevation) movements of the scapula or mandible.
Opposition/Reposition
Opposition is the thumb movement that brings the tip of the thumb in contact with the tip of a finger. Thumb opposition is produced by a combination of flexion and abduction of the thumb at this joint.
Reposition is returning the thumb to its anatomical position next to the index finger.
How many bones are in the cranium?
There are 8 bones in the cranium: frontal, parietal, occipital, temporal, sphenoid and ethmoid bones.
What is the only movable bone in your skull?
The mandible A.K.A. the lower jaw.
What are the five vertebral regions (from superior to inferior)?
- Cervical (Neck)
- Thoracic (Upper back)
- Lumbar (Lower back)
- Sacral (Upper Tailbone)
- Coccyx (Lower Tailbone)
How many vertebrae are in cervical?
Seven bones.
How many vertebrae are in thoracic?
Twelve bones.
How many vertebrae are in lumbar?
Five bones.
Scoliosis
Scoliosis is where the spine (Thoracic and Lumbar) twists and curves to the side.
Kyphosis
Kyphosis is when there is excessive outward curvature of the spine (Thoracic and Cervical), causing what is called hunchback.
Lordosis
Lordosis is when the spine curves too far inward from the Lumbar section.
What does the thoracic cage protect?
The thoracic cage protects the heart and lungs.
Costal cartilage
The costal cartilages are bars of hyaline cartilage which serve to extrude the ribs forward.
Three types of ribs, and how many of each?
True ribs (7(14)), false ribs (3(6)), and floating ribs (2(4))
Main bones of the pectoral girdle
The clavicle and scapula.
Humerus (describe its location)
The humerus is the arm bone between your shoulder and your elbow.
Radius (describe its location)
The radius is one of two bones that make up the forearm on the lateral side (anatomic position) of the forearm between the elbow and the wrist joints, the other being the Ulna.
Ulna (describe its location)
The ulna is one of two bones that make up the forearm on the medial side (anatomic position) of the forearm, the other being the Radius.
Carpals (describe its location)
Located inside your wrists superior to your fingers and inferior to your forearm.
Metacarpals (describe its location)
The base bones of your hand that connect to your fingers and Carpals.
Phalanges (describe its location)
Your finger bones, inferior to the (meta)carpals.
Femur (describe its location)
Your thigh bones, inferior to your pelvis.
Tibia (describe its location)
One of 2 bones in the lower leg, inferior to your femurs and proximal to the Fibula, the other lower leg bone.
Fibula (describe its location)
One of 2 bones in the lower leg, inferior to your femurs and distal to the Tibia, the other lower leg bone.
Tarsals (describe its location)
Tarsals are located toward the back of the foot and in the heel.
Metatarsals (describe its location)
Located in the forefoot,
Distal to the tarsals.
Transverse fracture
A transverse fracture occurs when a bone breaks at a 90-degree angle to the long axis of the bone.
Oblique fracture
An oblique fracture is characterized by a break that is curved or at an angle to the bone.
Spiral fracture
A spiral fracture is a bone fracture that occurs when a long bone is broken by a twisting force.
Comminuted fracture
A comminuted fracture is a break in the bones that results in more than two, shattered pieces.
Impacted fracture
An impacted fracture occurs when the broken ends of the bone are jammed together by the force of the injury.
Greenstick fracture
A greenstick fracture occurs when a bone bends and cracks, instead of breaking completely into separate pieces.
Open (or compound) fracture
An open fracture, also called a compound fracture, is a fracture in which there is an open wound or break in the skin near the site of the broken bone.
Closed (or simple) fracture
Closed fracture occurs when the bone is broken, but the skin is intact.
