Anatomy 2.1 Skeletal Flashcards
What are the two main parts of the skeletal system?
Axial and appendicular
Axial skeleton
Consists of bones of the head, neck, and trunk
Appendicular skeleton
Consists of the bones of the limbs, including those forming the pectoral and pelvic girdles
Bone
Living tissue that is highly specialized (hard form of connective tissue that makes up most of the skeleton)
What does the bones provide?
Support to the body
Protection of vital structures
Mechanical basis of movement
Storage for salts
Continuous supply of new RBC
Perichondrium
Around cartilage
Compact bone
80% of lamellar bone (high density used for weight bearing activity)
Spongy bone
Less dense bone
Long bone
Are tubular
Short bones
Are cuboidal and found only in the tarsus and carpus
Flat bones
Serve protective functions
Irregular bones
Various shapes other than long, short, or flat
What do sesamoid bones do for the tendons?
They protect them from excessive wear and often change the angle of the tendons as they pass to their attachments
Where do bone markings appear?
Wherever tendons, ligaments, and fascias are attached or where arteries lie adjacent to or enter bones
Crest
Ridge of bone
Epicondyle
Eminence superior or adjacent to a Condyle
Foramen
Passage through a bone
Line (linea)
Linear elevation (sometimes called a ridge)
Malleolus
Rounded process
Process
Extension or projection serving a particular purpose, having characteristic shape, or extending in a particular direction
Protuberance
Bulge or projection of bone
Spine
Thorn like process
Trochanter
Large blunt elevation
Intramembranous ossification (membranous bone formation)
Mesenchymal models of bones form during the embryonic period, and direct ossification of the mesenchyme begins in the fetal period
Endochondral ossification (cartilaginous bone formation)
Cartilage models of the bones form from mesenchyme during the fetal period, and bone replaces most of cartilage
Primary ossification center
The bone tissue it forms replaces most of the cartilage in the main body of the bone model
Secondary ossification center
Appear in other parts of the developing bone after birth
Epiphyses
Parts of the bone ossified by the secondary ossification center
Metaphysis
Flared part of the diaphysis nearest the epiphysis
Epiphyseal line
The seam formed during the fusion process of the plates and is particular dense
Synostosis
Fusion process of epiphyseal plates
Nutrient arteries
One or more per bone and they pass obliquely through the compact bone of the shaft of a long bone through a nutrient foramina (supplies blood to bone marrow, spongy home, and deeper portions of compact bone)
Veins
Accompany arteries through the nutrient foramina
Joints
Unions or junctions between two or more bones of the skeleton
What type of joints are there?.
No movement (epiphyseal plates)
Slight movement (teeth)
Freely movable (shoulder joint)
Fibrous joints
United by fibrous tissue (amount of movement occurring at fibrous joints depends on the length of the fibers uniting the articulating bones)
What are types of fibrous joints?
Suture
Syndesmosis
Suture
Bones held close together (interlocking along a wavy line or overlapping)
Syndesmosis
Unities the bone with a sheet of fibrous tissue (partially moveable)
Cartilaginous joints
United by hyaline cartilage or fibrocartliage
Synchondrosis (primary cartilaginous)
Permits slight bending during early life (temporary unions) (united by hyaline cartilage)
Symphysis (secondary cartilaginous)
Strong, slightly movable joints united by fibrocartilage (intervertebral disks)
What is the most common type of joint?
Synovial joint
What do synovial joints provide?
Free movement between the bones they join (locomotion)
Plane/gliding joints
Permit gliding and sliding movements in the plane of articular surfaces (numerous and always small)
What are the types of synovial joints?
Plane/gliding
Hinge
Saddle
Condyloid
Ball and socket
Pivot
Hinge joint
Permit flexion and extension only
What is the joint capsule of hinge joints?
Thin and lax anteriorly and posteriorly where movement occurs
What type of movements are hinge joints for?
Movements that occur in one plane (Saggital)
Saddle joints
Permit abduction and adduction as well as flexion and extension
What movements occur around a saddle joint?
Around two axes at right angles to eachother (allow movement in Saggital and frontal plane)
What joint is a hinge joint known as?
Uniaxial joint
What joint is a saddle joint known as?
Biaxial joint
Condyloid joint
Permit flexion and extension as well as abduction and adduction (biaxial)
Ball and socket joint
Allows movement in multiple axes and planes
What type of movement does the ball and socket joint allow?
Flexion and extension
Abduction and adduction
Medial and lateral rotation
Circumduction (multiaxial)
Pivot joint
Permit rotation around a central axis (uniaxial)
Accessory (supernumerary) bones
Develop when additional ossification centers appear and form extra bones
Heterotopic bones
When bones form in soft tissues where they are not normally present
What happens to unused bones (paralyzed)?
Atrophy (decrease in size)
When would bones be absorbed?
Occurs in the mandible when teeth are extracted
What happens to bones that support increased weight for a long period?
Hypertrophy (enlarge)
What happens during bone healing?
Surrounding fibroblasts secret collagen which forms a collar of callus to hold bones together
Osteoporosis
Reduction in quantity of bone
Fractures involving the epiphyses may cause what?
Stunting of growth
When does proliferation of cartilage at the metaphyses slow down?
During starvation and illness
Avascular necrosis
Death of bone tissue due to loss of arterial supply to the epiphysis
What could a displaced epiphyseal plate be mistaken for?
Fracture
What could a separation of an epiphysis be interpreted as?
Displaced piece of fractured bone
Degenerative joint disease
Breakdown of joints due to heavy use over the years (osteoarthritis)
Arthroscopy
Procedure to allow surgeons to examine joints for abnormalities (torn meniscus)
What are the cartilaginous joints?
Synchondrosis (primary cartilaginous)
Symphysis (secondary cartilaginous)
Ligaments
Provide restraint in specific directions
What are types of ligaments?
Intrinsic (capsular)
Extrinsic (non capsular)
Concave on convex
If moving joint surface is convex sliding is in the opposite direction of bone
Convex on concave
If moving joint surface is concave sliding is in the same direction as the movement of bone
What connective tissue is the skeletal system made of?
Dense regular connective tissue
Cartilage, bone, and adipose
Where in the skeletal system do we find hyaline cartilage?
Over articular surface of bones within synovial joints
Ends of long bones
What kind of tissue is the capsule?
Dense connective tissue
What are the two different types of bone tissue?
Woven and Lamellar
Lamellar
Remodeled from woven bone and is present in normal regions of adult bone
What are two types of lamellar bone?
Compact and cancellous (spongy)
Where do joints form?
Where bones are joined
