Skeletal System Flashcards pt 1

Bones, joints, cartilage, & ligaments

Support and movement

Bones and ligaments provide structure for the body.

Bones act as levers and joints as fulcrums to transmit forces exerted by muscles.

Protection- Cover and surround internal organs

Storage-

-Minerals in the matrix (calcium, phosphorus)

-Red marrow in spongy bone.

-Blood cell production (hematopoiesis)

-Yellow marrow in medullary cavity

-Adipose tissue for fat (energy)

Proper levels of calcium in the blood are important for:

-Muscle contraction

-Nerve Conduction

Hypercalcemia

-Increased levels of calcium in the blood

The thyroid gland releases the hormone calcitonin

-Bones are stimulated to absorb and store calcium

-Calcium levels in the blood decrease

Hypocalcemia

-Decreased levels of calcium in the blood

-Parathyroid gland releases parathyroid hormone (PTH)

-Osteoclasts break down bone and release calcium into the blood

-Calcium levels rise

Bones may be classified according to their shape

-Long

-Short

-Flat

-Irregular

-Sesamoid

-Cylinder-like shape, longer than they are wide

-Used in the body for leverage

Examples: clavicle, metacarpals, metatarsals, phalanges

-Cube or block shaped

-Approximately equal in dimension for length, width, height, and thickness

-Provides stability and support while allowing some motion

Examples: carpals, tarsals

-Shallow height, broad width

-Protect internal organs

-Attachment for muscles

Examples: cranial bones, ribs, hip, sternum, scapula

-Unusually shaped

-Provide structure, muscle attachment, and protection of internal structures

Examples: facial bones, hyoid, vertebrae, sacrum, coccyx.

Regions:

-Epiphysis (Proximal/Distal)- wider end of long bones containing red bone marrow in spongy bone

-Metaphysis- the area where epiphysis and diaphysis meet which contains the epiphyseal line/plate

Diaphysis-long and narrow middle section of bone containing yellow bone marrow in the medullary cavity

Articular cartilage- hyaline cartilage in the joint protecting the ends of long bones

Spongy bone- open network of bone in the epiphyses (proximal and distal) containing red bone marrow

Red bone marrow-newly produced blood cells in the spongy bone (hematopoiesis)

Epiphyseal line/plate-

--Plate: area of cartilage for longitudinal bone growth

--Line: ossified cartilage indicating completion of longitudinal bone growth.

-Compact bone,

-medullary cavity,

-yellow bone marrow,

-endosteum,

-periosteum,

-nutrient artery

Dense hard layer of osseous tissue around the outside of bones, especially in the diaphyseal region

Open space in the diaphysis containing bone marrow

Adipose tissue (fat) stored in the medullary cavity

Thin membranous lining covering the inner surface of bone

Thin membranous lining covering the outer surface of bone

Supplies and circulates blood to bone

Articulation- Location where two bone surfaces come together (joint)

Projection- An area of bone that rises above the surface of the bone, attachment point for tendons and ligaments

Foramen- Opening through bone

The process of forming bony (osseous) tissue

-Osteoblasts: Bone builders

-Osteoclasts: Bone destroyers

-Osteocytes: mature bone cells (anchored in solid bone matrix)

Compact and spongy

-Dense and hard

-Found on outer surface of bone

-Inside compact bone

-Many open spaces

-Decreases weight

-Contains red marrow

-Osteon

-Central Canal

-Lamella

-Osteocytes in lacunae

-Canaliculli

-Structural unit of compact bone

-Layers of solid bony matrix (lamella) surrounding a central canal which contains blood vessels and nerves

-Osteocytes in lacunae are found between lamellar rings interconnected by canaliculi

-Large tunnel through the middle of an osteon

-Contains blood vessels and nerve fibers to serve osteocytes

-Concentric rings of solid matrix within an osteon surrounding the central canal

-Alternating directions of collagen fibers between each lamellar ring

-Resists torsional (twisting) forces.

-Mature bone cells found in lacuna

-Lacuna: the space within the solid compact bony matrix surrounding an osteocyte

-Canaliculi connect lacunae to each other and to the central canal

-Trabecula

-Lamella

-Osteocytes in lacunae

-Canaliculi

-Structural unit of spongy bone

-Contain lamella, osteocytes, and canaliculi but DO NOT contain a central canal

Endochondral and Intramembranous

-Process that forms flat bones

-Bone develops between two sheets of fibrous connective tissue

-Spongy bone (diploe) is sandwhiched between two layers of compact bone

Ex.) Scapula, cranium, mandible, clavicle, ribs

-Process that forms long bones

-Bones ossify from a hyaline cartilage model

-Most bones in the body form this way

An embryo is a cartilage skeleton until 8 weeks

Bone elongates by ossifying cartilage from the inside of the bone toward the growth plate.

At the end of adolescence chondroblasts top dividing, allowing the plate ossify

-Epiphyseal plate (open)- cartilage present

-Epiphyseal line (closed)- cartilage has ossified

A break in a bone

-Complete: All the way through

-Incomplete: Partially through

Types of bone fractures

-Closed (simple) fracture- Break that does not penetrate the skin

-Open (compound) fracture- broken bone penetrates through the skin

Fracture Hematoma:

Blood flows into the damaged are from blood vessels broken in the periosteum, osteon, and/or medullary cavity, contributing to inflammation and pain while providing some amount of immobilization.

Fibrocartilaginous (soft) callus formation:

Chondrocytes in the endosteum and periosteum along with osteoblasts form a soft callus of fibrocartilage to stabilize the fracture.

Bony (hard) callus formation

Osteoclasts and osteoblasts replace the soft fibrocartilaginous callus w/ a hard bony callus through endochondral ossification.

Remodeling:

The fully calcified connection in the bone is reshaped according to applied stresses.

-Osseous tissue is added or removed in order to balance forces through the bone.

-Osteoblasts deposit bone in greater areas of greater stress

-Osteoclasts break down bone in areas of lesser stress

Axial Skeleton (80 Bones):

-Skull

-Vertebral Column

-Thoracic Cage

Appendicular Skeleton (126 bones):

-Upper limb and girdle

-Lower limb and girdle

Eight bones surrounding the brain:

Frontal bone (1): Single bone forming the forehead and upper eye orbits

Parietal bones (2): Paired right and left bones of the upper lateral cranium

Temporal bones (2): Paired right and left bones on the lower lateral sides

-External auditory meatus: ear tunnel

-Zygomatic process: anterior cheek bone

Occipital bone (1): single bone forming the posterior skull and inferior cranium

-Foramen magnum: large hole

Sphenoid bone (1): single bone of the skull centrally located contacting nearly all other skull bones

Ethmoid bone (1): single bone contributing to the anterior cranium, upper nasal cavity, and medial eye orbits

-Flat bones of the cranium are locked together w/ immovable joints

-Coronal suture: side to side across the skull joining frontal to the parietal bones

-Sagittal suture: extends posteriorly from the coronal suture joining the two parietal bones

-Lambdoidal suture: extends downard and lateral from the sagittal suture joining the occipital bone w/ the parietal and temporal bones

-Squamous suture: lateral skull joining temporal bones w/ parietal bones

-Fibrous membranes connecting the cranial bones.

-Allow flexibility of the skull for birthing and brain growth.

-Convert to bone within 24 months after birth.

Fourteen bones:

-Maxilla (2): hard palate, medial eye orbit, lateral base of nose, upper jaw.

-Palatine (2): lateral nasal cavity, medial eye orbit, posterior hard palate

-Zygomatic (2): Lateral inferior eye orbit, anterior, zygomatic arch cheekbone'

-Nasal (2): lateral walls of nose (bridge of nose), broken nose bone.

-Lacrimal (2): anterior medial eye orbit, tears

-Inferior Nasal Conchae (2): Curved projection into the inferior nasal cavity.

Vomer (1): Posterior inferior nasal septum

-Mandible (1): Only moveable bone in the skull, two pieces fuse together at 1 yr old, lower jaw.

-Hollow air-filled spaces in certain bones of the skull

-All communicate with the nasal cavity

-Lined w/ mucosal epithelium

-Lighten skull and resonate sound

-Hyoid (1):

-"U" shaped bone located above the larynx at the base of the tongue.

-Only bone which does NOT articulate w/ another bone.

Ear Ossicles (6)

-Malleolus (hammer)

-Incus (anvil)

-Stapes (Stirrup)

-Extends from skull to pelvis

-Contains 26 irregular bones

-Vertebrae named according to their locations

Vertebrae named according to their locations

-Cervical (C1-C7): neck

-Thoracic (T1-T12): Chest

-Lumbar (L1-L5): Low back

-Sacral (5 fused): sacrum (pelvic girdle)

-Coccygeal (4 fused): tailbone

-Vertebral body: thick bony anterior for weight bearing

-Vertebrale foramen: opening to house spinal cord

-Spinous process: posterior projection for ligament and muscle attachnent

-Transverse processes: lateral projections for muscle attachment

-Transvere foramen: opening for vertebral arteries

-Bifid spinous process: split spinous process

-Upper two vertebrae are specialized (C1, C2)

C1 Atlas:

-No anterior body

-Supports skull

-Skull rocks forward and backward, "yes" motion

C2 Axis:

-Dens (Odontoid process): anterior post

-Skull and C1 rotate around Dens, "no" motion

-Spinous processes: long and slender for broad muscle attachment

-Costal facets: attachment locations for ribs

-Large, thick, and blunt for increased weight bearing

-Fibrocartilaginous discs between vertebral bodies

-Absorb compression and provide flexibility

-Bulging or ruptured disc protrudes posteriorly to one side

-May impact spinal nerve and cause radiating pain

Absorb compressive forces

Lordosis: backward bend (think lean back when kicked)

-Cervical

-Lumbar

Kyphosis: forward bend

-Thoracic

-Sacral

(think already have been kicked so you lean forward)

-Abnormal lateral curve of the spine

-Forms the thorax (chest) portion of the body

-Consists of 12 pairs of ribs w/ their coastal cartilages and the sternum

-Ribs are anchored posteriorly to each thoracic vertebrae (T1-T12)

-Provides protection of underlying structures

-Allows flexibility for movement and breathing

Ribs 1-7 are true ribs

-Each has individual attachment to the sternum (vertebrosternal)

Ribs 8-12 are "false" ribs

-Do not connect directly to the sternum, if at all

Ribs 8-10

-Attach anteriorly to the costal cartilage of the rib above (vertebrochondral)

Ribs 11-12

-Do NOT attach anteriorly (vertebral or "floating")

Manubrium: Upper portion of sternum

Body: Middle portion of sternum

Xiphoid Process: lower portion of sternum

Comprised of 126 bones:

-Pectoral Girdle: bones that attach the arm to the axial skeleton.

-Upper Extremity: bones of the arm

-Pelvic Girdle: bones that attach the leg to the axial skeleton

-Lower Extremity: bones of the leg

Clavicle (1)

Scapula (1)

Humerus (1)

Radius (1)

Ulna (1)

Carpals (8)

Metacarpals (5)

Phalanges (14)

Clavicle (collar bone):

-Articulates medially w/ sternum and laterally w/ scapula.

-Brace for UE

Scapula (shoulder blade):

-Articulates w/ clavicle and humerus

-Glides on thoracic cage.

-Acromion Process: top of shoulder above humeral head where clavicle attaches.

-Spine: long bony ridge

-Glenoid cavity (fossa): socket of the shoulder joint

-Coracoid process: attachment for muscles and ligaments

-Located in the brachial region

-Articulates proximally w/ the scapula (shoulder joint) and distally w/ the radius and ulna (elbow joint)

Bony markings of the humerus:

-Humeral head: superior rounded surface forming the ball of the shoulder joint.

-Deltoid tuberosity: roughened slightly elevated area where the deltoid muscle attaches laterally

-Located in the antebrachial region

-In anatomical postion ulna is medial, radius is lateral

-Ulna functions in elbow flexion/extension, radius functions in hand rotation (distal radius follows the thumb).

Bony markings:

-Olecranon process: bony elbow feature on proximal ulna.

-Carpals (wrist): eight short bones in two rows of four

-Metacarpals (palm): five long bones in mid-hand region, numbered 1-5 beginning w/ the thumb.

-Phalanges (fingers): bones of the fingers (three) and thumb (two), numbered same as metacarpals 1-5.

-Os coxa (1)

-Femur (1)

-Patella (1)

-Tibia (1)

-Fibula (1)

-Tarsals (7)

-Metatarsals (5)

-Phalanges (14)

-Two coxal bones that connect the LE to axial skeleton

-Two coxal bones, the sacrum, the coccyx, and the pubic symphysis

-Hip bone

-Comprised of three bones that have fused together:

---->Ilium = superior

----> Ischium - inferior

----> Pubis --- anterior

-Iliac crest: upper ridge of illium, "top of hip" (think top of hill)

-Acetabulum: location where all three portions of the os coxa meet, socket of hip (think ace as all skills come together)

-Obturator foramen: large inferior opening in coxal bone

Ischial tuberosity: enlargement on inferior ischium, "seat" bone

-Larges bone in the body located in the femoral region

-Articulates proximally w/ the acetabulum of the os coxa at the hip joint and distally w/ the tibia and patella at the knee joint

-Femoral head: rounded ball portion of the hip ball-and-socket joint

-Greater trochanter: enlargement of bone where gluteus medius attaches

-Lesser trochanter: enlarged area of bone where hi adductors attach

-Medial/lateral condyles: rounded ends of the femur that allow it to roll on the menisci of the tibia in the knee joint.

-Bone embedded in the tendon of the quadriceps muscle

-Articulates with the femur

-Prevents rubbing of muscle tendon on the femur

-Increases leverage for the quadriceps muscle

Tibia:

-Larger medial bone of the lower leg.

-Weight bearing

Fibula:

-Thinner lateral bone of the lower leg

-Ankle motion

Tibia:

-Tibial tuberosity: enlarged roughened surface where patella tendon attaches.

-Medial malleolus: inner ankle bulge

Fibula:

-Lateral malleolus: outer ankle bulge

-Tarsals (ankle): seven short bones in the ankle area

-Metatarsals (arch): five long bones in mid-foot region numbered 1-5 beginning medially w/ the big toe.

-Phalanges (toes): bones of the toes (three) and big toe (two), numbered same as metacarpals 1-5

A place where two bones come together (articulate) and make a connection.

Classified according to:

-Function: the amount of movement allowed

-Structure: the way the bones are joined together

-Fibrous joint: connected by fibrous connective tissue

-Cartilaginous joint: joined by hyaline cartilage or fibrocartilage

-Synovial joint (most common): combined through a combination of structures

-Suture: between cranial bones

-Syndesmosis: between bones in antebrachium and lower leg

-Gomphosis: between tooth and jaw

-Synchondrosis: joined by hyaline cartilage

-Symphsis: joined by fibrocartilage

Characteristics:

-Joint cavity: connecting bones do not make direct contact

-Articular capsule: fibrous connective tissue surrounding the entire joint

-Articular cartilage: hyaline cartilage covering the ends of the bones in the joint.

-Synovial membrane: lining the inner surface of the articular capsule, secretes synobial fluid that lubricates joint and helps maintain seperation.

-Ball and Socket

-Condyloid (Ellipsoidal)

-Plane (Gliding)

-Hinge

-Pivot

-Saddle

Ball and Socket: rounded head into concave socket

-Hip, shoulder

Oval head into oval socket.

-Knuckles (MCP), radiocarpal joint, temporomandibular joint (TMJ)

Two flat surfaces

-Intercarpal and intertarsal joints

Motion in a single plane.

-Interphalangeal joints (PIP, DIP), elbow, knee

Rotation around a single axis

-Proximal radioulnar joint, atlantoaxial (C1/C2)