Ch.6 Flashcards
Skeletal system
- Consist of the body’s 206 bones
- cartilage,ligaments,joints belong to skeletal system
Cartilage
Entire skeleton is made up of cartilage
-gets replaced by bone(ossifies) during embryonic development
-remains where a flexible skeleton is needed
Support with flexibility
Structure of cartilage
- chondrocytes
- avascular(all cartilage is surrounded by perichondrium)
Perichondrium
A layer of dense irregular connective tissue that supplies nutrients to the cartilage
Types of cartilage
Hyaline, fibrocartilage, elastic
Location hyaline Cartilage
- Articular cartilage covers the ends of bones within joints
- costal cartilage connects the ribs to the sternum
- respiratory cartilage forms the skeleton of the respiratory system(nose, larynx,trachea)
Fibrocartilage location
- intervertebral discs
- menisci of knee joints
- pubic symphysis
Elastic cartilage location
Ear
Epiglottis
Bone
Each bone in the body is an individual organ
- all four tissue types are present
- bone(osseous) connective tissue is the dominant tissue type
Functions of bone
Support Protection Movement Hemopoiesis Mineral and energy storage
Bone-Support
Provide the body it’s shape/form
Bone-protection
- the skull protects the brain
- the vertebral column protects the spinal cord
- the thoracic cage protects the heart and lungs
- the pelvic girdle protects the pelvic cavity viscera
Bone-movement
Muscle attach to bones and move them when they are contract
Bone-hemopoiesis
Blood cells production occurs in the bones of red marrow -in adults not found in all bones
- the spongy bone of the flat skull,ribs,sternum have red marrow as do vertebrae and hips.
- the only long bones to have red marrow are the proximal epiphyses of the femur and humerus
Bone mineral and energy storage
- bone is reserve for calcium and phosphate
- fat is stored in the bones yellow marrow
Classification of bones
- long bones
- short bones
- flat bones
- irregular bones
Short bones
-equal length and width(approximately cube shaped)
Ex: all limb bones that are not long bones(carpals,tarsals, and patellar)
Flat bone
-flat and thin
-usually slightly curved
Ex:sternum, ribs, scapulae, and most skull bones
Irregular bone
-complex shapes that can not be described as long, short or flat
Ex:vertebrae,ossa coxae, and certain skull bones(sphenoid, ethmoid)
Gross anatomy of long bone(diaphysis)
- the shaft of a long bone
- a ring of compact bone surrounding the medullary cavity
- the medullary cavity contains yellow marrow (fat)
Gross anatomy of long bones(epiphyses)
- the 2 expanded ends of a long bone
- an outer layer of a compact bone surrounding inner spongy bone
- red marrow fills in the spaces of the spongy bone in the proximal epiphyses of the humerus and femur.
Metaphyses
- the junction between the diaphysis and the epiphyses
- the location of the epiphyseal plate or epiphyseal line
Epiphyseal plate
A layer of hyaline cartilage that allows bind growth
Epiphyseal line
The ossified remnant of the epiphyseal plate when the bone is no longer growing
Epiphyses are surrounded by?
Articular cartilage(hyaline cartilage -very thin, lacks perichondrium,heals very poorly
The diaphysis and metaphyses are surrounded by
Periosteum
- Dense irregular connective tissue
- anchored to the compact bone of diaphysis by way of perforating fibers
- a nutrient foremen in the periosteum allows blood vessels to pass through to the bone tissue
The medullary cavity of the diaphysis is lined by…
Endosteum(a membrane similar to the outer periosteum)
A gross anatomy of flat bone
A less complex anatomy
-no diaphysis,medullary cavity,epiphyses, or metaphyses
Simply a layer of spongy bond sandwiched between two layers of compact bone(periosteum still covers the compact bone)
In which part of spongy bone red marrow exist?
Skull, ribs, sternum, vertebrae, hips
In which part of lone bone red marrow exist?
Proximal epiphyses of the femur and humerus
Compact bone
-relatively solid and dense
-formed by many cylindrical Osteons that run the length of the bone
-a central canal runs through the middle of each Osteons
Blood vessels and nerves run through the canal
Lamella
Concentric rings that encircle the central canal, forming the bulk of Osteon
Location of osteocytes within lacunae
Found at the junctions between lamella
Canaliculi
- tiny channels that connect osteocytes within lacunae to the osteon’s blood supply in the central canal
- canaliculi run within Osteons
Perforating canals
- Larger channels that connect all of the central canals of all of the Osteons within a bone
- they also connect central canals to the outer nutrient foremen and inner medullary cavity
- perforating canals therefore run between Osteons
Trabeculae
Bony structures
Form a crisscrossing network of bone
Red marrow is found within the spaces among the Trabeculae
Chemical composition of bone
-The organic component of bone consists of cells(osteocytes),collagen fibers, and ground substance
-the inorganic component of bone consists of salts crystals(calcium hydroxyapatite)
The salts make the ground substance and therefore the entire bone tissue hard and durable
Effects of exercise on bone
- mechanical stress(I.e, muscle contraction and gravity) stimulates increase in bone density by increased osteoblasts activity
- athletes who engage in these types of activities, on average, have greater bone density
Causes of bone fractures
- stress
- traumatic
- pathological
- soft tissue involvement (simple, compound)
Stress
A thin break due to repetitive loafs(tend to be in weight-bearing bones, eg. Pelvis and lower limb)
Traumatic
Results of impact or increased tension or torsion from outside source
Pathologic
Weakened by disease(osteoporosis)
Simple
Bone does not protrude through skin
Compound
Broken ends of bone protrude through skin
