Exam 2 Flashcards
Functions of a skeleton
Support Protection Movement Electrolyte balance Acid-base balance Blood formation
Osseous tissue
Connective tissue
Necrosis
Bone death
Shapes of bone
Long bones
Short bones
Flat bones
Irregular bones
Long bones
Arms and legs
Longer than wide
Produce leverage for movement
Short bone
Bones in ankle
Usually function by supporting and gliding
Flat bones
Cranium and ribs
Protection, attachment site for muscles
Irregular bones
Some skull bones
Don’t fit into another category
Bone features
Epiphysis and diaphysis
Epiphysis and diaphysis
Separate in children (growing bone) by the epiphyseal plate (cartilage)
Anatomy of a flat bone
Usually limited marrow
Larger area of spongy bone
Makes sense with its function
Osteogenic cells
Stem cells, found in the endosteum
Osteoblasts
Bone-forming cells
Synthesize bone matrix
Osteocytes
Trapped former osteoblasts
Reside in lacunae and communicate with other cells via gap junction, resort bone matrix, deposit bone matrix, contribute to calcium-phosphate levels in blood and bone density, strain sensors in bone remodeling
Osteoclasts
Bone-dissolving cells, different origin than other bone cells, fusion of stem cells
The matrix
- 1/3 organic matter- (glyco-) synthesized by osteoblasts; collagen, glycosaminoglycans, proteoglycans, glycoproteins
- 2/3 inorganic matter- mostly hydroxyapatite; calcium carbonate; magnesium, sodium, potassium, fluoride, sulfate, carbonate, hydroxide
- contaminants- many mineral contaminants can concentrate in bone; heavy metals (usually not harmful in the bone because they kill your kidneys first); radioactive metals can cause problems; examples: uranium (found in the drinking water in NE NV), radium
Physical properties of bone matrix
-Is a composite material(like wood, fiberglass sports equipment)
-Strong, but brittle(ceramic component, mineral)
-flexible, but weak (polymer, collagen, protein/fly an component)
Wood has to be flexible lignin and brittle/strong cellulose fibers
Bone development
- Ossification- formation of bone
- Growth (long bone and flat bone)- elongation, widening and thickening
- remodeling- 10% of bone is recycled per year in a process called remodeling
Intramembraneous ossification
Formation of flat bones- within a fibrous sheet
Endochondral ossification (long bone usually)
-development in pre-existing hyaline cartilage
Bone elongation
- child’s hand
- epiphyseal plates- when they disappear, it becomes a line
- disappear when growth stops
Epiphyseal plate
Zones of growth
Bone widening and thickening
- similar to intramembraneous ossification
- osteoblasts deposit matrix on the inner surface of the periosteum
- they then get trapped (osteocytes)
- produces circumferential lamellae
- marrow cavity widens- osteoclasts of the endosteum
- bone grows by creating more bone in the inside
Bone remodeling
- bone continually remodeled
- collaboration of osteoclasts(resorb bone and breaks it down) and osteoblasts(lay down bone matrix)
- bone mass is greater in athletes and manual laborers
- osteoclasts respond to electrical charges that come from strain on hydroxyapatite
- if it is out of balance- several different pathologies such as osteoporosis
Bone physiology
Deposition, resorption, calcium and phosphate homeostasis
Physiological of osseous tissue
- is influenced by and influences the rest of the body- principle organ for storing calcium and phosphate
- mineral deposition
- mineral resorption
- calcium and phosphate homeostasis- hormonal control
Mineral deposition
- osteoblasts lay down collagen fibers in a helical pattern along the length of the osteon
- this is where our discussion of equilibrium comes in
- this is inhibited in most tissues, not in osseous tissue
Eptopic calcification
Getting calcification where you don’t want it
Eptopic ossification
- if the inhibition disappears ossification can happen in the wrong tissues (lungs, brain, eyes, muscles, tendons, arteries, etc)
- this is what happens in arteriosclerosis
Mineral resorption
- free minerals from the bone and makes then available in the blood
- carried out by osteoclasts
- H+ pumps in the membranes of osteoclasts cause a locally acidic environment that dissolves bone
- acid phosphates (an enzyme) dissolved the collagen- works under highly acidic conditions
Calcium homeostasis
- acts as a cellular second messenger, cofactors on many enzymes, neurons, muscle contraction, blood clotting, exocytosis
- maintained at 9.2-10.4 mg/dL (narrow range)
- deficiency in blood called hypocalcemia- symptoms: CNS depression, muscle weakness, sluggish reflexes, cardiac arrest
Phosphate homeostasis
- component in many biological molecules (DNA, RNA, phospholipids), acid-base balance
Hormonal control of calcium balance
- calcitriol
- calcitonin
- parathyroid hormone
Calcitriol
- A form of vitamin D, server also positive effects on blood Ca
- synthesis and effects- UV light breaks the bond
Calcitonin
- thyroid gland hormone, served all negative (lowering) effects on blood Ca
- osteoclasts inhibition
- osteoblasts stimulation- increases bone deposition
- plays an important role in children
- osteoclasts are highly active in children
Parathyroid hormone
- several positive effects on blood Ca
- negative feedback loop
Bone disorders
- fractures and repair
- other disorders such as osteoporosis
Types of fractures
Open, displaced Greenstick Comminuted Linear Transverse, nondisplaced Oblique, nondisplaced Spiral Colles Pott
Hematoma formation
The hematoma is converted to granulation tissue by invasion of cells and blood capillaries
Soft callus formation
Deposition of collagen and fibrocartilage converts granulation tissue to a soft callus
Hard callus formation
Osteoblasts deposit a temporary bony collar around the fracture to unite the broken pieces while ossification occurs
Bone remodeling
Small bone fragments are removed by osteoclasts, while osteoblasts deposit spongy bone and then convert it to compact bone
Rickets
Defective mineralization of bone in children, usually as a result of insufficient sunlight or vitamin D, sometimes due to a dietary deficiency of calcium or phosphate, or to liver or kidney diseases that interfere with calcitriol synthesis. Causes bone softening and deformity, especially in weight-bearing bones of the lower limbs
Osteomalcia
Adult form of rickets, most common in poorly nourished women who have had multiple pregnancies. Bone become softened, deformed, and more susceptible to fractures
Osteoporosis
Loss of bone mass, especially spongy bone, usually as a result of lack of exercise or deficiency of estrogen after menopause. It results in increasing brittleness and susceptibility to fractures.
Too much bone is being dissolved by osteoclasts.
Treatable with medication (fosamax)- directly inhibits the activity of osteoclasts.
Osteitis deformans (paget disease)
Excessive proliferation of osteoclasts and resorption of excess bone, with osteoblasts attempting to compensate by depositing extra bone. This results in rapid, disorderly bone remodeling and weak, deformed bones. Osteitis deformans usually passes unnoticed, but in some cases it causes pain, disfigurement, and fractures. It is most common in males over the age of 50.
Osteomyelitis
Inflammation of osseous tissue and bone marrow as a result of bacterial infection. This disease was often fatal before the discovery of antibiotics and is still very difficult to treat.
Osteogenesis imperfecta (brittle bone disease)
A defect in collagen deposition that renders bones exceptionally brittle, resulting in fractures present at birth or occurring with extraordinary frequency during childhood; also causing tooth deformity, and hearing loss due to deformity of middle-ear bones
Osteoma
A benign bone tumor, especially in the flat bones of the skull; may grow into orbits or sinuses.
Osteochondroma
A benign tumor of bone and cartilage; often forms spurs at the ends of long bones
Osteosarcoma (osteogenic sarcoma)
The most common and deadly form of bone cancer. It occurs most often in the tibia, femur, and humerus of males between the ages of 10 and 25. In 10% of cases, it megastores to the lungs or other organs; if untreated, death occurs within 1 year.
Chondrosarcoma
A slow-growing cancer of hyaline cartilage, most common in middle age. It requires surgical removal; chemotherapy is ineffective.
Axial skeleton
Central supporting axis of the body
Appendicular skeleton
Lints, pectorals, and pelvic griddles
The skull of a child and the fontanels
- due to our huge heads we are born less developed than other mammals
- the bones of a newborn skulls are not fused
- allows for flexibility during birth
Fontanels
Spaces between infused cranial bones, filled with fibrous membrane
Abnormalities of the fontanels
- palpating tests performed by obstetric nurses
- cranial bones may override each other or there may be indications of damage in the newborn skull from an especially difficult delivery
- hydrocephalus (excess cerebral spinal fluid) may cause the fontanels to be especially large
- bulging fontanels indicate abnormally high intracranial pressure
Functions of the vertebral column
- supports the skull and trunk
- protects the spinal cord
- absorbs compression stresses from movement like walking
- attachment of the limbs, thoracic cage, postural muscles
- consists of vertebrae and intervertebral discs
Scoliosis
Sometimes from poor development of a body and arch on one side of a vertebra
Kyphosis
Caused usually by osteoporosis, or other disorders, seen also in boys who lift weights or wrestle too much and too early
Lordosis
Similar causes to kyphosis, also from extra weight of pregnancy
Vertebrae and herniated disc
- gelatinous cartilage surrounded by fibrocartilage
- the intervertebral disc absorbs all the shock in the spinal column
- excessive force (often with fake ire) can cause a tear or crack in the anulus
- this allows the nucleus pulposus to extrude and put pressure on nerves or the spinal cord.
The pelvis and lower limb differences between males and females
Males: pelvic inlet is narrow, and pubic arch is 90 degrees
Females: pelvic inlet is wider, and the pubic arch is 120 degrees
Skeletal adaptation for bipedalism
- humans are the only mammals that spend most of the time upright on our back legs
- require adaptation of feet, legs, spine, and skull
Foot
- springy arch
- tarsal bones are tightly articulated- stronger and bigger
- calcaneous more developed- strength and speed because of the larger calcaneous
- great toe is non-opposable and developed for pushing off
- ape foot doesn’t have an arch
- arch is flexible because of cartilage and absorbs shock
- medical implications- humans are more likely to have foot problems that apes because of only walking on two feet
Knee
Angled inward so the weight is over the joints and not out to the side
Lockable so we can stand for long periods of time
Pelvic shape
Our pelvis supports the abdominal viscera
Our pelvic outlet is narrow and this makes childbirth very difficult
Gluteal muscles
In apes the legs move laterally. This makes them have a rocking motion kind of like ice skating
In humans the muscles pull back at the end of a stride
Other muscles shift the weight from one leg to another when walking
Curvature of the spine
The body’s center of gravity is significantly shifted to the rear. The legs hold us up while apes arms hold them up
Keeps us from getting fatigued (weight over our legs keep us fatiguing)
Skull
Balanced on the vertebral column at the fulcrum point
One reason for the very large supraorbital ridge in apes is to hold the head up and the muscles attach to it
Bony joints
Completely ossified bone
Found in the first rib to sternum in elderly, some bones of the skull(not sutures), sutures in elderly
Fibrous joints
Also called synarthrosis- adjacent bones joined by collagen fiber
Teeth, sutures, tibia-fibula, radius-ulna
Cartilaginous joints
Also called amphora this is- two bones linked by cartilage
Ribs, pubis, vertebrae
Synovial joints
Two bones separated by a film of lubricating synovial fluid
Most of the things you think of as joints in your body
Suture
Two bones connected by fibrous tissue
Gomphysis
Teeth
Syndesmosis
Looser fiber to allow movement
Serrated suture
(Serrate- scissor or teeth) hold together because it increases the surface area. It also creates things that are impossible to pull apart. Kitchen cabinets have dovetail joints (interlocking joints)
Lap suture
They are overlapping. Increasing the surface area of contact. Allows more collagen fibers
Plane suture
Weakest suture.m- just had collagen holding things together.
Synochondrosis
Joined by hyaline cartilage
Epiphysis, diaphysis, first rib attachment to sternum
Symphysis
Joined by fibrous cartilage
Pubic symphysis, joint between vertebrae
Synovial joints- general anatomy
Lubricated by synovial fluid
Synovial fluid is a protein
Joint cavity had the synovial fluid
Synovial membrane halos keep the fluid in
Bursea
Muscles and tendons are sometimes lubricated by bursa (fibrous sac filled with synovial fluid)
Keeps tendons from getting inflamed
Bursitis
Inflammation of the bursea
Exercise and articulate cartilage
Warming up thins the synovial fluid it is then able to penetrate articulate cartilage
Articulate cartilage is essentially non-vascular but it contains living cells
Synovial fluid flowing in and out of cartilage can nourish the cells and carry away wastes
Lever systems
First class- how your head is held up
Second class- how a wheel borrow works. Jaw opening
Third class- paddling a paddle board. The point is speed
Abduction
Away from the body
Ball and socket
Shoulder and hip
Condylomata (ellipsis) joints
Oval convex joint surface
Metacarpal joints
Saddle joints
Both bones have a saddle-shaped surface
Trapezio-metacarpal joint
Rheumatoid arthritis
An autoimmune disease where the synovial membranes are attacked by an antibody
New treatments are immunosuppressive- can allow infections and cancer
Arthoplasty
Like a knee replacement
Knee joint and ligament-injuries
Hinged synovial joint
Ligaments connect bone to bone
Common injuries- PCL, ACL, MCL, LCL, and Meniscus
Arthristis
Broad term embracing more than 100 types of joint rheumatism
Dislocation
Displacement of a bone from its normal position at a joint, usually accompanied by a sprain of the adjoining connective tissues. Most common at the fibers, thumb, shoulder, and knee
Gout
A hereditary disease, most common in men, in which Utica acid crystals accumulate in the joints and irritate the articulate cartilage and synovial membrane. Causes gouty arthritis, with swelling, pain, tissue degeneration, and sometimes fusion of the joint. Most commonly affects the great toe
Rheumatism
Broad term for any pain in the supportive and locotory organs of the body, including bones, ligaments, tendons, and muscles.
Sprain
Torn ligament or tendon, sometimes with damage to a meniscus or other cartilage
Strain
Painful overstretching of a tendon or muscle without serious tissue damage. Often results from inadequate warmup before exercising
Synovitis
Inflammation of a joint capsule, often as a complication of a sprain
Tendinitis
A form of bursitis in which a tendon sheath is inflamed
Condyle
A rounded knob that articulated with another bone
Facet
A smooth, flat, slightly concave or convex articular surface
Head
The prominent expanded end of a bone, sometimes rounded
Crest
A narrow ridge
Epicondyle
A projection superior to a condyle
Line
A slightly raised, elongated ridge
Process
Any bone prominence
Protuberance
A bony outgrowth or protruding part
Spine
A sharp, slender, or narrow process
Trochanter
Two massive processes unique to the femur
Tubercle
A small, rounded process
Tuberosity
A rough elevated surface
Alveolus
A pit or socket
Fossa
A shallow, broad, or elongated basin
Fovea
A small pit
Sulcus
A groove for a tendon, nerve, or blood vessel
Canal
A tubular passage or tunnel in a bone
Fissure
A slit through a bone
Foremen
A hole through a bone, usually round
Meatus
An opening into a canal
