Name the 5 functional importance of bones
1) Mineral Storage- Calcium Phosphate
2) Protection of soft organs like the brain
3) Support of the body
4) Blood cell formation
What is the functional importance of bone markings (2)
1) Attachement sites for muscles
2) Passageway for nerves and blood vessels
What is compact bone composed of, what is it's function and where is it found?
composed of osteons. Gives bone strength. Found on the outside of bone.
What is spongy bone composed of, what is it's function and where is it found?
Composed of interconnected trabeculae which houses red marrow.
Found in the middle of irregular, flat and long bones. It is found in the epiphyses of long bones.
What is the function or organic components of bone.
Monitor bone health and carryout bone remodeling
What are the organic bone components?
1) Osteocytes- monitor bone health and reside in lacunae
2) Osteoclasts- breakdown bone or bone resorption
3) Osteoblasts- build bone
Where do Osteoclasts and osteoblasts reside
Under bone membranes
What are the inorganic parts of bones
Hydroxyopities- calcium phosphate salts- function to give bone strength.
What is Wolff's Law?
Bones are thickest where they experience the most stress
What is calcitonin and what does it do?
It is a hormone secreted by the thyroid in response to high blood calcium. It activates osteoblasts which build bone and lower blood Ca.
Takes calcium out of the blood and puts it into building bones.
What is PTH and what does it do? (Parathyroid Hormone)
It is released in response to low blood Ca. Activiates Osteoclasts which breakdown bones and increase blood calcium levels.
What is the process of fracture repair
1) Hematoma formation
2) Fibrocartilagenous callus formation (soft)
3) Bony callus formation
4) Bone remodeling
What is osteomalacia
bones poorly mineralized and soft. May deform
What is osteoporosis
Bones are poreous and thin
What is Paget's disease
Abnormal bone formation (deposition) and resorption. Hyperactive osteoblasts and osteoclasts
What changes occur in bone and bone mass over time?
w age bone becomes less dense esp in women after menopause
The embryonic skeleton begins as hyaline cartilage. Newborns have 305 bones.
What are fontanels?
Unossified fibrous membranes of the skull
What is the function of the spinal curvatures
provide flexibility and resiliance
List three natural factors that stabilize synovial joints
1) Reinforcing ligaments
2) Shape of bone ends(ex femur head and acetabulum
3) Muscle tissue
How are bursae and tendon sheaths similar
1) Both serous membranes
2) Secrete synovial fluid
What is bursitis
inflammation of the the bursae aka water on the knee
What is tendonitis
Inflammation of a tendon sheath
What are the differences between bursae and tendon sheaths
1) Bursae are flattened synovial membranes present within joints
2) Tendon sheaths are synovial membranes which surround tendons
Name three types of arthritis
1) OA- Osteoarthritis
2) RA- Rheumatoid Arthritis
3) Gouty Arthritis
What is OA?
Osteoarthritis is wear and tear arthritis (most common). Articular cartilage gets eroded.
What is RA?
Rheumatoid Arthritis is an autoimmune disease which targets synovial membranes causing inflammation and ankylosis (bones fuse together)
What is Gouty Arthritis?
Caused by high levels of uric acid which crystalize in synovial joints. It is most common in the 1st metatarsal phyllangeal joint(ball of the foot)
What are the 5 most common joint injuries?
1) Sprain- stretched or torn ligament
2) torn cartilage or menisci
3) Tendonitis and busitis
5) Subluxation- partially dislocated joints
Aside from injury, w age what are some factors that disturb joint homeostasis
1) Ligaments shorten
2) arthritis occurs
3) Joint capsules dehydrate
4) Intervertebral discs may herniate
What is muscle tone
The sustained, partial contraction of skeletal muscle. They are never completely relaxed
What is atrophy
The breakdown of muscle tissue due to disuse
What are the contractile units of skeletal muscle called
Explain the sliding filament mechanism of muscle contraction
Microfilaments DO NOT shorten. During contraction actin thin filaments are pulled over myosin thick filaments. REQUIRES ATP. Myosin heads/extension/cross bridges bind to the actin in the presence of calcium
What are isometric contractions
no movement. Muscle tension increases but the muscle doesn't shorten
What are Isotonic contractions
Muscle shortens during contractions
What is a motor unit
1 motor neuron and all the skeletal muscle cells innervated by that motor neuron
What are graded contractions
Skeletal muscle is capable of producing different amounts of force to move a load. The greater the load the more motor units will be activated
What are the three pathways of energy formation
1) Direct Phosphoralation (anaerobic)
2) Anaerobic Glycolysis
3) Cellular Respiration
Explain Direct Phophoralation
Creatine Phosphate + Adenosine Diphosphate ---> Creatine and ATP
When there is no more creatine phosphate the process stops. Anaerobic
Explain Anaerobic Glycolysis
No Oxygen required
-requires lots of glucose
-occurs in cytoplasm/cytosol
-produces 2 ATP per glucose
-Results in lactic acid formation which causes fatigue
Explain Cellular Respiration
-Starts in cytoplasm end in mitochondria
-Slower than glycolysis
-Produces 36 ATP per glucose
What is oxygen debt
the extra amount of oxygen required to resynthesize creatine phosphate, glycogen reserves and to get rid of the lactic acid in skeletal muscles.
What is muscle fatigue
caused by excessive levels of lactic acid resulting from anaerobic glycolysis
What is the primary factor that affects muscle contraction
total number of available non-fatigued muscle
Why are smooth muscle cells fatigue resistant and skeletal muscle cells are not
Skeletal muscle fibers must individually be innervated by motor neurons.
Smooth muscle cells are coupled by gap junctions and innervated by wide synapses called varicosities which release neurotransmitters on entire sheets of smooth muscle which then contract simultaneously NOT individual muscle fibers.
Where does muscle come from meso, ecto or endoderm
What changes occur in skeletal muscle as a result of age
1) muscle tissue atrophies
2) Muscle mass decreases
How many cervical vertebrae are there and what are 3 distinguishing features
1) transverse foramina
2) C1 (atlas) has no body
3) C2 (axis) has the dens
How many thoracic vertebrae are there and what is a distinguishing feature?
Have facets on transverse processes to articulate with ribs
How many lumbar vertebrae are there and what are two distinguishing features
1) Big bodies
2) Receive the most stress
How many sacral vertebrae are there and what is a distinguishing feature
5 fused sacral
Articulate with the hips laterally
How many coccyx vertebrae are there and waht are two distinguishing features
4 fused vertebrae
1) Most inferior
2) Has no canals or foramen present