First class lever
Fulcrum with resistance & effort on each side
What is an example of a first class lever?
atlanto-occipital joint (cervical spine & base of skull)
second class lever
resistance with fulcrum & effort on each side
What is an example of second class lever?
standing on your tippy toes
third class lever
effort with resistance & fulcrum on each side
What is an example of a third class lever?
effort applied by the biceps muscle is applied to the forearm
merocrine gland
simple tubular glands; watery perspiration that helps thermoregulation
-means for losing water & electrolytes
Apocrine glands
ducts that lead to nearby hair follicles; produce sweat that is thicker, milky, & contains fatty acids
mammary glands
milk producing glands that develop only during pregnancy & lactation
-controlled by complex interaction between gonadal & pituitary hormones
sebaceous glands
sebum: oily secretions; glands with ducts opening into hair follicles
-inactive in childhood; activated during puberty
ceruminous gland
produces ear wax; only in external ear canal
-helps lubricate the external acoustic meatus & eardrum
When an increase in Ca+2 occurs what happens?
thyroid gland releases calcitonin
osteoclast activity is inhibited
Ca+2 reabsorption in the kidney decreases
Ca+2 level in blood decreases
When there is a decrease in Ca+2 what occurs?
parathyroid glands release PTH
osteoclasts release Ca+2 from bone
calcium is reabsorbed from urine by the kidneys
calcium absorption in the small intestine increases via Vitamin D synthesis
Ca+2 levels in blood increases
How does vitamin do become calcitriol?
UV turns into Vitamin D & released in the blood
blood passes through liver & converts to calcidiol
blood passes through the kidney & converts to calcitroil
red bone marrow
hematopoietic, reticular CT, developing blood cells, & adipocytes
osteogenic
stem cells found in endosteum, periosteum, & in central canals
osteoblasts
bone forming cells; single layer of cells under endosteum & periosteum
-produce osteoid which then hardens by mineral deposition
osteocytes
osteoblasts that have become trapped in the matrix
-lacunae: where the osteocytes resides
- canaliculi: channels that connect lacunae
-maintain that bone matrix & detect
osteoclasts
bone-dissolving cells found on the surface
bone formation
calcification subsequently occurs to the osteoid when hydroxyapatite crystals deposit in the matrix
-when calcium & phosphate reach a certain level
bone resorption
bone matrix is destroyed by substances by released from osteoclasts into the extracellular space
-occurs when calcium level are low
alopecia
thinning of hair or baldness; immune system attacks mistakenly the hair follicles
hirsutism
Excessive or undesirable hairiness in areas that aren’t usually hairy; PCOS
male pattern baldness
hair loss occurs in specific regions of the scalp; genetic & hormonal influence
osteitis deformans
excessive bone resorption
achondroplasia dwarfism
abnormal conversion of hyaline cartilage; normal torso short limbs
rickets
low blood calcium; bowlegged
osteoporosis
decrease bone mass, weakened bones prone to fracture; estrogen replacement treatment
cleft lip
incomplete fusion of upper jaw components of embryo
cleft palate
congenital fissure in palate midline; left & right maxillary & palatine are incompletely fused
crainiosyntosis
premature fusion of 1 or more cranial bone
kyphosis
exaggerated lumbar curvature; hunchback
lordosis
exaggerated lumbar curvature; swayback
scoliosis
abnormal lateral curvature
duchenne muscular dystrophy (DMD)
defective or insufficient dystrophin; incurable patients dont live past 30
smooth muscle
narrow cylindrical fibers, nonstriated & uninucleate; involuntary
cardiac muscle
striated, branched, generally uninucleate fibers; involuntary
skeletal muscle
striated, tubular, multinucleated fibers; voluntary
What are the characteristics of muscles?
excitability, conductivity, contractility, extensibility, elasticity
Where does the bulk of most fibers volume come from?
myofibrils
What is the muscle fiber triad relationship?
T-tubules conduct electrical impulses that stimulate calcium release from the sarcoplasmic reticulum
What is the sliding filament theory that would be apparent in a sarcomere?
H zone becomes less obvious & the Z disc gets closer together
What stimulates the muscle to contract?
depolarization
Depolarization the sarcolemma is most permeable to
sodium ions
What are the 3 types of fibrous joints?
sutures, gomphoses, syndesmoses
What is gomphosis?
fibrous joint attachment of a tooth to its socket
-held by collagen fibers
-allows tooth to move
When bones are bound by hyaline cartilage?
synchondrosis
Where is symphysis located in the body?
-pubic symphysis
-bodies of vertebrae and intervertebral discs
What is the articular cartilage made up of?
hyaline cartilage
What is located in the joint capsule?
connective tissue capsule
What is a bursa function/location?
fibrous sac filled with synovial fluid, located between adjacent muscles, where tendon passes over bone, or between bone and skin
Where is the hyoid bone located?
inferior to the skull between the mandible & the larynx
What is syndesmoses?
fibrous joint where two bones are bound by longer collagenous fibers
-more mobility
-interosseous membrane
What is in the inner synovial membrane?
Areolar CT with fibroblast like cells and macrophages
Pivot joint
radius & ulna (bone spins)
-one bone has a projection that is held in place by a ring like ligament
Saddle joint
carpal to metacarpal
-noth bones have articular surface that is concave in one direction and convex in the other
condylar joint
metacarpal to phalanx
-oval convex surface on one bone fits into concave depression on the other
Hinge joint
humerus & ulna(elbow)
-one bone with convex surface fits into a concave depression on other bone
Plane joint
intercarpals
-flat articular surfaces in which bones slide over each other with relatively limited movement
Autoimmune attack against the joint tissues
rheumatoid arthritis
-antibodies attack synovial membrane
What is the most common form of arthritis and what happens to the body?
osteoarthritis
-articular cartilage softens and degenerates
What is synovial fluid made up of?
albumin & hyaluronic acid
What part of the back is in the primary curvature?
thoracic & sacral
What part of the back is secondary curvature?
cervical & lumbar
endochondral ossification
1)hyaline cartilage
2)primary ossification
3)secondary ossification
4)all cartilage is replaced
intramembranous ossification
1)thick center of mesenchyme
2)undergo calcification
3)woven bone & surrounding periosteum
4)lamellar; compact & spongy bone