Actual Exam 3 Flashcards
What are the four layers of the epidermis?
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum
What cell types are in the stratum basale?
stem cells
What cell types are in the stratum spinosum?
dendritic cells
What type of cells are in the stratum granulosum?
contains cells that have dark-staining keratohyalin granules
What type of cells are in the stratum lucidum?
dead cells
What are the functions of the DERMIS, where is it located on the body?
connective tissue layer beneath the epidermis, houses hair follicles and nail roots, ranges from eyelids to palms/soles
What are the functions of the HYPODERMIS, where is it located on the body?
subcutaneous tissue, pads body and binds skin to underlying tissues. technically not part of the skin but the dermis does anchor to it.
Define melanin.
most significant factor in skin color, produced by melanocytes
What are the two forms of pigment that determine skin color?
eumelanin, phomelanin
What are the three parts of hair structure?
Bulb, Root, and shaft
Define pilus.
another name for hair
What are the four processes of losing hair?
Anagen (early), Anagen (mature), Catagen, and Telogen.
Mammary Glands
milk producing glands located in the breasts
Ceruminous Glands
glands of the ear canal that produce wax
Sudoriferous Glands
sweat glands
What is basal cell carcinoma?
most common type of skin cancer, least dangerous, forms in stratum basale
What is squamous cell carcinoma?
arises from keratinocytes of stratum spinosum
What is malignant melanoma?
arises from melanocytes, typically fatal
What level of the skin does a first degree burn effect?
only the epidermis
What level of the skin does a second degree burn effect?
involves part of the dermis
What level of the skin does a third degree burn effect?
involves epidermis, all of the dermis, and often deeper
What is the periosteum?
external sheath covering most of bone
What is the endosteum?
thin layer of reticular connective tissue lining marrow cavity
What are OSTEOGENIC CELLS, where are they located?
stem cells, found in endosteum and inner layer of periosteum
What are OSTEOBLASTS, where are they located?
bone forming cells, they form a single layer of cells under endosteum and periosteum.
What are OSTEOCYTES, where are they located?
former osteoblasts that have become trapped in the matrix they deposited.
What are OSTEOCLASTS, where are they located?
bone-dissolving cells found on bone surface
What is the general idea of resting membrane potential? (originally set at ~-70 mV) (3 steps)
- Look at the outside and inside of the membrane. We notice that there is a little bit more negative on the inside, and a bit more positive on the outside.
- Extract electrodes from the inside (recording electrode) and outside (reference electrode) of the membrane, these will be the electrodes measuring voltage.
- Starting at a range from 100mV to -100mV (0 being the middle, and where we start), we can insert the recording electrode cell, this would then drop it to a -70mV.
Compare spongy bone to compact bones.
compact bones = reveal osteons
spongy bones = consist of lattice of the bone covered with endosteum and have few osteons.
What are the major factors in setting the resting membrane potential? (~-70 mV) (3-steps)
- Na+/K+ pump (taking sodium out of our cells and putting it in the extracellular fluid, as well as potassium conc. gradient)
- Proteins with (-) animo acids. These are inside the cells, always stuck
- K+ leak channels, sit inside the cell membrane and allow potassium to move around.
What/How are local/graded potentials generated via gated receptors?
they are reversible, transient, exist on a continuum.
What is the difference between hyperpolarization and depolarization?
hyperpolarization = negative bump on continuum
depolarization = positive bump on continuum
Define compact bone.
dense outer shell of bone
Define spongy bone.
loosely organized bone tissue4
Define ossification.
the formation of bone
In a human fetus/infant, what are the two methods in which bone develops?
intermembranous ossification and endochondral ossification
What is the difference between endochondral and intermembranous ossification?
endochondral = during infancy and childhood, the epiphyses fill with spongy bone, by late teens, all remaining cartilage in the epiphyseal plate is generally consumed
intermembranous = produces flat bones of cranium and face in fetus, compact bone surrounds trabecular bone, thickens long bones throughout life
What is Metaphysis?
the zone of transition facing the marrow cavity
What are the 5 zones of metaphysis and interstitial growth? (highest to deepest on the bone)
- zone of reserve cartilage
- zone of cell proliferation
- zone of cell hypertrophy
- zone of calcification
- zone of bone deposition
What is mineral deposition?
process in which calcium, phosphate, and other ions are taken from blood and deposited in bone
What is mineral resorption?
process of dissolving bone and releasing minerals into blood
What are the three hormones that regulate calcium homeostasis?
calcitriol, calcitonin, and parathyroid hormone
How does CALCITONIN regulate calcium homeostasis?
secreted by C cells of thyroid gland when blood calcium levels rise too high, lowers blood/calcium concentration.
How does CALCITRIOL regulate calcium homeostasis?
the liver and kidney adding hydroxyl group to the vitamin D we receive on our skin, they convert it into calcitriol (the most active form of vitamin D)
How does parathyroid hormone regulate calcium homeostasis?
raises calcium blood level by four mechanisms, PTH released when calcium levels are low in blood
What is a stress fracture?
break caused by abnormal trauma to a bone (ex. in a fall)
What is a pathological fracture?
break in bone weakened by disease (ex. bone cancer/osteoporosis)
What is the importance of action potentials at the axon hillock, and voltage gated channels?
voltage gated channels do not open for a ligand, they open to response to a change in voltage.
voltage gated channels detects when the cell is depolarizing over the threshold at -45 mV, this then makes voltage gated channel to open, allowing Na+ to enter. (as much as possible)
What are the four stages of healing a fracture?
- hematoma formation
- soft callus formation
- hard callus formation
- bone remodeling
What is the most common bone disease, and what happens to the bones?
osteoporosis - severe loss in bone density, the bones in the body lose mass and become brittle due to loss of organic matrix and materials.
What is orthopedics?
branch of medicine dealing with prevention, correction of injuries, and disorders of bones, joints and muscles.
