Test 2 (Ch. 5, 6, 7, 8) Flashcards
Tight junction
completely encircles an epithelial cell near its apical surface and joins it tightly the neighboring cells. Regulate what can pass between cells
Desmosomes
a patch that holds cells together like the snap on a pair jeans. Hook-like J-shaped proteins. Mechanical strength between keratinocytes.
Gap junctions
formed by a connexon, six transmembrane proteins arranged in a ring. Exchange of communication between cells.
Endocrine glands
secretions (hormones) released directly into the blood
Exocrine glands
secretions made locally through ducts (sweat, mammary, tear)
Totipotent stem cells
embryonic stem cells, have the potential to develop into any type of fully differentiated human cell
Pluripotent stem cells
can develop in any cell type of the embryo, but not into the accessory organs of pregnancy
Multipotent stem cells
able to develop into two or more different cell types, but not just any type of body cell. Blood cells
Unipotent stem cells
can only produce one mature cell type. Keratinocytes
Hyperplasia
tissue growth through cell multiplication
Hypertrophy
enlargement of preexisting cells
Atrophy
shrinkage of a tissue through a loss in cell size or number. Results form both normal aging and lack of use of an organ
Necrosis
premature, pathological tissue death due to trauma, toxins, infections, etc.
Apoptosis/programmed cell death
normal death of cells that have completed their function and best serve the body by dying and getting out of the way
Layers of the epidermis from deepest to most superficial
stratum basale/germinativum (melanocytes and tactile cells), stratum spinosum (keratinocytes and drendritic cells- phagotize other cells), stratum granulosum (keratinocytes die), stratum lucidum (only in thick skin), stratum corneum (dead skin cells).
Functions of the skin
resistance to trauma and infections, other barrier functions, vitamin D synthesis, sensation, thermoregulations, and nonverbal communication
Melanin
2 types. Eumelanin-brownish. Pheomelanin- reddish yellow, contains sulfur.
Cyanosis
blueness of the skin resulting from a deficiency of oxygen
Meissner’s corpuscles
Tactile sensory receptors located within the dermal papillae.
pacinian corpuscles
Tactile sensory receptors located in the reticular layer.
sudoriferous gland
produces sweat. Sweat glands are of two types: (1) apocrine (found in the gr
Ceruminous glands
found in the ear and secrete earwax.
Lunula
The half-moon-shaped area at the proximal end of the nail that appears whiter in color because the epithelium is thicker and inhibits the vascular tissue below from showing through.
Hyponychium
The thickened portion of epidermis located under the free edge of the nail.
Eponychium
The portion of the epidermis that surrounds the nail, also called the cuticle.
Basal cell carcinoma
most common, least deadly because it seldom metastasizes. From stratum basale and invades the dermis
Squamous cell carcinoma
from keratinocytes of stratum spinosum, chance of recovery is good with early detection and surgical removal
Melanoma
from the melanocytes. Most deadly, metastasize quickly, extremely aggressive and drug resistant
yellow bone marrow
where lipids are stored in the medullary cavity of a long bone, primary function is triglyceride storage
Osteocytes
mature bone cells that no longer secrete matrix but maintain the balance of minerals and proteins in the matrix, exchanges nutrients and wastes with the blood
Osteogenic cells
stem cells that develop form embryonic mesenchymal cells, multiply continually
Circumferential lamella
located below the periosteum and is added as a bone grows in diameter
Intramembranous ossification
1) Mesenchyme condenses, enlarge, and differentiate into trabecular
2) Osteogenic cells gather on trabecular and differentiate into osteoblasts. These cells deposit in osteoid tissue. Some become osteocytes and others turn into periosteum
3) Osteoblasts continue to deposit forming bony trabeculae. Some stay as permanent spongy bone. Osteoclasts resorb others to form a marrow cavity
4) Trabeculae at the surface continue to calcify, turning spongy bone into compact bone
Endochondral ossification
1) Mesenchyme develops into hyaline cartilage
2) Perichondrium starts producing osteoblasts. Chondrocytes are enlarge and matrix is reduced to thin walls. Primary ossification center
3) Blood vessels enter the primary ossification center and it becomes the primary marrow cavity. Osteoblasts form trabeculae. Osteoclasts dissolve cartilage turning it into bone at metaphysis. Secondary ossification center
4) Secondary ossification center hollows out and becomes a secondary marrow cavity
5) Epiphyses are filled with spongy bone during development. Cartilage turn into epiphyseal plate
Zone of reserve cartilage
farthest from the marrow cavity, consist of typical hyaline cartilage that show no sign of transforming into bone
Zone of cell proliferation
chondrocytes multiply and arrange themselves into longitudinal columns of flattened lacunae
Zone of cell hypertrophy
chondrocytes cease to divide and begin to enlarge. The walls of matrix between lacunae become very thin
Zone of cell calcification
minerals deposited in the matrix between columns of lacunae and calcify the cartilage
Zone of bone deposition
walls between the lacunae break down and chondrocytes die. Osteoblasts begin depositing matrix while osteoclasts dissolve the calcified cartilage
Hypocalcemia
a calcium deficiency
Hypercalcemia
blood calcium excess
Calcitonin
secreted when blood calcium is too high. Lowers blood calcium by osteoclast inhibition and osteoblast stimulation
Parathyroid hormone
secreted by parathyroid gland, released when blood calcium is low
Fractures
Nondisplaced fractures- bone is still lined up
Displaced fractures- bones have shifted out of place
Comminuted fractures- more than 2 bones broken, shattering
Greenstick fracture- bone bends, more often in children
Healing process of fractures
1) Formation of hematoma- hematoma is converted to granulation tissue by invasion of cells and blood capillaries
2) Soft callus formation- deposition of collagen and fibrocartilage converts granulation tissue to a soft callus
3) Hard callus formation- osteoblasts deposit a temporary bony collar around the fracture to unite the broken pieces while ossification occurs
4) Bone remodeling- small bone fragments are removed by osteoclasts, while osteoclasts deposit spongy bone and then convert it to compact bone
hypophyseal fossa
the depression that is located in the sella turcica of the sphenoid bone and houses the pituitary gland. It is located in the inferior side of the brain.
Greater and lesser cornua
The two horn-like processes that serve as muscle attachment sites
Paranasal sinus
located in the maxillary bone, frontal bone, sphenoid bone, and ethmoid bone, decrease the weight of the skull and act as a resonating chamber for the voice.
Transverse process of vertebrae
This extends laterally from each side of the vertebral arch and functions as a muscle attachment site.
Pedicle of vertebrae
The portion of the vertebra extending posteriorly from the body to the transverse process.
Body of vertebrae
A large, disc-shaped portion of the vertebra that forms the anterior wall of the vertebral foramen.
Lamina of vertebrae
The portion of bone between the transverse and spinous processes that forms the posterior wall of the vertebral foramen.
Odontoid process
The superior projection of the axis, which allows for side-to-side movement of the head.
conoid tubercle
located near the acromial end of the clavicle, is an attachment site for muscles of the shoulder.
