lecture anatomy exam 2 Flashcards
What catalyzes the synthesis of vitamin D in epidermis?
UV light
What type of cells does melanin accumulate in the skin?
Melanin accumulates in melanosomes, which are then transferred to keratinocytes.
What layer of the epidermis has the fastest rate of mitosis?
stratum basale
Which epidermal cell has an immunological function?
dendritic or langerhans’s
What is the function of the lamellated granules of the cells of the stratum granulosum?
to make the skin water-resistant
What is absent in thin skin?
stratum lucidum
How do nutrients reach the epidermis of the skin?
dermal papillae extend into the epidermis to supply it with blood vessels and nerve endings.
Where are dermal papillae most conspicuous?
friction ridges, on hands and feet.
How many layers comprise the epidermis and dermis?
E: 4 or 5 layers, stratum basale is deepest and actively mitotic. Stratum spinosum resists tension and pulling. Stratum granulosum waterproofs the skin and keratinization begins. Stratum lucidum is a few clear layers of dead cells; absent in thin skin. Stratum corneum is superficial and the thickest layer; it provides protection with its many layers of dead, keratinized cells.
D: 2 layers; papillary is thin, superficial, and made of areolar tissue with collagen fibers for support. Reticular is deep, thick, made of dense irregular connective tissue, and contains majority of dermal structures.
Why can the hypodermis act as a shock absorber?
it is composed of fatty tissue (adipose).
What are the parts of a hair from deepest in the skin to the part above the surface?
Hair root: hair papilla (nutrient supply for hair), hair matrix (actively mitotic area), hair bulb (expanded, inferior portion of follicle); hair shaft: medulla, cortex, cuticle; all of which are layers consisting of dead, keratinized cells.
What type of sudoriferous gland produces milky sweat due to high amounts of lipids?
apocrine
What type of modified sudoriferous gland secretes a wax? What is that wax called?
ceruminous, cerumen
What type of modified sudoriferous gland secretes milk?
mammary
What gland secretes sebum oil at the base of the hairs?
sebaceous
What glands are most responsible for cooling the skin?
eccrine sweat glands
What integumentary glands normally develop at puberty?
sebaceous glands, apocrine glands
What are the major characteristics of basal cell carcinoma, squamous cell carcinoma, and malignant melanoma?
BCC: least malignant and most common; stratum basale cells invade dermis.
SCC: common and can metastasize; involves keratinocytes of stratum spinosum; often presents as red and scaly.
MM: cancer of melanocytes; highly metastatic and resistant to chemotherapy; ABCD: asymmetry, border irregularity, color is dark/or variable, diameter is larger than 6mm.
What are the main functions of the skeletal system?
support for body, protection for vital organs, movement when combined with muscles, hormone production, stores fat and minerals (calcium and phosphate), blood formation (hematopoiesis).
How is the skeletal system aid in the maintenance of acid-base balance?
phosphate can alter acid base balance and is stored in bones.
Describe and give examples of long and short bones.
long bones are longer than it is wide, most of the bones in extremities (humerus, femur). Short bones relatively equal in length and width (carpals and tarsals).
What bone type can vary in number from person to person?
accessory, sutural bones.
What classification is the vertebrae considered to be?
irregular
Define the shaft.
diaphysis
Define epiphysis
bone ends
Define periosteum
covers bones surface and contains bone cells (osteoblasts), blood vessels, and never fibers.
Define epiphyseal line
area of rapid growth during adolescence.
Define endosteum
lines internal bone cavity.
Define metaphysis
junction of epi/diaphysis, contains epiphyseal line.
Define articular cartilage
hyaline cartilage on bone ends for protection.
Define diaphysis
shaft or midsection of bone.
Define spongy bone
honeycomb arrangement of bone that creates open spaces filled with marrow.
Define compact bone
smooth, superficial covering of bone.
Define medullary cavity
opening within diaphysis, contains bone marrow.
Define osteoclasts and osteoblasts
Osteoclasts (are bone dissolving cells) Osteoblasts (bone-forming cells)
What is diploe?
spongy bone sandwiched within a flat bone.
Bone tissue is more rigid than other tissue because its ground substance contains inorganic salts, these contribute to the formation of what crystals in the bones?
hydroxyapatite (65% make up the bone).
What would we need to have less of to make our bones more brittle and susceptible to spontaneous fractures?
collagen fibers
What are osteocytes and where are they located?
mature bone cells, lacunae.
What structures are found in a haversian canal?
nerves, blood, and lymphatic vessles.
What allow osteocytes to transport their wastes to the bloodstream for removal?
canaliculi
What is the framework called that is made up of spongy bones?
trabeculae
Bone histology is much easier to understand when one recognizes that bone tissue is organized around what?
structural units and osteon
Where does hemopoiesis typically occur within the skeletal system?
red bone marrow
Why is yellow bone marrow yellow?
made of adipose tissue.
In bone formation, what is the term that refers to bone tissue?
osseous
In bone formation, what is the term that pertains to embryonic tissue that later turns into bone?
osteoid
How do the bones of the face and the clavicle develop? How do the other bones develop?
fibrous connective tissue membranes and a cartilage model.
When does the ossification of the ends of long bones take place? What is this site called?
By age 25 ossification is complete, Epiphyseal plate.
In the embryological development of long bones, when does the medullary cavity develop?
periosteal bud (blood supply) invades cavities and forms spongy bone.
What is it called when an adolescent grows in height? And what causes these events to occur?
interstitial, in epiphyseal plate of long bones of the skeleton.
in what direction does the epiphyseal plate grow?
New cells move upwards, pushing epiphysis away from diaphysis.
What effect does appositional growth have on a long bone?
bone widens naturally as it lengthens due to stress of getting bigger.
What do the lysosomal enzymes dissolve when the bone is being resorbed?
matrix
Compare and contrast calcitonin and parathyroid hormone.
PTH secreted in response to low blood calcium levels and stimulates osteoclasts. Calcitonin is secreted in response to high blood calcium levels which inhibit osteoclasts.
How is calcitriol made and what is it converted into?
derived from a steroid and converted into vitamin D by sunlight.
What hormones cause osteoblasts to deposit more bone matrix?
testosterone, estrogen, growth, and thyroid.
Describe the 3 classification of a bone fracture.
position: displaced (out of alignment) nondisplaced (in alignment). completeness: complete (all the way through) incomplete (partial or hairline fracture). skin penetration: compound/open (out of the skin) simple/closed (stays within the skin).
What is the main reason why osteoporosis is most common in elderly women?
estrogen levels drop at menopause, causing less osteoblast activity which result in weak bones.
What are some factors in delaying osteoporosis?
weight bearing exercise, intake of calcium, healthy diet, fewer carbonated drinks.
What is it called when children have a vitamin D deficiency?
rickets
What vitamins and minerals are needed for normal bone formation and growth?
calcium, phosphate, vitamin D, and proteins.
What hormone is most important for bone growth as an adolescent? What does excess or deficiency cause?
growth hormone from pituitary gland, excess (gigantism), deficiency (dwarfism) in adults excess is acromegaly nothing for deficiency.
What are the functions of thyroid hormones on the skeletal system? Calcitriol?
thyroid hormones regulate cellular metabolism and growth hormone. Calcitriol stimulates intestines to absorb more calcium.
What does Wolf’s law state?
bones are going to grow and remodel based on the stress that is put on them.
What are the stages of healing a bone fracture?
hematoma formation: (blood vessels that causes swelling and inflammation) fibrocartilage callus formation: (cartilage model made of new vessels) bony callus formation: (replacing fibrocartilages) bone remodeling occurs.
