AP Exam 2 Flashcards
the homeostatic control of body temperature through sweat (epidermis) and adjusting blood flow(dermis)
thermoregulation
light touch, pressure, vibration, tickle, heat, cold, and pain sensed on the skin
cutaneous sensations
passage of material from the external environment into body cells (minor role of skin)
absorption
UV radiation which is then broken down by enzymes in the liver and kidneys to form active Vitamin D
Synthesis of Vitamin D
superficial layer of the skin; composed of keratinized stratified squamous epithelium with 4-5 strata
Epidermis
deep layer of skin composed of loose areolar CT and dense irregular CT
Dermis
a membrane that separates the dermis and the epidermis
Basement Membrane
ridges that provide better grip and are called “fingerprints”; reflect underlying dermal ridges
Epidermal Ridges
What are the four types of cells in the epidermis?
Keratinocytes, Langerhans cells, Melanocytes, and Merkel Cells
most abundant cell in the epidermis (90%) which produce keratin and lamellar
Keratinocytes
a tough, fibrous protein that helps protect the skin and underlying tissues
Keratin
bodies which secrete water-repellant sealant
Lamellar Granules
stem-cell precursors of keratinocytes; arising from the stratum basale, these differentiate into keratinocytes as they become more superficial
Basal Keratinocytes/Basal Cells
the differentiation process that replaces the contents of keratinocytes with the protein keratin (2-4 weeks)
Keratinization
the sloughing off of superficial keratinized cells as new cells are synthesized in the stratum basale
Desquamation
a common skin cancer, arising from basal keratinocytes
Basal Cell Carcinoma
dendrite cells of the epidermis; most prominent cells in the stratum spinosum; function as macrophages
Langerhans Cells
pigment-producing cells in the stratum basale
Melanocytes
cancers arising from melanocytes
Melanomas
specialized sensory-receptor cells found in the stratum basale that have an associated nerve
Merkel Cells
What are the four layers of the epidermal strata called?
Thin Skin
What are the 5 layers of the epidermal strata, which only appear on the palms, soles, and digits, called? Hint: it’s hairless
Thick Skin
thinnest epidermis (0.05 mm)
Eyelids
Thickest Epidermis
Palms and soles (1.5 mm)
What is the order of all the stratum?
Corneum, lucidium, granulosum, spinosum, basale
deepest layer of the epidermis which is attached to the basement membrane and is composed of basal cells. Contains melanocytes and merkle cells
stratum basale
thickest layer of the epidermis with “spiny” keratinocytes. Also includes Langerhans cells
Stratum Spinosum
the layer of the epidermis where keratinocytes flatten and lose their organelles (apoptosis). this layer also synthesizes lipids to aid in waterproofing the skin and also stains the darkest
Stratum Granulosum
A layer of epidermis only found in thick skin; “clear/translucent”
Stratum Lucidium
most superficial layer of the epidermis consisting of 10-30 layers of “dead, keratin-filled sacs” which will “slough off”
Stratum Corneum
increased keratinization
cornification
the “sloughing off” of the stratum corneum
desquamation
the presence of too much keratin which then flakes off
dandruff
active form of vitamin D which the epidermis produces from inactive vitamin D, obtained from UV radiation
calcitrol
vitamin that promotes bone health and immunity against bacterial, viral, and fungal infections
vitamin d
the superficial layer of the dermis, consisting of loose areolar CT and dermal papillae
papillary layer
nipple-like structures of the dermis that extend into the epidermis and create epidermal ridges on the hands/feet
dermal paillae
finger-like extensions of the dermis into the epidermis
interdigitation
deep layer of the dermis, composed of dense irregular CT which appears like a “reticular meshwork” and supports hair follicles, oil, and sweat glands
reticular layer
where the hair originates from; epidermal penetrations into the dermis and is present in most thin skin. includes oil glands and erector pili muscles. functions: protection, reduced heat loss, and sensing light touch
hair follicles
oil glands; typically associated with hair follicles and produce sebum; don’t usually appear in thick skin
sebaceous glands
sweat glands. functions: regulate body temperature and elimination of wates
sudoriferous glands
the hypodermis which is composed of adipose tissue to store fat as well as allow passage of blood vessels and nerve endings; not part of the skin
subcutaneous layer
glands which secrete cerumen (earwax) and are located in the external auditory meatus
ceruminous glands
head, dead, keratinized epidermal cells which provides protection for the digits
nails
layer of dead skin which “rides out” on the nail to form a protective seal
cuticle
an infection around the nail
paronychia
the white, crescent shape at the proximal end of the nail
lunula
results of the edema separating the epidermis from the dermis
blisters
Tissues in Bones (6)
bone tissue, cartilage, dense CT, epithelium, fat tissue, nervous tissue
what are six functions of bones?
- structural framework
- movement
- hemopoiesis
- protection
- mineral homeostasis
- fat storage
minerals stored in bones
calcium and phosphorus for mineral homeostasis
the formation of blood cells which occurs in red bone marrow
hemopoiesis (hematopoiesis)
the shaft of long bones and is made mainly of compact bone and stores yellow bone marrow in the medullary cavity
diaphysis
the end of the bone that articulates with adjacent bones and are covered with hyaline cartilage (articular cartilage)
epiphysis
the zone of growth on a long bone, located between the diaphysis and epiphysis and also includes the epiphyseal plate. it also serves to transfer the load of weight-bearing joint surfaces to the diaphysis
metaphysis
area of hyaline cartilage for bone growth located in the metaphysis, along the epiphyseal border
epiphyseal plate or growth plate
closed growth plate
epiphyseal line
the cavity in the diaphysis which contains yellow bone marrow (triglycerides) and is lined by endosteum
medullary canal
a thin, vascular layer of tissue that lines the inner surfaces of bones and has osteogenic capabilities (similar to periosteum). During appositional growth, assists in bone resorption on inner surfaces
endosteum
most superficial layer of bone; contains osteogenic cells which can differentiate into osteoblasts to assist in bone repair and growth. contains nerves to sense damage and pain
periosteum
bone tissue consisting of widely separated cells surrounded by a large amount of matrix and has 4 main cell types
osseous tissue
what are the four main cell types of the osseous tissue?
osteogenic cells, osteoblasts, osteocytes, osteoclasts
cells that undergo cell division and develop into osteoblasts; most primative/stem cells
osteogenic cells
bone-building cells which promote bone deposition
osteoblasts
mature bone cells that maintain bone tissue
osteocytes
bone cells derived from monocytes which break down bone tissue (resoprtion)
osteoclasts
a type of white blood cell
monocytes
a structural support surrounding the bone cells, composed of inorganic salts (hardness) and collagen fibers (strength)
matrix
the deposition of calcium carbonate salts into a framework of collagen fibers; can only occur with the presence of collagen fibers
calcification (mineralization)
uncalcified bone matrix
osteoid
dense, hard bone arranged in osteons and found on the outer aspect of bones
compact bone/cortical bone
the central canal of osteons that contains blood vessels, nerves, and lymphatic vessels and are surrounded by concentric lamellae
haversian canal
vascular channels in compact bone allowing for the passage for blood vessels, lymphatics vessels, nerves of the medullary cavity, periosteum, and connection of central canals
Volkmann Canals
rings of hard, calcified ECM
Concentric Lamellae
little, pit-like space which house osteocytes
lacuna
a small channel that radiates from a lacuna and are filled with ECF and provide routes for nutrients and oxygen to reach the osteocytes
canaliculus
forms the interior structure of short, flat, and irregular bones and epiphysis of long bones and contains trabeculae and is filled with red bone marrow for hemopoiesis
spongy bone/trabecular bone
irregular latticework of thin columns of bone surrounding many spaces filled with red bone marrow
trabeculae
maintaining proper levels of calcium in the body, particularly in the blood stream. Important for muscle contractions, nerve impulses, and enzyme activity
calcium homeostasis
chemical messengers released into the blood stream that travel to a different location of the body for a physiological affect
hormones
hormones for Ca2+ homeostasis
PTH, calcitrol, calcitonin
the hormone secreted by the parathyroid gland which increases blood Ca2+ through bone resorption decreased Ca2+ in urine, and indirect increase of Ca2+ absorption from the gut through activation of calcitriol
PTH
active form of vitamin D which increases blood Ca2+ through increasing Ca2+ absorption from the gut and decreasing Ca2+ in the urine
Calcitrol
hormone secreted by the thyroid gland which decreases Ca2+ levels by inhibiting osteoclastic acitivty
Calcitonin
most prominent artery to the bone
nutrient artery
hole in the bone through which the nutrient artery passes through
nutrient foramen
central canals of the osteons through which nutrients for the osteocytes travel
nutrient canal
bone formation through initial formation, bone growth, remodeling and repair
ossification
embryonic type of CT from which all types of CT arise
mesenchyme
formation of bones directly from mesenchyme and only for formation of flat bones
intramembrous ossificaiton
what are the four steps of the intramebranous ossification
- development of ossification centers
- calcification of bone matrix
- formation of trabeculae
- development of the periosteum and compact bone
The first step of intramebranous ossificication where mesenchymal cells differentiate into osteogenic cells, then into osteoblasts which lay down uncalcified bone matrix (osteoid)
development of ossification centers
bone formation including a cartilage model; bone formation for ALL bones but flat bones
endochondrial ossification
what are the six steps of endochondrial ossification
- development and growth of hyaline cartilage model
- development of bone collar
- development of a primary ossification center
- development of medullary canal
- development of secondary ossification centers
- formation of articular cartilage and epiphyseal plate
a layer of compact bone, formed by the osteoblasts, which runs the length of the diaphysis under the periosteum which blocks nutrients from entering the cartilage, allowing it to die
bone collar
growth of bones that occurs at the epiphyseal growth plate; cartilage, formed by chondroblasts, is degraded and replaced by osseous tissue; plate closes between 18-25 yrs. of age
longitudinal bone growth
bone growth in diameter, accomplished through bone resorption in the medullary cavity; necessary for bone remodeling
appositional bone growth
the ongoing replacement of old bone tissue with new bone tissue; old bone is destroyed by osteoclasts and new bone is constructed by osteoblasts; for normal growth and repairing injuries
bone remodeling
loss of bone minerals which can be prevented through weight-bearing activities
demineralization
what are the elements necessary for bone remodeling?
- weight-bearing activities
- vitamins (A, C, and D)
- minerals (calcium, phosphorus, and magnesium)
- hormones (hGH and sex hormones)
a break in a bone
fracture
a series of microscopic breaks in a bone, often without evidence of injury
stress fracture
a fracture caused by diseased or weakened bones
pathologic fracture
fracture where skin is intact
simple fracture
fracture where skin is broken
compound fracture
occurs straight across the bone
transverse fracture
a fracture that runs down the bone
linear fracture
occurs at an angle across the bone
oblique fracture
a fracture in which the bone has been twisted apart; often a sign of abuse
spiral fracture
a break in which the broken bones retain their alignment
non-displaced fracture
a break where bone ends are out of normal alignment
displaced fracture
where a young bone bends and only partially breaks
greenstick fracture
bone breaks into many fragments
comminuted fracture
a fragment of bone tears away from the main bone
avulsion fracture
one bone fragment is firmly driven into another
impacted fracture
what are the treatments for a bone fracture? (3)
- anatomic realignment (if necessary)
- immobilization
- restoration of function
an infection of the bone, resulting from a compound fracture
osteomyelitis
what are the four body repairs for fractures?
- phagocytes (clean up dead bone tissue)
- chondroblasts (form fibrocartilage at broken ends)
- osteoblasts (replace fibrocartilage with spongy bone)
- bone modeling
a condition resulting from demineralization of bone and bone resorption outpaces bone formation
osteoporosis
softening and weakening of bones in children due to vitamin D deficiency; leads to bow leggedness
rickets
“brittle bone disease” caused by a genetic mutation affecting collagen formation. Blue sclera is a common indication
Osteogenesis Imperfecta
shortening of a muscle to produce force
contraction
the lengthening of a muscle to return to a non-contracted state
relaxation
voluntary muscle which attaches to bones and cartilage, providing movement
skeletal muscle
often called “muscle fibers”
muscle cells
the cell membrane of muscle fibers which contains transverse tubules and can carry APs
sarcolemma
oxygen-binding protein that stores oxygen and speedily delivers it to the mitochondria to aid in ATP production; located in the muscle cell rather than the blood
Myoglobin
located on the periphery of the skeletal muscle cell; multinucleated
nuclei
proteins that generate force; myosin and actin
contractile proteins
protein in thick myofilaments
myosin
main component of thin filaments that myosin-binding sites
actin
function as “on/off” switches of contractions; tropomyosin, troponin
regulatory proteins
two other protein components of thin myofilaments besides actin
troponin and tropomyosin
proteins that keep thick and thin filaments in proper alignment; titin
structural proteins
giant protein and main structural anchor/spring; connects the Z disc to the M line to limit ROM to the sarcomere; third most abundant protein in the muscle
Titin (connectin)
lightly organized thick and thin filaments within a skeletal muscle cell
myofilaments
basic contractile unit of a muscle that extends from Z disc to Z disc; shortens during a muscle contraction which shortens the entire muscle; striated
Sarcomere
arrangement of many sarcomeres connected end-to-end along the entire muscle cell; tube-like structure that’s wrapped in sarcoplasmic reticulum
myofibrils
network of saccules and tubes that house calcium which is released to cause muscle contractions and reabsorbed during relaxation; covers myofibrils
sacroplasmic reticulum
type of skeletal muscle fiber which contracts slowly but is fatigue resistant; uses aerobic respiration, thus has increased mitochondria and myoglobin
slow oxidative (SO)
type of skeletal muscle fiber which can contract quickly but fatigues more easily than SO; uses aerobic respiration but can switch to anaerobic (glycolysis); “intermediate fibers”
Fast Oxidative-Glycolidic (FOG)
type of skeletal muscle fiber that can contract powerfully and rapidly but also fatigues quickly; uses anaerobic glycolysis; few myoglobin (thus, pale in color)
Fast Glycolytic (FG)
sheet of CT (rather than a cord) which surrounds the epimysium among other things
Fascia
a bundle of muscle fibers
fascicle
highly deadly poison produced by clostridium botulinum prevents the release of ACh leading to botulism (muscle weakness)
Botulinum Toxin
bacteria taht causes botulism
clostridium botulinum
an abnormal decrease in muscle tone normally due to brain, spinal cord, or nervous system damage; “floppy baby syndrome” in infants
hypotonia
decreased reflexes
hyporeflexia
a state of limpness in which muscle tone is lost
flaccid
excessive muscle tone often accompanies by hyperreflexia; often result of damge to upper motor neurons (stroke, brain tumor, Parkinson’s); muscle rigidly or spasticity
hypertonia
overly strong reflex
hyperreflexia
a phasic change in muscle tone where a limb will “snap” back from passive stretching
spasticity
a decrease in the size of an organ or body part due to the decrease size of the cells; “wasting away” often due to underuse
atrophy
what are the three factors that determine tension?
- # of fibers in a motor unit
- type of fibers in a motor unit
- stretch of the fibers before contraction
what are the three factors that determine tension?
- # of fibers in a motor unit
- type of fibers in a motor unit
- stretch of the fibers before contraction
what are the three types of fibers?
- type 1 (SO)
- type 11a (FOG)
- type 11b (FG)
fibers that are smallest in diameter and least powerful
Type 1 (SO)
fibers that are intermediate in diameter and have strength
Type 11a (FOG)
Fibers that are greatest in diameter and have strength
Type 11a (FG)
sthe immediate and direct source of energy for muscle contractions, but is in limited amounts
Cytosolic ATP
catabolizing the small amounts of creatine phosphate in the skeleatl muscle cells generates ATP for inital conttractions
Creatine phosphate