a&p fall final Flashcards
what are common characteristics of connective tissue?
all arise from embryotic tissue (mesenchyme)
highly vascularized
composed mainly of extracellular matrix that allows it to bear weight and withstand tension
list the structural elements of CT
ground substance, cells, and fibres
what are the CT found in the body?
areolar, adipose, reticular, dense reg, dense irreg, and elastic
also cartillage, bone, and blood
what is ground substance?
ground substance- gel like material that fills the space between cells. consists of interstitual fluid, adhesion pros, proteoglycans, and protein fibres.
what are the cells in CT? what do they do?
cells- “blasts” are immature cells that actively work. “cytes” are mature cells arent active and maintain health of matrix. fibroblasts in CT proper, chondroblasts in cartiallge, and osteoblasts in bone.
what are the fibres in CT?
fibres- fibre and ground sub make up extracellular matrix, collagen fibres provide strength, elastic fibres provide stretch, and reticular fibres provide branches between CT and other tissue and found where filtration occurs
what is a cutaneous mem?
a dry mem known as skin. consists of keratinized
stratified squamous
epithelium over areolar connective tissue and dense irregular connective tissue.
help protect the rest of the body’s tissues and organs from physical damage.
what is a mucous mem?
wet membranes that line body cavities that open to the
outside of the body.
made of stratified squamous
or simple columnar epithelia over a layer of areolar connective tissue called lamina propria
what is a serous mem?
lines the walls of cavities and organs within closed ventral body cav.
made of simple squamous epithelium on top of a layer of areolar CT
The cavity between layers is filled with serous fluid to reduce friction
what is a Synovial membrane?
line joint cavities and secrete synovial fluid to lubricate and support bones that move. They lack epithelium and are considered a specialized connective tissue
what is muscle tissue? what are the 3 types?
Muscle tissues are highly cellular, well-vascularized tissues responsible for movement. contains myofilaments made of actin and myosin responsible for contraction.
skeletal, smooth, and cardiac
what is skeletal muscle tissue?
voluntary muscle that attaches to the skeleton and when they contract cause movement of the skeleton. aka musc fibres
composed of long cylinder cells that have multiple nuclei around the edges. has visible striations.
what is smooth muscle tissue?
non voluntary, unstriated,
uninucleate and spindle-shaped cells. They are found in
the walls of the hollow organs, in dig tract, pushes food thru tract by contracting and relaxing (peristalsis)
what is cardiac muscle tissue?
striated, single nucleus, and branched.
located linging walls of the heart, has intercalated discs where the cardiac cells join at gap junctions and desmosomes. the contractions of the musc pump blood thru the body, involuntary
what is nervous tissue?
main component of nerv sys, has CNS and PNS, regulates and controls body functions. contains neurons and neuroglial cells.
found in the brain, spinal chord, and nerves
what 2 ways does tissue repair occur?
regeneration, in which damaged cells are replaced with the same type of cell.
fibrosis, which replaces damaged cells with fibrous connective tissue. happens in tissues that do not regenerate
what is the first step of tissue repair?
Inflammation
prepares the area for repair by
dilating blood vessels and increasing in blood vessel permeability. Inflammatory chemicals are released by damaged tissues.
Scabbing and clotting occurs.
what is the second step in tissue repair?
Organization
process that replaces the blood
clot with granulation tissue (new capillary-rich tissue), restoring blood supply. Macrophages phagocytize dead and dying cells and, Fibroblasts produce collagen fibres to in a process called fibrosis, and surface epithelial cells multiply and migrate over
the granulation tissue.
what is the final step in tissue repair?
Regeneration and/or fibrosis
restores tissue the scab detaches as fibrous tissue matures.
Epithelium thickens and begins to resemble adjacent tissue
what tissues regen well?
epithelial tissues, bone, areolar connective tissue,
dense irregular connective tissue, blood-forming
tissue
what tissues do not regen?
cardiac muscle and nervous tissue of brain and spinal cord
what are the two layers of skin?
super- epidermis
deep- dermis
what is the subcutaneous tissue?
aka hypodermis, consisting mostly of adipose tissue that anchors the skin to underlying muscle, allows skin to slide over muscle, and acts
as a shock absorber and insulator
what are the cells in epidermis?
keratinocytes- keratinized strar sqaumous
melanocytes- synth pigment and prtect against UV
longerhorns- WBC
tacktile- sensory
what are the layers of epidermis starting with the deepest?
stratum basale
stratum spinosum
stratrum granulosum
stratum lucidum
stratum corneum
what is the stratum basale layer?
attached to dermis
always actively dividing(mitotic)
has melanocytes
what is the stratum spinosum layer?
3-5 cells thick
has keratinocytes and melanocytes
web-like system of intermediate
pre-keratin filaments attached to desmosomes. This allows them to resist tension and pulling.
what is the Stratum granulosum layer?
4-5 cells thick
Cells flatten, nuclei and
organelles disintegrate and keratinization begins
Cells above this layer die because they are too far from dermal capillaries to survive
what is the Stratum lucidum layer?
only found in skin that covers the palms , soles of the feet and
the surfaces of fingers and toes
It consists of thin, translucent band of two to three rows of clear, flat, dead keratinocytes
what is the Stratum corneum layer?
the outermost layer of the epidermis,constantly being replaced by cells beneath
what is ther dermis?
composed of strong, flexible
connective tissue and is
supplied with blood vessels,
nerves and lymphatic
vessels
it has two layers, papillary layer and reticular layer
what is the papillary layer?
superficial layer
composed of areolar connective tissue that forms dermal papillae that result in fingerprints.
what is the reticular layer?
80% of the thickness of the dermis
It consists of dense fibrous connective tissue with stretchy elastic fibers and durable collagen fibers
has felxure lines which are found at folds of joints on your hand
has tention lines caused by collagen fibres running parrallel to skin surface. easily allows for cuts to be made without scaring, and dermal tears are called striae aka stretch marks
what is melanin?
a group of skin and hair pigments that are brown or black (eumelanin) or pinkish red
(pheomelanin)
how does melanin protect against UV?
physical barrier that scatters UV and reduces UV penetration thru epidermis
why are there different skin colours?
skin colour differences are due
to the amount and type of melanin
what is carotene?
a yellow-orange pigment found in
certain foods
why is there a pinkish hue seen in fair skin?
due to hemoglobin in blood seen thru transparency of skin
what gives skin its colour?
melanin and hemoglobin
what is Cyanosis? Jaundice? Erythema?
-blue skin due to low O
-yellow skin due to liver disorder
-red skin due to anger or fever
what is Pallor? bronzing? bruising?
-pale skin
-steroid hormones causes over-
expression of melanin
-Bleeding or coagulated blood under the skin
outside of the blood vessels (hematoma)
what are the parts of a hair follicle?
peripheral connective tissue sheath- a thickened
basement membrane from the dermis
inner epithelial root sheath- derived from the epidermis
what is hair? what is its function?
flexible strands of dead keratinized cells produced by hair folicules made of hard keratin
-insulating against heat loss
-protecting head against physical trauma
-shielding skin from sunlight
what are the 2 main regions of hair?
hair shaft- projecting from skin
hair root- embedded in skin
what are the 3 layers of hair starting deepest?
medulla (in thick hair)
cortex
cuticle
how does hair get its colour?
melanocytes at the base of the hair follicle, combos of diff melanocytes create diff hair colours
what is a hair follicule?
folds down from the epidermis into the dermis and occasionally into the hypodermis
hair bulb
contains the dermal papilla and hair matrix,regulates hair growth
hair matrix
mitotically active in the hair bulb
hair papilla
a knot of capillaries that supplies nutrients to growing hair
what is the muscle that allows hair to stand up?
arrector pili muscle
what is vellus hair?
pale, fin, thin hair
what is terminal hair?
long, coarse, thick hair
what does hair growth depend on?
age, sex, location, hormones, and nutrition
how does hair on your head grow?
in increments;
grow continuously for 2-7 years, then slow down for 2-3 weeks and rest for 2-4 months before growing begins again.
why do ppl bald or have thinning hair?
hair has a limited amount of cycles.
bald- genetic,
thinning-hair is not replaced as quickly as it is lost, which leads to hair thinning and some degree of
balding
what are Sebaceous glands?
holocrine glands that secrete sebum (oil) into a hair follicle or to a pore on the surface of the skin to softens and lubricates the hair and skin, slows water loss, reduce friction, and is bactericidal
what are Eccrine sweat glands?
merocrine glands
ducts are connected to glands to produce sweat
regulated by the
sympathetic nervous system and is used to prevent
the body from overheating
what are Apocrine sweat glands?
only in armpit, They produce a fat and protein-rich true sweat causing body odur
starts at puberty
what are the two modified sweat glands?
Ceruminous glands- are modified apocrine sweat glands found lining the ear canal that secrete ear wax
Mammary glands- are modified apocrine sweat glands that secrete milk
what is a nail?
scale-like modification of the epidermis that forms a protective covering on the dorsal side
of the distal finger or toe
do toe or finger nails grow faster?
fingernails
what is the structure of nails?
made up of hard keratin and have a free edge, a nail body attached to the skin, and a root
embedded in the skin
what is the nail matrix?
proximal part of nail bed, mito active and responsible for gorwth
what is the free edge of the nail?
extends past finger or toes
what is the nail body?
attached to skin
what is Proximal nail fold and lateral nail folds
the skin covers over the edges of the nail, holds in place
what is Lunula on the nail?
white half circle on nail bed, thickest
what is the eponychium(cuticle)?
the stratum corneum of
the epidermis at the proximal nail fold
what is the nail root?
not viable, embedded in skin where the nail grows
what is the nail bed?
the skin below the nail body
what is the hyponychium?
secures nail to finger
what is the distal phalanx?
bone under nail
what are the 3 barriers skin provides?
protects from external enviro,
chem- protect from UV by secreting secretions low in pH
physical- hardness of the
keratinized cells
biological- living cells (WBC) that change and adapt that look for things that have gotten thru the physcial barrier
what are the 5 functions of skin?
barrier
regulation and sensation
metabolism
body temp regulation
heat exchange
how does skin regulate body temp?
by manufacturing sweat to
cool the body and causing constriction of dermal
capillaries to prevent heat loss
what provides sensation in skin?
cutaneous
sensory receptors
how does skin contribute to metabolism?
makes vit D precurser when exposed to sunlight
can be a blood reserve (can hold 5% of blood) to be used when needed like in exercise
what is apart of core body?
skull, abdom and thorasic cavities
37 degrees
vital organs that must be protected
what is the shell?
skin, has lowest body temp
what are the 4 mechanisms of heat exchange?
radiant- heat exchange from skin to external enviro
conductive- flow of warmth from warmer to cooler objects
convective- movement of warm air away from the body
evaporation- heat loss of fluids from the lungs, oral mucosa, and the skin
what is insensible heat loss?
heat loss you dont feel youre losing
ex heat loss when you breathe
what is sensible heat loss?
feel yourself cooling down
ex sweating
what causes heat cramps
loss of water and salt
what are the 3 major types of skin caaner?
Basal cell carcinoma, sqamous cell carcinoma, and melanoma
Basal cell carcinoma
least malignant, most common, slow growth, and can be surgically removed
Squamous cell carcinoma
can metastasize, derives from keratinocytes in stratum spinosum, seen as scaly red patches, grow rapidly and can be removed or use radiation
melanoma
most dangerous, resistant to chemo, cancer of melanocytes, looks like moles or patches
what is cancer?
occurs when DNA of a cell is damaged or mutated causing it to grow uncontrolably and dividing rapidly
what is a burn?
denatures proteins and cause cell death by heat or electricity or chemical damage
what are risks of a burn?
dehydration, fluid loss, and infection
what is the rule of nine?
body div into 11 sections that account for 9% of body, except genitals which acc for 1%, used to evaluate burns and estimate
volume of fluid loss
what are first and second degree burs?
1- epidermis damage only, red, swells, pain
2- epi and dermis damage, blisters
what are partial thickness burns?
burns through epidermis and upper dermis are involved
what are third degree burn?
full thickness burns, goes thru epi, dermis, and underlying tissue.
skin turns grey, red, or black and nerve endings are destoryed
what are 4-6th degree burns?
all layers of skin, burn the underlying fat, muscle and bone
what are the 6 functions of bone?
-support for body and organs
-protection of brain, spine, and organs
-movement for musc action
-mineral and growth storage of calcium and phosphorus
-blood cell formation (hematopoiesis), in red bone marrow
-fat storage in yellow bone marrow, which can be used for energy
what is the function of red bone marrow?
produces RBC
what is the function of yellow bone marrow?
produces and fat WBC
what is compact bone?
outer layer that is smooth and solid
what is spongy bone?
inner layer, helps to reduce stress.
consists of pieces of trabeculae instead of osteons
what is articular cartilage?
hyaline cartillage, provides support
what is periosteum?
covers surface of bone, contains osteogenic cells
hold blood vess and nerves in place thru nutrient foramen openings
contains an outer fibrous layer of
dense irregular connective tissue that secure the membrane to the bone matrix.
anchoring point for tendons and ligaments.
what is endosteum?what cells does it contains? what are the functions?
covers internal surface, contains osteogenic cells
covers the trabeculae of spongy
bone. It lines the canals that pass through compact bone
functions in remodelling, repairing and building cells in the membranes
what are osteogenic/osteoprogenitor cells?
give rise to all bone cells
can create new cells
mitotically active
found in peri and endo
what are osteoblasts?
bone forming cells that secrete un-mineralized bone matrix called osteoid (form matrix)
what are osteoclasts?
large ultinuclei cells that produce macrophages to break down bone by releasing dig enzymes and acids
found in resorption bays which is the location that bone is broken away at
when their job is done they die by adoptosis
what are osteocytes?
mature bone cells in lacunae that no longer divide.
They maintain bone matrix and
They send information to
osteoblasts and osteoclasts
so bone remodeling can occur.
what are periosteal cells?
bone lining cell found on external surface
They are found on bone surfaces in places where there aren’t any osteoblasts or osteoclasts
what are endosteal cells?
bone lining cell found on internal surface
They are found on bone surfaces in places where there aren’t any osteoblasts or osteoclasts
what is trabeculea?
in spongy bone, gives strength
consists of irregularly arrrenged lamelle and osteocytes connected by cannaliculi
what is the diaphysis?
shaft of bone in between the two ends of long bones, hollow.
made of an outer layer of compact bone around a central medullary cavity filled with yellow bone marrow
what is the epiphysis?
ends of long bones, has proximal and distal ends.
compact bone around spongy
bone filled with red marrow.
what is the medaphysis?
place on the bone where the epiphysis turns to the diaphysis.
includes the epiphyseal line
what is the epiphyseal line?
remnant of the childhood epiphyseal plate where bone growth occurs making you taller
after puberty this hardens so you no longer grow.
what is the osteoid?
un-mineralized bone matrix made of collagen and calcium that turns bone hard
not mito active
what is an osteon?
the structural unit of compact bone that acts as a weight bearing pillar
consists of many rings of bone matrix called lamelle
what is lamelle?
rings of bone matrix in an osteon.
contains collagen fibres that run in different directions in adjacent rings, to withstand stress and resist twisting. Bone mineral
salts are found between collagen fibres.
what is a central (Haversian) canal?
runs thru centre of osteon
contains blood vessels and nerves
what are perforating (Volkmann’s) canals?
lined with endosteum and occur at right angles to the central canal.
transmits blood vessels from the periosteum into the bone and communicates with the Haversian canals
what are Lacunae?
small cavities that contain osteocytes
what are Canaliculi?
hairlike canals that connect the lacunae to each other and the central canal
when do canaliculi form?
when bone matrix hardens and cells are trapped
how do bone cels communicate?
maintain contact with each other via cell projections with gap junctions
what are the organic components of bone? what do they do?
organic component of bone is the osteoid, which contains ground substance, proteoglycans, glycoproteins and collagen fibers.
allows for flexability and tensile strength
without it, bone would be very brittle and it would break if twisted or stretched.
what are the inorganic components of bone? what do they do?
hydroxyapatite, aka mineral salts. consists of tiny calcium phosphate crystals in and around collagen fibres.
responsible for hardness and resistance of compression
what is bone remodeling? what cells are involved?
consists of both bone deposit
and bone resorption. It occurs at the surfaces of both the periosteum and the endosteum
osteoblasts and clasts
why do hormones regulate bone
remodelling?
Hormonal control of remodelling is mostly used to maintain blood calcium homeostasis and balances activity of parathyroid hormone and calcitonin.
what is interstitial lamelle?
lamellae that are not
part of osteon. Some fill gaps between forming
osteons; others are remnants of osteons cut by
bone remodelling
what is circumferential lamelle?
layers of lamellae that extend around entire surface of diaphysis that help to resist twisting
explain bone depositing
a new matrix is deposited by blasts at the osteoid seam, which is a band of unmineralized bone
matrix that marks areas of new deposition
what are Triggers for bone deposit?
mechanical signals, increased
concentrations of calcium and phosphate ions and matrix proteins or enzymes to bind calcium and phosphate ions
explain bone remodeling. what cells are involved?
osteoclasts dig grooves as they break down the matrix by secreting dig enzymes and acids