Final Exam Flashcards
characteristics of connective tissue
1 mesenchyme 2 varying degrees of vascularity 3 extracellular matrix
structural elements of connective tissue
1 ground substance 2 fibers 3 cells
Unstructured material that fills space between cells
ground substance
three types of fibers
collagen, elastic, reticular
Strongest and most abundant type
Tough; provides high tensile strength
collagen
Networks of long, thin, fibers that allow for stretch and recoil
elastic
Short, fine, highly branched collagenous fibers (different chemistry and form than collagen fibers)
Branch, forming networks that offer more “give”
reticular
types of cells
blasts and cytes
Immature form; mitotically active; secrete ground substance and fibers
blast
Mature form; maintain matrix
cyte
Specialized nerve cells that generate and conduct nerve impulses
neurons
Supporting cells that support, insulate, and protect neurons
neuroglia
Skin
Keratinized stratified squamous epithelium (epidermis) attached to a thick layer of connective tissue (dermis)
Dry membrane
cutaneous membrane
indicates location not cell composition
Line body cavities open to the exterior
mucous membrane
found in closed ventral body cavity
Simple squamous epithelium (mesothelium) resting on thin areolar connective tissue
moist membrane
serous membrane
tissue repair stages
1 inflammation 2 organization restores blood supply 3 regeneration and fibrosis
Connective tissue replaces destroyed tissue
Original function lost
fibrosis
Same kind of tissue replaces destroyed tissue
Original function restored
regeneration
(main cell type) Produce fibrous protein keratin Most cells of epidermis Tightly connected by desmosomes When die, look scalelike
keratinocytes
10-25 %of cells in deepest epidermis
Produce pigment melanin – packaged into melanosomes
Protect apical surface of keratinocyte nucleus from UV damage
melanocytes
arise from bone marrow
Macrophages – key activators of immune system
dendritic/langerhans
Sensory touch receptors
tactile/merkel
prickly layer Several layers thick Cells contain web-like system of intermediate prekeratin filaments attached to desmosomes Abundant melanosomes and dendritic cells Look like iron spiked balls Mostly keratincytes
stratum spinosum
Thin – three to five cell layers Cell appearance changes Cells flatten Nuclei and organelles disintegrate Keratinization begins Cells accumulate keratohyaline granules Help form keratin in upper layers Cell accumulate lamellar granules Their water-resistant glycolipid slows water loss Cells above this layer die
stratum granulosum
clear layer
Only in thick skin
Thin, translucent band superficial to the stratum granulosum
A few rows of flat, dead keratinocytes
stratum lucidum
20–30 rows of dead, flat, anucleate keratinized membranous sacs
Three-quarters of epidermal thickness
Though dead, its cells have functions of protection
horny layer
corneum
Areolar connective tissue with collagen and elastic fibers and blood vessels Loose tissue Phagocytes can patrol for microorganisms Dermal papillae Superficial peglike projections
papillary layer
~80% of dermal thickness
Dense fibrous connective tissue
Elastic fibers provide stretch-recoil properties
Collagen fibers
reticular layer
Also called sudoriferous glands
All skin surfaces except nipples and parts of external genitalia
~3 million per person
Two main types
sweat glands
Widely distributed
Not in thick skin of palms and soles
Most develop from hair follicles and secrete into hair follicles
Relatively inactive until puberty
Stimulated by hormones, especially androgens
Secrete sebum
sebaceous
oil glands
Most numerous Abundant on palms, soles, and forehead Ducts connect to pores Function in thermoregulation Regulated by sympathetic nervous system Their secretion is sweat(filtration of blood)
eccrine
Confined to axillary and anogenital areas
Sweat + fatty substances + proteins
Viscous; milky or yellowish
Odorless until bacterial interaction body odor
Larger sweat glands
Ducts empty into hair follicles
Begin functioning at puberty
apocrine
functions of integumentary
Protection Body temperature regulation Cutaneous sensation Metabolic functions Blood reservoir Excretion
Least malignant; most common
Stratum basale cells proliferate and slowly invade dermis and hypodermis
Cured by surgical excision in 99% of cases
basal cell carcinoma
Second most common type
Involves keratinocytes of stratum spinosum
Usually scaly reddened papule on scalp, ears, lower lip, and hands
Does metastasize
Good prognosis if treated by radiation therapy or removed surgically
squamous cell carcinoma
Cancer of melanocytes
Most dangerous
Highly metastatic and resistant to chemotherapy
Treated by wide surgical excision accompanied by immunotherapy
Key to survival is early detection – ABCD rule
melanoma
immediate threat of burns is
Dehydration and electrolyte imbalance
Provides support, flexibility, and resilience
Collagen fibers only; most abundant type
Articular, costal, respiratory, nasal cartilage
hyaline cartilage
Similar to hyaline cartilage, but contains elastic fibers
External ear and epiglottis
elastic cartilage
Thick collagen fibers—has great tensile strength
Menisci of knee; vertebral discs
fibrocartilage
Chondrocytes divide and secrete new matrix, expanding cartilage from within
interstitial growth
Cells secrete matrix against external face of existing cartilage
appositional growth
Long axis of body
Skull, vertebral column, rib cage
Protection and support
axial skeleton
Bones of upper and lower limbs
Girdles attaching limbs to axial skeleton
movement
appendicular skeleton
Longer than they are wide
Limb but not wrist or ankle bones
long bones
Cube-shaped bones (in wrist and ankle)
Sesamoid bones (within tendons, e.g., Patella)
Vary in size and number in different individuals
short bones
Thin, flat, slightly curved
Sternum, scapulae, ribs, most skull bones
flat bones
Complicated shapes
Vertebrae, coxal bones
irregular bones
seven functions of bones
Support Protection Movement Mineral and growth factor storage Blood cell formation Triglyceride (fat) storage Hormone production
Bone forms by replacing hyaline cartilage Bones called cartilage
bones
Forms most of skeleton
endochondral ossification
Bone develops from fibrous membrane
Bones called membrane bones
Forms flat bones, e.g. clavicles and cranial
bones
intramembranous ossification
Three functional classifications of joints
synarthroses, amphiarthroses, diarthroses
three structural classifications of joints
fibrous, cartilaginous, synovial
Bones joined by dense fibrous connective tissue
No joint cavity
Most synarthrotic (immovable)
three types
fibrous
three types of fibrous
sutures, syndesmoses, gomphoses
Bones united by cartilage No joint cavity Not highly movable
cartilaginous joints
separated by a joint cavity
diarthrotic
most joints in body
synovial
six features of synovial joints
1 articular cartilage 2 joint cavity 3 articular capsule 4 synovial fluid 5 different ligaments 6 nerves and blood vessels
Sacs lined with synovial membrane
Contain synovial fluid
Reduce friction where ligaments, muscles, skin, tendons, or
bones rub togethe
bursae
Elongated bursa wrapped completely around tendon subjected
to friction
tendon sheaths
three natural factors that stabilize synovial joints
shapes of of articular surfaces (minor role) Ligament number and location (limited role) Muscle tendons that cross joint (most important)
