lecture exam 3 Flashcards
the skeletal system is composed of?
bones and joints
the connective tissue (i.e., bone tissue): matrix composed of collagen fibers and hydroxyapatite ground substance
Bone,
gives strength under tensile forces
Collagen:
: inorganic mineral substance (containing calcium), giving strength under compressive forces
Hydroxyapatite
the organ: composed primarily of bone tissue + other types of connective tissue, as well as nervous and epithelial tissues
Bone,
Function of the skeletal system
A. Provides structure, support, and protection
B. Essential for locomotion and movement
C. Site of blood cell formation (i.e., hematopoiesis)
D. Storehouse for some inorganic minerals, especially calcium
E. Indicator of sex, age, height, weight, geographic ancestry, and (to some extent) medical history
bone shaft; primary center of ossification
Diaphysis:
often associated with area of articulation with another bone or site of strong muscle attachment; secondary center of ossification
Epiphysis:
connecting diaphysis and epiphysis; composed of hyaline cartilage
Epiphyseal plate (aka, disk):
membranes covering outer and inner bone surfaces, respectively
Periosteum and endosteum:
cavity at the center of a long bone
Medullary cavity (aka, marrow cavity):
typically, covering bone where it articulates with other bones; composed of hyaline cartilage
Articular cartilage:
Types of mature bone tissue
- Spongy (aka, cancellous or trabecular) bone
2. Compact (aka, cortical) bone, composed of osteons (aka, Haversian systems)
concentric layers of bone tissue
Lamellae:
, containing blood vessels and nerves
Central (aka, osteonic or Haversian) canal
holes found between lamellae
Lacunae:
passageways connecting lacunae to each other and to the central canal
Canaliculi:
connecting central canals to each other
Perforating (aka, communicating or Volkmann’s) canals:
found underlying articular cartilage, making up facet surface
Subchondral bone:
lay down new bone tissue, located within central canal and within the periosteum (deep layer) and endosteum
Osteoblasts:
destroy bone tissue; large and multinucleated – originate from the fusion of several monocytes
Osteoclasts:
a bone remodels its shape in response to the forces traveling through it
Wolff’s Law:
- Intramembranous (aka, dermal) bones: top of the skull + clavicle
- Endochondral (aka, cartilaginous) bones: bones of skull base + all postcranial bones, including part of clavicle
Types of bones, (bone growth) developmentally
Ontogenetic process in endochondral bone growth
- Process starts with template/model formed of hyaline cartilage
- Cartilage disintegrates and excavates interior of the template; blood vessels invade, bringing undifferentiated connective tissue cells
- Connective tissue cells differentiate into osteoblasts, which start forming spongy bone
- At the same time, the periosteum forms; osteoblasts in the deep layer of the periosteum form compact bone
a. Growth between epiphysis and diaphysis (interstitial growth)
i. Blood vessels invade ends of bone as well, which become secondary ossification centers
ii. Epiphyseal plate: zone of hyaline cartilage remaining between primary and secondary ossification centers, site of active growth
iii. Growth ceases when epiphyseal plate ossifies
Increase in overall size (appositional growth)
i. New compact bone is deposited by osteoblasts just below the periosteum
ii. Osteoclasts at inner bone surface destroy bone tissue and enlarge the medullary cavity (if present); remodel compact bone/spongy bone interface
Ontogenetic process in intramembranous bone growth
- Membrane forms around blood vessels
- Undifferentiated connective tissue cells around blood vessels differentiate into osteoblasts, which start forming spongy bone
- At the same time, the periosteum forms; underlying connective tissue cells differentiate into osteoblasts which start forming compact bone below periosteum
- Remaining growth takes place via process resembling appositional growth
Nutritional and hormonal disorders
a. Vitamin C deficiency leads to scurvy
b. Vitamin D deficiency leads to rickets (in children) and osteomalacia (in adults)
excess of secretion leads to bone tissue thinning and weakening
Parathyroid hormone (PTH):
i. Excess of growth hormone in children leads to gigantism; in adults, to acromegaly
ii. Deficit of growth hormone in children leads to dwarfism
Pituitary growth hormone
Trauma and injury:
fracture
bone broken but skin is not broken
Simple:
bone breaks through the skin
Compound:
bone is fragmented
Comminuted:
bone is compressed or telescopes into itself
Compression:
incomplete fracture + bending of bone, common in children
Greenstick:
tendon or ligament pulls bone away at site of attachment
Avulsion:
Healing of fracture
a. Fracture hematoma formed from ruptured blood vessels
b. Soft callus forms
c. Hard callus forms by mineralization and remodeling of soft callus d. Remodeling of hard callus to mature bone
the reduction in bone density due to deossification, most prevalent in middle-aged and elderly women
Aging: osteoporosis,
articulations are composed of
A. Bones
B. Cartilage: hyaline and/or fibrocartilage
C. Fibrous [aka, dense] connective tissue
articulations are classified by
A. Degree of movement
- Synarthrosis: immovable
- Amphiarthrosis: slightly movable
- Diarthrosis: freely movable
bones fastened together by thin bands of fibrous (i.e., dense regular) connective tissue
Fibrous:
joint consists of broad fibrous band to form interosseous ligament; movement classification = amphiarthrosis
Syndesmosis:
only between flat bones of the skull (sutural ligament); movement classification = synarthrosis
Suture:
articulation between tooth root and bony socket (periodontal ligament); movement classification = synarthrosis
Gomphosis:
: connection consists of hyaline and/or fibrocartilage
Cartilaginous
bones united by a plate of hyaline cartilage; movement classification = synarthrosis
Synchondrosis:
bone articular surfaces covered by hyaline cartilage, which in turn is attached to a thick pad of fibrocartilage; movement classification = amphiarthrosis
Symphysis:
space between articulating bones filled with synovial fluid
Synovial:
Freely movable; movement classification =
diarthrosis
Articular ends of bone covered with thin layer of hyaline cartilage
(i.e., the articular cartilage)
Joint encased in joint (aka, articular)_______
capsule
(aka, fibrous layer/membrane, capsular ligament): thick, fibrous outer layer contiguous with periosteum of bones
Fibrous joint capsule
thin inner layer covering all non-cartilaginous surfaces
Synovial membrane:
secreted by synovial membrane, filling synovial (aka, joint) cavity
Synovial fluid:
fibrocartilage pad located between articular surfaces
Articular disk (e.g., meniscus of knee):
closed fluid-filled sac
Bursa:
globular/spheroidal surface of one bone articulates with a cup-shaped surface of another bone; triaxial
Ball-and-socket (aka, spheroidal):
convex oval-shaped surface of one bone articulates with a concave elliptical surface of another bone; biaxial
Condyloid (aka, ellipsoidal):
articulating surfaces have both concave and convex regions; surface of one bone fits complementary surface of another; biaxial
Saddle (aka, sellar):
articulating surfaces are nearly flat; nonaxial
Gliding (aka, arthrodial):
convex cylindrical surface of one bone articulates with concave cylindrical surface of another; uniaxial
Hinge (aka, ginglymoidal):
cylindrical pin of one bone rotates within a ring formed of bone and ligament; uniaxial
Pivot (aka, trochoidal):
Synovial joint movements
A. Angular
B. Circular
C. Special movements
Movements within a sagittal plane of the body
a. Flexion, extension, and hyperextension
b. Dorsiflexion and plantar flexion: at the talo-crural (ankle) joint only
Movements within a coronal plane of the body
a. Abduction and adduction
movement of body part around its own long axis
Rotation:
________ and _______ at the proximal radio-ulnar joint
Supination and Pronation
movement in which the distal end of the bone moves in a circle while the proximal end remains relatively fixed
Circumduction:
movements of the sole of the foot medially or laterally, respectively
Inversion and eversion:
movement of a body part upwards or downwards, respectively
Elevation and depression:
movement of a body part forward or backward, respectively, parallel to the horizontal surface
Protraction and retraction:
displacement of a bone within a joint; partial (subluxation) or total (luxation)
Dislocation:
overstretching or tearing of connective tissue (primarily, ligaments) associated with a synovial joint
Sprains:
inflammation of a bursa
Bursitis:
a. Autoimmune disease involving synovial joints
b. Characterized by inflammation of the synovial membrane
c. Typically bilateral, affecting small joints of the hands and feet
d. Genetic in nature; relatively early age of onset
Rheumatoid arthritis (RA)
a. Progressive degeneration of synovial joints through ‘wear and tear’
b. More likely to affect high-use joints, large weight-bearing joints, or joints previously involved in acute trauma
c. Relatively late age of onset
d. Often associated with development of accessory bone at periphery of joint facets
Osteoarthritis (OA)
what are the functions of the muscular system
- Movement (movement of body parts, transport of materials)
- Stabilization (body postures, organ function)
- Thermogenesis (predominantly skeletal muscle)
what are the general characteristics of the musicular system
- Possess irritability, contractility, extensibility, and elasticity
- Composed of elongated cells
- Capable of repair/healing, but not necessarily replacement by cell division
3 types of muscles
A. Skeletal (aka, voluntary or striated)
B. Smooth (involuntary and non-striated)
C. Cardiac (involuntary and striated)
Location: somatic/skeletal muscles, upper part of _______ ,________
esophagus, diaphragm
Repair and regeneration: cells cannot ______ , but can be replaced; repair process aided through ________
divide
hypertrophy
Multinucleated (originate through the ______ of several myoblasts)
fusion
A single muscle cell/fiber is surrounded by an ________
endomysium
A bundle of muscle fibers is called a_______ , and is surrounded by a ________
fascicle
perimysium
A group of______ makes up the ______ , and is surrounded by an ________
fascicles
muscle
epimysium
At the ends of the muscle, the _______, _________, and __________ come together to form ______ _____, which attach the _____ __ _______
endomysium, perimysium,
epimysium
muscle tendons
muscle to bone
the cell membrane of a muscle fiber
Sarcolemma:
a continuation of the sarcolemma, extending into the interior of the muscle fiber, surrounding the myofibrils
Transverse tubules (aka, T tubules):
specialized endoplasmic reticulum, forms a tubular network around the myofibrils
Sarcoplasmic reticulum:
large chambers of sarcoplasmic reticulum encircling the myofibril, on either side of the transverse tubule; storage of calcium ions
Cisternae:
unit of a transverse tubule and flanking cisternae encircling a myofibril
Triad:
made up of microfilaments, arranged into sarcomeres
Myofibril:
_____ filaments, made up primarily of the protein ______
Thin, actin
_____ filaments, made up primarily of the protein _____
Thick, myosin
stabilize the position of the thin and thick filaments (structural proteins), or regulate the interactions between the thin and thick filaments (regulatory proteins)
Other proteins:
the functional unit of muscle contraction
Sarcomere:
dark band, primarily made up of thick filaments
A band:
center of the A band, made up of structural proteins holding the thick filaments in place
M line:
lighter zone on either side of the M line, contains only thick filaments
H zone:
overlapping zone of thin and thick filaments
Zone of overlap:
light band, made up entirely of thin filaments
I band:
boundary between two sarcomeres, made up of structural proteins holding the thin filaments in place
Z line:
Sarcolemma is stimulated by signals (i.e., an action potential) from the_____ _______
nervous system
sudden change in electric charge of the cell membrane
Action potential:
Action potential travels through the _____ ______ to the _________
transverse tubules,
myofibrils
Action potential triggers release of calcium ions from the _______, positioned over the ____ __ _______ of the __ ______
cisternae,
zone of overlap
A band
______ _____ cause exposure of binding sites on the ____ _______ of the _____ _____
Calcium ions
actin molecules
thin filaments
______ binds to myosin and causes the _____ _______ to slide past the ____ ________, toward the M line, resulting in ________ of the muscle fiber
Actin
thin filaments
thick filaments
contraction
Muscle contraction _____ when the nervous system signal______
stops
ceases
i. Action potential stops traveling through the transverse tubules
ii. Calcium ions are pumped back into the cisternae
iii. Thin filaments stop sliding toward the M line
iv. Sarcomere returns to resting length under passive stretching of the muscle
contraction stops
primary muscle responsible for specific joint movement
Agonist (aka, prime mover):
muscle which produces opposite action to the agonist
Antagonist:
muscle which assists the agonist
Synergist:
when muscles contract under circumstances where little/no muscle shortening can occur
Isometric:
contractions where muscle fibers change length
Isotonic:
muscle is shortened
Concentric:
overall length of muscle increases during a contraction
Eccentric:
muscle wasting (i.e., decrease in muscle size and/or strength)
Atrophy:
fibers become smaller in diameter and less elastic; healing process slows
Aging:
a painful, involuntary contraction of a muscle or muscles, typically caused by fatigue or strain
cramp
smooth muscles are located?
visceral organs, blood vessels, lower part of esophagus, skin, spleen
smooth muscles have what type of nucleus
single centrally located nucleus
sheets of fibers with numerous connections between fibers; all fibers contract as a single unit
Visceral (single-unit) smooth muscle:
fibers loosely organized; individual cells must be stimulated separately
Multiunit smooth muscle:
smooth muscles repair and regenerate through
hyperplasia, and hypertrophy
cardiac muscles are located?
Location: heart (myocardium layer), roots of great vessels adjoining the heart
cardiac muscle has what type of nucleus?
single centrally located
shape of cardiac muscle
a. Thin/actin and thick/myosin filaments arranged into sarcomeres, which produces a striated appearance
b. Branching cells arranged end to end, with cells interconnected and branching in complex networks
c. Cells connected by intercalated discs which transmit impulses between cells
i. Functional syncytium: stimulation in one part of net causes contraction within whole unit
heart functions in the absence of nervous or hormonal input
Autorhythmicity:
Repair and regeneration of cardiac muscle :
cells cannot divide or be replaced; repair accomplished only through hypertrophy
