Study Guide - Lecture Test 2 Flashcards
Location & function of Chondrocytes
Mature cartilage cells found within small space called lacunae
Maintain matrix
Location & function of Chondroblast
Produce matrix cartilage
Become chondrocytes when completely surrounded by matrix
Location & function of Osteoprogenitor cells
Found in the endosteum, inner layer of periosteum, central canals
Differentiate into osteoblasts
Location & function of Osteoblast
Bone forming cells
Line endosteum and inner layer of periosteum
Add to bone matrix
Location & function of Osteocyte
Mature bone cells
Located in lacunae
Maintain bone matrix
Location & function of Osteoclast
Bone dissolving microphages
Remove bone matrix
Functions of bones
Support
Protection
Movement
Hemopoiesis
Storage of minerals and energy reserves
Structure of long bones
Diaphysis
-elongated, cylindrical shaft
-walls composed of compact bone
-provides leverage and weight support
Epiphysis
-expanded end
-spongy bone tissue surrounded by thin layer of compact bone
-attachment for ligaments and tendons
Metaphysis
-region between epiphysis and diaphysis
-contains epiphyseal plate/line
Medullary cavity
-central cavity of diaphysis
-filled with yellow bone marrow
Endosteum
-covers internal surfaces of bone
Epiphyseal plate
-growth plate
-becomes epiphyseal line when ossified
Articular cartilage
-hyaline cartilage
-provides smooth surface for joint
Periosteum
-fibrous connective tissue covering outer bone surface
Nutrient foramen
-allows blood vessels, nerves and lymphatic vessels to enter/leave bone
What is the main inorganic material in bone matrix?
Hydroxyapatite
What is the main protein in bone matrix?
Collagen
What is the structural unit of spongy bone? Compact bone?
Spongy bone - trabeculae
Compact bone - osteon
Structure of the Osteon
Central Canal
-carries nerves/blood vessels
Lamellae
-concentric rings of bone matrix surrounding central canal
Osteocytes
-within lacunae between adjacent lamellae
Canaliculi
-small canals between lacunae
-nutrients diffuse from central canal through canaliculi to surrounding osteocytes
Perforating Canals
-transverse passages
-contain blood vessels and nerves
Circumferential lamellae
-rings of bone just internal to periosteum or endosteum
Interstitial lamellae
-leftover parts of osteons that have been partially reabsorbed
Describe how blood vessels enter bone and reach medullary cavity
Enters the bone through nutrient foramen
Via perforating and central canals to medullary cavity
Where is yellow marrow found in adult bones? Where is red marrow located?
Yellow bone marrow
- medullary cavity
Red bone marrow in children
-spongy bone and medullary cavity
Red bone marrow in adults
-flat bones of the skull, vertebrae, ribs, sternum, hip bones
Name and describe the 2 types of bone formation (ossification).
Intramembranous Ossification
-produces flat bones of skull and clavicle
-begins as a fibrous sheet
Endochondral Ossification
-bone develops from hyaline cartilage
-six weeks fetal development to early 20s
-most bones develop this way
What is the difference between appositional growth, interstitial growth and bone
remodeling?
Appositional growth
-bone widening and thickening
Interstitial growth
-bone elongation
-occurs at epiphyseal plate
Remodeling
-reshaping of bones due to mechanical stress
-absorption of old bone and deposition of new bone
What are the actions of calcitonin and parathyroid hormones?
Calcitonin
-secreted by Thyroid gland
-stimulates osteoblast activity
-decreases blood Calcium
Parathyroid hormone
-stimulates bone reabsorption by osteoclasts
-increases blood Calcium
What is the difference between pathological and stress fractures?
Pathological
-due to weakening of the bone causes by disease or osteoporosis
Stress
-caused by abnormal trauma to the bone
Be able to identify a bone as part of the axial or appendicular skeleton. Be careful
about the scapula, clavicle, hyoid and coxal bones.
Axial
-skull
-vertebral column
-thoracic cage
-hyoid
Appnedicular
-pectoral girdle
-pelvic girdle
-scapula
-clavicle
-coxal bones
-upper and lower extremities
How many bones in typical adult?
206
Know how many bones in each region particularly # facial bones, # cranial bones, #
vertebrae in adult (total and by region), # vertebrae in child (total and by location).
Axial
-80 bones
Appendicular
-126 bones
Skull
-8 cranial
-14 facial
Vertebral Column - child
-33 total
-7 cervicle
-12 thoracic
-5 lumbar
-5 sacral
-4 coccygeal
Verterbral column - adult
-26 total
-1 sacrum
-1 coccyx
Know location of cranial bones and bones of orbit. Examples: Which bones form the
skull cap or the floor of the cranium? Which bones form the medial wall of the orbit?
Cranial bones - roof
-squamous part of frontal bone
-parietal bones
-squamous part of occipital bone
Cranial bones - floor
-ethmoid, sphenoid, occipital and temporal
Orbit bones - medial wall
-maxilla, lacrimal bone, ethmoid
Orbit bones - lateral wall
-zygomatic bone, sphenoid bone, frontal bone
Location/functions of paranasal sinuses
Located within frontal, sphenoid, ethmoid and maxillary bones
Reduce weight of skull
Resonate voice
What are fontanels? Functions?
Connective tissue membranes that cover the gaps between developing cranial bones
Permits molding during birth and accomodates rapid growth of brain
Ossification complete by 18-24 months
Unique feature of hyoid?
Does not articulate with any other bone
Normal and abnormal curvatures
Normal
-Thoracic and pelvic curvature, present at birth
-Cervical and lumbar, develop after birth
Abnormal
-Scoliosis: abnormal lateral curvature
-Kyphosis: abnormal posterior thoracic curvature
-Lordosis: abnormal anterior lumbar curvature
Know unique features of each type vertebrae; difference between vertebral foramen and intervertebral foramen
Intervertebral foramen - between two vertebra. Allows nerves to exit/enter vertebral canal
Vertebral foramen - forms canal
Intervertebral discs - shock absorbers
Cervical vertabrae
-Transvere foramen
-Atlas
-Axis
Thoracic vertebrae
-Costal facets
-Spinous process is relatively pointed
-Giraffe head
Lumbar vertebrae
-Thick body
-Blunt spinous process
-Moose head
Sacrum
-5 fused vertebrae
-Being fusing around age 16, completed by 26
-Articulates with hip bones
Coccyx
-4 fused vertebrae
Differences between types of ribs.
True ribs
-first 7 pairs
-connect to sternum via costal cartilage
False ribs
-pairs 8-12
-indrect attachment
Floating ribs
-pairs 11 and 12
-do not attach to sternum
Joints of pectoral girdle. What joint attaches upper extremity to axial skeleton?
Sternoclavicular joint
-medial end of clavicle with sternum
-attaches upper limb to axial skeleton
Acromioclavicular joint
-later end of clavicle with scapula
Glenohumeral joint
-scapula with humerus
How many bones in each region of upper and lower extremities? (# carpal,
metacarpal, tarsal, metatarsal bones, phalanges – thumb/big toe?)
Upper: 30
-Humerus, radius, and ulna
-Carpal, 8 bones
-Manus, 19 bones
-Metacarpal, 5 bones
-Phalanges, 14 bones
Lower: 30
-Femur, patella, tibia and fibula
-Tarsal, 7 bones
-Pes, 19 bones
-Metatarsal, 5 bones
-Phalanges, 14 bones
Pelvic girdle – bones that fuse together, inlet, outlet, difference between male and
female.
3 fused bones - ilium, ischium, pubis
Inlet - opening circumscribed by pelvic brim
Outlet - inferior opening bounded by coccyx. ischial tuberosity, and inferior border
Female - wider; shallower. Larger pevlic inlet and oulet
Male - narrower; deeper. Smaller pelvic inlet and outlet
Describe polydactyly, syndactyly and clubfoot
Polydactyly - extra finger or toes
Syndactyly - webbed digits
Clubfoot - feet are adducted and planter flexed with soles turned medially
Name/location of carpal bones
trapzium, trapezoid, capitate, hamate, scaphoid, lunate, triquetrum, pisiform
Name/location of tarsal bones
calcaneus, talus, navicular, cuboid, medial cuneiform, intermediate cuneiform, lateral cuneiform
Functional classification of joints
Synarthrosis - little or no movement at joint
Amphiarthrosis - slightly movable
Diathrosis - freely moveable
Structural classification of joints
Fibrous joint - bones held together by fibrous connective tissue
Cartilaginous joint - bones joined by cartilage
Synovial joint - fluid-filled joint cavity separates cartilage-covered articulating surfaces
Description/ location of different types of fibrous joints
Gomphoses
-tooth to socket
-held in place by periodontal membrane
-some movement due to stress of chewing
Sutures
-immobile fibrous joint
-interlocking irregular edges of bone held together by short collagen fibers of dense regular connective tissue
-joints may ossify
-between bones of skull
Syndesmoses
-amphiarthroses
-long collagen fibers of dense regular connective tissue bind two bones
-interosseous ligaments
-radius/ulna
-tibia/fibula
Description/ location of different types of cartilaginous joints
Synchondrosis
-synarthroses
-hyaline cartilage between bone elements
-epiphyseal plate
-first rib/sternum
Symphyses
-amphiarthroses
-fibrocartilage between bone resists compression and tension; acts as shock absorber
-pubic symphisys, intervertebral discs
What is unique about synovial joints? Describe main features of a typical synovial
joint
ALL diarthrodial joints
Articular capsule
Joint cavity
Synovial fluid
Articular cartilage
Ligaments
Tendons
Fat pads
Bursa
Fibrocartiage pads
Describe the 6 types of synovial joints
Plane
-articulating surfaces flat
-uniaxial joint: side to side movement
-between carpal or tarsal bones
Hinge
-convex surface of one bone fits into concave depression on another bone
-uniaxial joint: flexion/extension
-knee, elbow, interphalangeal joints
Pivot
-rounded surface of one bone fits into a ring formed by a ligament and another bone
-uniaxial joint: rotation
-between axis and atlas
Condylar
-oval, convex surface on one bone articulates with concave surface of second bone
-biaxial joint: flexion/extension, abduction/adduction
-metacarpophalangeal joints (fingers 2-5)
Saddle
-articulating surfaces have both concave and convex regions
-multiaxial
-carpometacarpal joint of thumb
Ball-and-Socket
-spherical articulating head of one bone fits into rounded cup of second bone
-multiaxial joint: 3 axes; mostly freely moveable
-glenohumeral joint; hip joint
Unique features/location of temporomandibular joint, glenohumeral joint, hip joint,
knee joint and ankle joint
Temporomandibular joint
-articular disc: allows TMJ to be both a hinge joint and gliding joint
Glenohumeral joint
-most freely moveable joint
-supported by tendons on all side by anterior
Hip joint
-round ligament
Knee joint
-most complex joint
-cruciate ligements - limit anterior/posterior movements
-menisci - stabilize medially and laterally
Ankle joint
-2 joints in one capsule
-tibia and talus
-fibula and talus
Connective tissue associated with fibers, fascicles and muscle
Endomysium
-surround individual muscle fibers
Perimysium
-bundles muscle fibers into fascicles
Epimysium
-fibrous sheath that surrounds entire muscle
Define tendon, aponeurosis, origin and insert.
Tendon - usually thick, cordlike structure that attaches muscle to bone
Aponeurosis - thin, flat tendon sheet
Origin (older term) - muscle attachment on less moveable bone
Insertion (new term) - muscle attachment on move moveable bone
Structure of thin filament
Thin filament
-actin - binding site for myosin
-tropomyosin - covers the active sites on actin, preventing myosin from biding to actin
-troponin complex - calcium binding site, allows myosin to bind to actin
Structure of thick filament
-composed of several hundred myosin
-during contraction myosin heads bind to actin and form crossbridges
Structure of A band and I band
A band (darker)
-length of thick filament
-contains entire thick filament and some of the thin filament
I band (lighter)
-contains only portions of thin filament
Which proteins are contractile proteins; which are regulatory proteins?
Regulartory - tropomyosin and troponin complex
Contractile - myosin and actin
Functions of sarcoplasmic reticulum (SR), t-tubules, mitochondria
SR
-surrounds myofibrils, stores Calcium
T-Tubules
-quickly transports a muscle impulse from the sarcolemma throughout the entire muscle fiber
Mitochondria
-produce ATP
Describe the structure of the neuromuscular junction and general function of each
part, as appropriate. What occurs here?
Motor nuerons
-skeletal muscle fibers are innervated by somatic motor neurons
Synaptic knob
-enlargement at axon terminal
-contains synaptic vesicles filled with ACh
Motor-end Plate
-folds of sarcolemma directly beneath the synaptic knob
-contains receptors for ACh
-contains AChE
Synaptic cleft
-narrow space between synaptic knob and junction folds
Schwann cell
-covers NMJ; isolates from surrounding fluids
What neurotransmitter is released by motor neuron?
Acetylcholine (ACh)
What part of the peripheral nervous system innervates skeletal muscle fibers?
Somatic Nervous System
What is a motor unit? What muscles might have small innervation ratios (size of
motor unit); which might have large innervation ratios (motor units)?
Motor unit - single motor neuron and all the muscle fibers it controls
Small innevation ratios
-eyes
Large innevation ratios
-biceps brachii
What is the function of Ca+2?
To bind to troponin so binding sites on actin are exposed
What needs to happen for a muscle to relax?
-motor neuron stops releasing ACh
-stimulation of muscle fiber stops
-Calcium ion is pumped back into SR
-troponin-tropomyosin move back into a position to cover myosin binding site
-actin-myosin no longer interact
Differences between isotonic, isometric, eccentric and concentric contractions
Isotonic - tension generated is equal or greater than the resistance
Concentric - muscle actively shortens during contraction
Eccentric - muscle actively lengthens during contraction
Isometric - length of muscle does not change
Atrophy verses hypertrophy
Atrophy
-wasting of tissue that results in reduction in muscle size, tone, and power
Hypertrophy
-increase in muscle size due to increase in number of myofibrils within each fiber
Define agonist, antagonist, prime mover, and synergist
Agonist
-prime mover
-produces main force of action
Antagonist
-opposes prime mover
-antagonistic pair - act on opposite sides of joint
Synergist
-aids prime mover
-stabilizes join
Review structure of skeletal, cardiac and smooth muscle tissues
Skeletal
-multinucleated
-striated
-voluntary
-abundant SR
-extensive t-tubules
-sacromeres
Smooth
-single nucleus
-no striations
-almost no SR
-no t-tubules
-no sacromeres
-involuntary
Cardiac
-single nucleus
-striated
-intercalated discs
-moderate SR
-extensive t-tubules
-sacromeres
-involuntary
What muscle make up the rotator cuff? hamstrings? quadriceps femoris?
Rotator cuff
-supraspinatus, infraspinatus, teres minor, subscapularis
Hamstrings
-biceps femoris, semitendinosus, semimembranous
Quadriceps Femoris
-rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
Function of rotator cuff muscles?
Help stabalize the shoulder
Events at the NMJ
- Nerve signal arrives at the synaptic knob.
- Synaptic vesicles release ACh.
- ACH diffuses across the synaptic cleft
- ACh binds to its receptor on the motor-end plate.
- ACh-R binding initiates an action potential on the sarcolemma.
Steps of excitation-contraction cycle
Steps of excitation-contraction cycle
1. Action Potential travels along sarcolemma and down t-tubules
2. SR releases Ca+2 into cytoplasm
3. Ca+2 binds to troponin and the troponin-tropomyosin complex shifts position
exposing the myosin binding site on actin
4. Myosin binds to actin
5. Pi is released from myosin head
6. Myosin flexes, pulling thin filament toward center of sarcomere
7. ADP is released from myosin head
8. ATP bind to myosin head and it detaches from actin
9. ATP is hydrolyzed to ADP and Pi and myosin head “recocks”
10.Myosin head binds to next actin
11.Cross-bridge cycling continues as long as Ca+2 is present
