muscloskeletal system Flashcards
types of skeletal system
hydrostatic, exoskeletal, endoskeleton
coelom
fluid-filled compartment within the body
under hydrostatic pressure because of the fluid and supports other organs
what animals is coelom found in
soft-bodied animals like anemones, earthworms, cnidaria and other invertebrates
what do hydrostatic skeletal systems have
coelom
exoskeleton
external skeleton that supports the body, provides defense against predators, and allows for movement through the contraction of attached muscles
what percentage of chitin do exoskeletons have
30-50%
endoskeleton
internal skeleton; consists of hard, mineralized structures
what are the functions of the endoskeleton
provides support
stores minerals and fats
produces blood cells
protects internal organs
allows for movement through contraction of muscles attached to the skeleton
how many bones does the human skeletal system have and what is it separated into
206; axial skeleton and appendicular skeleton
human axial skeleton
bones of the skull, ossicles of the middle ear, hyoid bone, vertebral column and rib cage
what are the bones of the skull
mandible, maxilla, lacrimal, nasal, ethmoid, sphenoid, frontal, parietal, occipital, zygomatic
what are the cranial bones
frontal, parietal and sphenoid
what are the facial bones
orbit, temporal, lacrimal, palatine, zygomatic, nasal, vomer, maxilla, and mandible
what does the vertebral column consist of
seven cervical vertebrates
twelve thoracic vertebrate
five lumbar vertebrae
sacrum
coccyx
intervertebral discs
-fibrocartilage cushions impacts
- bind vertebrate together
spinal curves increase strength and flexibility of the spine
thoracic cage
rib cage protects the heart and the lungs
ribs- 12 pairs
sternum-3 fused bones
thoracic vertebrae-12
costal cartilages-10 pairs
appendicular skeleton
composed of a pectoral girdle, pectoral limbs, pelvic girdle, and pelvic limbs
pectoral girdle
shoulders
to adapt to reproductive fitness, female compared to male pelvis is lighter, wider, shallower
has a broader angle between the pubic bones
pectoral limbs
arm, forearm, and hand
pelvic girdle
hips
pelvic limbs
thigh, leg, foot
shoulders
pelvic girdle consists of clavicles and scapulae
which forms and stabilizes shoulder joint and allows for movement of arms
upper limbs
conssits of humerus, radius, ulna, carpals(8 bones), metacarpals(5 bones), phalanges(14 bones)
pelvic girdle composition
coxal bones, pubic symphysis and sacrum
coxal bones
illium, ischium, and pubis
lower limbs consist of
femur, patella, tibia, fibula, tarsals(7bones), metatarsals(5bones), and phalanges(14 bones)
what are the types of bones
long bone
short bone - cube-like, ankles and wrists, sesamoid (bones embedded in tendon
flat bone - spongy bone embedded within parallel layers of thin compact bone
irregular bone- vertebrae and hip bones, complicated shapes
long bone
longer than wide and bones of limbs
has diaphysis and epiphyses
diaphysis
in long bone
shaft
compact bone
contains bone marrow in the marrow cavity
epiphyses
in the long bone
articulating ends
spongy bone
covered by articular cartilage
compact bone
elongated cylinders parallel to bone long axis
lamella and central (haversian canal)
perpendicular canals(perforating or volkmanns)
lacunae
canaliculi
lamella
concentric rings
adjacent lamella have collagen in opposite direction
central(haversian) canal
core of osteon
blood vessels and nerve
perpendicular canals perforating or volkmanns
connect periosteum to central and medullary cavities
blood supply and nerve
lacunae
cavities containing osteocytes
canaliculi
connect lacunae to each other and central canal
spongy bone
trabeculae
trabeculae
needle-like(flat0 pieces
less organized than structures of compact bone
- no osteon
- organization is based on lines of stress
- lamella and osteocytes are irregularly organized
osteogenic cells
also called osteoprogenitor cells
motically active stem cells in periosteum and endosteum
when stimulated differentiate into osteoblasts or bone lining cells
osteoblasts
bone forming cells
secret unmineralized bone matrix or osteoid
actively mitotic
osteocytes
mature bone cells in lacunae
monitor and maintain bone matrix
act as stress or strain sensors
- respond to and communicated mechanical stimuli so bone remodeling can occur
- stimulate osteoblast to rebuild bone and osteoclasts to destroy bone
osteoclasts
giant, multinucleate cells for bone resorption
ruffled border increases surface area for enzyme degradation of bone
two types of ossification
intramembranous ossification
- bone develops in between fibrous membranes and produces flat bones of the skill, some facial bones, mandible, most of clavicle
endochondral ossification
- bone forms by replacing hyaline cartilage
endochondral- within cartilage
forms the rest of the skeleton
intramembranous ossification
ossification centers appear in the fibrous connective tissue membrane
- central mesenchymal cells cluster
- differentiate into osteoblasts
- form an ossification center that secretes osteoid
osteoid undergoes calcification
- osteoid calcifies in a few days
- trapped osteoblasts become osteocytes
woven bone and periosteum form
- osteoid forms between embryonic blood vessels to create a network of trabeculae called woven bone
- vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum
lamellar bone replaces woven bones, just deep to the periosteum. red marrow appears
- trabeculae just deep to the periosteum thicken. mature lamellar bone replaces them, forming compact bone plates
- spongy bone consisting of distinct trabeculae, persists internally and its vascular tissue becomes red marrow
endochondral ossification
forms most all bones inferior to base of skull except clavicles
uses hyaline cartilage models
requires breakdown of hyaline cartilage prior to ossifcation
fracture repair
healing takes a few months or more and occurs in a series of steps
a fracture hematoma forms
a fibrocartilaginous (soft) callus forms
a bony(hard) callus forms
the bone is remodeled
what are the three types of joints
fibrous, cartilaginous joints , synovial joints
fibrous joints
bones joined by dense fibrous connective tissue
no joint cavity
most synarthrotic(immovable)
depends on length of connective tissue fibers
type of connective tissues
gomphosis
sutures
syndesmoses
cartilaginous joints and what are the types
bones that are connected by cartilage
synchondrosis , symphyses
cartilaginous joints; synchondrosis
bones are joined by hyaline cartilage
found in the epiphyseal plates of growing bones in children
cartilaginous joints; symphyses
connection between bones occurs through fibrocartilage
found at the joints between vertebrae
very little movement
synovial joints
only joints that have a space or synovial cavity in the joint
cavity is filled with synovial fluid which lubricated the joints
what are the types of synovial joints
planar - carpal bones in the wrist
hinge- elbow joint where the radius articulates with the humerous
pivot- joint in the neck
condyloid- metacarpophalangeal joints in the finger
saddle- carpometacarpal joints in the thumb
ball- and- socket - the shoulder joint
what is the purpose of the muscoskeletal system
cause or control movement;
support– maintain an upright posture
allow movement - body transport, manipulate objects
protect
types of muscular tissue
skeletal muscle
cardiac
smooth
skeletal muscle tissue
found in skeletal muscle
voluntary
cardiac muscle tissue
found in walls of heart
involuntary
smooth muscle tissue
mainly in walls of hallow organs other than heart
involuntary
smooth muscle tissue
mainly in walls of hallow organs other than heart
involuntary
skeletal muscle fiber
plasma membrane called the sarcolemma
cytoplasm called the sarcoplasm
composed of many fibrils, packaged into orderly units
sacromere
a sarcomere is a regsarcomeresion from one Z line to the next Z line
many sacromeres are present in a myofibril, resulting in the striation pattern characteristic of skeletal muscle
sliding filament model of contraction
when a sarcomere contracts, the Z lines move closer together and the I bands gets smaller
the A band stays the same width and, at full contraction, the thin filaments overlap
