Unit One- Musculoskeletal Systems; Muscles and Bones You Need to Know Flashcards
Muscle
bundled contractile cells arranged in a parallel fashion
Skeleton
support structure required for movement
3 types of skeleton:
-hydrostatic skeleton
-exoskeleton
-endoskeleton
Sea anemone has a ___ skeleton
hydrostatic
Insects have a ___ made of hardened chitin
exoskeleton
Endoskeleton
-made of cartilage and/or bone
-internal framework that receives the force of muscles to support and move the body
-found in vertebrates (amphibians, reptiles, birds, mammals)
Echinoderms
have endoskeleton located within their dermis consisting of ossicles
What do all vertebrates have?
an endoskeleton
Fins or limbs attach to ____ and ______ ______
pectoral and pelvic girdles
5 Shapes/Types of Bones
-Long
-Short
-Flat
-Irregular
-Sesamoid
How many bones are in the human body?
206
axial skelleton
bones of the skull, vertebral column, ribs, sternum, and hyoid
appendicular skeleton
bones of the pectoral girdle, arms, hands, bones of the pelvic girdle, legs, feet
Functions of Bone
-Movement
-Support
-Protection
-Mineral storage
-Blood cell formation
Functions of Bone: Movement
Bones interact with skeletal muscle and change or maintain the position of the body and its parts
Functions of Bone: Support
Bones support and anchor muscles
Functions of Bone: Protection
Many bones are organized as hard compartments that enclose and protect soft internal organs
Functions of Bone: Mineral Storage
Bones are a reservoir for calcium and phosphorus ions. Deposits and withdrawals of these minerals help maintain essential ion concentrations in body fluids
Functions of Bone: Blood Cell Formation
Only certain bones contain regions where blood cells form
Components of Long Bone Structure
-compact bone
-spongy bone
-bone marrow
Compact Bone Structure
consists of many cylindrical Haversian systems
Osteon
the functional unit of the skeletal system
Types of Bone Marrow
-Yellow marrow
-Red marrow
Yellow marrow
-cavities of adult long bones
-is largely fat
Red marrow
-occurs in spongy bone of some bones
-produces blood cells
In adults, bone building and bone breakdown occurs ______
constantly
osteoblasts
bone forming cell
osteocyte
mature bone cell
osteoclasts
secrete enzymes that degrade bone
Remodeling
adjusts bone strength and helps maintain blood calcium levels
When ____ activity outpaces ______ activity, then bone loss occurs
-osteoclast
-osteoblast
bone density
the measure of mineral composition of bone
Exercise can ___ bone density
increase
osteoporosis
-can decrease bone density
-may occur when the action of osteoclasts outpaces that of osteoblasts
-may also occur as result of inability to absorb calcium or a diet poor in calcium
joints
areas of near contact between bones
3 types of Joints
-Fibrous joints
-Synovial joints
-cartilaginous joints
Fibrous joints
connected by short fibers (soft spot of skull)
Synovial joints
-have ligaments that connect bones
-may have a bursae filled with fluid to lubricate the joint
Knee* and elbow* (hinge joint) have ___
flexion
** type of synovial joint
*hip and *shoulder (ball and socket joints) have ____ _____
rotational movement
**type of synovial joint
Cartilaginous joints
cartilage allows slight movement (ribs, vertebrae)
connective tissues in joint
-tendon
-ligament
tendon
connects muscle to bone
ligament
connects bone to bone
types of joint injuries:
-strain
-sprain
-dislocation
strain
-tearing of a muscle or tendon
-normally results in swelling with bruising
sprain
-tearing of ligaments
-normally only swelling with no bruising
Why don’t sprains result in brusing?
ligaments are largely avascular (no blood vessels)
dislocation
separation of a joint
Arthritis
degenerative disorder with joint inflammation
Osteoarthritis
cartilage ends of the bone wears off due to overuse/genetics
rheumatoid arthritis
synovial membranes inflame and thicken
-cartilage wears and bones deposits in spaces
limiting motion and causing bones to become
“fixed” in position
-autoimmune response in which body attacks itself
-may be genetic, bacterial or viral
-*also affected by smoking
What is muscle?
tissue consisting of fibers arranged in a parallel fashion that can contract to cause directional movement of the body
3 types of muscle
-skeletal
-cardiac
-smooth
How many skeletal muscles in the body?
600
Creatine
as a supplement has been effective in pumping up muscles in controlled studies, may have applications for muscular dystrophy and other muscular disorders; too much strains the kidneys
a muscle is made up of ___ cells
muscle
one single muscle cell=
muscle fiber
each bundle of muscle fibers contains many ___
myofibril
sacromere
the functional unit of the muscular system
where is the sacromere found?
within the myofibril
Neuromuscular Junction
where a motor neuron synapses with a muscle cell
Sarcoplasmic Reticulum
membrane chamber that takes up, stores, and releases calcium
What causes active movement?
a nerve impulse causes calcium to flow out of the sarcoplasmic reticulum to initiate muscular contraction
Relaxation of a muscle causes _____ movement
passive
microfilaments of the sarcomere
-actin/thin filaments
-myosin/thick filaments
actin/thin filaments
like two strands of beads twisted together
myosin/thick filaments
each myosin molecule has a tail and a double head
sliding-filament theory/model
*** also called the Ratchet Theory
actin fibers move over the myosin fibers to cause a contraction
myosin heads attach to ___ filaments
actin
myosin heads tilt toward center, pulling actin ____
inward
even though actin fibers ____, the myosin does the work
slide
only the ____ shortens during a contraction
sacromere
_____ fibers move back
relaxation
Two Types of Contractions
-Isotonic contraction
-Isometric contraction
Isotonic contraction
-movement
-contracted muscle shortens
isometric contraction
-force, no movement
-contracted muscle doesn’t shorten
Origin
where the muscle attaches to the fixed bone of a joint
insertion
where the muscle attaches to the free-moving bone of a joint
belly
thick portion of a muscle
motor unit
motor neuron and attached muscle cells
tension
mechanical force a contracting muscle exerts on a bone-may or may not result in movement (isotonic vs isometric)
twitch
single brief stimulus to a motor unit
cramp
involuntary contraction that resists release
tetanus
continued stimulations of a muscle due to a pathogen
fatigue
declined capacity to generate a force
*due to Glycogen depletion
Calcium is stored in bones but released to bloodstream for:
-nerve function
-muscle contraction
-bone and teeth density
-maintains blood calcium
Vitamin d produced by exposure to UV light:
stimulates absorption of dietary calcium
tetanus is called by the bacterium ____ _____
Clostridium tetani
Occipitofrontalis (front and back)
muscle that covers the frontal portion of the skull
Orbicularis oculi
Masseter
Aponeurosis
Temporalis
Occipitalis
Sternocleidomastoid
Trapezius
Deltoid
Pectoralis major
Pectoralis minor
Intercostal muscles
-serratus anterior
-external oblique
serratus anterior
external oblique
Biceps brachii
Brachioradialis
Rectus abdominus
Thenar (Hypothenar)
Brachioradialus
Triceps bracchii
Latissimus dorsi
Gluteus maximus
Gluteus medius
Biceps femoris (Hamstrings)
Semitendinosus
Gastrocnemius
Sartorius
Gracilis
Pectineus
The Quads:
-Rectus femoris
-Vastus medialis
-Vastus lateralis
Rectus femoris
Vastus medialis
Vastus latealis
Tibialis anterior
Achilles Tendon (Calcaneal)
Mandible
Maxilla
Zygomatic (zygomatic arch)
Skull (frontal, parietal, temporal, occipital) and occipital protuberance
