ch. 11 Flashcards
name the three muscle tissues we have and what NS does it follow
- skeletal: somatic NS (voluntary)
- cardiac: only in heart ANS) (involuntary)
- smooth muscle: lines our organs on the inside (ANS) (involuntary)
skeletal muscles are attached how on the bone? they are connected by what structure? define
skeletal muscles are attached at two ends and are connected by tendons: strong connective tissue made up of collagen
how can skeletal muscles move a joint (four ways)
they can move by flexing (small angle) or extending (big angle). by either abducting (moving away from body) or adducting (moving toward the body)
what is the origin
the point where the bone is attached to the muscle closest to the body
what is the muscle insertion
the point where the bone is attached to the muscle farthest to the body
muscle movement occurs when
one muscle contracts and one muscle relaxes
what is an antagonistic muscle pair
muscles that move in opposite directions, tricep relaxes and bicep contracts
what is a synergistic muscle
muscles that move in same direction
what is a fascicle?
a connective tissue that holds contractile muscle together to allow flexibility in the muscle
what is a myofiber?
myofiber is a bundle of single skeletal muscle cells
what is the nucleus activity of skeletal muscle cell? how are they innervated?
they have multiple nuclei that came from fusion of cells from development and theyre innervated by one nerve
what are myofibrils
which is a specialized organelle that causes striated look and generates contractile force
what is the sequence of muscle cell anatomy from smallest to biggest
smallest: myofibrils to myofibers to fasicle : biggest
what are the proteins that generate contraction in myofibrils? what are their respective thickness? what is a overlapping of these proteins?
actin are thin filaments while myosin are thick filaments and the overlapping is called a sarcomere
each sarcomeres are bound by what lines? parts of overlapping is called what?
sarcomere is bound by 2 z lines where actin binds to this but myosin is not. the overlapping of actin and myosin filaments are called A band
parts with no actin are called? parts with no myosin are called?
no actin: is called H zone and no myosin: is called I zone
what occurs in the sarcomeres when contraction occurs? what powers this?
thin and think filaments slide across each other bringing the z lines closer together. this is powered by atp by enzyme myosin
actin and myosin are bound by what when contraction occurs?
cross bridge
what are the steps of contractile cycle
- myosin head binds to myosin binding site on actin called a cross bridge formation, atp is bound here
- the power stroke occurs when myosin head moves and pulls the actin chain toward the center and ADP is released
- to release actin from myosin head, a new ATP needs to be present.
- ATP hydrolysis occurs and myosin head is cocked back to start again
what is rigor mortus?
when a power stroke occurs but theres no more ATP to cause the release of the myosin head from actin
what is the troponin-tropomyosin complex? what stimulates it?
a complex that has tropomyosin a protein that blocks all the myosin binding sites on actin. and troponin is another protein that when bound to tropomyosin causes it to expose all the myosin binding sites. It is stimulated by increased levels of Ca2+
what is the neuromuscular joint? what is the NT used here?
NMJ is the synapse between the axon terminus and the myofiber and NT used is ACH
AP in muscle opens what channels? what is depol of the muscle clalled?
it opens calcium channels and the depol is called end plate potential and any small amount of ACH could cause a mini EEP
what structure helps AP’s get into cells?
what is the sarcoplasmic reticulum?
transverse tubules.
SR has special smooth ER that holds Ca2+ for AP
the smallest contraction is called? NS can increase force of contraction by?
the smallest contraction is a twitch. NS can increase force by 1. motor unit recruitment and 2. frequency summation
motor unit recruitment
a motor unit is a group of myofibers. NS can innervate many motor units to active them to increase force on contraction.
frequency summation
adding fast contractions since it doesnt allow calcium levels to go down and cause more contraction force
what are the muscle fiber types?
- Slow twitch (red slow)
- Type IIa (intermediate/oxidative)
- Type IIb
Slow twitch/red slow characteristics
speed is slow. force is low. has many mitochondria. very good blood flow. and has very high fatigue resistance (hours)
Type iia characteristics
speed is medium. force is medium. has some mitochondria. medium blood flow. medium fatigue resistance (30 mins)
type iib characteristics
speed: very fast. force is high. mito: very few. low blood flow. and low fatigue resistance (1 min)
what are the similarities of cardiac and skeletal muscle cells
- also has sarcomeres that causes striated look
- T-tubules present
- uses troponin-tropomyosin complex
- also has long and short segments
what are the difference of cardiac and skeletal muscle cells
- cardiac cells have one nucleus and skeletal have multiple
- cardiac cells have gap junctions
- cardiac calcium source is extracellular while Skeletal source is intracellular
- cardiac is controlled by ANS
- Ap in cardiac needs sodium and calcium channels which cause longer depol
what are the similarities of smooth muscle and skeletal muscle cells
- contraction is done by actin and myosin
- triggered by influx of ca2+
- they dont branch out
what are the difference of smooth and skeletal muscle cells
- smooth is shorter and narrow
- t tubules are not present
- not striated
- smooth has one nucleus and gap junctions
- troponin isnt used while calmodulin is used
- smooth uses extra cell calcium
- AP varies on location of smooth muscle
- long contractions by ANS
- constant fluctuation of RMP
what is calmodulin and myosin light chain kinase?
the regulation of contraction where calmodulin binds calcium and causes phosphorylation of myosin to cause contraction (MLCK),like troponin tropomyosin complex but for smooth muscle, doesnt use troponin but uses calmodulin
vertebrates have what kind of skeleton? what does it do?
endoskeleton that supports body, frames movement, protects organs, and provides calcium
the endoskeleton is divided into
axial: skull, vertebral column, and rib cage
appendicular: everything else
bone is what kind of tissue? where do these cells come from
they are connective tissue and come from fibroblasts that make collagen and elastin
what other cells come from fibroblasts
adipocytes (fat), chondrocytes (cartilage) and osteocytes (bone cells)
connective tissue is made up of
extracellular material called the matrix with some cells scatter around and ground substances
there are two types of connective tissue, define them
loose connective tissue: includes fat cells and packing tissue
dense connective tissue: tissues with large amount of fibers like tendons, ligaments, and bone
what tissues hold two bones together
ligaments
what are the two bone shapes? name the shaft of the bone and the ends of the bone.
theres flat bones (skull, ribs) and long bones (leg and arm bones). the shaft is called diaphysis and ends is called epiphysis
bones can be what two things? define them
compact (dense) or spongy: always surrounded by a compact bone
what is bone marrow? what are the two types? define them
bone marrow is non bony material found inside of diaphysis of compact bones and in pores of spongy bones. there red marrow that makes RBC and yellow marrow made of fat
what is inside anatomy of spongy bone?
they have spikes of bone within called spicules of trabeculae
what is inside anatomy of compact bone?
base unit is called osteons that has a osteon hole/canal that holds blood, nerves, and lymph. surrounding the canal is lamellae.
what are the central space inside the osteon canels?
they are launae where osteocytes or mature bone cells exists.
cartilage is made up of what cells? name the three types?
made up of chondrocytes. the three are hyaline, elastic, and fibrous
hyaline cartilage
strong and somewhat flexible found in trachea and larynx
elastic cartilage
found in outer ear and other places that need support and more flexible
fibrous cartilage
very rigid and found in places where very strong support is needed
what is the blood flow into cartilage
they do not have blood therefore takes longer to heal
movable joints have what fluid in between
synovial fluid
what are the three joints of ligaments
immovable (points where bones fused), slight moveable, and freely moveable
most bone growth occurs by? how
endochondral ossification where hyaline cartilage is made and replaced by bone
kids have what kind of plate?
epiphyseal plate made of hyaline cartilage in between diaphysis and epiphysis and once we become adults, this plate causes fusion of the bones called epiphyseal line
bone doesnt elongate what occurs?
they are remade in remodeling
osteoblast function
laydown collagen until its surrounded by bone
osteocyte function
after osteoblast lay down cartilage, it turns into mature bone cell or osteocyte
osteoclast function
destroys bone to start remodeling
PTH causes what to
stimulates osteoclast activity where kidneys and intestines absorb ca2+
Promotes remodeling
calcitriol causes what to bone
may stimulate osteoclasts but minor. kidneys reabsorb Po2- and intestines still absorb calcium
calcitonin causes what to bone
inhibits osteoclast activity and kidneys decrease calcium absorption
