Anatomy and Physiology Lecture Exam 10-12

Muscle tissue, muscular system, and nervous tissue

What are the three types of muscles

Skeletal, cardiac, and smooth

move the body by pulling on bones

skeletal muscle

pumps blood through the cardiovascular system

Cardiac muscle

pushes fluids and solids through internal passageways and organs

smooth muscle

What are four common property’s of muscle tissue

excitability, contractility, extensibility, and elasticity

ability to receive and respond to stimuli

excitability(responsiveness)

ability of cells to shorten

contractility

ability of the muscle to stretch

extensibility

ability of muscle to recoil to its resting length

elasticity

what are the three layers of connective tissue

epimysium, perimysium. endomysium

layer of collagen fibers that surrounds the entire muscle and separates it from surrounding tissue

epimysium

surrounds individual fascicles

perimysium

surrounds individual muscle cells and loosely interconnects them

endomysium

what attaches skeletal muscles to bones

tendons or aponeuroses

develop by fusion of embryonic cells called what

myoblasts

the plasma membrane of a muscle fiber

sarcolemma

what surrounds the sarcoplasm (cytoplasm of a muscle fiber)

sarcolemma

narrow tubes continuous with the sarcolemma, which extend from the surface of the muscle fiber deep into the sarcoplasm

transverse tubules (T tubules)

a tubular network similar to the smooth endoplasmic reticulum

sarcoplasmic reticulum (SR)

What forms chambers that attach to t tubules

terminal cisternae

two terminal cisternae plus a t tubule form a what

triad

organized collections of myofilaments that are responsible for muscle contraction

myofibrils

bundles of contractile protein filaments

myofilaments

what are the two types of myofilaments

thin filaments- composed primarily of actin

thick filaments- composed primarily of myosin

repeating structural and functional units of a myofibril

sarcomeres

what are the smallest contractile unit of the muscle fiber

sarcomeres

what are the bands of the sarcomere

z lines and titin

mark the boundaries between adjacent sarcomeres

z lines

elastic protein which extends from the tips of thick filaments to the z line

titin

what acts as a molecular spring to recoil and return the sarcomere to its resting length

titin

what do thin filaments contain

tropomyosin and troponin

covers the active sites on G actin and precents actin myosin interaction

tropomyosin

a globular protein that holds tropomyosin in place and binds to calcium ions

troponin

thick filament myosin molecules consist of what

tail- binds to other myosin molecules

head- made of two globular protein subunits

during a contraction the thin filaments slide toward the center of the sarcomere alongside the thick filaments

sliding filament theory

the membrane potential becomes less negative due to influx of sodium ions

depolarization

the membrane potential becomes more negative due to outflow of potassium ions

hyperpolarization

return to the resting membrane potential after depolarization

repolarization

neurons and muscle cells have electrically excitable membranes and can produce electrical impulses called what that can propagate along the plasma membrane

action potentials

the synapse between a motor neuron and a skeletal muscle fiber

neuromuscular junction (NMJ)

skeletal muscle will only contract if they are stimulated by motor neurons

true

expanded end of the axons of the motor neuron

axon terminal

the folded membrane of the skeletal muscle fiber at the NMJ

motor end plate

narrow space between the axon terminal and the motor end plate

synaptic cleft

a chemical released from the axon terminal into the synaptic cleft

neurotransmitter

the neurotransmitter at the NMJ

acetylcholine

the link between the generation of an action potential in the sarcolemma and the start of muscle contraction

excitation contraction coupling

a series of molecular events that enable muscle contraction

contraction cycle

how the myosin heads bind to the action sites

cross bridges

the myosin head uses energy from ATP to pivot and pull on active towards the M line

power stroke

muscle stiffens after death resulting from a muscle being locked in a contracted position

rigor mortis

a motor neuron and all the muscle fibers it controls

motor unit

involuntary muscle twitch which is caused by the synchronous contraction of one motor unit

fasciculation

increase in muscle tension due to the increase of active motor units

recruitment

relay approach in which some motor units are contracting, and some are resting and recovering

motor unit summation

anaerobic metabolism that breaks down glucose to pyrocitrate in the cytosol

glycolysis

oxygen dependent process in which mitochondria use organic substrates to produce ATP

aerobic metabolism

the time required for muscles to return to pre-exertion conditions

recovery period

the amount of oxygen required to restore normal pre-exertion conditions

Oxygen debt or excess postexercise oxygen consumption (E P O C)

found around other tissues and internal organs

smooth muscle tissue

arrector pill muscles erect hairs

integumentary system

smooth muscle around blood vessels and airways regulates blood pressure and airflow

cardiovascular and respiratory systems

smooth muscle moves materials along and out of the body and forms sphincters

digestive and urinary system

smooth muscles help transport gametes and are responsible for delivery of fetus

reproductive system

no t tubules myofibrils or sarcomeres

nonstriated muscle

thin filaments attach to what

dense bodies

skeletal muscle fibers form bundles called what

fascicles

muscles are classified based on pattern of fascicle arrangements

°Parallel muscles

°Convergent muscles

°Pennate muscles

°Circular muscles

fascicles are parallel to the long axis of muscle

parallel muscles (ex. rectus abdominus)

muscle fascicles spread in a broad area on one side and converge on an attachment site on the other

convergent muscles (ex. pectoralis muscles)

the fascicles form a common angle with the tenson

pennate muscles

types of pennate muscles

°Unipennate – all fascicles on same side of tendon

Example: extensor digitorum

°Bipennate – fascicles on both sides of a central tendon

Example: rectus femoris

°Multipennate – the tendon branches within the muscle

Example: deltoid

the fascicles are concentrically arranged around an opening

circular muscles (sphincters) (ex. orbicularis oris of the mouth)

rigid structure that moves on a fixed point called fulcrum (F)

lever

a lever moves when muscles provide a pressure called what to overcome a load

applied force

bones act as levers and joint are fulcrums and muscles provide the applied force

true

fixed (less movable) point of attachment of a muscle to a bone

origin

more movable point of attachment of a muscle to a bone

insertion

specific movement produced by the contraction of a muscle

action

muscles work in groups to maximize efficiency

muscle interactions

what are the four functional types of muscles

agonist, antagonist, synergist, and fixator

the main muscle responsible for producing a particular movement

agonist (prime mover)

opposes the movement of the agonist

antagonist

a smaller muscle that assists an agonist

synergist

a synergist that assists an agonist by precenting movement at another joint

fixator

agonist and antagonist work in pairs

true, when one contracts the other stretches (ex. flexors - extensors and abductors-adductors)

names of muscles include descriptive information about what 

°the region of the body (e.g., temporalis)

°the position, direction, or fascicle arrangement

°the structural characteristics

°the action

muscles visible at body surface

externus

deeper muscles

internus

superficial muscle that positions or stabilizes an organ

extrinsic

located entirely within an organ

intrinsic

runs across the longitudinal axis of the body

transverse

runs at a slant to the longitudinal axis of the body

oblique

straight muscle that runs along the longitudinal axis of the body

rectus

what contains two kinds of cells

nervous tissue

what supports and protects neurons

neuroglia (glial cells)

what is the brain and spinal cord

central nervous system

all nervous tissue outside the central nervous system

peripheral nervous system

bundles of axons with associated connective tissues and blood vessels

nerves (peripheral nerves)

what nerves connect to the brain

cranial nerves