A&P ch 9-11

• origin - galea aponeurotica
• insertion - skin of eyebrows, roots of nose
• movements - raise eyebrows

• origin - occipital and temporal bones
• insertion - galea aponeurotica
• movement - fixes aponeurosis and pulls scalp posteriorly

• origin - manubruim of sternum and medial portion of clavicle
• insertion - mastoid process of temporal bano and superior nuchal line of occipital bone
• movement - flexes and laterally rotates the head

• origin - clavicle, sternum, cartilage of ribs 1-6, aponeurosis of external oblique muscle
• insertion - fibers converge to insert by short tendon into intertubercular sulcus and greater tubercle of humerus
• movement - prime mover of arm flexion, adducts, medially rotates arm

• origin - lateral part of clavicle, acromion and spine of scapula
• insertion - deltoid tuberosity of humerus
• movement - prime mover of arm abduction when all fibers contract simultaneously

• origin - occipital bone, ligamentum nuchae, spinous processes of C₇ and all thoracic vertebrae
• insertion - acromion and spine of scapula, lateral 3rd of clavicle
• movement - stabilizes, raises, retracts and rotates scapula

• origin - indirect attachment to spinous processes of lower 6 thoracic vertabrae, lumbar vertabrae, last 3-4 ribs and iliac crest
• insertion - floor of intertubercular sulcus of humerus
• movement - prime mover of arm extension, adducts and medially rotates arm at shoulder

• origin - short head, corocoid process, long head - supraglenoid tubercle and lip of glenoid cavity, tendon of long head runs within capsule and into intertubercular sulcus of humerus
• insertion - radial tuberosity
• movement - flexion of elbow, supination of forearm

• origin - long head, infraglenoid tubercle of scapula, lateral head - posterior shaft of humerus, medial head - porterior humeral shaft distal to radial groove
• insertion - by common tendon into olecranon process of ulna
• movement - powerful forearm extensor (prime mover medially)

• origin - lateral supracondylar ridge at distal end of humerus
• insertion - base of styloid process of radius
• movement - synergist in forearm flexion

• origin - anterior superior iliac spine
• insertion - winds around medial aspect of knee and inserts into medial aspect of proximal tibia
• movement - flexes, abducts, and laterally rotates thigh, flexes knee

• origin - by two heads from medial and lateral condyles of femur
• insertion - porterior calcaneus via clacaneal tendon
• movement - plantar flexes foot

• 1 local depolarization and generation of an end plate potential - binding of ACh molecules to ACh receptors opens chemically gated channels that allow Na⁺ and K⁺ to pass (more Na⁺ will pass in than K⁺ will pass out
• 2 generation and propogation of the action potential (reaction spreads in all directions)
• 3 repolarization

• 1 calcium ions enter the cytosol form the ECF (extracellular fluid) via voltage-dependent or voltage-independent Ca²⁺ channels, or from the scant SR
• 2 Ca²⁺ binds to and activates calmodulin
• 3 activated calmodulin activates the myosin light chain kinase enzymes
• 4 activated kinase enzymes catalyze transfer of phosphate to myosin, activation the myosin ATPases
• 5 activated myosin forms cross bridges with actin of the think filaments and shortening begins

• skeletal
• cardiac
• smooth

• attached to bones and skin
• striated
• voluntary
• powerful

• only in heart
• striated
• involuntary

• in the hollow walls of organs
• not striated
• involuntary

• excitability
• contractility
• extensibility
• elasticity

• movement of bones or fluid
• maintaining posture and body position
• stabilizing joints
• heat generation (especially skeletal)

• muscle - surrounded by epimysium
• fascicle - surrounded by perimysium, bundle of muscle cells
• muscle fiber (cell) - surrounded by first the sarcolemma (the cell's plasma membrane), then the endomysium
• myofibril or fibril - complex organelle, composed of bundles of myofilaments,
• sarcomere - segment of a myofibril, contractile unit, composed of myofilaments made up of contractile proteins
• myofilament or filament - 2 types - thick or thin, the thick contain myosin molecules, the thin contain actin molecules, their interaction is essentially movement

• interconnecting tubules surrounding each myofibril
• lots of mitochondria and glycogen for energy during contraction
• major role is to regulate intracellular levels of ionic calcium (stores Ca and releases it on demand)

• part of the sarcoplasmic reticulum that forms a larger perpendicular cross channels at the A band I band junction
• part of the triad with T tubules

• sarcolemma protrudes deep into the cell creating an elongated tube
• part of the triad with terminal cisternae of SR
• spread signal for contraction rapidly and deep within the myofibrils

• during contraction, the thin filament slides past the thick ones, so that the myosin and actin overlap to a greater degree
• when muscle fibers are stimulated by the nervous system, the myosin heads on the thick filaments latch onto myosin binding sites on actin in the thin filaments, and the sliding begins. the cross bridge attachments are formed and broken several times during a contraction, like tiny ratchets to generate tension and propel the think filaments toward the center of the sarcomere

contains - axonal endings, synaptic cleft and the junctional folds of the sarcolemma

• 1 action potential arrives at axon terminal of motor neuron
• 2 voltage-gated Ca²⁺ channels open and Ca²⁺ enters the axon terminal
• 3 Ca²⁺ entry causes some synaptic vesicles to release their contents (acetylcholine) by exocytosis
• 4 actylcholine, a neurotransmitter, diffuses across the synaptic cleft and binds to receptors in the sarcolemma
• 5 ACh binding opens ion channels that allow simultaneous passage of Na⁺ into the muscle fiber and K⁺ out of the muscle fiber. More Na⁺ ions enter than K⁺ ions leave and this produces a local change in the membrane potential (depolarization)
• 6 ACh effects are terminated by its enzymatic breakdown in the synaptic cleft by acetylcholinesterase

• 1 local depolarization and generation of an end plate potential - binding of ACh molecules to ACh receptors at the neuromuscular junction opens chemically (ligand) gated ion channels that allow Na⁺ and K⁺ to pass, making the interior slightly less negative
• 2 generation and propagation of the action potential - spreads as a wave in all directions, opening other gated ion channels
• 3 repolarization - repolarization in wave, Na⁺ channels close and voltage gated K⁺ channels open to allow repolarization

• the sequence of events by which transmission of an action potential along the sarcolemma leads to the sliding of myofilaments
• 1 action potential is propagated along the sarcolemma and down the T tubules
• 2 calcium ions are released. Transmission of AP along the T tubules of the triads causes the voltage-sensitive tubule proteins to change shape. the shape change opens the Ca²⁺ release channels in the terminal cisternae of the sarcoplasmic reticulum, allowing massive amounts of Ca²⁺ to flow into the cytosol within 1 millisecond
• 3 calcium binds to troponin and removes the blocking action of tropomyosin. when Ca²⁺ binds, troponin changes shape, exposing binding sites for myosin (active sites) on the thin filaments
• 4 contraction begins. Myosin binding to actin forms cross bridges and contraction (cross bridge cycling) begins. at this point, E-C coupling is over

• a motor unit consists of a motor neuron and all the muscle fibers it supplies
• some supply many fibers, some few
• some big, some small

the response of a motor unit to a single action potential of its motor neuron

• 1 latent period - 1st few ms, following stimulation, excitation-contraction coupling is occurring.
• 2 period of contraction - cross bridges are active, from the onset to the peak of tension development, and the myogram tracing rises to a peak
• 3 period of relaxation - lasting 10-100 ms, initiated by reentry of Ca²⁺ into the SR. muscle contracts faster than it relaxes

• isotonic - muscle length changes and moves the load
• concentric contractions - muscle shortens and does work
• eccentric contractions - muscle generates force as it lengthens

isometric contractions - tension may build to the muscle's peak tension-producing capacity, but the muscle neither shortens nor lengthens

• 1 direct phosphorylation - CP couples with ADP to create ATP very quickly, but for a short duration
• 2 anaerobic pathway - glucose is broken down anaerobically producing a small amount of ATP and lactic acid
• 3 aerobic respiration - occurs in mitochondria, requires oxygen, glucose and oxygen go in to produce CO₂ , water, and ATP, this is slower, but yields far more ATP

• physiological inability to contract even though the muscle still may be receiving stimuli
• usually caused by ionic imbalance

the extra amount of oxygen that the body must take in for these resorative processes - replenish oxygen reserves, lactic acid reconverted to pyruvic acid, glycogen stores replaced, ATP and creatine phosphate reserves resynthesized

• number of fibers stimulated
• size of the fibers (hypertrophy)
• frequency of stimulation (allows stair effect)
• length-tension relationship (strongest contraction is 80-120% resting length)

• 1 same principles apply to contraction of a single fiber and a whole muscle
• 2 contraction produces tension, the force exerted on the load or the object to be moved
• 3 contraction does not always shorten a muscle
• 4 force and duration of contraction vary in response to stimuli of different frequencies and intensities

• 1 muscle fiber type - (1)speed of contraction (2)metabolic pathways for ATP synthesis
• 2 load
• 3 recruitment

• location - sk - attached to bones or skin - sm - single-unit muscle in walls of hollow visceral organs, multiunit muscle in intrinsic eye muscles, airways and lg arteries
• cell appearance - sk - single, very long cylindrical, multinucleate cells with obvious striations - sm - single, fusiform, uninucleate, no striations
• connective tissue components - sk - epimysium, perimysium, and endomysium - sm - endomysium
• presence of myofibrils composed of sarcomeres - sk - yes - sm - no, but actin and myosin filaments are present throughout, dense bodies anchor actin filaments
• presence of T tubules and site of invagination - sk - yes, 2 in each sarcomere at A-I junctions - sm - no, only caveolae
• elaborate SR - sk - yes - sm - less than sk, some SR contacts the sarcolemma
• gap junctions - sk - no - sm - yes, in single unit muscle
• individual neuromuscular junctions - sk - yes - sm - not in single unit, yes in multiunit
• regulation of contraction - sk - voluntary via axon terminals of the somatic nervous system - sm - involuntary, autonomic nerves, hormones, local chemicals, stretch
• source of Ca² for calcium pulse - sk - SR - sm - SR and extracellular fluid
• site of calcium regulation - sk - troponin on actin-containing thin filaments - sm - calmodulin in the cytosol
• pacemakers - sk - no - sm - yes in single unit muscle only
• effect of nervous system stimulation - sk - excitation - sm - excitation or inhibition
• speed of contraction - sk - slow to fast - sm - very slow
• rhythmic contraction - sk - no - sm - yes in single unit muscle
• response to stretch - sk - contractile strength increases with degree of stretch - sm - stress-relaxation response
• respiration - sk - aerobic and anaerobic - sm - mainly aerobic

• 1 embryonic mesoderm cells undergo cell division to increase number and enlarge
• 2 several myoblasts fuse together to form a myotube
• 3 myotube matures into skeletal muscle fiber

myoblast-like cells associated with skeletal muscle help repair injuired fibers and allow very limited regeneration of dead skeletal muscle fibers

• develops in head-to-toe and proximal-to-distal direction
• by mid adolescence, we reach the peak of our natural neural control of muscles
• with good nutrition and moderate exercise, relatively few problems afflict skeletal muscles

• also agonist
• muscle that has the major responsibility for producing a specific movement

muscles that oppose or reverse a particular movement

help prime movers by 1. adding a little extra force to the same movement or 2. reducing undesirable or unnecessary movements that might occur as the prime mover contracts

a synergist that immobilizes a bone or a muscle's origin so that the prime mover has a stable base on which to act

• location- temporalis
• shape- deltoid
• relative size- maximus
• direction of muscle fibers- rectus
• number of origins- biceps
• location of attachments- sternocleidomastoid
• action- flexor

• circular
• convergent
• parallel
• fusiform
• pennate (uni, bi, multi)

• effort X length of effort arm = load X length of load arm
• (force X distance) = (resistance X distance)

the more effort distance relative to load distance, the easier the load is to move

• first class - effort at one end, load at other with fulcrum somewhere between
• second-class - effort at one end, fulcrum at other end with load between - lever of strength
• third-class - effort is applied between the load and the fulcrum - speedy, but always operate at a mechanical disadvantage

• 1 sensory input
• 2 integration (process and interpret sensory info and decide what to do
• 3 motor output (the response)

• afferent (sensory) impulses from receptors to CNS
• efferent (motor) impulses from CNS to effectors
• - somatic nervous system (voluntary) impulses from CNS to skeletal muscles
• - autonomic nervous system (involuntary) impulses from CNS to cardiac and smooth muscles and to glands
• _-sympathetic division mobilizes body systems during activity
• _-parasympathetic division promotes housekeeping functions during rest

• also glial cells
• 6 types
• 4 in CNS
• -1 astrocytes
• -2 microglia
• -3 ependymal cells
• -4 oligodendrocytes
• 2 in PNS
• -1 satellite cells
• -2 Schwann cells

• most abundant and most versatile
• support and brace neurons anchoring them to food supply (blood capillaries)
• making exchanges between capillaries
• determine capillary permeability
• guiding migration of young neurons
• synapse formation
• control chemical environment around neurons (clean up leaked K⁺ and recapturing neurotransmitters)

• defensive cells
• processes touch nearby neurons
• when health of neurons is at risk mocroglia migrate toward them
• can transform into special type of macrophage that phagocytizes the microorganism or neuronal debris

• squamous to columnar
• many are ciliated
• line central cavities of the brain and the spinal cord
• circulate cerebrospinal fluid

• fewer processes than astrocytes
• line up along thicker neuron fibers in the CNS and wrap their processes tightly around the fibers, producing myelin sheaths

• surround neuron cell bodies located in the peripheral nervous system
• function similar to astrocytes in CNS

• also neurolemmocytes
• surround and form myelin sheaths around the larger nerve fibers in the peripheral nervous system
• vital to regeneration of damaged peripheral nerve fibers

• also nerve cell
• structural units of the nervous system
• extreme longevity
• amitotic - no mitosis
• exceptionally high metabolic rate and require continuous and abundant supplies of oxygen and glucose

• cell body(also perikaryon or soma) - spherical nucleus with conspicuous nucleolus
• processes - 2 types -1 - dendrites 2 - axons

• origin - anterior inferior iliac spine and superior margin of acetabulum
• insertion - patella and tibial tuberosity via patellar ligament
• movement - extends knee and flexes thigh at hip

• origin - greater trochanter, intertrochanteric line, linea aspera
• insertion - patella and tibial tuberosity via patellar ligament
• movement - extends and stabilizes knee

• origin - linea aspera, intertrochanteric and medial supracondylar lines
• insertion - patella and tibial tuberosity via patellar ligament
• movement -extends knee

• origin - anterior and lateral surfaces of proximal femur shaft
• insertion - patella and tibial tuberosity via patellar ligament
• movement - extends knee

• origin - ischial tuberosity (long head), linea aspera, lateral supracondylar line and distal femur (short head)
• insertion - common tendon passes downward and laterally (forming lateral border of popliteal fossa) to insert into head of fibvula and lateral condyle of tibia
• movement - extends thigh and flexes knee

• origin - ischial tuberosity
• insertion - medial aspect of upper tibial shaft
• movement - extends thigh and flexes knee

• origin - ischial tuberosity
• insertion - medial condyle of tibia, via oblique popliteal ligament to lateral condyle of femur
• movement - extends thigh and flexes knee