Ch 10-12 Flashcards
Ability to shorten, thicken
Contractility
(Irritability) the ability of muscles and nerves to respond to a stimulus
Excitability
Ability to lengthen and thin out
Extensibility
Fine sheath of connective tissue surrounding each muscle fiber
Endomysium
Fibrous connective tissue that surrounds bundles of muscle fibers called fascicles
Perimysium
Dense irregular connective tissue that surrounds the entire muscle
Epimysium
Broad, flat tendon that attaches muscle to bone, another muscle, Or skin
Aponeuroses
Muscle cell membrane
Sarcolemma
Cytoplasm of muscle cell
Sarcoplasm
Specialized smooth E.R.; tubes fuse to form clternae in each segment.
- in a relaxed muscle, S.R. Stores Ca++(active transport pumps)
- when stimulated, Ca++ leaves through Ca++ release channels (voltage gated)
Sacroplasmic reticulum
Chemical that communicated across synaptic cleft
Neurotransmitter
Tension increases, but muscle does not
- shorten/lengthen (ex: holding a book; maintaining posture)
Isometric
Tension remains constant
Isotonic
Red pigment that stores oxygen
Myoglobin
2 strands twisted into a helix
-each ~~~~~ molecule has a myosin binding site
Actin
Binding site on actin molecule
Myosin
A smaller molecule bound to tropomyosin
-has calcium binding sites
Troponin
Motor neuron & all fibers it connects to -
All connected fibers contract / a nerve fiber & all the muscle cells that t controls
Motor unit
Cardiac muscle
Striated & involuntary discs
- branching, Y-shaped cells
- many mitochondria, large transverse tubules
- intercalated discs- thick area b/w cells w/ gap junctions (allows network to contract as a unit)
- stimulation from autotorhytmic cells
- larger refractory period
Smooth muscle
- located in walls of blood vessels, digestive organs, bronchioles, ureters, & uterus
- spindle shaped cells
- nonstriated; involuntary
- influenced by neurotransmitters & hormones
Skeletal muscle
Body movement, posture, protection/support
-each muscle made of hundred/thousands of cells or muscle fibers
Acetylcholine is _____ _____ by acetylcholinesterase
Broken down
Insufficient oxygen, glycogen depletion, lactic acid buildup
3 things that lead to muscle fatigue
Regular exercise can lead to do what 2 changes that can help reduce muscle fatigue?
Regular exercise stimulates; new capillary growth & increase in mitochondria
What processes supply muscle cells with energy?
ATP; Phosphogen system; cellular respiration
When not enough oxygen is available _____ ____ fermentation takes place
Lactic acid fermentation
What causes the oxygen debt that develops during exercise?
(Extra oxygen taken in after exercise) –Lactic acid → glucose (liver) –Replace creatine phosphate –Replace ATP –Replace oxygen in myoglobin –Replace glycogen
Is the least moveable attachment
Origin
Is the more moveable attachment
Insertion
Provides the main force for a specific movement
Agonist
Muscles that oppose or reverse a motion
Antagonist
Aids agonist by promoting movement or stabilizing
Synergist
Muscle names are influenced by;
Location; shape; size; direction of fibers; # of origins; location of origin or insertion; muscle action
Deltoid = ?
Triangle
Longus = ?
Long
Brevis = ?
Short
Rectus = ?
Straight, parallel to midline
Maximus = ?
Large
Minimus = ?
Small
Brain & spinal cord
Central nervous system ( CNS)
Cranial nerves (from brain) & spinal nerves (from spinal cord)
Peripheral nervous system (PNS)
Nerves are in ___?
PNS
Tracts are in ___?
CNS
Membrane becomes more negative bc ___ ?
It’s hyperpolarized
Membrane becomes less negative because __?
It depolarizes
Presynaptic neuron
Sends signals
Post synaptic neuron
Receives signals
Voluntary control; CNS to skeletal muscle
Somatic division
Involuntary control; cardiac muscle, smooth muscle, glands
Autonomic motor division
Perikaryon
Cell body
Cytoplasm of neuron
Neuropharmacologist
(Chromatophillic substance) rough ER sections that make proteins
Nissl bodies
Dendrites
Usually short, many processes that conduct impulses toward cell body (afferent process)
Axon
-Long process that carries impulses away from cell body
In a axon
-side branches
Collaterals
Ends in axon terminals (part of axon)
Teleodendra
Supplies the myelin sheathes to the axons in the PNS
Schwann cells
Outer layer of Schwann cells contains cytoplasm
Neurilemma
Gaps between Schwann cells
Nodes of ranvier
Occurs along myelinated axons- myelin acts as electrical insulator
Saltatory conduction
Dense irregular CT around nerve
Epineurium
Dense irregular CT around fascicles of axons
Perineueium
Areolar CT around each axon
Endoneurium
Outer spinal cord, inner brain
Nerves of PNS, tracts in CNS
Myelinated process
White matter
Unmyelinated process
Neuron cell bodies, dendrites, neuralgia, axons without myelin sheath
Inner spinal cord, outer brain
Gray matter
Only axons into the _____ can regenerate
PNS
One process that splits with peripheral part (dendrite) & central part (axon)
In sense organs & hang,is outside CNS
Unipolar
1 dendrite & 1 axon
In retina, inner ear, small receptors
Bipolar
1 axon & many dendrites
In brain & spinal cord
Most common type of neuron
Multipolar
Transmit impulses from sensory receptors towards CNS (afferent)
Most unipolar, some bipolar
Sensory
Link other neurons
Most multipolar
Interneurons
Transmit impulses from CNS to effectors
All are multipolar
Motor
Long process that carries impulses away from cell body
Efferent
Short, many process that conduct impulses toward cell body
Afferent
Star shaped cells with many oricesses and functions
Blood brain barrier, control composition of tissue, fluid, structural network. Assist neuron dev.
Astrocytes
Ciliates epithelial cells; work with Capillaries to form choroid plexus & produce cerebrospinal fluid
Ependymal cells
Small cells with s,ended branches; remove debris from damaged tissue
Microglia
Processes wrap around axons to form myelin sheath; most common glial cell of the CNS
Oligodendrocytes
Supply the myelin
Sheathes to the axons in the PNS- aids in the regrowth of damaged peripheral axons
Schwann cells
Flattened cells found around the cell bodies of,neurons in ganglia
- regulate exchange of substance between neurons &’environment
Satellite cells
Buildup of negative ions inside membrane & positive ions outside membrane ; making it polarized
Resting membrane potential is around - 70mV
Resting potential
Action potential
Initial part of axon serves as trigger zone because has many voltage gates Na+ channels
Depolarization
Action potential
Depolarization arrives & K+ channels & K+ flows out - membrane repolarizes as inside of membrane becomes negative again - K+ gates close
Repolarization
an action potential cannot be started, even with a strong stimulus (Na+ gates activate)
Absolute refractory period
High intensity threshold stimulus might cause an action potential (K+ gates open)
Relative refractory period
Lost the four classes of a neurotransmitter
Ach; monoamines; amino acids; neuropeptides chains
What happens to a neurotransmitter left over after an impulse?
Degradation- broken down by an enzyme
Reuptalce- reabsorbs by axon
Axons originating from different parts of the NS lead to same neuron, making it possible for s neuron to sum impulses (summation)
Convergence
One impulse leaving a neuron goes to several neurons. May amplify impulse, allowing ,any muscle cells to contract or allowing sensors info to reach severs, areas of CNS
Divergence
What is an effector and name 2 types
Muscles & glands
