Cardiac - Muscle - Autonomics - Important Terms Flashcards
Mechanoreceptors
stretch, sound waves
Osmoreceptors
Solute concentration
Chemoreceptors
Specific chemicald (smell, taste, O2, CO2, glc, aa, fats)
Antagonistic Dual Innervation
actions of the SNS and PSNS counteract each other
can work on same or different cells
Complementary Dual Innervation
Actions produce similar effects
Cooperative Dual Innervation
actions produce different effects that work together to produce desired effect
Parasympathetic Tone
Parasympathetic nervous system dominates in dual innervation
Sympathetic Tone
Sympathetic nervous system dominates in dual innervation
Sympathetic Vasomotor Tone
a base firing frequency of sympathetics
Muscarinic Receptor (mAChR)
Autonomic NT receptor
Binds GTP
Slower
Metabotropic Receptors
G Protein-Coupled Receptor
slower
a lot of metabolic steps
bind GTP
muscarinic receptor
Ionotropic Receptor
Ligand-gated ion channel
Faster
nicotinic
Single Unit Smooth Muscle
only a few muscle fibers innervated in each group
stimulatd together, contract together
Slow Wave Potentials
coordinate muscle contractions in the gut by controlling the appearance of a second type of depolarizing event
Multiunit Smooth Muscle
neurogenic
requiring stimulation by autonomic nerves
Singleunit smooth muscle
myogenic
able to initiate its own contraction w/o any external influence due to automatic shifts in ion fluxes
Sarcomere: Light Band
I Band
Sarcomere: Dark Band
A Band
Sarcomere: I Band
Remaining portion of thin filaments that are not included in A band
only thin filaments
shortens
Sarcomere: Z Line
middle of I Band
stabilizes thin filament
entire sarcomere
Sarcomere: H Zone
Lighter area in middle of A Band
Thin filaments do not reach
only thick filaments
shortens
Sarcomere: M Line
mid point of sarcomere
stabilizes tick filament
Sarcoplasmic Reticulum (SR)
modified ER
consists of interconnecting tubules surrounding each myofibril like a mesh sleeve
Bring action potentials from surface to center of cell
T-Tubule
invagination of plasma membrane that runs perpendicular to the surface and bring action potentials into the muscle fiber
Black Widow Spider Venom
Alters Release of ACh
toxin can form pores in presynaptic membrane
explosive release of ACh
results in respiratory failure
Clostridium Botulinum Toxin
Blocks release of ACh
interferes with share proteins
can result in respiratory failure
used as medicine
Curare
Reverisbly binds to ACh receptor, blocking it from activating
antagonist
causes paralyzation and respiratory failure
Myasthenia Gravis
antibodies inactivate ACh receptor, blocking it
Organophosphates
Irreversibly inhibits AChase, preventing inactivation of ACh
results in respiratory failure
Graded Potential
Resultant change in membrane potential causes by ionic movements through open membrane channels
Synapse
A junction between 2 neurons
Excitatory (EPSP) or inhibitory (IPSP)
Neuromuscular Junction (NMJ)
Exists between a motor neuron and a skeletal muscle fiber
always excitatory (EPP)
Slow Twitch fibers
Type 1
Oxidative metabolism
used for walking and posture
fatigue resistant
Fast Twitch a fiber
Type IIa
moderatly high ox capacity
high glycolytic capacity
not as common as Type I and Type IIx
Fast Twitch x fiber
used for power
low oxidative capacity
highest glycolytic capacity
Motor Unit
1 motor neuron + all the muscle fibers it innervates
Isometric (static) contraction
Muscle produces force but does not change length
Joint angle does not change
Myosin cross-bridges for and recycle, no sliding
Isotonic (dynamic) contraction
Muscle produces force and changes length
Joint movement produced
Concentric Contraction
Muscle shortens while producing force
most familiar type of contraction
sarcomere shorten, filaments slide toward center
Eccentric Contraction
Muscle lenthens while producing force
Cross-bridges form but sarcomere lengthens
Muscle Fibers
long, cylindrical, multinucleated muscle cells
Saromere
an ordered arrangement of thick and thin filaments
Neurogenic
only contracts when externally stimulated by a nerve
steric inhibition
troponin-tropomyosin complex slips back into its blocking position
Sliding filament mechanism
the relationship between the length of the muscle and the tension it can develop
Optimal Length
active force generated is maximal
Immediate ATP pathway for contraction
high energy phosphates from stored creatine phosphate
Non-oxidative pathways muscles obtain ATP for contraction
synthesize ATP w/o O2 and uses glycogen stores and generates lactic acid
ex: glycogenolysis and glycolysis
Oxidative phosphorylation pathway muscles use to obtain ATP for contraction
efficiently extracts large amounts of ATP from nutrient molecules but requires suffiecent O2
Right Heart
Volume Pump
Delievers high volumes of blood at low pressures
Pulmonary Vessels
Function in blood-gas exchange and serve as volume reservoirs
Left Heart
Pressure Pump
The energy source for the circulatory system
Elastic Arteries (Aorta)
Their basic behavior allows them to serve as a “surge pump”
Energy is stored in the elastic fibers during the contraction phase(systole) and released during the relaxation phase (diastole)
Systole
Contraction Phase
Ventricles contracted
Tricuspid and Mitral Valves closed
Pulmonic and Aortic Valves open
Increased Ca2+ in cell
Diastole
Relaxatio Phase
Ventricle Relaxation
Tricuspid and Mitral valves open
Pulmonic and Aortic Valves closed
Decreased Ca2+ in cell
Muscular Arteries
Function as low resistance conduits that rapidly deliver blood to the tissues
Arterioles
Collectively termed “resistance vessels”
Serve as resistors that regulate the flow of blood into capillary beds
Capillaries
One cell layer separates blood from tissue space
Site of nutrent and waste exchange
Venous Vessels
Serve as volume reservior
These vessels function in both the storage and mobilizatio of blood
Pulmonary Circulation
Blood flows through lungs
Systemic Circulation
Blood flows through all organs of the body except lungs
Systemic Circulation: Arterials
LV to Capillaries
High Pressure
Low Volume
Systemic Circulation: Venous
Low Pressure
High Volume
High Compliance
Epicardium
Outer muscle layer in the heart
Edocardium
Inner muscle layer in the heart
Pulmonary Capillary Wedge
Estimation of LA pressure