RAT #4 Flashcards
What type of signals does the sympathetic division create
Activities related to response intended to minimize or counter threats to homeostasis
The autonomic nervous system
Governs activities of the urinary bladder, the eye, and muscles involved in accomplishing the act of swallowing
The autonomic nervous system is involved in….
Pupil dilation or constriction
Fight or flight
Urination
Swallowing
What type of drug would decrease heart rate?
- Muscarinic agonist
- Beta agonist
- Muscarinic antagonist
- Nicotinic antagonist
Muscarinic agonist
- Decreased HR is associated with nerve impulses delivered via the release of acetylcholine…Acetylcholine receptors are the muscarinic type
During strenuous exercise which systems are likely to be more active
Sympathetic nervous system and somatic nervous system
Similarities between autonomic neuroeffector synapses and the neuromuscular junction include
The presence of enzymes such as acetylcholinesterase or monoamine oxidase and the requirement for calcium to produce transmitter release
The sympathetic nervous system can exert effects on specific target organs via the
Collateral ganglia
Activation of _____ adrenergic receptors raises the concentration of cAMP in effector cells
Beta 1 and beta 2
T/F Some blood vessels contain alpha adrenergic receptors that cause vasoconstriction in the presence of epinephrine, whereas others have beta 2 adrenergic receptors that cause vasodilation in the presence of epinephrine
True
Where is acetylcholine released by in the autonomic nervous system
All preganglionic sympathetic neurons, all preganglionic parasympathetic neurons, and all postganglionic parasympathetic neurons
Muscarinic receptors are located on ______.
Parasympathetic target organs
Drugs to treat asthma attacks might include
Alpha agonists and beta agonists
CNS areas that are involved in the control of autonomic functions include the ____
Spinal cord, hypothalamus, and pons
What organs are controlled by both the sympathetic and parasympathetic branches of the autonomic nervous system?
Lungs, urinary bladder, heart, pancrease
Which of the following is likely to occur when someone stands up quickly?
Increased release of norepinephrine and increased activity at adrenergic receptors
Sympathetic preganglionic neurons emerge from the __________ portion of the spinal cord.
Lumbar and thoracic
In the autonomic nervous system, acetylcholine is released by __________.
all preganglionic sympathetic neurons, all preganglionic parasympathetic neurons, and all postganglionic parasympathetic neurons
Which of the following cell types or structures can be found in both the sympathetic and the parasympathetic nervous system?
Preganglionic neurons and chain ganglia
The autonomic nervous system innervates __________.
cardiac muscle, blood vessels, and adipose tissue
Synapses between postganglionic neurons and effector organs are different from other synapses in that __________.
there are no distinct postsynaptic sites on the effector organs and transmitter is released from several areas on the postganglionic axon
The major neurotransmitters/neurohormones of the autonomic nervous system are __________.
Acetylcholine, epinephrine, and noreponephrine
The autonomic nervous system innervates __________.
cardiac muscle, blood vessels, and adipose tissue
Which of the following cell types or structures can be found in both the sympathetic and the parasympathetic nervous system?
Preganglionic neurons and chain ganglia
Afferent Neurons
Neurons that bring information into the central nervous system
Efferent Neurons
Neurons taking information away from the central nervous system
The autonomic neurons are _____, and typically control tissues and organs that are under ______ control.
Efferent; involuntary
Somatic motor neurons control _____ muscle, most of which we have ______ control over.
Skeletal muscle; voluntary
What types of organ system do the autonomic nervous system exert control over
State of contraction of blood vessels, the heart, endocrine glands, the digestive tract, sweat glands etc.
Primary transducing cell for touch
Mechanoreceptor neuron
Primary transducing cell for smell
Olfactory neuron
Primary transducing cell for taste
Taste receptor cells
Primary transducing cell for hearing
Hair cells
Primary transducing cell for vision
Rods and Cones
Stimulus for touch
Bending of membrane
Stimulus for smell
Binding of odorant molecules
Stimulus for taste
Binding of sweet, bitter, umami tastiest maybe movement of Na+ or H+ through ion channels
Stimulus for vision
Photons of light
Transduction mechanism for touch
Membrane bends, mechanically gated Na+ channels open causing a GP then an AP if threshold is released then exocytosis of NT
Transduction mechanism for smell
Bind as ligands on receptor proteins on dendritic membrane of olfactory neurons increasing cAMP which causes GP when cAMP gated Na+ channels open causing an AP at threshold causing NT of exocytosis
Mechanism of transduction taste
Bitter, sweet, umami bind as ligands on receptor proteins on membrane of taste receptor cells which activates 2nd messengers causing an increase in cytosolic calcium from SER causing exocytosis of NT (No AP in taste receptor cell)
Mechanism of transduction hearing
Airwaves move tympanic membrane causing middle ear bones to move which then causes ripples in cochlear fluid via oval window then causes bending of hair cells opens and closes ion channels causing aGP then release of NT (No AP in hair cell)
Mechanism of transduction Vision
Rhodopsin splits to form opsin and retinal which activates 2nd messenger system causing closing of Na+/Ca2+ channels causing graded hyper polarization. Change in NT release by cell causing NT release by bipolar cell. Change in GP and AP’s by ganglion cells (No AP in rod cell or bipolar cell
Neuroanatomical pathway touch
NT binds with R on second neuron in pathway –> thalamus –> somatosensory cortex
Neuroanatomical pathway taste
NT binds with R on gustatory neuron (GP and AP) –> brainstem –> thalamus –> somatosensory cortex
Neuroanatomical pathway smell
NT binds with R on second neuron in olfactory builds –> olfactory cortex
Neuroanatomical pathway hearing
NT binds with R on cochlear neuron (GP and AP) –> brainstem–> thalamus –> somatosensory cortex
Neuroanatomical pathway vision
Ganglion cells –> thalamus –> visual cortex –> visual association cortices
“Labeled line” coding
means that the brain “knows” the origin of al of the neurons that enter the cerebral cortex.
How does the brain know if you were touched softly or touched firmly?
A stronger touch would result in a higher frequency of AP being fired, more touch receptors responding or even different receptors responding.
Neurotransmitters are typically released _____ into a synapse
- From the pre-synaptic membrane of neurons
- From the post synaptic membrane of neurons
- From the endoplasmic reticulum of glands
- From the nucleus of neurons
- From the axonal membrane
From the pre synaptic membrane of neurons
Which of the following is part of an afferent neural pathway
- motor neurons
- parasympathetic neurons
- baroreceptor neurons
- sympathetic neurons
- sympathetic neurons
- ADH-secreting neurons
baroreceptor neurons
Transduction in the olfactory system depends on
ligands binding to receptor neurons causing a graded and an action potential
Slow twitch muscle fibers use ____ to enhance ATP production by _____
Myoglobin; oxidative phosphorylation
A toxin that block acetylcholine-gated sodium channels on skeletal muscle is likely to
Cause flaccid paralysis of skeletal muscle
A drug that increases the activity of myosin kinase has potential to
- Decrease BP be causing vasodilation in patients with hbp
- Decrease the rate of contractions in the large intestine
- Make breathing easier for asthmatics by relaxing airway circular smooth muscle
- Increase uterine contractions to induce labor
Increase uterine contractions to induce labor
Describe the role of Ca2+ in the excitation-contraction coupling reaction?
Ca2+ will bind to troponin which leads to a conformation shift in tropomyosin allowing for acting and myosin to attach
Put these events in the correct chronological sequence for skeletal muscle
- 1 T-tubules convey action potentials into the interior of the cell
- 2 Acetylcholine binds to receptors on the sarcolemma
- 3 Ca2+ is released from the sarcoplasmic reticulum
- 4 Ca2+ ions bind to troponin, pulling on tropmyosin
2, 1, 3, 4
What causes the myosin head to disconnect from actin?
Binding of ATP
Skeletal muscles are stimulated to contract when _________.
ACh binds to receptors on the sarcolemma, causing an electrical disturbance
he elaborate network of membranes in skeletal muscle cells that functions in calcium storage is the _________.
Sarcoplasmic reticulum
An individual has just ingested a chemical that binds irreversibly to the ACh receptors on the motor end plate of the sarcolemma. This prevents normal ACh binding. The consequence to skeletal muscle would be __________.
No contraction at all by nervous stimulation
What is the function of T tubules?
They conduct action potentials from the sarcolemma to the interior of the muscle cell.
Which of the following statements is(are) TRUE about the excitation-contraction coupling mechanism in skeletal muscle?
Calcium binds to tropomyosin causing a shift in troponin exposing the binding sites on actin for myosin.
An action potential in a T tubule opens calcium channels in the membrane of the sarcoplasmic reticulum.
Calcium binds to troponin causing a shift in tropomyosin exposing the binding sites on actin for myosin.
Which ion links excitation to contraction in a skeletal muscle fiber?
Calcium
What is the role of calcium ions in the contraction of skeletal muscle?
Calcium ions bind to the troponin-tropomyosin complex and remove their inhibitory action on actin/myosin interaction.
The functional unit of a skeletal muscle fiber is the ________.
Sarcomere
Interactions between thin and thick myofilaments of the sarcomere are responsible for ________.
Muscle contraction
During muscle contraction, all of the following occur EXCEPT ________.
Calcium concentrations in the sarcoplasm decrease
During a muscle contraction, muscle fibers shorten when ________.
Thin myofilaments are pulled toward the center of the sarcomere by the pivoting of the myosin heads
The cross bridge cycle ends when the calcium ________.
Is actively transported back into the sarcoplasmic reticulum
somatic motor neurons
Efferent neurons that control skeletal muscles
Autonomic neurons
Efferent neurons that control smooth muscle, cardiac muscle, many glands, and some adipose tissue
Explain how the autonomic nervous system exerts antagonistic control over the heart
The heart receptors for both sympathetic and parasympathetic response making it under antagonistic control. Sympathetic causes heart rate to increase and parasympathetic causes it to decrease.
Skeletal muscles are _____ tissues controlled by somatic motor neurons
Effector
What type of receptors on the heart cause vasoconstriction
Alpha-adrenergic
What type of receptors on the heart cause heart rate to increase
Beta adrenergic receptors
Tissue morphology of smooth, skeletal, and cardiac muscle
uninecleate; multinucleate; uninucleate
Control of skeletal, smooth and cardiac muscle
Ca2+ and troponin; Ca2+ and calmodulin; Ca2+ and troponin
explain how toxins and diseases can cause flaccid or tetanic paralysis, given their specific mode of action.
Taking a drug/toxin that blocks Acetylocholinesterase would result in acetylcholine being kept in the synapse longer causing the muscle to keep contracting “tetanic paralysis”
When acetylcholine is prevented from being released the muscle wouldn’t be able to contract called flaccid paralysis
ex: polio, botulism, and curare
For the actin-myosin cross bridge cycle, describe how ATP is used
ATP binds to the myosin head and is hydrolyzed to ADP and a phosphate. The energy released from the hydrolyzing of ATP activates the myosin head forcing it into a cocked position. ATP binding is also responsible for releasing actin and myosin
Describe the metabolic types of skeletal muscle and give their distinguishing features
Slow oxidative skeletal muscle
-dark (myoglobin) responds well to repetitive stimulation w/o becoming fatigued ex: body posture muscles
Fast oxidative skeletal muscle
-intermediate, responds quickly and to repetitive stimulation w/o becoming fatigued ex: working muscles
Fast-glycotic skeletal muscle
-white, used for quick bursts of strong activation ex: muscles used to jump/sprint
Myasthenia gravis
-Immune system destroys Ach receptors
Poison arrow frog
- Keeps Ach-G Na+ channels kept open
- tetanic paralysis
Black widow spider bite
Causes massive release of Ach
-causes tetanic paralysis
Botox injection
Prevents release of Ach
-flaccid paralysis
Eat improperly prepared pufferfish
Tetrodotoxin blocks V-G Na+ channels
-flaccid paraylsis
Get exposed to sarin gas
Blockes acetylcholesterase activity
Develop MS
Autoimmune that demyelinates myelin sheaths
Black mamba bite venom
Contains a nicotinic cholinergic receptor agonist
-Tetanic paralysis
What causes skeletal muscle to fatigue?
Failure of action potentials along t-tubules
