Practice lecture 3 questions Flashcards
Lecture 3 questions from Cassidy + other lecture 3 content I need to review
What causes a runners high?
The analgesic system’s release of enkphalin
What are the 3 parts of the analgesic system? Is it ascending or descending?
Periaqueductal gray matter, medulla, and reticular formation; descending
Tissue damage releases ______ which enhances pain by lowering the activation threshold of nociceptors.
prostaglandins
Mechanical and thermal receptors use which type of pain fiber to reach the CNS?
A-delta fibers
Glutamate binding with _______receptors ultimately transmits pain signals, while when glutamate binds with ________ receptors the injured area is more sensitized.
AMPA transmits, NMDA sensitizes
What consists of a two-neuron efferent pathway?
The ANS
What organs are not affected by the parasympathetic nervous system?
Liver’s glycogen stores, Adipose cells, sweat glands, adrenal medulla, and brain activity
__________ receptors are nicotinic and muscarinic, while __________ receptors are Alpha 1 & 2 and Beta 1 & 2.
Cholinergic, Adrenergic
Penis and clitoris blood vessels receive what kind of innervation?
Both sympathetic and parasympathetic (unlike all other blood vessels)
Mucous-y and thick saliva is a result of what part of the ANS?
Sympathetic
Watery and enzyme-rich saliva is a result of what part of the ANS?
Parasympathetic
In the sympathetic nervous system, the preganglionic cell body releases Ach to postsynaptic cell body’s ___________ receptors, which then releases NE to ________ and_________ receptors on effector organ.
nicotinic; A1, A2, and B1, B2
In the parasympathetic nervous system, preganglionic fibers release Ach to the postsynaptic body’s nicotinic receptors, which then release ________ to ________ receptors
Ach to muscarinic receptors
True or False? Muscarinic receptors are on the postganglionic cell bodies in all autonomic ganglia.
False; nicotinic receptors are
A1 receptors are found on most __________ tissues and have a ____________ response. They respond to the neurotransmitter ______________.
sympathetic; excitatory; norepinephrine
What receptors are found in digestive tissues and have an inhibitory response?
A2
Metoprolol is an example of an ______, since it blocks the production of a response in a receptor by decreasing blood pressure, heart rate, and force of heart contractions.
antagonist
Alpha receptors have an affinity for what NT?
Norepinephrine (over epinephrine)
What receptors are only found in the heart and kidneys?
B1 adrenergic receptors
What type of receptors only bind with epinephrine?
B2
What type of receptor has an equal affinity for NE and E?
B1
Which has an inhibitory response, B1 or B2 receptors?
B2
What type of receptors are found in the smooth muscles of arterioles and bronchioles?
B2
What binds to an NT’s receptor and causes same response the NT would?
Agonists
What medication actives B2 adrenergic receptors, dilating bronchioles in asthma without stimulating the heart excessively?
Albuterol
What receptors does metoprolol block in order to decrease blood pressure by decreasing heart rate and force without affecting bronchioles?
B1 adrenergic receptors
Give 3 examples of spinal-cord integration (autonomic reflexes)
Urination, defecation, erection
What controls cardiovascular, respiratory, and digestive autonomic activity?
Medulla of brainstem
Emotional expression, such as blushing when embarrassed, comes from which portion of the brain?
Prefrontal association cortex
True or False? Subconscious activity such as walking, posture, and balance are part of the somatic system and under voluntary control.
True
True or false: Unlike two-neuron chain of the autonomic fibers, the axons of motor neurons continue to their endings on skeletal muscle
True
What do the axons of motor neurons release?
Ach
True or false: The only way the CNS can influence skeletal muscle is by acting on motor neurons
True
True or false: motor neurons only receive excitatory presynaptic inputs
False; both excitatory and inhibitory
Nerves and __________ cells do not come into direct contact
muscle
True or false: the somatic nervous system does not use electrical transmission to control muscles
True; gap between neuron and muscle is too large, uses NTs instead
What triggers the release of acetylcholine in the neuromuscular junction?
Calcium
List the steps between a neuron’s action potential and a muscle fiber contracting (6 steps)
1) Action potential triggers opening of calcium channels in neuron
2) Calcium triggers Ach to be released by neuron
3) Ach binds to nicotinic receptors of muscle membrane
4) Triggers channels to open and an influx of Na+
5) Causing depolarization
6) Depolarization spreads throughout muscle fiber, muscle contracts
True or false: for a muscle contraction, an action potential triggers opening of voltage-gated calcium channels in only some of the terminal buttons of a motor neuron
False; triggers opening of Ca channels in all terminal buttons
What provides feedback for motor control?
Afferent muscle innervation
LMNs are found in the _________ horns of the spinal cord
ventral
The knee-jerk reflex when the patella is hit is an example of a ___________ _____________reflex
myotatic (muscle stretch) spinal reflex
The two types of spinal reflexes are myotatic and ______________________
flexor withdrawal
List the 5 tracts of the CNS where you can find upper motor neurons
1) Corticospinal
2) Corticobulbar
3) Rubiospinal
4) Vestibulospinal
5) Reticulospinal tracts
Position and movements of the head is part of the ______________ tract and innervates __[direction]____from the brain stem.
Vestibulospinal; ipsilateral
What tract mainly controls the upper limbs and descends on the contralateral side?
Rubrospinal tract
What descending motor tract controls reflexes, truck/limb muscles, and posture control?
Reticulospinal
The pons and medulla influence what descending motor tract?
Vestibulospinal
What descending motor tract has both ipsilateral and contralateral control?
Reticulospinal
What areas of the brain influence the rubrospinal tract?
Red nucleus receives input from cerebellum and cerebral motor areas
Injuries to what two areas can produce upper motor neuron sign?
Motor cortex or corticospinal tract
What helps control rhythmic things like chewing gum or walking?
Central generator programs
The ___________ is the origin of descending tracts that influence posture and movement
brainstem
Define decerebrate posturing
Rigid extension
Define decorticate posturing
Abnormally flexed
When you’re actively wanting to move:
1) What part of your brain says “I want to get over there, how do I move there?”
2) What area organizes patterns of movements?
3) What area executes the act of moving?
4) What area keeps you from tripping over stuff while walking and knows when to stop walking?
1) Prefrontal cortex: plans movement
2) Premotor cortex: organizes
3) Primary motor cortex: executes
4) Posterior parietal: stops
Where is the primary motor cortex?
Frontal lobe in the precentral gyrus
What part of the brain involved in movement has somatotopic organization/ homunculus?
Primary motor cortex
What is the tract that is involved in rapid, skilled, discrete movements of the hands and descends down the contralateral side?
Corticospinal tract
What is the primary efferent tract from the cortex?
Corticospinal tract
Besides the prefrontal cortex and primary motor cortex, what aids in the preparation and initiation of movement?
The basal ganglia (and cerebrocerebellum)
What part of the cerebellum is involved in maintaining balance and eye movements?
Vestibulocerebellum
What part of the cerebellum coordinates complex voluntary movements?
Spinocerebellum
Planning and coordination of movement input to the cortical motor areas comes from which division of the cerebellum?
Cerebrocerebellar
If you have nystagmus, what part of the cerebellum isn’t working?
Vestibulocerebellum
The intrinsic circuitry of the cerebellum is regulated by what type of cell and neurotransmitter? Is this excitatory or inhibitory?
Purkinje cells, which use GABA and are inhibitory
Give 6 potential consequences of cerebellar lesions
1) Hypotonia: muscle flaccidity
2) Dysdiadochokinesia: rapid alternating movements
3) Dysarthria: Garbled speech
4) Intention tremor
5) Decrease in motor learning
6) Ataxia in general
True or false: The cerebellum is only involved in movement
False; many other roles including working memory, learning, emotion, addiction, pain, etc.
What does poliovirus destroy?
Cell bodies of motor neurons
What disorder causes degeneration of motor neurons, which keeps them from being able to contract?
ALS
What can cause explosive release of ACh at all cholinergic sites, causing muscles to be unable to relax?
Black widow venom
What blocks ACh release from motor neuron terminal buttons, keeping muscles from responding to nerve impulses?
Botulinum toxin
