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Midterm Exam PSL311

Terms in this set (40)

Why is it advisable to record data, such as heart rate, for up to 60 seconds vs. only 15 or 30 seconds?
Heart rate may change in a span of longer than 15 seconds so the HR may not be accurate
True or False: Standard deviation is a measure of variance
true
True or false: Standard deviation is a measure of data dispersion
true
True or False: standard deviation is a measure of difference from the mean
true
True or false: standard deviation represents the average
false
Explain any differences, issues, and benefits of using various measurement devices for taking body temperature? Which of our modalities gives a closer measure to the "core" temperature? Why?
Some locations for taking temperature are more closely located to the body's core, therefore, the temperature reading would be more accurate
Describe some confounding issues when taking oral temperature?
Hot or cold food and drinks
What determines how cold an object feels?
- the temperature of your hand
- how well the object conducts heat and removes heat from your hand
How can wet and wind affect temperature?
- Water and wind make things cool down at a faster temperature because they speed up the rate of evaporation that cools that body
- Evaporative water loss which results in heat loss, causing temperature to drop
Be able to describe all the physiological events that occur between the delivery of stimulus through synaptic transmission, to muscle twitch and recorded EMG response.
a. Once the AP reaches the NMJ, a series of events will cause the release of acetylcholine into the synapseb. The Ach will diffuse across the synaptic cleft and bind to Ach receptors on the muscle of the nicotinic typec. These receptors will open ion channels which are cation selective, allowing an increase in the flux of these ions across the muscle fiber membrane, depolarizing the muscle end plate.d. The newly formed muscle AP will then initiate the release of calcium from the SR and set off a series of events resulting in muscle contraction.e. Ache will terminate the binding of Ach on the motor end plate, which will end excitation of the muscle fiber, enabling it to go back to rest
Explain the specific process for a typical nerve conduction velocity test.
The nerve is stimulated, usually with surface electrode patches attached to the skin. Two electrodes are placed on the skin over the nerve. One electrode stimulates the nerve with a very mild electrical impulse and the other electrode records it.
Give me two variables or nerve characteristics that would influence nerve conduction velocity?
1. if the nerve is myelinated or not- myelinated will make faster conduction velocity2. increase in nerve diameter- faster conduction velocity
Give two differences between an evoked action potential and a single nerve impulse.
1. Single impulse is a movement of the AP long the nerve, also not prominent on a monitor2. Evoked is a depolarization of a nerve as a result of a deliberate stimulation, central feature of a monitor
How would you calculate nerve conduction velocity if the variables are provided for you?
Distance traveled/difference in latency at the two areas
What are some physiological or pathological conditions that may influence the observed reflex response of say a Patellar or Achilles deep tendon reflex? How might these change the response? Be able to describe the changes that an upper vs lower motor neuron lesion may have on reflex response.
Upper motor neuron lesions prevent signals from traveling from your brain and spinal cord to your muscles. Your muscles can't move without these signals and become stiff and weak. Damage to upper motor neurons leads to a group of symptoms called upper motor neuron syndrome:
In lower motor neuron lesions (damage to the nucleus or nerve), the upper and lower facial muscles on the same side as the lesion are paralysed. Inability to close the eyelids may lead to corneal ulceration, especially if reflex lacrimation is also lost.
Knee jerk: In a knee jerk reflex, the patellar tendon is tapped using a hammer. This stimulates the stretch receptors AKA muscle spindles in the quadriceps, which elicits an extension of the leg. This is done by stimulating the afferent receptor then the afferent nerve. Information is processed in the CNS where there is a synapse between the sensory and motor nerves and the signal is transferred to the efferent nerve which extends the knee. The lower motor neuron ability is tested with the knee jerk reflex test. With an upper motor neuron lesion the response would still happen but with a lower motor neuron lesion, there wouldn't be a response.
Achilles: distal attachment site is the calcaneus. The muscle group activated is the gastrocnemius which is innervated by the tibial nerve. The level of the spinal cord that innervates this muscle is the S1 which eventually elicits a response from the tibialis anterior. The tibialis anterior then causes dorsiflexion of the foot. A lower motor neuron lesion would prevent this reflex from occurring.
What are some strategies that may enhance or improve one's reflex response of the patellar tendon? How might these be helpful when assessing a patient?
Simple reflexes have a lower latency and a higher amplitude when compared to the Jendrassik maneuver. Higher level areas of the nervous system (CNS) can influence the reflexes by allowing you to be more conscious and resistant to the response. The Jendrassik response would affect the simple response by diverting attention to the pressure in other parts of the body. This is helpful because then the reflex can be tested more accurately.
pupillary light reflex
Pupillary: oculomotor nerve carries the efferent response from the midbrain, oculomotor nerve innervates the pupillary muscles, optic nerve is responsible for carrying light information to the midbrain.
Parasympathetic: innervates the iris circular muscles-contraction causes the iris to constrict
Sympathetic: supply the iris radial muscles-contraction of the radial muscles leads to dilation of the pupil
patellar response
Patellar: In a knee jerk reflex, the patellar tendon is tapped using a hammer. This stimulates the stretch receptors AKA muscle spindles in the quadriceps, which elicits an extension of the leg. This is done by stimulating the afferent receptor then the afferent nerve. Information is processed in the CNS where there is a synapse between the sensory and motor nerves and the signal is transferred to the efferent nerve which extends the knee. The lower motor neuron ability is tested with the knee jerk reflex test. With an upper motor neuron lesion the response would still happen but with a lower motor neuron lesion, there wouldn't be a response.
Achilles response
Achilles: When the ankle jerk reflex was initiated, we were tapping on the Achilles tendon which is attached the calcaneus. The muscle group that is activated is the gastrocnemius which is innervated by the tibial nerve. The S1 portion of the spinal cord responds to this reflex. The gastrocnemius then causes dorsiflexion of the foot.
Be able to explain direct and consensual pupillary responses to light.
Consensual light reflex is when the pupil constricts in the right eye while light is in the left eye.
Direct light reflex is when the pupil constricts in the left eye while light is in the left eye.
Left direct pupillary reflex is the left pupil's response to light entering the left eye.
Left consensual pupillary reflex is the left pupil's indirect response to light entering the right eye, the contralateral eye.
Be able to describe the technique for attempting a Babinski reflex. What are the typical normal and abnormal observations in an adult?
The Babinski reflex should start at the bottom of the foot and over toward the big toe. This is also called the plantar response. A typical response would result in plantar flexion of the toe, which means that the toes should curl downwards. A brain lesion could result in dorsiflexion of the toes.
Be able to describe the steps in the physiological process from nerve impulse to muscle contraction/relaxation.
Motor endplate conditions: 1-signal from motor neuron arrives at terminal. 2-Ca moves into endplate. 3-Ach is released into NMJ and binds to Ach receptors. 4-influx of Na initiates an AP in the muscle fiber.
. Be able to identify any receptors involved in muscle contraction/relaxation which includes voltage receptors, mechanical receptors, calcium receptors, and receptors for neurotransmitters (ligand receptors).
Action potentials arriving at the axon terminal trigger the release of acetylcholine into the synaptic cleft of the neuromuscular junction.
The acetylcholine diffuses through the junctional cleft and binds to the nicotinic acetylcholine receptors on the motor end plate.
The bound receptors open cation-selective ion channels, which depolarizes the muscle end plate and leads to the release of calcium from the sarcoplasmic reticulum.
The increased cytosolic calcium sets in motion the biochemical events that underlie contraction.
Acetylcholine is rapidly hydrolyzed by acetylcholinesterase, which terminates the muscle contraction signals.
Be able to describe the two primary mechanisms by which force production of a muscle can increase.
Encouragement and visual feedback and brief periods of rest.
Why are muscles arranged in antagonistic pairs? Be able to explain the concept of reciprocal inhibition.
Agonist muscles are the prime moves and responsible for generating movement through their contraction. Antagonist muscles control or oppose specific movement and return the muscle to its initial position. Reciprocal inhibition is how opposite pairs
Describe the significance of motor units with respect to increasing force output of a muscle.
As weight is added to the muscle, the muscle becomes more activated. There is a larger amplitude when weight is added to the muscle. As the weight increases, the number of motor units increases because they are recruited to respond to the increase in strength in the muscles. The size also increases because all of the small motor unit are being fired and will need additional help. The large units are recruited to handle the load.
How would you define muscle fatigue? What strategies, as demonstrated in the lab, can be implemented to reduce fatigue of a muscle?
Buildup of lactate and associated H+ ions in muscles, failure of neuromuscular propagation, loss of central drive, reduction in ionized Ca2+ release in excitation contraction coupling.
State of physiological inability to contract effectively. It is associated with a variety of psychological and physiological factors. To reduce fatigue, rest the muscles to allow blood flow to carry away the lactic acid which is broken down in the liver.
Be able to explain the results of an ABO blood typing test. Which blood types contain which types of antibodies and antigens?
Type A blood contains Antibody B, and A antigen.
Type B blood contains Antibody A, and B antigen.
Type AB blood contains no antibodies, and both the A and B antigen.
Universal recipient, low prevalence.
Type O blood contains both the A and B antibodies, and no antigens.
Universal donor, high prevalence.
What happens of someone is given the wrong type of blood in a tranfusion?
In general, Rh negative blood is given to Rh-negative patients, and Rh positive blood or Rh negative blood may be given to Rh positive patients. Rh-negative
If incorrect blood types are infused, they will agglutinate. Agglutination is a binding reaction whereby antibodies in the blood plasma of one individual, will recognize and eliminate the antigen group of particular foreign type cell. These foreign type cells will have a different surface antigen than is typically recognized in the organism thus causing the blood cells to form large clumps. These clumps will then block and damage small capillaries particularly in the kidneys.
Describe the major mechanistic differences between agglutination and coagulation? While they both can have a similar end result, how does the mechanism differ?
Agglutination causes red blood cells to undergo clumping and intravascular hemolysis. Blood coagulation is the process of converting blood into a semisolid jelly-like substance
Describe the role of hemoglobin as an oxygen carrier. How many O2 molecules are able to be carried per hemoglobin? What is a normal range for hemoglobin and males/females? How is hemoglobin used to diagnose anemia?
- 4 oxygen molecules
- Lower than normal hemoglobin levels indicate anemia. The normal hemoglobin range is generally defined as 13.2 to 16.6 grams (g) of hemoglobin per deciliter (dL) of blood for men and 11.6 to 15. g/dL for women.
Can a person have a high hematocrit but have a low hemoglobin content? Describe how this can be true.
If a person has low hemoglobin content , it means he have low RBC contentAnd if RBC is low , then hematocrit usually decreases ( as it is directly proportional to the RBC value )But in some conditions , where the total volume of blood decreases in a person (like in dehydration) then the hematocrit value increases (as hematocrit is inversely proportional to the total blood volume) inspite of low hemoglobin contentThis means as the total blood volume decreases , the RBC per volume of blood increases leading to high value of hematocrit
Be able to discern the various layering in a microhematocrit tube after it has been centrifuged and identify how hematocrit is then determined.
Bottom to top: clay stopper, RBCs, WBCs (buffy layer), plasma and air. Hematocrit can be determined by lining up and sliding the tube until the top of the RBC matches the column on the table
What two laboratory measures are used to assess bleeding time in a clinical environment? Which typically assess the extrinsic vs intrinsic clotting pathways?
Prothrombin Time (PT): Extrinsic Clotting PathwayPartial-Prothrombin Time (PPT): Intrinsic Clotting Pathway
What does it mean to have a high PT-INR value? How might a high or low value predispose a patient to certain pathology?
A high value means your blood clots more slowly than desired.
What are the components of a SOAP note? In what portions of the SOAP note would a patient's discussion of their symptoms go? Where their clinical tests and measures would go? A patient's diagnosis? Etc.
Subjective, Objective, Assessment, Plan
S: patients/ family recolletion
O: doctor's opinion
A: patients response
P: follow-up
In which type of receptor, phasic or tonic, does the receptor potential fall below threshold, even as the stimulus continues?
phasic receptors
Hyperpolarizing receptor potential makes the membrane potential ______ (more or less) negative and ______ (increases or decreases) the likelihood of action potentials occurring.
more; increases
While recording the responses of a mechanoreceptor to stimulation of the skin, an investigator observes an increase in the number of action potentials. This increase usually signifies?
increased intensity of a stimulus
If the head is rotated to the right, which horizontal semicircular canal (right or left) is activated during the initial rotation? When the head stops rotating, which canal (right or left) is activated?
right then left
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