Test 3 Gen Physio Flashcards
Receptors change sensory signals into electrical signals, these electrical signals induce what?
An Action Potential
What is a sensory receptor?
A biological transducer that changes a stimulus to electrical energy allowing us to understand what is happening either in our bodies or in our environment.
What are Nociceptors?
Receptors that detect pain, a type of naked receptor.
What are encapsulated receptors?
Sensory endings encapsulated with connective or epithelial tissues, where if encapsulation is lost then the receptor loses function.
How do olfactory receptors detect smell?
A modified cell that has cilia, the receptor portion, transduction occurs and carries the signal towards the brain.
How do taste receptors work?
A special columnar shaped cell that has a micro villus border and is synaptically linked to a fiber at the bottom of the cell. Saliva allows molecules to dissolve, are then picked up by the micro villus border (the receptor), then causing the receptor to release dopamine as a neurotransmitter to the post synaptic cell, then carrying the signal to the brain.
What are characteristics of a graded potential?
- Decremental (strength decreases with distance)
- Magnitude varies with the strength of the stimulus
- Undergoes Summation effects
- Hyperpolarization or depolarization
- Only short distances
What is the relationship between stimulus strength, Action Potential and the Generator Potential?
As a stimulus increases the generator potential increases and only the frequency of the action potential changes.
How do beta cells in the pancreas work to release insulin?
K channels are open and Ca channels closed. ATP production is low, but as glucose increases in the cell after a meal there is an increase in ATP production, causing phosphorylation of the K channel from increased cell ATP causing the K channel to close. This causes a depolarization in the cell causing Ca to open under a voltage gaiting effect, Ca acts as a secondary messenger with a protein, and promotes the exocytosis of insulin.
What receptor encourages the release of insulin?
Beta cells in the pancreas.
What kind of receptor is the olfactory receptor?
A chemo receptor.
How do olfactory receptors work?
Cilia receptors, located in roof of the nasal cavity, are moist, because of mucus, allowing odorants to dissolve and make contact with the cilia, binding, transduction, brain interpretation.
What are papillae on the tongue responsible for?
Bumps on the tongue that house the taste receptors “taste buds”.
What type of receptors are taste receptors?
Chemio receptors
What cell carries taste receptor information to the brain?
Goostatory cells related to the cranial nerve IX Glossopharyngeal nerve.
What are the different types of taste receptors?
Salty, sour, bitter, sweet, and umami (protein taste).
What are Rods?
Photoreceptors in the eye that detect shades.
What are cones?
Photoreceptors in the eyes that detect colors.
How do Rod cells work (cones work in a similar way)?
Photoreceptors that respond to light. Light hits Rod Cells, cis-rhodopsin and retinal are bound together but in light a photo isomerization causes the cis for to turn to trans and un-binds rhodopsin and retinal, rhodopsin is bound to transducin (G protein GTP), this activates phosphodiesterase that breaks CGMP and closes Na channels causing a hyperpolarization, this causes cells to become inactivated, allowing transduction to occur in bipolar cell.
What protein keeps Na channels open in the eye during the dark?
CGMP
What is a sensory unit?
A sensory neuron with all of its endings?
What does the brain need to interpret about a typical sensory stimulus?
Strength, location, and frequency. The brain achieves this by interpreting the pathway signals take to reach the brain.
How does the brain interpret the strength of a signal?
By interpreting the frequency of the Action Potential. Low frequency is a weak stimulus, and a high frequency is a strong stimulus.
What are two types of pain detected by nociceptors?
Acute pain (pathological pain) and Chronic pain (Neuropathic pain).
What causes chronic pain?
Glial cells that release sensitizers that increase the sensitivity of pain tracts. Elevates sensitivity and recruits other glial cells to release sensitizers. CB2 receptors on glial cells, Endocannibanoid receptors, can deminish’s chronic pain.
What is a reflex?
A sensory neuron that sends a signal through the dorsal root of the spinal cord, to the inter neuron, and then to a motor neuron bringing about the reflex. A reflex arc.
What are the components of a reflex arc?
Genetically controlled Receptor Afferent fiber Inter neuron Efferent fiber Effector
What is a flexor?
A reaction that decrease the angle between two bones.
What is extension?
Increases the angle between two bones.
Flexor muscles and extensor muscles are ______________ to each other.
Antagonistic.
They’re antagonistic because if they contracted at the same time there would be no movement.
What is the withdrawal reflex?
A protective flection reflex, spinal reflex. Receptor sends signal to spinal cord, reacts with 2 inter neuron, 1 synapses with a flexor motor neuron (excitatory) and the other synapses with extensor motor neuron (inhibited). Flexors activated and inhibition of extensors.
What are poly synaptic reflexes?
Reflexes that posses multiple synapses between inter neurons, motor neurons, and sensory neurons.
What is cross extensor reflex?
It is the innervation of two limbs where extensors are excited in one and flexors are excited in the other. Strong stimulus creates a summation effect on 4 inter neurons creating a crossover effect, thus effecting 2 limbs.
What is a stretch reflex?
Activated by stretching the muscle, a change in muscle shape, causing a shortening of a muscle. An encapsulated receptor, a muscle spindle, contains intrafusal fibers have sensory fibers (alpha sensory) that detect muscle stretching, enter the dorsal root, and synapses directly with a motor neuron in the ventral root (alpha motor)
What kind if reflex is a stretch reflex?
A monosynaptic reflex.
What is alpha gamma coactivation?
Adjusts spindle sensitivity to muscle length
What is the inverse myotastic reflex?
Tension is the stimulus. The Golgi tendon organ, a receptor, responds to tensions, and inhibits muscle innervation.
What is involved with descending signals?
The motor cortex Signal modification (cerebellum, basal ganglia)
What is the cortical spinal pathway?
A paired motor pathway from the brain that cross over at the brain stem, pyramid decrization.
What are proterosomes?
Destroy abnormal proteins in cells.
Where is the Golgi tendon organ, and what does it do?
A receptor in a tendon, responsible for inhibition of a muscle group to protect from over contraction.
What induces sleep?
Andenosine and histamine. Histamine is most important.
What is Non REM Parasomnia?
You are unconscious, but still preforming motor functions (driving, eating, murder).
What happens during Non REM sleep?
Sowing down of metabolic activities, decrease in resperation, heart rate, temperature.
What triggers Non REM sleep?
Sleep On Neurons in the cerebrum.
What occurs during REM sleep?
Rapid Eye Motion Sleep and dreaming. Development of sleep paralysis.
What allows you to enter REM Sleep?
“Sleep On Neurons” found in the brain stem.
What is the condition in which you enter sleep paralysis while awake?
Narcolepsy
What device can measure brain activity?
EEG (Electroencephalogram)
How many cycles per second do alpha waves in the brain have?
8-13
How many cycles per second do beta waves in the brain have?
14-25
Which brain wave corresponds to sleep?
Delta waves with about 3 cycles per second.
What is autism?
A syndrome with a broad spectrum where the hippocampus, memory center, and amygdala, emotional center, and neurons, called mirror neurons, are effected.
What are mirror neurons?
Allow a person to recognize the outcome of a certain event, such as life threatening situations.
What causes autism?
- Medication called Flutamide, alleviated morning sickness.
- Genes
- Very speculative
What causes Alzheimer’s?
- Abnormal accumulation of APP-peptide, causing apoptosis of neurons.
- Abnormal Tao protein that makes up neurofilaments in cytoskeleton. Become hyper phosphorylation creating neural fiber tangles.
What is savant syndrome ?
A mentally challenged individual with a low IQ where during brain development damage occurs in the left hemisphere but the right hemisphere enlarges and takes over and enlarges. Theory suggests that the right hemisphere of the brain that helps faster. Could be caused by early exposure to testosterone in the uterus.
What is Huntington’s disease?
A genetic disease on autosome #41 causing a deterioration of brain cells between the ages of 30 and 40. Huntingtin defective protein causing glutamine to be generated in long protein. Possesses genetic anticipation.
What is Williams syndrome?
Genetic cause, a loss of at least 20 genes during myosis causing defects in the right hemisphere of the brain and and compensation of the left hemisphere. Elastase is lost which breaks down elastin creating elf like features.
What is synesthesia?
The activation of two sensory centers at the same time activating two senses at a time
Ex: seeing colors while reading
What is a closed circulatory system?
The maintaining of blood within a series of tubes or vessels.
What do arteries do?
Carry blood away from the heart.
What do veins do?
Carry blood towards the heart.
What is microcirculation?
Circulation in capillaries, arterials, and venules.
What is macro circulation?
Circulation in the heart, veins, and arteries.
What are the three circuits of blood flow?
Coronary circuit- flow of blood through the heart.
Pulmonary circuit- blood flow between the heart and lungs.
Systemic circuit- blood flow from heart to body.
What is portal blood flow?
Flow from capillaries, to veins, and back to capillaries. The hyppattic portal system and hypothalamus to pituitary.
What’s the significance of having so many capillaries in the body?
For easy exchange of blood and cells.
What feature allows for easy exchange at the capillaries?
One cell layer thick, simple epithelium.
What are the three types of capillaries?
Continuous- predominates in the brain, basal lamina connected by tight junctions
Fenestrated- predominates in endocrine glands and kidney, capillaries with with perforations and a continuous basal lamina
Sinusoidal- predominates the liver and spleen, large openings between epithelial cells with a discontinuous basal lamina.
What composes veins and arteries?
Tunica Interma- composed of simple squamous
Tunica Media- made of circular smooth muscle, can contract. Thick in arteries thin in vein.
Tunica Adventitia- contains blood vessels, nerves, glands; binds with external structures.
What modification do veins have that arteries lack?
Presence of valves, allows for uni-directional blood flow. Extensions of the tunica Interma.
What is auto regulation of blood flow?
The local regulation of blood flow by decreasing the resistance in Venules by having smooth muscle relax (dilate). Active hyperemia is an example.
What is reflex blood flow?
Effected by nervous system, sympathetic and parasympathetic with norepinephrine as the neurotransmitter, causing vesso constriction.
What is end diastolic volume? What maintains EDV?
The volume of blood in the ventricles prior to contraction. Muscle pump, contraction of muscles from moment (walking around). Respiration also squeezes blood below the diaphragm creating a pressure gradient. Can also be maintained by sympathetic innervation.
What is the primary mechanism where materials are transferred from the ECF to capillaries?
Simple diffusion
Where is carrier mediated transport the primary mechanism where materials are exchanged between the ECF and capillaries?
In the brain
What is the vesicular movement?
A vesicle forms, binds, and releases it’s materials through exocytosis.
What is bulk flow?
Provides a transport mechanism for materials into the ECF, from plasma to the ECF and ECF to plasma, at the capillary level.
What is the function of a four chambered heart?
To provide tissues, organs, and cells with oxygen and nutrients. O₂ deficient and O₂ rich blood never mix.
What structures are found in the heart?
L and R artria (receiving chambers)
L and R ventricles (contracting chambers)
Septum separates the chambers (intertween and atrial septum)
Valves (bicuspid/mitral valve on left and tricuspid on right)
What are valves made of?
Fibrous skeleton, cardiac connective tissue.
What are the three layers of tissue is associated with the heart?
Pericardium- turns into the epicardium from the pericardium sacs
Myocardium- thickest layer, the middle layer.
Endocardium- lining of the heart, made of simple squamous endothelium.
What blood vessels are associated with the left atrium?
Four veins, the pulmonary veins, that bring oxygen rich blood back. Enters the left atrium, and leaves through the aorta, the largest artery in the body.
What blood vessels are associated with the right atrium?
Two large veins, the inferior and superior vena cava, supply oxygen deficient blood. as blood passes through the bicuspid and into the right ventricle, it enters the pulmonary artery to become oxygenated in the lungs.
What is the normal sequence of events of a heartbeat?
The atria contract as the ventricles relax, when the ventricles contract the atria are relaxing. Systally contractions and dystol are relaxations. Allows for uni-directional blood flow.
What prevents valve prolapse in the heart?
Two structures: Cordi tendoni (heartstrings)- strong connective tissues that attach to the base of the heart to papillary muscles.
What are the structural components f the aorta?
Ascending aorta- three branches, subclavian (on left) common carodic (external and internal branches on left) and the brachial sympatic (right subclavian and right carodic)
Aortic arch-
Descending aorta- all major arteries branch off from this location
Coronary arteries- branch off from the aorta and supply blood to the heart.
How does the autonomic nervous system control and regulate the heart?
Sympathetic- 2 accelerator nerves and norepinephrine neurotransmitter reacting with beta 1 receptor. Speeds up heart rate and the force of contraction.
Parasympathetic- Vegas nerves and ACH neurotransmitter reacting with muscarine receptor. Slows down heart rate and decreases the force of contraction.
What regulates the heart beat?
The conduction system and gap junctions control and regulate heart rate.
Cardiac cells are:
Striated, branched, post mytotic, syncytial, 2 or 3 nucli, and a intercalated disc.
The intercalated disc has a desmosome, an adhesion junction, and gap junctions to signal other cardiac cells.
What is the conductance system in the heart?
1) SA Node (pacemaker)- initiates heartbeat (myogenic cells)
2) AV Node- slows signal down to prevent the atria and ventricle’s from contracting at the same time.
3) Bundle of Hiss-
4) Pukingie fibers-
Pacemaker cells are dependent on what ion?
Ca
What does the QRS Complex represent?
Atrial repolarization and ventricle depolarization
What does T- wave represent?
Ventricular repolarization
What does the PQ interval represent?
The slowing down of the the signal from the AV Node
What is excitation coupling in cardiac muscles?
AP in the sarcolemer of cardiac muscles AP moves down the transverse tuble In T-tuble AP encounters DHP DHP opens Ca channels Ca influx creates voltage gaiting effect on RYR causing Ca to surge out ELECTROCHEMICAL COUPLING
What are long lasting Ca channels?
L-Ca channels allows Ca to enter the sarcolemma from the ECF.
In the heart what does calcium bind to?
Ca binds to the C site on troponin.
In cardiac contractile muscle cells why is there a plateau phase during the action potential? Why is there a delay in repolarization?
K channels are closing, however L-Ca channels take a longer time to open before it can close this allows Ca to enter the cell for longer periods of time. This causes positive ions to be inside and outside the cell. This contraction is Na dependent.
What is cardiac output?
Rate (L/min) and Stroke Volume (L/beat)
What factors can effect heart rate?
Sympathetic and parasympathetic nervous system.
Sympathetic- rate and contraction force increases
Parasympathetic- rate and contraction force decreases
Hormones- glycogon, epinephrine, and others.
Electrolytes
Temperature
What changes stroke volume?
Changing end diastolic volume (EDV).
EDV- the volume of blood in the ventricles during relaxation
What effects EDV (end diastolic volume)?
Venus return pressure, increase in pressure from vesso constriction increases EDV. Pressure increases effect ventricle walls by stretching ventricle walls creating a more forceful contraction (Starlings Law of the Heart).
What is Starlings Law of the Heart?
An increase in pressure of ventricle walls to increase the force of contraction.
What is ANF (Antinuritic Factor)?
A natural blood pressure lowering hormone, by promoting the excretion of Na and water in the kidneys. The substances are excreted because it changes blood volume.
What increases contractility?
The sympathetic nervous system.
What is aldosterone?
Works predominately on the kidneys and promotes the absorption of Na and water in the distal convoluted tubule and collecting duct. Aldosterone is inhibited by ANF.
Which hormone is phylogenetically conserved?
ANF (antiniuretic factor)
What is endothelin?
Produced in the endothelium of the heart, induces vasoconstriction effecting blood flow.
During repolarization and cardiac cells, what is happening with the K channel?
K is opening while L-Ca are closing. L-Ca take a long time to open/close, having positive charges on both sides of the membrane creating a delay.
What contributes to resistance in small vessels?
The size of the lumen, it’s diameter. The larger the diameter the less pressure is exerted, the smaller the diameter the more pressure is exerted.
What is peripheral resistance?
Is the amount of pressure in the vascular system at any given time.
Where is the cardiac control center located?
The Maduell oblongata, controls cardiac output.
CIC- cardiac inhibitory center (neural control of cranial nerves from the parasympathetic)
CAC- cardiac accelerator center (neural control from sympathetic
accelerator nerves)
How do CAC nerves work?
By releasing norepinephrine, effecting the B1 receptor, and increase rate/force of contraction. Also effects peripheral vessels by inducing construction. Increases blood pressure.
How do you CIC nerves work?
The vagus nerve (left and right) contain parasympathetic nerve fibers and release ACH and binds to muscarine, causing a drop in rate/contractility. Decreases blood pressure.
What is the Baros Receptor Compex?
Activates from an increase in blood pressure and responds by lowering pressure. Baro receptors are mechanical receptors that respond to distortion of the vessel wall stretching from increased pressure. Baro receptor in the aortic arch, the aortic arch baro receptor, cardiac artery, cardiac sinuses, detect pressure change and lowers the pressure. Detects pressure changes by Glossopharyngeal and Vagus (afferent pathways)
What is tachycardia?
Accelerated heart rate, approximately 200 bpm, and can be lowered by corardic massage (exerts pressure on the baro receptor).
What is brachycardia?
Extremely low heartbeat, that could cause a person to faint. Poorly delivering blood to organs and other parts of the body.
What is orthostatic hypotension?
Low blood pressure because the baro receptor reflex is still effecting blood pressure regulation.
What are coronotropic factors?
Effect heart rate, either positive to increase heart rate (norepinephrine) or negative to decrease heart rate (ACH) coronotropic factors
What are ionotropic factors effecting the heart rate?
Change the contractility of the heart, positive increases contractility (norepinephrine) or negative decreases contractility (ACH)
What improper electrolyte balances will throw off heart rate?
Ca, Na, K
What is hemorrhaging?
Excessive blood loss (decrease in blood volume), sympathetic activation will constrict vessels to conserve blood except in heart and brain.
What is hypertension?
High blood pressure (over 150/90). Can cause many issues:
Stroke
Hemorrhage
Heart disease
What is carcinogenic shock?
Insufficient blood flow to the heart
What is FAC?
Familial hypertrophic cardiomyopathy; genetic disease caused by a dominant gene creating an abnormally large heart. Results in arythmias (stops pumping blood).
What is atherosclerosis?
A build up of LDL, lipid material, in vessels. Leads to clotting and embolisms.
What is the lymphatic system composed of?
A group of organs tonsils, spleen, thymus, and lymph nodes. Primarily function in defense against pathogens.
What does the lymphatic system produce to defend against pathogens?
Lymphocytes:
• B-cells- adaptive immune reaction, produce antibodies
• T-cells- adaptive immune reaction, cell mediated immunity. An antigen presenting cell.
What is endothelin?
Heart hormone that promotes veso constriction
ACH acts via what receptor?
Muscarine receptor
Myogenic cells in the heart rely on what ion?
Ca
What is cytopempsis?
Active vascular movement
Papillary muscles and heartstrings prevent _____________ in the heart.
Prolapse
What is starlings principle?
Balance between osmotic and hydrostatic pressure
What is the formula for cardiac output?
BPM • L
What’s a lacteals?
Lymphatic system can absorb fat in a lymphatic capillary, lacteals, found in the villus of small intestine.
What is systole?
Contraction
What is distal?
Relaxation
What is the sensuous membrane component in the heart?
W
What is chylomicrons?
Transports dietary lipids
Vasodilation of blood vessels is induced by NO because it activates the enzyme ____________ within smooth muscles of vessel.
Guanglyl cyclase
What is the ductus venosa?
A pathway for blood to bypass the liver in a fetus.
What are fossa ovalis?
The fossa ovalis is a depression in the right atrium of the heart, at the level of the interatrial septum, the wall between right and left atrium. The fossa ovalis is the remnant of a thin fibrous sheet that covered the foramen ovale during fetal development.
What becomes the internal iliac arteries after birth?
Umbilical arteries
What is phospholamdin?
Activates SERCA
