Final Exam Flashcards
1
Q
What do photoreceptos do when stimulated/light stimualtion?
A
They hyperpolarize on light absorption
2
Q
The greater the number of muscle fibres required to contract, the greater the…?
A
the greater the total muscle tension
3
Q
What is muscle Fatigue?
A
The inability to maintain muscle tension at a specified level
4
Q
In what two ways is the stapes dissipated in the ear? Which results in sound reception?
A
- ) Displacement of the round window-Stapes pulls the oval window backward that dissipates pressure
- ) Deflection of the basial membrane, which allows for sound reception, allows for this because the hair cells on the basial membrane move up and down as the basial membrane oscillates
5
Q
What are the 3 different steps in the contraction-relaxation process that require ATP? What does each step do/allow?
A
- ) Spliting of ATP on the myosin head by myosin ATPase
- This provides the energy for the power stroke of the cross-bridge - ) The binding (not splitting) of a fresh molecule of ATP to the myosin head
- This lets the bridge detach from the actin filament at the end of the power stroke so that the cycle can be repeated - ) Active transport of Ca2+ back into the SR during relaxation
- This depends on the energy derived from the breakdown of ATP
6
Q
What is the Olfactory Mucosa? What does it contain?
A
is a patch of mucosa in the ceiling of the nasal cavity that contains 3 cell types: Olfactory receptor cells, supporting cells (secrete mucus) and basal cells
7
Q
What cells terminate in the glomeruli and refine the smell signals and relay them to the brain for further processing?
A
Mitral Cells
8
Q
What is Intensity (loudness) discrimination? What happens hear consequently?
A
Depends on the amplitude of the vibration
the smallest detectable change is a constant fraction of the intensity of the stimulus
The greater tympanic membrane deflection is converted into a greater amplitude of basial membrane movement in the region of peak responsivness
9
Q
How does Botulism effect the NMJ?
A
- Blocks the relase of ACh that causes paralysis
- FLACCID paralysis
10
Q
Pacemaker activity/potential? What cells use this?
A
autorhythmic cells, their membrane potential slowly depolarizes between action potentials until the threshold is reached, at which time the membrane fires or generates an action potential
11
Q
Steps of the Spread of cardiac excitation?
A
A.)Before they depolarize they will hyperpolarize, this is because it allows both Na+ and K+ to work/flow through it…(“ If” channels are called hyperpolarization-activated channels or the ACN channels, second messenger channels (they are talking about cuclaic AMP)
B.) Calcium Transient channels will complete depolarization which is very SLOW
C.) Threshold is approx -40Mv
D.)Complete depolarization/rising phase where it ends up at 0mv and is due to a completely different channel open, it is the Ca+ L channel
E.) Repolarization is = to the current
12
Q
The steps involving the extracellular first messenger in the receptor of the G complex in the cAMP cycle occur in? and lead to?
A
The plasma membrane and leads to the activation of the second messenger
13
Q
What can amplification by second messenger pathway create?
A
Very low concentrations of extraceulluar chemical messengers, such as hormones can trigger pronounced responses
14
Q
Afterload on a heart? combination of?
A
Forces that the heart is contracting against, combination of EDV and pressure the ventricles are contracting against
15
Q
What is the neromuscular Junction?
A
When a motor neuron reaches a skeletal muscle, it divides into many terminal branches, each of which forms a neuromuscular junction with a single muscle cell (muscle fibre).
16
Q
Why will you never see summation in cardiac muscles? How long is the refractory period?
A
Because of the prolonged refractory period, refractory period is equal the time of the action potential
250Ms
17
Q
Lub-Dub-Swish?
A
Insufficient-diastolic, Insufficient semilunar valve
18
Q
What does the connective tissue surrounding the skeletal muscle do? What is it primarily made up of?
A
Made up of collagen and to a lesser extent elastin, it provides structure to the muscle and allows the the transfer of force to the bone. This provides tension for stabilization and/or movement.
19
Q
What is the fluid in the cochlea called?
A
perilymph
20
Q
What happens once a hormone is secreted?
A
The hromone travels in the blood to its distant target cells, where it regulates or directs a particular function
21
Q
What is Tropomyosin? What is its function?
A
Threadlike proteins that lie end to end alongside the groove of the actin spiral
22
Q
How does Myasthenia Gravis effect the NMJ?
A
-Is an autoimmune disease that is charcterized by extreme muscular weakness where the body produces antibodies against its own motor end plate ACh receptors (inactivates ACh receptors)
Treated with drug called neostigmine
23
Q
Why is left sided heart failture more dangerous?
A
Backward faiture of the left side leads to pulmonary odemea (excess tissue fluid in the lungs) because blood backs up in the lungs and inadequate blood flow to the kidneys which causes twofold problems
24
Q
Troponin
A
The protein complex is made up of 3 polypeptides units, one binds to tropomyosin, one binds to actin and the thrid binds to Ca+
25
Where is smooth muscle found?
Found in walls of hollow organs and tubes
26
What is a thick filament made up of?What do they form?
A thick filament is made up of myosin molecules lying lengthwise parallel to one another. Half are orientated in one direction and half in the opposite direction.
-The globular heads, which protrude at regular intervals along the thick filaments, form cross-bridges
27
In what 2 ways is sounds perceived in?
1. ) Amplitude of sound
- Volume/loudness of sound
- Meaured in dB(desibals)
2. ) Frequency of sound
- You measure the pitch of the sound here
- Number of waves arriving at your ear=Frequency (measured in hertz)
28
In cariac muscles cells interconnected by? and fibers are joined by?
Interconneced by gap junctions and fibres are joined in a branching network
29
In coronary blood flow most blood flow occurs during? Why?
Most blood flow occurs during diastole because the coronary vessels are compressed almost completely during systole
30
Which membrane holds the hair cells in the cochlea?
tectorial membrane
31
Endocrine system by contrast to the CNS does....?
Primarly controls activities that require duration rather than speed, regulates, cordinates, and intergartes cellular and organ function at a distance
32
What is the First and second heart sounds? What are they showing you? What kind of sounds are they?
1. ) Lub, showing you closure of the AV valve, low-pitch soft sound
2. ) Dub, Showing you closure of semilunar valve, High-pitch sharp sound
33
What are catecholamines?What are they secreted by? What is a primary example of one?
Hydrophilic hormone that is derived from the amino acid tyrosine and is specifically secreted by the adrenal medulla, Epinephrine
34
What two ways can you revive a failing heart?
Short term with the sympatheitc system which increases heart contracitabilty toward normal or by the kidneys, they retain salt and water and with this retention it increases plasma and increases stroke volume
35
What breaks away to start the cyclic AMP second messenger system? What enzyme is activated?
Alpha breaks away to start the mechanism/ chain reaction and will activate the enzyme adenylyl cyclase(This converts ATP into cyclic AMP that becomes the second messenger)
36
Normal pacemaker activity of the heart? 7 steps?
1.)Cardiac impulse originates at the SA node
2.) 3.)Action potential spreads throughout the right and left atria
Impulse passes from atria into ventricles through the AV node
4.)Action potential briefly delayed at AV node-Approx 100ms, this delay is important because we need to wait for the ventricle to refill with blood
5.)Impulse travels rapidly down the interventricular septum by means of a bundle of His
6.)Impulse rapidly disperses throughout the myocardium by means of Purkinje fibres
7.)The rest of the ventricular cells are activated by the cell-to-cell spread of impulse through gap junctions
37
What must happen in order for a substance to be smelled?
1. ) Be Sufficiently volatile (easily vaporized) some of its molecules can enter the nose in the inspired air
2. ) Be sufficiently water soluble so that it can dissolve in the mucus that coats the olfactory mucosa
38
Actin
Is the primary structural proteins of the thin filament
| Each Actin molecule has has a special binding site for attachment with myosin cross bridge
39
What are the 3 steps required for contraction-relaxation requiring ATP
1. ) Splitting of the ATP by mysoin ATPase providing energy for the power stroke of cross bridge
2. ) Binding of a fresh molecule of ATP to myosin that lets cross bridge detach from actin filament at the end of the power stroke so that the cycle can be repeated
3. ) Active transport pf Ca2+ back in the SR during relaxation
40
What 3 filaments are in smooth muscle?
1. ) Thick myosin filiaments
2. )Thin Actin filaments which contain tropomoysin
3. ) Filaments of intermediate size, which don't directly participate in contraction but are part of the cytoskeletal framework that supports the cell shape
41
What holds the AV valves in place and prevents back flow?
Chordae tendineae
42
Length-tension relationship
Maximal force can be achieved by on a subsequent titanic contraction, more tension can be achieved during tetanus when beginning at the optimal muscle length than can be achieved when the contraction begins with the muscle less than or greater than its optimal length
43
What does cross-bridge activity do?
Pulls the thin filaments inward relative to the stationary thick filaments, the myosin cross bridges from a thick filament can bind with the actin molecules in the surrounding thin filaments
44
Why are Rods more sensitive?
Because they can bring about action potentials in response to small amounts of light
45
What is Hypertrophy? When does it occur?
- It is an increase in mass or girth of a muscle and can be induced by a number of stimuli but most specifically resistance training
- Results primarily from the growth of each muscle fibre, rather than an increase in the number of muscle fibres
46
A1 receptors Vs A2 receptors what system do they use?
A1:
- elicits the desired response via the Ca2+ second messenger system
- Usually brings about an excitatory response
- Present in most sympathetic target tissues
A2:
- Binding of neurotransmitter to A2 receptor blocks cyclic AMP production on the target cell
- Activation brings about an inhibitory response in effector organ such as decreased smooth muscle contraction in the digestive tract
47
Difference between Inner ear hair cells and outer ear hair cells?
Inner ear hair cells transform the mechanical forces of sound into electrical impulses of hearing and communicate via a chemical synapse to afferent nerve fibres making up the auditory (cochlear) never
Outter ear cells enhance the response of the inner ear cells- the real auditory sensory receptors- making them more sensitive to sound intensity and high discriminatory between various pitches of sound
48
What is a Isometric Contraction?
-Is a contraction in which the muscle is activated, but instead of lengthening or shorting it's at a constant length
Does not move a load, but does create a force/tension just without moving a load
-Ex.) Yoga moves, planking
-Muscle length is unchanged
49
What is lateral inhibition? What does it increase?
Strongly excited cone pathways suppress activity in surrounding pathways of weakly stimulated cones, this increases the dark bright contrast to enhance sharpness of boundaries
50
In the sympathetic system during heart rate control what is released? what does it bind to? via?
Neurotramsitter norepeinephrine binds with B1 adreneric receptors nd is coupled to a stimulatory G protein that accelerates the Cyxlic AMP pathway in the target cells
51
During photoreceptor activity in the light what G-protein is activated? What enzyme does it use?
Transducin is used and degradtes cGMP
52
What does the corticospinal system mediate?
Performance of fine, discrete, voluntary movement of the hands and fingers
53
Role of Titian in skeletal muscles?
1. ) Helps stabilize the position of thick filaments in relation to thin filaments
2. ) Acting like spring, it greatly augments a muscles elasticity
Titan helps a muscle stretched by an external force to passively recoil or spring back to its resting length when the stretching force is removed
54
What is a photo receptor? what is its 3 layers? What two kinds are there?
- Is a specilized type of neruon in the eyes retina
- Rods and Cones
1. ) Outer segment, which lies closest to the eyes exterior, facing the choroid-Detects light stimulus
2. ) Inner segment- Lies in the middle of the photoreceptors lengths-contians all major organelles and metabolic mechanisms
3. ) Synaptic terminal, lies closest to the eyes interior, facing the bipoloar cells- Transmits the signal generated in the photoreceptor on light stimulation to next cells in the visual pathway
55
Structures and functions of inner ear?
1. ) Chochlea-Oval window connects to this, sound goes into/through this tube like structure and exits the round window (exit point)
2. ) Vestibular apparatus-Invloved in balance and equilibrium
56
Sympathetic nerves supply? (Cardiac)
sympathetic nerves supply the atria and ventricles
57
What three proteins make up thin filaments?
Actin, tropomyosin and troponin
58
what are the 2 Abnormalities in heart rate?
1. ) Tachycardia- Fast heart rate ( more than 100 BPM)
| 2. ) Bradycardia-Slow heart rate (60 BPM)
59
3 reason why less muscle tension can be developed at muscle lengths less then Io?
1. )Thin filaments from the opposite sides of the sarcomeres become overlapped, which limits the opportunity for the cross bridge to interact with actin
2. )The ends of the thick filaments become forced against the Z-lines so further shortening is impeded
3. )Not as much Ca2+ is releasted during excitation-contraction coupling for unknown reasons
60
What is the prime defect in heart failure?
Decrsed caridac contractibalitly, cardiac muscles contract less effectively, intrinsic control
61
What is a single skeletal muscle cell, known as?
A muscle fiber
62
How is muscle contraction accomplished in thin filaments?
Contraction is accomplished by the thin filaments from the opposite sides of each sarcomere sliding closer together between the thick filaments
63
What are the purposes of neuroendocrine reflexes?
To produce a sudden increase in hormone secretion in response to a specific stimulus, frequency if a stimulus to the external body
Ex.) Increased secretion of cortisol (stress hormone) by the adrenal cortex during stress response
64
What does the enteric nervous system control?
Functions within the gestational tract and influences the pancreas, liver, gallbladder, thereby controlling gadtration motility, secretion, and blood flow
65
What is End-plate potential? What does its magnitude depend on? Where does it occur?
Is a small graded potential created by the NMJ that becomes a flow blown action potential to create a muscle contraction
-Its magnitude depends on the amount and duration of ACh at the end plate
66
What crinal nerve connected the cochlea and vestibular apparatus?
8
67
slow-oxidative (type I) muscle fibres have?
An abundance of mitochondria
68
3 portions of the neural portion of the retina? Outer to innermost layer?
1. ) Outermost layer closest to the choroid containing rods and cones
2. ) Middle layer of bipolar cells
3. ) Inner layer of ganglion cells
69
How do concave and convex surfaces distribute light rays?
Convex surfaces converge light rays (bring them closer together) where as concave surfaces diverge light rays (spread them farther apart)
70
Hormones and their metabolites are typically elminated from?
The blood by urinary excretion
71
Hormones secreted by the adrenal cortex such as cortisol, and the sex hormone secreted by the reproductive organs are?
Steroids
72
What is order discrimination based on?
Its based on different patterns of glomeruli activation achieved by various scents
73
At what 3 points in time on a ECG is no net current flow occurring so the ECG remains baseline
1. ) During AV nodal dely -PR segment
2. ) When the ventricles are completly depolarized and the cardiac contractile cells are undering going the plateau phase of their action potential before they repolarize-ST segment
3. ) When the heart muscle is completely repolarized and at rest znd ventricular filling is taking place after the T wave and before the next P wave-TP Interval
74
How are dense bodies held togehter in smooth muscle?
By intermediate filaments
75
What two structures in a muscle cell interact to form a cross bridge?
Actin and myosin
76
What is the point of distinct vison? Why? what area surrounds it?
The fovea, because it contains only cones, the macula lutea directly surrounds the fovea
77
How are bitter taste receptors activated?
This mechanism expands the ability of the taste receptor to detect a wide range of potentially harmful chemicals. The first G protein in taste—gustducin—was identified in one of the bitter-signalling pathways. This G protein, which sets off a second-messenger pathway in the taste cell, is very similar to the visual G protein, transducin.
78
What is the area between two Z lines called?
Sarcomere
79
what two proteins are Contractile Proteins?
Myosin and Actin
80
What is AChE function? What does it allow?
AChE inactiavtes ACh,
- Removal of AChe end the EPP, so that the remainder of the muscle cell membrane returns to rating potential
- AChE permits the choice of allowing relaxation to take place (no more ACh released) or keeping the contraction going (more ACh released) depending on the body momentary needs
81
Contractile cells Vs Autorhythmic cells?
Contractile cell-account for 99% of cardiac muscle cells and do the mechanical work of pumping
Autorhythmic cells- Do not contract but are specialized for initiating snd conducting the action potentials responsible for contraction on the working cells
82
1.) What neurotransmitter does parasympathetic post ganglion fibres release? 2.) What neurotransmitter do Sympathetic post ganglion fibres release?
1. )Acetylcholine
| 2. ) Norepinephrine
83
How are skeletal muscles stimulated to contract?
By the release of acetylcholine at the NMJ between motor-neuron terminals and muscle fibres
84
What two factors are important/needed to accomplish gradation of whole-muscle tension?
1. ) Number of muscles fibres contracting within a muscle (motor unit recruitment)
2. )The firing frequency of each contracting fibre (frequency of summation)
85
During muscle relaxation what threadlike protein covers cross bridge bridging sites on actin?
Tropomyosin
86
Frank-Starling Law of the heart
Force you create is related to the stretch of the heart
- What ever you bring in during stretch you will pump out during stroke
- The heart pumps out during systole the volume of blood returned to it during diastole
- Increased venous return results in increased stroke volume
87
What is the Optimal IO length structure of a skeletal muscle? What happens at this length?
Thin filaments optimally overlap the regions of the thick filaments from which the cross-bridge binding sites
-At this length a maximal number of cross-bridge binding sites are accessible to the myosin molecules for binding and bending
88
What does the term muscle excitation-contraction coupling refer to?
the series of events linking muscle excitation (presence of an action potential in a fibre) to muscle contraction (cross-bridge activity that causes thin filaments to slide closer together to produce sarcomere shortening)
89
What is a hormone?
A chemical substance that is secreted in low quantities into the blood by a cell or grouping of cells and exerts a physiological effect on specific target tissue
90
Does Smooth muscle contain intermadiate filament? and tropomyosin?
yes
91
Why are tropomyosin and troponin called regulatory proteins?
Because of their roles in preventing or permitting muscle contractions
92
All horomes ultimate influence their target cells by altering the cells proteins through what 3 general means?
1. ) Few hydrophilic hormones on binding with a target cell surface receptors, change the cells permeability by altering the conformation (shape) of adjacent channel forming proteins already in the membrane
2. ) Most hydrophilic hormones function by activating second messenger systems within the target cell this activation directly alters the of intracellular target proteins (usually enzymes) to produce the desired effect
3. )All lipophilic hormones function mainly by activating specific genes in the target cell to cause formation of new intracellular proteins, which in turn produce the desired effect (can be structural or enzymatic)
93
Compare the relationship of myofibrils and a muscle fibre with the relationship between muscle fibres and a whole muscle
A muscle fibre is composed of myofibrils that extend the entire length of the muscle, in general, the larger-diameter muscle fibres have a greater number of myofibrils. A whole muscle is composed of muscle fibres that extend the entire length of the muscle; in general, the larger diameter muscles have more muscles fibres
94
What 4 factors play an important role in plasma concentration in the endocrine system?
1. )Hormones rate of secretion into the blood by the endocrine gland
2. )Rate of metabolic activity
3. )for lipid hormones: the extent of binding to plasma proteins
4. )Rate of removal from the blood by metabolic inactivation and excretion of urine
95
M line?
Extends vertically down the middle of the A band within the centre of the H zone
96
Hypersecretion?
(liker hyposecretion,)By a particular endocrine gland is designated as primary or secondary depending on whether the defect lies in that gland or is due to excessive stiumulation
97
What is another name for catecholamine receptors? or what are they? how do they act?
Adrenergic receptors, and epinephrine and norepinephrine , act through secondary messengers to transfer the signal from the cell surface into the cytoplasm, in order to influence metabolic process and thus cellular function
98
What two nerotrasmitter does that parasympatheitc Pre and Post ganglion fibre use?
Pre: Nicotinic
Post: Muscarinic
99
Skeletal muscle consists of?
A number of muscle fibres lying parallel to one another bundled together by connective tissue (fibres usually extend the entire length)
100
Larger muscles consiting of more muscle fibres can generate more....then smaller muscles with fewer fibres
Tension
101
Slow oxidative muscles Vs Fast Glycolic muscles
Slow oxidative:
-Has larger amount of mitochondria, high levels of myoglobin, low glycogen content and relatively few glycolytic enzymes
Fast Glycolic
-Has relatively few mitochondria, low levels of myoglobin, high glycogen content and an abundance of g;glycolytic enzymes
102
Forward pressure gradient Vs Backward pressure gradient? what is important to note about backward pressure gradient?
Forward pressure gradient forces the valve open while backward pressure gradient forces the valve close. Backward pressure gradient can force the valve closed but can't force it to swing open in the opposite direction (valves aren't like swinging doors)
103
Strength of cardiac muscle contraction and stroke volume can be graded by?
1. ) Varying the initial length of the muscle fibres, which in turn depends on the degree of ventricular filling before contraction (Intrinsic control)
2. ) varying the extent of sypmathritc stimulation (extrinsic control)
104
What is a hydrophilic Hormone? long chan Vs short chain
A hormone that has high water solouablitly and low lipid solubility, most are peptide or protein hormones consisting of specific amino acids arranged in a chain of varying length.
Short chains: Peptides
Long Chains: Protiens
105
The field of view that can be seen without moving the head is known as?
The visual field
106
What does whole muscle tension rely on?
1. ) Frequency of stimulation
2. )Length of the fibre at the onset of contraction
3. )Extent of fatigue
4. )Thickness of fibre
107
Function of ganglion cells in eye?Location?
Important in retinal processing of light stimulus, form optic nerve
-inner layer of nerve cells in retina
108
Three main layers of the eye from outermost to innermost layer?
1. )Sclera/cornea
2. )Choroid/ciliary body/iris
3. )Retina
109
Diurnal (circadian) rhythm
repetitive oscillation in hormone levels that are very regular and cycle once every 24 hours
110
What does the myofibril display in skeletal muscles?What do they produce?
Display alternating dark A bands and light I bands, The bands of all myofribils lined up parallel to one another collectively produce the striated or striped appearance of skeletal muscle fibres
111
How is salty taste receptor potential activated?
Direct entry of positively charged Na+ ions through specialized Na+ channels in the receptor potentials membrane, a movement that reduces the cells internal negativity, is responsible for depolrization in response to salt
112
Positive feedback loops in endocrine system?
Not common, the release of oxytocin during childbirth is the best example
-Positive feedback means that the actions of a hormone cause further release of the hormone
113
What is a sarcomere? what are the 4 regions?Where are they found?
- The smallest component of a muscle fibre that can contract
- Found between two Z-lines
- Contains A band, H zone, M line, and I band
114
Pulmonary circulation Vs Systemic circulation?
Pulmonary-consists of a closed loop of vessels carrying blood between the heart and lungs, systemic circulation is a circuit of vessels carrying blood between the heart and other body systems
115
How does each half of the visual cortex receive information?
Simultansoly from the same part of the visual field as received by both eyes
116
1. ) Sclera?
2. )Cornea?
3. ) Choroid? What does it become anteriorly?
1. ) Forms visible white part of eye
2. )Transparent outer layer through which light rays pass into the interior of the eye
3. )Middle layer underneath the sclera, which contains blood vessels that nourish the retina, becomes specialized anteriorly to form the ciliary body and retina
117
Factors that can influence how much tension can de developed by a contracting muscle fibre? How do they vary?
Frequency of summation and the muscle length at the onset contraction
118
What does the premotor and supplementray motor areas mediate?
Plan voluntary motor command that is issued to the appropriate motor neruons by the primary motor cortex through the descending system
119
1. )Glycolytic (anaerobic) Yeild how much ATP?
| 2. )Oxidative (Aerobic) Yeilds how much ATP?
1. ) 2 ATP Glycolysis
| 2. ) 38 (36 according to binthi) Glycolysis, KREB, ETC
120
Wavelength Vs Intensity?
Wavelength is the distance between two wave peeks where as intensity is the amplitude of the wave
121
Location/binding sites for hydrophilic and Lipophilic Hormones?
Hydrophilic bind with specific receipts located on the outer plasma membrane surface of the target cell
Lipophilic Sterioids and thyroid horomes easily pass through the surface membrane to bind with specific receipts located on the Inside of the cell
122
In smooth muscle where does it store or where does Ca2+ come from? and what does it do?
Comes from the SR and draws out major amounts of Ca+ from the ECF
123
Complete heart block? Artificial pacemaker? Ectopic Focus?
CHB- When conducting tissue between the atria and ventricles is damaged
AP-When a person has an abnormally low heart rate, SA node failure
EF-Abnormally excitable area, imitates premature action potential that speed through the rest of the heart
124
In smooth musdles how does calcium ultimately turn on cross bridges?
By including a chemical change in myosin in the thick filaments
125
What structure serves as the first relay station in the brain for processing olfactory information and plays a key role in organizing scent perception?
Glomeruli
126
Order of recruitment in a skeletal muscle fibre?
Slow twitch-fast twitch A-fast twitch X
127
What two neurotransmitters are used for effector neurones?
Acetylcholine and norepinephrine
128
what are Amine Hormones?
Steriod and Thyroid hormones coming together because of their common tyrosine derivation
129
How is sweet taste receptors activated?
Sweet taste is evoked by the particular configuration of glucose. Binding of glucose or another chemical with the taste cell receptor activates a G protein, which turns on the cAMP second-messenger pathway in the taste cell. The second-messenger pathway ultimately results in phosphorylation and blockage of K+ channels in the receptor cell membrane, leading to a depolarizing receptor potential.
130
How deos Organophosphate affect the NMJ?
-Is a group of chemicals that modiy the NMJ by irreversibly inhibiting AChE, this inhibition prevents the inactivation of released ACh, death from this is due to respatory failure because the diaphragm can not replarize and return to resting conditions
131
Lub-Swish-Dup?
Insufficient, systolic, Insufficient AV valve
132
What are the two Cholinergic receptors that ACH has?
1. ) Nicotinic receptors-excitatory, a by-product of tobacco plant (Receptors in the ganglion are nicotinic receptors that are excited by nicotine)
2. ) Muscarinic Receptors- Excited by muscarine (Poisson)
133
Right half of heart receives? while left side receives?
Right- O2 poor blood
| Left-O2 Rich blood
134
What is the Vomeronasl organ (VNO) responsible for?
It detects pheromones and is sometimes referred to as the "sexual nose"
135
What is the result of a cascade of amplification events, with one triggering the next event in sequence is?
Is a tremendous amplification of the initial signal
136
Small motor units allow for?
Very fine control over muscle tension
137
What is the common precursor for all steroid hormones?
Cholesterol
138
Describe the relationship between actin, tropomyosin, and troponin in a relaxed muscle?
The regulatory protein, troponin, binds to both actin and tropomyosin. In the relaxed state, troponin assumes a conformation that causes tropomyosin to cover the myosin cross-bridge binding sites on the actin molecules
139
What does a targets cells response to a hormone correlate with?
The number of cell receptors occupied by molecules of that hormone which depends not only on the plasma concentration of the hormone but also on the number of receptors in the target cell for that hormone
-The response of a target cell to a given plasma concentration of a hormone can be fine-tuned up or down by varying the number of receptors available for hormone binding
140
What is a Isotonic Contraction? What two kinds are there?
- It is creating a force and moving a load (working out)
1. ) Concentric Contraction
- Dynamic contraction that produces tension during a shortening motion
- Actin filimanets are pulled together by the myosin filmanets which move the Z lines together shortening the sarcromere, shorting the whole muscle
- Moving a load towards the centre of the body, needs to be a slow movement for good movement
- EX.) Bicep curl
2. ) Eccentric Contraction
- Dynamic contraction that produces tension while lengthening
- Going away from the centre of the body
- Needs to be even slower than concentric contraction because it can cause injury
- Actin filaments are pulled apart, moving the Z lines farther from the center and lengthening the sarcomere, which lengthens the whole muscle
141
Diastolic failutre Vs Systolic failture?
Systolic faliure= the decrease in cardiac contractility,
| Diastolic= Heart has trouble filling, does not pump out as much blood as it should
142
What are the events at the NMJ?
1. ) An action potential in a motor neuron is propagated to the axon terminal (terminal button)
2. ) This local action potential triggers the opening of voltage gated Ca2+ channels and the subsequent entry of Ca2+ into the terminal button
3. ) Ca2+ triggers the release of ACh by exocytosis from a portion of the vesicles
4. ) ACh diffuses across the space separating the nerve and muscle cells and binds with receptor channels specific for it on the motor end plate of the muscle cell membrane
5. ) The binding brings about the opening of these nonspecific catian channels, leading to a relatively large movement of Na+ into the muscle cells compared to a smaller movement of K+ outward
6. ) The result is end-plate potential. Local current flow occurs between the depolarized plate and the adjacent membrane
7. ) The local current flow opens volatge- gated Na+ channels in the adjacent membrane
8. ) The result Na+ entry reduces the potential to threshold, initiating an action potential, which is propagated throughout the muscle fibres
9. ) ACh is subsequently destroyed by AChE, an enzyme located on the motor-end- plate membrane, terminating the muscle cells response
143
Slow wave potential Vs Pacemaker potential? Where are they found?
Slow:
- Smooth muscle (in Digestive Tract only)
- Gradual alternating hyperpolarizing and depolarizing swings in potential caused by automatic cycle changes in active ionic transport across the membrane
- Produce a bunch of action potential once the threshold is reached if a depolarizing event brings the membrane to threshold
Pacemaker:
- Smooth muscle, cardiac muscle
- Gradual depolarization of the membrane on its own because of shifts in passive ion fluxes accompanying automatic changes in ion permeability
- Only fire when they need to
- Always depolarize at the threshold
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What is the role of the vestibular apparatus? What does it consist of?
The portion of inner ear provides essential information for the sense of equilibrium and for coordination of head movements with eye and postural movements
Consist of Semilunar canals and Otolith organs
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Role of the middle ear? how is this accomplished?
Transfer the vibratory movements of the tympanic membrane to the fluid of the inner ear, accomplished by movement of the ossicles
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SA Node
AV Node
Bundle of HIS and Purkinje Fibers
SA Node: In the right atrial wall, a normal pacemaker sets the pace of beating the heart at 70-80-BPM
AV Node: At the base of the right atrium close to the septum, 40-60BMP
Bundle of HIS: atrioventricular bundle- originates at the AV node and enters the interventricular septum, latent pace making 20-40BPM
Purkinje Fibers: extend from the bundle of HIS and Spread throughout the ventricles to conduct very fast electrical activity
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What is located in the middle of each I band?
Z line
148
What is a Thrombolembolism?
The enlarging atherosclerotic plague can break through the weekend endothelial lining that covers it
-Can enlarge gradually until it completely occulates the vessel at that site
149
DO endocrine glands secret their hormones at a constant rate?
No, secretion of hormones vary, subject to control often by a combination of several complex mechanisms
150
What are the two Cholinergic receptors that ACH has?
1. ) Nicotinic receptors-excitatory, a by-product of tobacco plant (Receptors in the ganglion are nicotinic receptors that are excited by nicotine)
2. ) Muscarinic Receptors- Excited by muscarine (Poisson)
151
How is the entrance of the ear canal guarded?
By fine hairs and modified sweat glands that produce cerumen (ear wax)
152
How is muscle tension transmitted?
By tightening of series of elastic components (connective tissues and sheaths)
153
What is needed in order to focus on both distant and near light sources in the same distance?
A stronger lens must be used for the near source
154
What functional protein is not found in smooth muscle?
troponin
155
Fibres leaving the olfactory bulb travel in two different routes? What are they?
1. ) A subcortical route going primarily to regions of the limbic system, especially the lower medial sides of the temporal lobes (considered the primary olfactory cortexA portion of the cortex involved in olfaction). This route, which includes hypothalamic involvement, permits close coordination between smell and behavioural reactions associated with feeding, mating, and direction orienting.
2. ) A route through the thalamus to the cortex. As with other senses, the cortical route is important for the perception and fine discrimination of smell.
156
What is a tropic hormone? What is its function?
Primary function of the regulation of hormone secretion by another endocrine glass, they stimulate and maintain their enclosed target tissues
Ex.) TSH
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What is a single-unit smooth muscle (myogenic) what do they maintain? How?
- Is a self-excitable cell that does not require nervous stimulation for contraction
- Does not maintain a constant resting potential, instead their membrane potential inherently fluctuates without any influence of external factors to the cell
-Mainted by Pacemaker potentials and slow depolarization wave potentials
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What is pitch discrimination? How it its capacity defined?
The ability to distinguish between various frequencies of incoming sound waves, Narrow ends nearest to the oval window vibrate best with high wave frequencies pitches, whereas the wide end nearest to the helicotrma vibrates maximally with low frequency tones
159
T-tubules and sarcoplasmic reticulum in relationship to the myofibrils
The T-tubules are membranous, perpendicular extentions of the surface membrane that dip deep into the muscle fibre at the junctions between A and I bands of the myofibrils. The SR is a fine, membranous network that runs longitudinally and surrounds each myofibril, with separate segments encircling each A band and I band. The ends of each segment are expanded to form lateral sacs that lie next to adjacent T tubules
160
What are slow twitch and fast twich muscle fibers supplied by?
Slow-supplied by motor neruons that exibit a low frequency pattern of electrical activity
Fast-Innervated by motor neurons that display intermittent rapid bursts of electrical activity
161
The number of muscle fibres participating in the whole muscle's total contractile effort depends on?
The number of motor units recruited and the number of muscle fibres per motor unit in that muscle
162
What kind of vision do cones provide us with? How they influenced?
They provide us with sharp vision with high resolution for fine detail, A single ganglion cell is influenced by only one cone, bright daylight is intense enough to induce a sufficient receptor potential in the cone to ultimately bring the ganglion cell to threshold
-A small receptor potential induced by dim light in a single cone would not be sufficient to bring its ganglion to threshold
163
A motor unit is?
One motor neuron plus all the muscle fibres it innervates
164
What does the parasympathetic nerve Vegas nerve supply? (cardiac)
The atrium, especially the SA and AV nodes
165
What is atrophy? what are the two different kinds?
-Loss of muscle mass
1. ) Disuse Atrophy
- Takes place when the skeletal muscles are not physically stressed on a regular basis (muscles not worked out)
2. ) Denervation Atrophy
- Occurs after the nerve supply to a muscle is lost
166
What is the role of adenosine? (cardiac)
It indices dialtion of the coronoary blood vessels, which allows for more O2 rich blood to flow to more active cardiac cell to meet their increased O2 demand
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B1 receptors Vs B2 receptors Vs B3
```
B1:
-Have equal affinities for norepinephrine and epinephrine
-Found primarily in the heart
-Causes an excitatory response
-
```
B2:
- Typically bind with epinephrine
- Generally being about an inhibitory response
- Ex.) Respiratory system/ airways are controlled by this system
B3:
- Uses cAMP pathway
- Has excitatory effect
- Found in fat tissue or adipose tissue
168
What is Glaucoma?
Plugging of the canal of schemm-draining dosent happen and pressure builds up in the eye and as a result, the optic nerve is harmed and looses it capabilities to send its messages.
-Can lead to blindness
169
How is inherit hormonal rhythmicity and entrainment accomplished?
Not by the endcrine glands themselves but as a result from the CNS changing the set point of these glands
170
Lub-Whistle-Dup?
Stenotic, systolic, Stenotic semi-lunar valve
171
Cycilic AMP second messenger system steps?
1. ) Binding of extracellular messenger to receptor activates a G protein (alpha breaks away to start the mechanism/chain reaction which will activate adenylyl cyclase)
2. ) Adenylyl cyclase converts ATP to cAMP
3. ) cAMP will active protien Kinase A
4. ) Protein Kinase A in turn phosphorylates (attaches a phosphate group from ATP) inactive target protein, making it active
5. )Active target protein brings out desired response
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What is a vascullar spasm? what it is an early sign of? what causes it?
- Is an abnormal spastic constriction that transietly narrows that coronary vessels
- Triggerd by exposure to cold, physical exertion or anxiety
- Ealry stage of CAD
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The first half of pacemaker potential is due to? second half is due to? Once threshold is reached the rising phase of the action potential is due to the opening of? where as the falling phase is due to the opening of?
First half-T-If cells
Second half- T-type Ca2+ cells
Rising -openng ofL-type Ca2+ channels
Falling-Opening of K+ channels
174
What makes up the muscular system?
Skeletal Muscles
175
How does spider venom affect the NMJ?
- Causes respiratory paralysis as a result of depolrization of the diaphragm, during this "depolariing block" volatged gated Na+ channels are trapped in their inactivated state thereby prohibiting the initiation of new action potentials
- Explosive release of ACh
176
Parasympathetic stimulation decreases the rate of SA nodal depolarization so that the.....1... Where as sympatheotc stimulation increases the rate of depolarization of SA nodal so that the .....2
1. ) Membrane reaches threshold more slowly and has fewer action potential
2. ) Membrane reaches threshold more rapidly and has more frequent action potentials
177
Positive feedback loops in endocrine system?
Not common, the release of oxytocin during childbirth is the best example
-Positive feedback means that the actions of a hormone cause further release of the hormone
178
What is a Golgy tendon organ? What is its function? Where is it located?
-Located in the tendons of the muscles, where they can respond to changes in the muscles tension rather than to changes in its length
- Forms junction between muscle and tendon
- Highly provided with afferent neurons providing the CNS with messages about the tension or force created and how much the muscle can endure
- Made of a connective tissue capsule and inside the capsule are fibers that are sctterd all over making it a stong supportive structure with collagen and also contain little branches of the affrent neuron
-Protects the muscles from excessively heavy loads by causing the muscles to relax and drop the load. Tell us how much load we can carry/endure
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What happens as the frequency of action potentials increase in skeletal muscles?
Duration of elevated cytosolic Ca2+ concentration increases, and contractile activity likewise increases until a maximum titanic contraction is reached
180
3 layers of heart walls?
Endocardium-outer layer
myocardium-middle layer
Epicardium-inner layer
181
Why can we not support heavy object for very long?
Because during maximal contractions to move heavy loads, when all the muscle fibres must participate it is impossible to alternate motor unit activity to prevent fatigue
182
Z line?
a flat cytoskeletal disc that connects the thin filaments of two adjoining sarcomeres
183
Lower chambers of heart? function?
Right and left ventricles, which pump blood from the heart
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Semilunar valves are also known as? what are their functions? location?
Aortic and pulmonary valave, lie at the juncture where the major arteries leave the ventricles, only let blood go in forward direction, made up of 3 little cusps resembling half mood shape
185
How does Curare effect the NMJ?
Blocks action of acetylcholine at receptor sites at the motor end plate because of this muscle action potentials can no longer occur in response to nerve impulses so paralysis occurs
186
What is lacking at IO skeletal muscle length?What is found there?
Where thin filaments overlap at IO,acks cross bridges, only myosin tails are found here
187
Photoreceptiveabilitly in darkness steps? Where does each step occur
Occurs in Outer segment
1. ) Retinal in 11-cis form
2. ) High concentration of cGMP
3. ) Keeps Na+ channels in outer segment open
4. ) Depolaraztion of photoreceptor- This spread to synaptic terminal
Occurs in synaptic terminal
5. ) Opens ca2+ channels in synaptic terminal
6. ) Relases neurotransmitter
Further retinal processing in bipolar and ganglion cells
7. ) Hyperpolarization of on center biopolar cells-Leads to no action potential in on centre ganglion cells
8. ) Depolarization of off-centre bipolar cells-leads to action potentials in off center ganglion cells
9. ) Propagation to visual cortex
10. ) Receptor field of photoreceptor perceived as darkness
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Sound wave Transduction steps? What are the 4 transductions in sound?
1. ) Sound waves come to the pina and are redirected into the ear canal (external ear canal) and then it hits the tympanic membrane (eardrum) -First Transduction/change in modality
2. ) -Tympanic membrane then starts to vibrant the ossicles (malleus-tanaus-stapes)
3. ) The oval window starts to vibrate set the basil membrane in motion (Second Transduction) fluid waves
4. ) Receptive hair cells are bent as the basil membrane is deflected up and down-Basial membrane starts to vibrate, this vibration moves the hair cells towards the long hair cells (Depolarization, that releases neurotransmitters (Third transductions -Chemical transduction)
5. ) Mechanical deformation of specific hair cells is transduction into neural signals that are transmitted to the auditory cortex of the temporal lobe of the brain for 4th sound transduction-Look at textbook diagrams
6. ) Electrical signals/Action potential is the fourth Transduction
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What are the two promary diseases of the NMJ? what do they cause?
Polio
- Polio virus that is usally ingested
- Comes through contaminated water or food (GI tract that reaches NMJ)
- Attacts motor neurons
- Will cause cellular death and paralysis
Amyotropic Lateral Sclerosis (ALS)/ Lou-gehrigs
- Attacts neurofillamnts that form the neuron
- Distrucption of the mitochondria
- Slow paralysis
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What is a Lipophilic Hormone? What 2 kinds are there?
Have high lipid solubility and are poorly soluble in water
2 kinds
1. )Steroid hormones
- Reproductive hormones
- All hormones here are derived from cholesterol
2. )Thyroid Hormones
- Derived from an amino acid called tyrosine
- Iodine is added
- Tyrosine is modified here in the thyroid gland
- True endocrine gland
191
What is motor unit recruitment for weak contractions vs stronger ones?
For weak contractions of the whole muscle, only a few of its motor units are activated, For stronger and stronger contractions, more and more units are recruited, or stimulated to contract
192
Primary means by which O2 can be made available to the heart is? how is it adjusted?
By increasing coronary blood flow, adjusted primarly in response to changes in the hearts O2 requirements
193
Two major components of the ciliary body?
The ciliary muscles and capillary network that produces the aqueous humor
194
Permissiveness, Synergism and Antagonism of hormones?
Permissiveness:One hormone must be present in adequate amounts for the full exertion of another hormones effect, in esse the first hormone, by enhancing a target cells responsivness to another hormone "permits" this other hormone to exert its full effect
Synergism: Occurs when action of several hormones are complementary and their combines effect is greater than the sum of separate effects
Antagonism: Occurs when hormones have opposing effects
195
What does smooth muscle have instead of Z lines? how are they held in place?
Dense bodies containing the same protein constituent found in Z lines, they are held in place by a scafold of intermediate filaments
196
What is the resting potential of cardiac excitation cells?
-60Mv
197
Smooth muscle contraction steps (6)
1. ) Muscle excitation
2. ) Rise in cytosolic Ca2+ (mostly from ECF)
3. ) Series of biochemical events
4. )Phosphorylation of myosin cross bridges in thick filament
5. )Binding of Actin and myosin at cross bridges
6. )Contraction
198
The asynchronous motor unit reqruitment is only possible for?
Submaxial contractions, during which only some of the motor units must maintain the desired level of tension
199
Visual Pathway?
1. ) Light enters the eye
2. ) Once light enters the eye it leaves it and criss-crosses at the optic chasm
3. ) Then goes to the optic tract
4. ) Optic tract goes to the thalamus
5. ) To optic radiation
6. ) Visual cortex
200
In the parasympathetic system during heart rate control, what is released? and what does it bind to? Via?
Via cyclic AMP-second messanger system Acetylcholine is released from the vegas nerve and binds to a muscine receptor and is coupled to inhibitory G protein that reduces the activity of the cyclic AMP pathway
201
A common second messanger cAMP can include?
A widely dofferong responses in differnet cells, depending on what proteins are modified.
-The type of proteins altered by a second messenger depends on the unique specialization of a particular cell type
202
I band?
Remaining portion of thin filaments that don't project into the A band
203
What is Rhodopsin? What does it do? What do they produce?
Is the rod photopigment that absorbes ALL visible wavelengths, using visual input from the rods the brain can not discrimate between various wave lengths in the visible spectrum. Therefore rods provide vision on in shades of grey by detecting different intensity, not different colours.
204
What are the 3 kinds of cones? What do they do?
Red-Green-Blue, they respond selectivatly to various wavelengths of light making colour vision possible
205
Intrinsic control (cardiac)
Refrs to the hearts inherent abilitly to vary stroke volume, depends on the direct correlation between end-diastolic volume and stroke volume
206
In what 3 ways can hearing loss occur?
1. ) Conductive loss
- Exessive ear wax in this area can cause hearing loss, this can be reversed
- Infections can occur here as well (External or Internal ear canal), this can be reversed
- As long as structures aren't harmed hearing loss can be reversed
2. ) Central Loss
- Stokes, Damage to temporal lobe
- Loss in the neural pathway or In the cortical region (temporal lobe)
3. ) Sensorineural Loss
- Loss due to the sensory neural regions (hair cells) being unable to transduce sound
- Hearing aide can assist to correct this
- Irreversible, permanent, deafness (deafness leads to more suicide than any other loss of senses)
207
What is Menieres Disease?
rssure build up in the ineer vestibular apparatus that causes it to misbehave (dizeness, ringing in the ear, tinnitus)- Vinciant Van Go suffered from this
208
What maintains the plasma concentration of a hormone a at given level?
Negative feedback
209
What happens with an action potential in a T-tubules
An action potential on the surface membrane also spreads down the T-tuble, rapidly transmitting the surface electrical activity into central portions of the fibre. The presence of a local action potential in the T-tubles induces permeability changes in a separate membranous network within the muscle fibre-the SR
210
Length-tension relationship
Maximal force can be achieved by on a subsequent titanic contraction, more tension can be achieved during tetanus when beginning at the optimal muscle length than can be achieved when the contraction begins with the muscle less than or greater than its optimal length
211
What is astigmatism?
The curvature of the cornea is uneven so the light rays are unequally refracted
212
Sympathetic stimulation increases cardiac output by?
Increasing both heart rate and volume
213
Calcium activation of myosin cross bridge in smooth muscle?
1. ) Calmodulin binds to Ca2+ to form Ca2+-calmodulin complex
2. ) Ca2+-Calmoudium complex activates Myosin light chain Kinase
3. ) ATP and Myosin light chain kinase activate phosphorylated myosin cross bridge which can bind with actin and initiate cross bridge energy cycle
214
How Is sour taste receptors activated?
Is caused by acids containing a free hydrogen ion (H+). Depolarization of the receptor sour tastings occurs because H+ blocks potassium in the receptor cells membrane. The result decrease in the passive movement of positively charged K+ out of the cell reduces the internal negativity, producing a depolarizing receptor potential.
215
What is sound localization? how dies it occur?
Localization of sounds that are approaching
Determined by:
1.) The soundwaves reach the ear closer to the sound source slightly before it arrives at the farther ear
2.) The sound is less intense as it reaches the farther ear, because the head acts as a sound barrier that partially disrupts the propagation of sound waves
216
Is cardiac muscle striated?
yes
217
The rights half of the heart recives...? while the left side of the heart receives?
Right side of the heart recives blood from the systematic circulation and pumps it into the pulmonary circulation while the left side of the heart recives blood from the pulmonary circulation and pumps it into systemic circulation
218
Process of Lipophilic hormones and protein synthesis?
1. ) Free lipophilic hormone diffuses through the plasma membrane of the target cell and binds with its specific receptor
2. )Each receptor has a specific region for binding with its hormone and another region for binding DNA, once the hormone is bound to the receptor hormone complex binds with DNA on the HRE( hormone Response Element) ON the DNA inside the nucleus
3. )Binding of the hormone receptor complex with DNA untimely turns on a specific gene within the target cell. The code of the activated gate is transcribed into complementary mRNA
4. )New mRNA leaves the nucleus and enters the cytoplasm
5. )mRNA binds to a ribosome that mediates the assembly of new proteins
6. ) Newly Synthesized protien produces the targets cells ultimate physiological response to the hormone
219
What are the 3 levels of Neural Imput?
1. ) Input from affrent neruons
- Usally through intervening internerons, at the spinal cord level
2. ) Input from the primary motor cortex
- Fibers orgiginating from nerual cell bodies
3.) Input from the brainstem
220
What condition is characterized by a loss of photo receptors in the macula lutea in association with advancing age and causes "doughnut" vision?
Macular Degeneration
221
What is Pitch, Intensity and Timbre? What do they depend on?
Pitch=tone and depends on the frequency
Intensity=loudness and depends on amplitude
Timbre=Quality and depends on overtones (additional frequencies superimposed on the fundamental pitch or tone)
222
What does the inner ear consist of? What is their functions?
Pinna (external cartilage)-collects sound waves and channels them down the ear canal
External auditory meatus (Ear canal)-Determines the location of the sound source
Tympanic Membrane (ear drum)
223
What is cardiac output? what are its two determinants?
1. ) Heart rate
2. )Stroke volume
Cardiac output is the volume of blood pumped by each ventricle per minute
224
What is a single action potential in a muscle fibre that produces a brief, weak contraction that is to short and weak to be useful and normally does not take place on its own?
Muscle twitch
225
What is the role of the semilunar canals in the vestibular apparatus?
They detect changes in rotational or angular acceleration or deceleration of the head (changes in rate of rotational movements)
They do not respond when your head is motionless or when moving in a circle at a constant speed
226
Where are slow-oxidative fibres and Fast glycolytic fibres found? What are their functions?
Slow oxidative
- Found in muscles specialized for maintaining low-intensity contractions for a long period of time without fatigue
- Ex.) Muscles at the back of the left support the bodies weight against the force of gravity
Fast-glycolytic
-Found in the arm muscles which ar adapted for preforming rapid, forceful movements such as lifting heavy objects
227
What is Rigor Mortis?
Stiff of death is a genralized locking in place of skeletal muscles that occur 3-4 hours after death.
Personas metabolism has stoped hens they wont produce ATP, becaue of this calcium ions wont go back and remain stuck where they are and myosin heads will also remain stuck where they are
-No contraction relaxation cycle and is stiffness of the muscle upon dealth
228
Self-excitable smooth muscle cells are specilaized to initiate? but are not eqipited to?
1. )Action potentials
| 2. )Contract
229
Diastole and systole of heart?
Diastole-Relaxation and Filling
| Systole-Contraction and emptying
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Single twitch Vs Twitch summation Vs Tetanus?
1. )Single twitch single action potential, after a muscle fibre is restmulated after it has been completely relaxed, the second twitch is the same magnitude as the first twitch
2. )If a muscle fibre is restimulated before it has completely relaxed the second twitch is added onto the first twitch resulting in summation
3. )If a muscle fibre is stimulated so rapidly that it does not have an opportunity to relax at all between stimuli, a maximal sustained contraction (tetanus contraction) occurs
231
Emmetropia?
Myopia? Corrected with?
Hyperopia? Corrected with?
Presbyopia?
Hyperopia: Farsightedness, occurs when the focal point falls behind the retina. Corrected by a convex lens.
Myopia: Nearsightedness, occurs when the focal point falls in front of the retina. Corrected by a concave lens
Presbyopia: Old age, degeneration of the lens. The center of the lens begins to degenerate. Corrected by reading glasses.
Emmetropia: Normal 20/20 vision
232
What is arrhythmia? What are the 3 different kinds?
Abnormailty in heart rhytum
1. ) Atrial fibrillation-Rapid irregular beating of atria, you wont have a P wave because it is rapid, irregular, depolarization of the atria)
2. ) Ventricular Fibrillation- Very serious rhythmic abnormalities in which the ventricular musculature exhibits unccordinated, chaotic contractions-use of paddles is needed I these kinds of situations and can lead to loss of blood supply to brain
3. ) Heart block-arises from defects in the cardiac conducting system. The atria still beats regularly, but the ventricles occasionally fail to be stimulated and thus do not contract following atrial contraction. Have 2:1 or 3:1 complex... 2 waves to 1 QRS complex or 3 waves to 1 QRS complex
Complete heart block-Impulses from the atria are not conducted to the ventricle at all
233
Pericardial Sac
2 layers:
Outter fibrous covering of the sac that attaches to the connective partition that separates the lungs and anchors the heart so that it remains properly positioned within the chest
Inner layer which provides lubriaction to prevent friction between the two layers
234
Steps of Calcium Second messenger system?
1. ) Binding of extracellular (first) messenger activates a G-protein and Alpha protein breaks away from beta and gamma and starts to activate an enzyme called phosoplipd C
2. ) Phospholipase C will convert PIP2 to second messangers IP3 and DAG
3a. )IP3 mobilizes intracellular Ca2+ second messenger from ER (Ca2+ takes over the second messenger role at this stage)
4. a)Ca2+ activates calmodulin and create Ca2+-calmodium complex
5a. )Ca2+-calmodulin complex activate Ca2+-calmodulin dependant protein kinase CaM kinase
5. a) CaM kinsase phosphorylates inactive target protein, activating it
7a. )Active target protein brings about desired response
3. bDAG activates second messenger messenger protein kinase C
4. b) Active protein kinase C phosphorylate inactive trget protein and activates it (uses ATP and changes shape and function)
5. b) Active target protein brings about desired response
235
Primary hyposecretion? Secondary Hyposecretion?
Primary: When an endocrine gland is secreting too little of its hormone based on an abnormality within the gland
Secondary: Occurs when an endocrine gland is functioning normal but is secreting too little of the hormone because of a deficiency of its tropic hormone
236
P wave
QRS Complex
T Wave
PR segment
ST segment
TP Interval
P wave- Atrial depolarization
QRS Complex- Ventricular depolarization
T wave- Ventricular repolarization
PR segment-AV nodal delay
ST-Time during ehcoh ventircles are contracting and emptying
TP interval-Time during which ventircles are relaxing and filling
237
What is an Athersclerosis? What is it made up of? where is it located? How are they characterized?
- It is a degenerative arterial disease that gradually leads to the blockage of affected vessels, reducing blood flow through them
- They are characterized by plagues forming benith the vessel lining within the arterial walls and consist of a lipid-rich core covered by an abnormal growth of smooth muscle cells, topped off by a collagen rich connective tissue cap
-
238
Activation of second messengers is a universal mechanism is employed by...
a variety of extracellular messengers in addition to hydrophilic hormones
239
What is an A band?What is it made up of? What defines it?
A band is made up of a stacked set of thick filaments along with the portions of the thin filaments that overlap both ends of the thick filaments. Thick filaments lie ONLY within the A band and extend its entire width.
* Two ends of the thick filaments within a stack define the outer limits of a given A band
240
What is the difference in the rate of secretion from peptide hormones to a steroid hormones?
Peptide-horome secretion is controlled primarily by regulating the release of presynthezied stored horomes
-Rate of steroid hormone secretion is controlled entirely by the rate of hormone synthesis
241
How does the pupil control its size?
Through the use of 2 sets of smooth muscle networks in the iris
1. )Circular (constrictor) muscle- These muscles fibres shorten when they contract, the pupuil gets smaller and contracts to from a smaller ring, occurs when light is to bright
2. )Radial (dilator) Muscle- When these shorten and constrict the size of the pupil increases, this occurs in dim light to allow more light in
242
Abnormal pacemaker activity of the heart..
SA Failure?
AV Failure?
Purkinjie node failure?
SA Failure- AV node will take over and lower BPM to 50BPM
AV Failure- Bundle of HIS and purkinjie fibres will take over at much lower speed of 30BMO
Purkinjie Failure-Heart will beat at a much faster rate called ectopic focus (out of focus)
243
Why are motor neruons considered the "final common pathway"?
Because the only way any other parts of the nervous system can influence skeletal muscle activity is by acting on these motor neruons
244
What mechanism (G-protein and enzyme) does the transduction of light use to form an image?
Rhodopsin
245
One motor neuron innervates a number of muscle fibres, but each fibre is supplied by?
one motor neuron
246
Lub-Dub-Whistle?
Stenotic-Diastolic- Stenotic AV valve
247
What is muscle fatigue? What are the two different kinds?
1.) Muscle fatigue (peripheral Fatigue)
Occurs when an exercising muscle can no longer respond to stimulation with the same degree of contractile activity
2. )Central Fatigue
- Occurs when CNS no longer adequately activates the motor neurons supplying the working muscles
- Often psychologically-based
- Associated with/ stem from discomfort associated with the activity
248
Where are T-tubules located?
At each junction of an A band and I band, the surface membrane dips into the muscle fibre to form a transverse tubule
249
depleted glycogen stores can cause?
Muscle fatigue
250
Structures in middle ear? Functions?
1. ) Ossicle-Ment to transduce souds-Malleus, Incus, Stapus (attached to oval windo)
2. ) Oval Window-send sound into chochlea
3. ) Eustachian Tube-Offten this area of the ear gets infected
- Infections of the middle ear come through the ventigial root (OTITIS
251
What neurotransmitter does the motor axon relase which brings about excitation and contraction of the innervated muscle cells?
Acetylcholine
252
What chemical messanger carries signlas between the neruon terminal and the muscle fibre of the NMJ?
Acetylcholine
253
Cardiac Cycle steps? (5 hearts)
1. ) Passive filling during ventricular and atreial diastole
- Heart is in diastole, passive filling, all AV valves are open on right and left aide blood is entering, 80% of blood fills in during this time
2. ) Atrial contraction
- Showing the end of diastole or filling, P-wave is going to happen and the rest of the 20% of blood is going to be squeezed because the atria is going through depolarization...Leads to EDV
-Ventricular Filling
3. ) Isovolumetric ventricular contraction
- Valves are closed here and nothing is going in or out of the heart, muscle fibers are at equal contraction levels,
- You know you're at ISO because it is at a constant volume
4. ) Ventricular Ejection/systole
- QRS complex is going to come into place, heart is going to empty, In ventricular contraction you will empty the heart immedetly and rapidly, ventricles are ejecting and will lead to ESV
- ESV, the volume remaining after it has pumped out blood...heart will leave 65ML
Ventriular emptying
5. ) Isovolumetic Ventricular relaxation
- The heart is relaxed and preparing itself to retart the cycle again
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How are Unami Taste receptors activated?
They are triggered by amino acids, especially glutamate, Glutamate binds to a G protein–coupled receptor and activates a second-messenger system, but the details of this pathway are unknown. In addition to giving us our sense of meaty flavours, this pathway is responsible for the distinctive taste of the flavour additive monosodium glutamate (MSG), which is especially popular in Asian dishes.
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disuse atrophy?
caused by mechanical unloading of muscle and this leads to reduced muscle mass without fiber attrition. Being bed ridden or wearing a cast for extended periods of time
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What two factors are subject to control to accomplish gradation of skeletal muscle contractions?
1. )Number of motor units stimulated
| 2. )The frequency of their stimulation
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What neurotransmitter reinforces the direct effect that the sympathetic nervous system has on the heat?
Epinephrine
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Both B1 and B2 receotors brings about the target cell response by means of the?
Cyclic AMP second messanger system
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What happens when the ciliary muscles are relaxed?
- Accomplished by the action of the ciliary muscle and suspensory ligaments.
- When the ciliary muscle is relaxed, the suspensory ligaments are taught and they pull the lens into a flat, weakly refractive shape
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What is EDV?
The amount of blood left in the hearts left ventricle just before it contracts
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What is night blindness? What is it a deficiencies of?
- Occurs a s a result of dietary deficiencies of vitamin A, in this condition both rods and cones are reduced but there is enough cone photopigment to respond to the intense stimulation of light except in most severe cases
- A person can see in the day using cones but cannot see at night because the rods are no longer functional
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Pacemaker of the entire heart?
SA Node
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During growth how does a muscle fibre increase its length?
By adding new sarcomeres on the ends of myofibrils, NOT by increasing the size of each sarcomere
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H Zone?
Lighter area within the middle of the A band, where thin filaments do not reach is the H zone
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adjacent cardiac muscle cells are joined end to end by intercalated dies which connect?
Desmosomes, which act as spot rivets mechanically holding the cells together and gap junctions, which permit action potentials to speed from one cell to adjacent cells
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Thick filaments Vs Thin filaments?
Thick-Myosin Thin-Actin
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Steps for processing hydrophilic hormones?
1. ) Preprohoromones, or procurer proteins are synthesized by ribosomes on the RER, they then migrate over to the Golgi complex in membrane closed vesicles that pinch off in the smooth ER
2. ) During their journey through the ER and golf couples, large preprohorome prosecutor molecules are closed to become active hormones
3. )The Golgi complex then packages the finished hormones into secretary vesicles that are pinched off and stored in the cytoplasm until an appropriate signal triggers their secretion
4. )On appropriate stimulation, the secretory vesicles fuse with the plasma membrane and release their contents to the outside by exocytosis. This is triggered by only specific stimuli and the blood will then pick up the secreted hormone
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What is CAD? what 3 mechanisms cause it?
Coronary artery disease (CAD)
- coronary blood flow may not be able to keep pace with rising O2 needs
- Pathological changes within the coronary artery wall that dimisnh blood flow through these vessels
1. ) profound vascular spasm of coronary artieris
2. ) Formation of atherosclerotic plaques
3. ) Thromboemolism
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What happens when troponin is not bound to Ca+?
It stabilizes tropomoysin in its blocking position over actions cross-bridge binding sites
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The solubility properties of a hormone determine the which 3 means?
1. ) The hormone is processed by the endocrine cell
2. )The way the hormone is transported in the blood
3. ) The mechanism by which the hormone exerts its effects at the target cell
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Double vision is called?
Diplopia
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If you attempt to lift a car or other immovable object, your arm muscles will experience which type of contraction?
isometric
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Heart Failure? What ways can it occur?
The hearts inabilitly of the cardiac output to sleep pace with the body demands for nutrient supplies and removal of wastes
Occurs by damage to the cardiac muscle as a result of heart attack or impared circulation or prolonged pumping against a chronically increased afterload such as elevated blood pressure
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Sympathetic and parasympathetic pre-ganglion fibres release which neurotransmitter?
Acetylcholine
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Processing steps for Lipophlic (steroid) hormones?
1. ) Cholesterol is the common precursor for all steroid hormones
2. ) Synthesis of various steroid horomes from chmlesertal requires a series of enzymatic reactions that modify the basic cholesterol molecule (each steroidogenic organ can produce only the steroid or hormone or hormones for which is has a complete set of enzymes for
3. )One formed a lipid soluable steroid horomes immediately diffuse through the steroidogenic cells lipid plasma membrane to enter the blood
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Because of the way myosin molecules are oriented within the thick filaments how do all cross-bridge stokes occur?
All cross-bridge stokes will stroke inward toward the centre of the sarcomere on each end of the sarcomere so that all six of the surrounding thin filaments on each end of the sarcomere are pulled inward simultaneously
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What is accommodation?
The ability of the eye to adjust the strength of the lens by adjusting its shape by using the ciliary muscle-Adjusts the eye to see vision
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Tympanic membrane? What must happen for the membrane to be free to move?
Eardrum, is stretched across the entrance to the middle ear, vibrates when struck by sound waves,
For the membrane to be free to move the resting pressure on both sides of the tympanic membrane must be equal
Outside is exposed to atmospheric pressure inside is exposed via eustachian (auditory) tube
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Upper chambers of heart?
Right and left atria/atrium, receive blood returning to the heart and transfer it to the lower chambers
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Action potential in cardiac contractile muscle cells?
1.)Rising Phase: activation of voltage-gated channels; reaches +30 mV
2.)Plateau Phase: maintained by activation of slow L-type
Ca2+
3.)Ca2+ entry through L-type channels in T tubules triggers a larger release of Ca2+ from sarcoplasmic reticulum
4.)Ca2+ induced Ca2+ release leads to cross-bridge cycling and contraction
5.)Falling Phase: activation of K
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Photoreceptiveabilitly in light
Phototransduction
1. ) Absorption of light, retinal changes to all-trans form, activating photopigment
2. ) Photopigment actives transducer
3. ) Transductin activates phosphodiesterase
4. ) This decreases the concentration of cGMP
5. Na+ Channels in outer segment close
6. ) Hyperpolarization of photoreceptor
Spreads to syntactic terminal
7. ) Closes Ca2+ channels in synaptic terminal
8. ) Relases neuron transmitter
Further retinal processing in bipolar and ganglion cells
9. ) Depolarization of on centre bi-polar cells activates action potentials in on centre ganglion cells
10. ) Hyperpolarization of off centre bipolar cells leads to no action potentials in off centre ganglion cells
11. ) Propogation to visual cortex
12.)Illuminated receptive field of photoreceptor perceived as part of visual image
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How do we prevent muscle fatigue?
During a sustained contraction involving only a portion of the of muscles motor units as is necessary in muscles supporting the weight of the body against the force of gravity Asynchronous recruitment of motor neurons
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Resistance in cardiac blood flow?
The opposition to blood flow, largely caused by friction between the flowing blood and vessel wall
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What is a murmur? what is it associated with?
Abnormal heart sound that is usally associated with cardiac disease
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What is the role of the Otolith organs in the vestibular apparatus? how does each organ react?
It provides information about the position of the head relative to gravity and also detects changes in the rate of linear motion (utricle and saccule)
Utricle- Is a saclike structure in a body chamber between the cochlea and semiluna canals, a gelatinous mass that shifts positions and bends the hairs in two ways:
1. ) In the direction of head tilt
2. ) Opposite direction of head tilit
Saccule- Lies next to the utricle and Responds selectively to tilting of the head away fro the horizontal position (getting out of bed) and to vertically directed linear acceleration and decerlartion (jumping up and down)
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What is the Force-velocity relationship in concentric contractions?
The velocity of shortening decreases as the force increases
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Decompensated Heart Failure? What is it also refers as ?why?
Somtimes refred to as congestive heart failture because of congestion of the venous system
This kind of heart failure is serious because it will lead to organ failure, at this point cardiac muscles fibers are stretched to a point where they are operating in the decsending limb if tension curve
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What is a muscle spindle structure? What Is its function? Where do they lie?
What does the extrafusal fibre supply?
-Consisits of collections of specilized mucle fibres known as intrfusal fibres
1. )Lie within spindle shaped connective tissue capsuals known as intrfusal fibres
2. ) Each spindle has its own private efferent and afferent nerve supply
3. ) Plays a key role in stretch relfex
1. ) The primary(annulospiral) Endings
- They are wrapped around the central portion of the intrafusal fibres and they detect changes in the length of the fibres during stretching as well as the speed at which it occurs
2. ) The secondary (flower-spray) Ending
- Clustred at the end segments of many intrafusal fibres, are sensitive only to changes in length
Intrafusal fibers works because it is provided with the gama motor neuron-contradile ends (flower spray endings) will pull and keep the muscle and contract it (contractle region of muscle spindle). On the inner of the muscle the annulospiral ends will not form any junction. Noncontractile region of muscles spindle
Extrafusal fiber is provided with the alpha motor neuron with the NMJ
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Right vs Left AV valves?
Right: Tricuspid valve, between right atrium and right ventricle,
Left: Bicuspid valve or martial valve,
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3 important point to remember when thinking about what an ECG represents?
1. ) It's not a direct recording of the actual electrical activity of the heart, it is a recording of that part of the electrical activity induced in body fluids by the cardiac impulse that reaches the body surface
2. ) It is a complex recording representing the overall spread of activity throughout the heart during depolarzation and repolarization. It's not a recording of a single action potential at a single point in time
3. ) The recording represents comparisons in voltage detected by electrodes at two different points on the body surface, not the actual potential
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Satellite Cells?
Cells that repair muscle fibers, they divide to give rise to myoblasts
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What are the treatment methods used for congestive heart failure?
Measures that reduce salt and water retention and increase urinary output as well as drugs that enhance the contractile ability of the weekend heart
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Function of middle ear?
Transfer vibrations of the tympanic membrane to the fluid in the cochlea
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What cranial nerve provides blood supply and releases ACh in the parasympathetic system and provides blood to the atria and AV node?
Vegas nerve (10)
