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WorksheetsĐề physiology 1
Total questions: 111
Worksheet time: 2hrs 51mins
Physiology is the study of:
How two organisms interact
How organisms function
The spread of diseases
The structure of the body
What is the principal function performed by epithelial cells?
Fat storage
Anchoring body structures.
Forming boundaries between body compartments.
Generating movement
Transmitting electrical signal
The cell type that is specialized to communicate with other cells and control their activities is:
Epithelial cells
Muscle cells
Connective tissue cells
Nerve cells
Which concept is the defining feature of the discipline of physiology?
Descent with modification
Homeostasis
Evolution
Dimorphism.
Differentiation
Describing a physiological variable as “homeostatic” means that it:
Has varied from the normal value, and will remain constant at the new value
Never varies from an exact set point value
Is in an equilibrium state that requires no energy input to stay at the normal value.
Is in a state of dynamic constancy that is regulated to remain near a stable set point value
Has no normal range, but will just change to match the outside environmental conditions
Shivering in response to a cold draft is an example of
A homeostatic mechanism.
Negative feedback
A physiological reflex.
Thermoregulation
All of the choices are correct
If the amount of sodium in the blood decreases, what would a negative feedback control mechanism be
expected to do?
Decrease the amount of sodium in the blood.
Increase the amount of sodium in the blood
Leave the amount of sodium unchanged
Change the set point for sodium
Inhibit the ingestion of more sodium
Which one of the following is the correct sequence for a regulatory reflex arc?
Stimulus, effector, efferent pathway, integrating center, afferent pathway, receptor.
Stimulus, receptor, efferent pathway, integrating center, afferent pathway, effector
Stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector.
Stimulus, effector, afferent pathway, integrating center, efferent pathway, receptor
Effector, efferent pathway, integrating center, afferent pathway, receptor, stimulus
How are endocine glands and hormones involved in homeostatic reflexes?
Endocrine glands can be receptors, and hormones can be effectors
Endocrine glands can be integrators, and hormones can be efferent pathways.
Endocrine glands can be efferent pathways, and hormones can be effectors.
Endocrine glands are not part of reflex mechanisms, but hormones can be afferent or efferent pathways.
They are not involved; reflexes only involve actions of the nervous system
Some neurons in the vagus nerve have synaptic connections to sinoatrial (pacemaker) cells in the heart. These neurons secrete acetylcholine, which ultimately results in a decreased heart rate. This is an example of:
Endocrine control.
Exocrine control.
Hormonal control.
Neural control
Paracrine control.
After spending several days at a high altitude, where oxygen pressure is low, a person will begin to produce more red blood cells, which enhances the ability of blood to carry oxygen to the tissues. What term best describes this type of response?
Developmental acclimatization
Positive feedback
Physiological acclimatization
Feedforward regulation
Evolution
One function of epithelial cells is to form selective barriers regulating exchange of materials across them.
(a)
Organs are generally composed of only one kind of tissue.
(a)
The respiratory system is primarily responsible for transporting blood to the body's tissues.
(a)
Homeostasis refers to the relative constancy of the external environment.
(a)
The extracellular fluid compartment includes the interstitial fluid and blood plasma.
(a)
When loss of a substance from the body exceeds gain, the body is said to be in positive balance for that substance.
(a)
What are the most common receptors for hydrophilic intercellular messenger molecules?
Peripheral membrane proteins
Integral membrane proteins
Specialized phospholipids within the membrane
Nucleic acids
Intracellular proteins
Which of the following are ways in which binding of an intercellular chemical messenger with a cell’s receptor can bring about a cellular response?
Opening or closing of specific ionic channels in the plasma membrane
Activation of an intracellular second – messenger system
Promoting or inhibiting the transcription of genes that code for the synthesis of cellular proteins
Activating or inhibiting intracellular enzymes
All of the choices are correct
Which of these is a lipid soluble messenger?
Thyroid hormone
Protein kinase
Glucose
Sodium
Cyclic AMP
Epinephrine activates the cyclic AMP pathway in liver cells. In this example, enpinephrine is a _____________, and cAMP is a _____________.
Ligand, receptor
First messenger, hydrophobic hormone
Second messenger, ion channel.
First messenger, second messenger
Enzyme, second messenger.
At very low concentrations, enpinephrine causes an artery to dilate. At higher concentrations enpinephrine causes the same artery to constrict. How can these different effects be explained?
There is one type of epinephrine receptor that uses two second messenger systems
There are two types of epinephrine receptors with different affinities for epinephrine that use two different second messenger systems
There are two types of receptors for epinephrine that use the same second messenger system
At higher concentrations epinephrine can pass through the plasma membrane and directly stimulate contraction within the cell
With regard to the action of hormones and neurotransmitters on cellular receptors, which of these describes “amplification”?
When the extracellular concentration of a chemical messenger reaches a very high level, it overwhelms transporter molecules and the chemical floods into the cell.
Only hydrophilic first – messenger molecules can activate second messenger molecules within the cell cytosol
A single first messenger molecule activates multiple second messenger molecules, each of which activate thousands of enzymes.
Some cellular receptors have such low affinity for chemical ligands that it can require a million or more molecules to activate them.
In which of these would an injected drug be the most effective agonist for an endogenous chemical messenger?
The drug has a lower affinity for the messenger’s receptors than the messenger does
The drug achieves 50% saturation of the messenger’s receptors at a lower concentration than that required by the messenger
The drug does not couple to the binding site of the messenger’s receptor
The drug binds to an alternate binding site on the protein receptor and reduces its affinity for the endogenous chemical messenger.
1. A fat cell responds to the presence of the hormone enpinephrine by increasing cytosolic cycling AMP production, which leads to the catabolism of both glycogen and fat. What is the most likely explanation for this phenomenon?
Epinephrine is binding to two types of receptors in the plasma membrane
The activated receptor complex stimulates production of two different second messengers
Cyclic AMP directly activates two kinds of enzymes.
Cyclic – AMP – dependent protein kinase activates two kinds of enzymes
Second messengers:
Are necessary for all receptor signal transduction mechanisms
Act in the cell cytoplasm
Only function as intercellular messengers
Always function to activate enzymes
Are always proteins
Amplification during a second messenger cascade is beneficial because amplification:
Takes small molecules and makes polymers out of them
Results in the production of more of the first messenger
Allows a cell to respond to more different hormones
Allows small amounts of hormones to produce large responses in target cells
What is a role of calcium ions in the second messenger cascade involving phospholipase C, diacylglycerol, and inositol trisphosphate?
It splits and activates G – protein subnits
It binds to the endoplasmic reticulum and causes the release of inositol trisphosphate
It phosphorylates cell proteins
It is the first messenger that binds to the integral membrane protein receptor
Along with diacylglycerol, it activates protein kinase C.
What second messenger most directly causes calcium ions to be released from intracellular stores?
Diacylglycerol
Adenylyl cyclase
Inositol trisphosphate
Phospholipase A
Phospholipase C
Aspirin and other nonsteroidal anti – inflammatory drugs are more specific in their effects on eicosanoid synthesis than are steroidal anti – inflammatory drugs.
(a)
Two cell types having the same type of receptor for a chemical messenger will always respond to that messenger in the same way
(a)
An antagonist blocks the action of a chemical messenger by binding to its receptor.
(a)
Phosphorylation is a necessary component of any enzyme activation
(a)
The enzyme that catalyzes the production of cAMP from ATP is phosphodiesterase
(a)
Competition for receptors is strictly a pharmacological phenomenon, since naturally occuring chemical messengers do not compete with each other for the same receptor site
(a)
Beta-1-adrenergic receptors on the heart are coupled to the Gs pathway. Which protein/ messengers are most likely going to be activated when a suitable ligand binds to a beta-1 receptor ?
cAMP
Adenylyl Cyclase
Guanylyl Cyclase
Calcium
More than 1 choice is correct
In a reverse scenario than question 36, M2 muscarinic receptors on the heart are primarily Gi coupled. What protein/ messengers are most likely activated when a suitable ligand binds to an M2 receptors ?
cAMP
Protein kinase A (cAMP-dependent protein kinase )
Guanylyl Cyclase
Some of the answer are correct
None of the answer are correct
Now, M3 receptors (another type of Muscarinic receptors, found on the lung , stomach and intestine ) are coupled to Gq. What proteins/ messengers are most likely activated as result of ligand binding to the M3 receptors ?
Inositol Triphosphate (IP3)
cAMP
cGMP
Adenylyl Cyclase
More than 1 answers is correct
According to information in question 36,37,38 and 39 what will the final effect of M3 receptor activation be ?
To increase heart rate
To decrease heart rate
To keep heart rate constant
Nothing. M3 receptor activation do not affect the heart
Not enough information provided to make a dechision
According to the approximation formula you received in your slides, if the plasma volume of a person is 6L (liters) , how much would the interstitial flud volume be ?
12L
18L
30L
50L
36L
According to the approximation formula you received in your slides, if the plasma volume of a person is 6L (liters) , how much would the intracellular flud volume be ?
10L
18L
36L
54L
42L
According to the approximation formula you received in your slides, if the plasma volume of a person is 6L (liters) , how much would the total body flud volume be ?
10L
18L
36L
54L
42L
According to the approximation formula you received in your slides, if the plasma volume of a person is 6L (liters) , how much would the amount of flud that albumin normally resides in the body be ?
6L
10L
18L
36L
54L
What is the best way that we can use in oder to measure total body fluid?
Uses albumin as a tracer and calculate the volume of fluid that contains albumin at equilibirium
Uses inulin as a tracer and calculatr the volume of fluid that contains inulin at equilibirium
Uses area as a tracer and calculate the volume of fluid that contains area at equilibirum
There;s no way to use a tracer to measure total body fluid
What is the best way that we can use in order to measure intracellular fluid volume?
Uses albumin as a tracer and calculate the volume of fluid that contains albumin at equilibirium
Uses inulin as a tracer and calculate the volume of fluid that contains inulin at equilibirum
Uses urea as a tracer and calculate the volume of fluid that contains urea at quilibirum
There's no way to use a tracer to measure intracellular fluid volume
What is the best way that we can use in order to measure extracellular fluid volume ?
Uses albumin as a tracer and calculate the volume of fluid that contains albumin
Uses inulin as a tracer and calculate the volume of fluid that contains inulin at equilibirium
Uses urea as a tracer and calculate the volume of fluid that contain
There's no way to use a tracer to measure extracellular fluid volume
What is one way to increase the filtration of fluid from capillary into the interstitial fluid ?
Increae the hydrostatic pressure in the capillary
Decrease the hydrostatic pressure in the capillary
Increase the oncotic pressure in the interstitial fluid
Decrease the oncotic pressure in the interstitial fluid
More than 1 choice is correct
If the oncotic pressure of the interstitial flui rises, what will happen ?
There will be an increase in filtration
There will be an increase in reabsorption
Fluid will move from interstitial fluid into blood plasma
Fluid will stay in the interstitial fluid
None of the answers is correct
What is one way to increase the hydrostatic pressure in the capillary ?
Increase the number of proteins in the blood
Increase the number of proteins in the interstitial fluid
Increase in blood pressure
Decrease in blood pressure
A failure in lymphatic drainage
Wucheria bancrofti (giun chỉ) is a parasite that has nasty habit of getting stuck inside the lymphatic vessels of the body, especially those in the lower limbs. When that happens, the infected lower limbs becomes swelled with fluid a condition called Elephatiasis (phù chân voi), What is most likely changed in the lower limbs as a result of this ?
Hydrostatic pressure in the capillary
Hydrostatic pressure in the interstitial fluid
Oncotic pressure in the interstitial fluid
This condition did not change anything
Hình thức vận chuyển thụ động có đặc điểm:
Vận chuyển cùng chiều gradient nồng độ
Chỉ vận chuyển được những phân tử phân cực
Cần cung cấp năng lượng cho quá trình vận chuyển
Tất cả đều đúng
Khi cho hồng cầu vào dung dịch nào sau đây thì hồng cầu sẽ phình to và có thể vỡ ?
Dung dịch đẳng trương
Dung dịch ưu trương
Dung dịch nhược trương
Dung dịch cao phân tử
Chất nào sau đây có thể khuếch tán qua lớp kép phospholipid kép ?
Acid amine
Ammoniac
Glucose
Na+
Hình thức vận chuyển qua màng tế bào của oxy là :
Khuếch tán đơn thuần
Khuếch tán được hỗ trợ
Vận chuyển tích cực nguyên phát
Vận chuyển tích cực thứ phát
Hình thức vận chuyển của glucose từ máu vào tế bào (gan, cơ, mỡ) là:
Khuếch tán đơn thuần
Khuếch tán được hỗ trợ
Vận chuyển tích cực nguyên phát
Vận chuyển tích cực thứ phát
Mức độ khuếch tán của một chất qua màng tế bào tỷ lệ thuận với :
Độ hòa tan trong lipid
Nhiệt độ
Sự chênh lệch nồng độ hai bên màng
Tất cả đều đúng
Mức độ khuếch tán qua màng tế bào của chất nào sau đây phụ thuộc vào số lượng protein mang ?
Oxy
Amoniac
Glucose
Tất cả đều đúng
Mức độ khuếch tán qua màng tế bào của một chất sẽ giảm khi ?
Nhiệt độ tăng
Trọng lượng phân tử tăng
Số kênh protein tăng
Độ hòa tan trong lipid tăng
Đặc điểm của hình thức vận chuyển tích cực ?
Vận chuyển cùng chiều gradient nồng độ
Không cần năng lượng
Đây là hình thức vận chuyển chủ yếu của các chất kém phân cực
Luôn cần protein mang
Hình thức vận chuyển nào sau đây không cần protein mang ?
Khuếch tán đơn thuần
Khuếch tán được hỗ trợ
Vận chuyển tích cực nguyên phát
Vận chuyển tích cực thứ phát
Ion nào sau đây là cation chính ở ngoại bào ?
Na+
Ca2+
Mg2+
K+
Ion nào sau đây là cation chính ở nội bào ?
Na+
Ca2+
Mg2+
K+
Chất nào sau đây làm tăng mức khuếch tán của glucose qua màng tế bào ?
Calcitonin
Aldosterol
Insulin
Thyroxin
Hình thức vận chuyển của ion H+ ở tế bào thành của dạ dày là:
Âm bào
Nhập bào qua trung gian thụ thể
Vận chuyển tích cực nguyên phát
Vận chuyển tích cực thứ phát
Năng lượng sử dụng trong hình thức ....... được lấy từ thế năng dự trữ của Natri, Chọn cụm từ thích hợp điền vào chỗ trống
Khuếch tán đơn thuần
Khuếch tán được hỗ trợ
Vận chuyển tích cực nguyên phát
Vận chuyển tích cực thứ phát
Hình thức vận chuyển vật chất nào sau đây làm biến đổi màng sinh chất ?
Vận chuyển tích cực nguyên phát
Khuếch tán được hỗ trợ
Nhập bào qua trung gian thụ thể
Vận chuyển tích cực thứ phát ngược chiều Natri
Bơm nào sau đây có vai trò ổn định thể tích tế bào ?
Bơm Na+, K+
Bơm Ca2+
Bơm H+
Tất cả đều đúng
Hình thức vận chuyển acid amin ở tế bào biểu mô ống thận là:
Khuếch tán đơn thuần
Vận chuyển tích cực nguyên phát
Nhập bào qua trung gian thụ thể
Vận chuyển tích cực thứ phát cùng chiều Natri
Xuất bào là phương thức đưa các chất ra bên ngoài tế bào với đặc điểm:
Không tiêu hao năng lượng
Biến đổi cấu trúc màng sinh chất
Là phương thức thải ra ngoài tế bào những chất phân cực mạnh
Tất cả đều đúng
Chất nào sau đây được đưa vào tế bào bằng hình thức nhập bào qua trung gian thụ thể?
LDL
Glucose
Acid béo
Acid amin
Which of the following is / are functions of the human nervous system?
Receiving, storing, and processing information on the internal and external environments
Bringing about changes in physiology and / or behavior to ensure optimal functions of homeostatic mechanisms
Secretion of hormones
Coordination of movement
All of the choices are correct
Which is not true of myelin?
It is a fatty membranous sheath
It is formed by glial cells.
It influences the velocity of conduction of an electrical signal down an axon
It covers all parts of the neuron, including the axon, cell body, and dendrites
Which is FALSE about neurons?
A given neuron can be either a presynaptic neuron or a postsynaptic neuron.
An individual neuron can receive information from multiple other neurons
An individual neuron can transmit information to multiple other neurons.
A neuron can simultaneously release more than one type of neurotransmitter
A neuron receives information on its axons and delivers it to other neurons through its dendrites.
Which of the following is NOT TRUE of glial cells?
They form the myelin for axons
Neurons outnumber glial cells 10 in 1 in the nervous system
They deliver fuel molecules to neurons and remove the waste products of metabolism
They are important for the growth and development of the nervous system.
They regulate the composition of the extracellular fluid in the CNS
Which is TRUE about the resting membrane potential?
It requires very few ions to be distributed unevenly
It has the same value in all cells
It is oriented so that the cell’s interior is positive with respect to the extracellular fluid
Only nerve and muscle cells have a potential difference across the membrane at rest.
It is not altered by changing concentration gradients of permeating ions
The membrane potential of most neurons at rest is:
Equal to the equilibrium potential for potassium
Equal to the equilibrium potential for sodium.
Slightly more negative than the equilibrium potential of potassium ion
More positive than the equilibrium potential for potassium
More positive than the equilibrium potential for sodium
Which would result from an increase in the extracellular concentration of K+ above normal?
Depolarization of resting nerve cells.
Hyperpolarization of resting nerve cells.
The potassium equilibrium potential of nerve cells would become more negative
The sodium equilibrium potential would become less positive.
The equilibrium potential of K+ ions in nerve cells is about -90 mV. The membrane potential of typical nerve cells at rest is -70 mV. Therefore,:
Increasing the permeability of a resting neuronal membrane to K+ will make the membrane potential more negative inside with respect to outside.
In resting neurons, there is a net diffusion of K+ into the cell
Changing the resting membrane potential of a neuron to -80 mV would increase K+ diffusion rate out of the cell
Potassium is the only permanent ion at rest
There must be another permanent ion with an equilibrium potential more negative than -90 mV.
Which is NOT an example of a graded potential?
A receptor potential in a sensory receptor cell
A depolarizing excitatory postsynaptic potential (EPSP)
A hyperpolarizing inhibitory postsynaptic potential (IPSP)
A depolarizing pacemaker potential.
A depolarizing action potential
An action potential in a neuronal membrane differs from a graded potential in that:
An action potential requires the opening of Ca2+ channels, whereas a graded potential does not
An action potential is propagated without decrement, whereas a graded potential decrements with distance.
An action potential has a threshold, whereas a graded potential is an all – or – none phenomenon
Movement of Na+ and K+ across cell membranes mediate action potentials, while graded potentials do not involve movement of Na+ and K+
Action potentials vary in size with the size of a thalamus, while graded potentials do not
A threshold stimulus applied to an excitable membrane is one that is just sufficient to:
Trigger an excitatory postsynaptic potential
Cause a change in membrane potential
Trigger an action potential
Be conducted to the axon hillock
Depolarize a dendrite
Which is most directly responsible for the falling (repolarizing) phase of the action potential?
Voltage – gated Na+ channels are opened
The Na+ / K+ pump restores the ions to their original locations inside and outside of the cell
The permeabiltiy to Na+ increases greatly
ATPase destroys the energy supply that was maintaining the action potential at its peak
The permeability to K+ increases greatly while that to Na+ decreases
Why are action potentials sometimes described as being “all – or – none” in character
They rate of propagation of an action potential down an axon is independent of stimulus strength
They are associated with an absolute refractory period.
A suprathreshold stimulus is required to stimulate an action potential during the relative refractory period
An action potential occurs whenever a suprathreshold stimulus occurs, and its amplitude does not vary with the size of a stimulus
Action potentials are always the same size, even when ion gradients vary in size
The relative refractory period of an axon coincides with the period of:
Activation and inactivation of voltage – dependent Na+ channels
Na+ permeability that is greater than that during the depolarization phase
Increased K+ flux into the cell
Increased K+ permeability of the cell.
Increased Na+ flux through K+ channels
Neuronal axons typically have abundant:
Voltage – gated channels for Na+ that open in response to depolarization
Voltage – gated channels for K+ that open in response to hyperpolarization
Receptor – mediated channels for Na+.
Receptor – mediated channels for K+
Voltage – gated channels for Ca2+
Which of the following statements regarding action potentials generated in a neuronal membrane is NOT TRUE?
Action potentials travel decrementally down the membrane
An action potential generates a new action potential in an adjacent area of membrane
An action potential generates a local current that depolarizes adjacent membrane to threshold potential.
Action potentials are usually initiated at the initial segment of a neuron
An action potential generated by a threshold stimulus is the same size as one generated by a suprathreshold stimulus
Which of the following statements concerning the properties of action potentials is TRUE?
The rate of propagation of action potential down an axon is independent of stimulus strength
Action potentials can undergo summation.
A suprathreshold stimulus can stimulate an action potential during the absolute refractory period
Action potentials generally propagate from the axon terminal toward the initial segment
Increasing the size of a stimulus will increase the amplitude of an action potential
How is the strength of a stimulus encoded by neurons?
By the size of action potentials
By the frequency of action potentials
By the duration of action potentials
By whether the action potential peak is positive or negative
Which of the following statements concerning the rate of action potential propagation is TRUE?
It is faster in small – diameter axons than in large – diameter axons.
It is faster for a strong stimulus than for a weak one
It is faster in myelinated axons than in nonmyelinated axons
It is faster in the dendrites than in the axon
It occurs at the same rate in all axons, regardless of their diameter
Which is TRUE about receptor potentials ?
They are action potentials
They always trigger action potentials
They vary in magnitude with stimulus strength
They propagate without decrement
They generally occur at the axon hillock of afferent neurons
A sensory unit is defined as:
All of the sensory receptors in a given area of the body that respond to the same stimulus
A single receptor ending and its afferent nerve fiber
A single afferent neuron and all its receptor endings
An afferent neuron and its postsynaptic interneurons
A reflex composed of an afferent neuron, an interneuron, and an efferent neuron.
What is the best definition of the “receptive field” of an afferent neuron?
The number of interneurons with which the central process of the afferent neuron makes synaptic contact via divergence.
The type of stimulus energy to which the afferent neuron is most sensitive
All of the interneuron cell bodies and dendrites onto which the afferent neuron synapses
The area of the cerebral cortex in which information from that afferent neuron is initially received
The area of the body that, when stimulated, leads to activity in that particular afferent neuron
Which of these is one reason you can distinguish between a needle prick on the foot and an ice cube on the wrist?
The ice cube stimulates a different class of receptors than the needle prick, even though both signals go to exactly the same location in the brain
The action potentials from the needle prick are inherently different from the impulse generated by the ice cube
The region of the brain to which one receptor pathway leads is different from the region to which the other pathway leads
The needle prick generates a stronger action potential in any one neuron than an ice cube does
The needle prick generates a higher frequency of action potentials than the ice cube does
Which of the following is most important for the determination of stimulus type?
The relative sensitivity of different receptors to different stimulus energies.
The presence of polymodal neurons in the sensory pathway
The intensity of a stimulus
The location on the body where a stimulus is applied
Propagation of a signal along a nonspecific ascending pathway.
Which of the following statements regarding the precision of locating a somatic stimulus is FALSE?
The precision is greater in areas of the body that have small, overlapping receptive fields than in areas with large, nonoverlapping receptive fields
The precision is greater in the lips and fingers than on the back
The precision is greater for the skin than for the internal organs
Lateral inhibition of parallel afferent pathways increases the precision of locating a stimulus
Convergence of afferent neurons onto common ascending pathways increases acuity
Which best describes lateral inhibition in the somatic sensory system?
The frequency of action potentials along pathways from the site of a stimulus is increased by lateral inhibition
The precision of locating a stimulus is increased by inhibiting signaling along nearby, parallel pathways.
The precision of locating a stimulus is enhanced by increasing the frequency of action potentials in nearby, parallel pathways
Stimuli of one particular modality in a region of the body block transmission of action potentials coding for other modalities generated in the same region of the body
Lateral inhibition reduces the contrast between the frequency of action potentials generated at the center of a stimulus and the frequency of action potentials in surrounding pathways
Which of the following would NOT be categorized as a "somatic" sensation?
Pressure
Cold and warmth
Sound
Proprioception
Kinesthesia
Which of the following statements regarding sensory pathways is correct?
All somatic sensory information that reaches the cerebral cortex is first processed in the thalamus
Somatic sensory information from the left side of the body projects to the left side of the somatosensory cortex
All somatic sensory information travels together in a single tract in the spinal cord.
Ascending pathways in the anterolateral column of the spinal cord carry information about fine
touch discrimination
Ascending pathways in the dorsal column of the spinal cord carry information about pain from the
back muscles
During normal viewing of a distant object, the:
Firing of parasympathetic nerves to ciliary muscles increases
Zonular fibers are slackened
Lens flattens.
Light rays striking the eyes are diverged by the cornea
Ciliary muscles are contracted
Which of the following statements about rods and cones in the retina is true?
Cones enable us to see in dim light; rods provide color vision
Rods and cones all have the same kind of opsin
Cones are found in highest density in the fovea; rods are more prevalent near the edges of the retina
Rods require brighter light to activate them than do cones
Rods provide higher visual acuity than do cones
Which of these occurs when light strikes photoreceptors?
The chromophore retinal undergoes a change of shape
There is an increase in neurotransmitter release from photoreceptor cells
The photoreceptor cell membrane becomes depolarized
The concentration of cyclic GMP inside cells increases
The photoreceptor cells are stimulated and fire action potentials
A pituitary hyperplasia (enlargement of the pituitary gland) can sometimes compress particular parts of the optic nerve, track and chiasm and make part loose its function. If position A is compressed, what will happen?
The patient will lose lateral (outer) visual fileds in both eyes, but the central visual fields remain intact
The patient will lose both lateral and central visual fields in only the left eye
The patient will lose the central visual fields in the left eye and the lateral visual fields in the right eye
The patient will lose both lateral and central visual fields in only the right eye
The patient will lose the central visual field in the right eye and the lateral visual field in the left eye
If position B (the left side of the optic chiasm, AFTER the fibers crossover) is compressed, what would happen ?
The patient will lose lateral (outer) visual fields in both eyes, but the central visual fields remain intact
The patient will lose both lateral and central visual fields in only the left eye
The patient will lose the central visual fields in the left eye and the lateral visual field in the right eye
The patient will lose both lateral and central visual fields in only the right eye
The patient will lose the central visual field in the right eye and the lateral visual fields in the left eye
If position C is compressed what would happen ?
The patient will lose lateral (outer) visual fields in both eyes but the central visual fields remain intact
The patient will lose both lateral and central visual fields in only the left eye
The patient will lose the central visual fields in the left eye and the lateral visual fields in the right eye
The patient will lose both lateral and central visual fields in only the right eye
The patient will lose the central visual field in the right eye and lateral visual field in the left eye
If the optic chiasm is completely cut in the middle (line D) because of an automoblie accident what would happen ?
The patient will lose lateral (outer) visual fields in both eyes but the central visual fields remain intact
The patient will lose both lateral and central visual fields in only the left eye
The patient will lose the central visual fields in the left eye and the lateral visual fields in the right eye
The patient will lose both lateral and central visual fields in only the right eye
The patient will lose the central visual field in the right eye and lateral visual field in the left eye
Fibers of the fasciculus cuneatus and fasciculus gracilis (the dorsal collums) cross-over to the other side at 1 or 2 spinal cord segmetns above the lever that they enter the spinal cord
(a)
The pathway for temperature and pain from temperature- related reasons cross-over to the other side at the level of the brainstem
(a)
If a patient damages her T7 spinal cord segment on the right side her clinical manifestations would be: loss of temperature and light touch sensation on her Left foot and loss of joint and muscular sensations (deep touch) on her right foot
(a)
According to information on question 36 and 37 if Beta-1-adrenergic receptor's final effect is to increase heart rate, what would the final effect of M2 receptor activation be ?
To increase heart rate
To decrease heart rate
To keep heart rate constant
Nothing M2 receptors are not located on the heart
What is the best way that we can use in order to measure plasma fluid volume ?
Uses albumin as a tracer and calculate the volume of fluid that contains albumin at equilibirium
Uses inulin as a tracer and calculate the volume of fluid that contains inulin at equilibirium
Uses urea as a tracer and calculate the volume of fluid that contains urea at equilibirium
There's no way to use a tracer to measure intracellular fluid volume
Accommodation for near vision requires:
Flattening of the lens
Rounding of the lens
Activation of the sympathetic nervous system
Increased rounding of the comea
Dilation of the pupil
