Unit 2 PSL 250
Which of the following is incorrect regarding sweat glands?
"body odor" is caused by the odiferous (smelly) nature of the type of sweat secreted in our axilla (armpits)
In terms of the perception of sound waves, the amplitude of the wave is equal to perceived _______________________ while the frequency of the wave is equal to perceived _______________ .
- amplitude = loudness - frequency = pitch
A receptor that is a ligand-gated ion channel is known as a(n) ___________ receptor. In contrast, a receptor that, when activated by the binding of a ligand, causes changes in the cells metabolism via intracellular second messengers is known as a(n) ________________________ receptor.
- ionotropic -metabotropic
In the autoimmune disease known as __________________ the body's own immune system attacks the cells that create the myelin sheath in the CNS called____________________________causing demyelination and an essential "short circuit" of the affected neurons.
- multiple sclerosis - oligodendrocytes
The cochlea consists of three fluid filled chambers (scala). The scala vestibuli and tympani are filled with a fluid called ____________________while the scala media (cochlear duct) is filled with a potassium rich fluid called _____________________
- vestibuli & tympani = perilymph - media = endolymph
There are _________ pairs of cranial nerves and ________________-pairs of spinal nerves.
-12 pairs of cranial nerves - 31 pairs of spinal nerves
How many pairs of spinal nerves are there? What are the five general types of spinal nerves that emanate from the spinal cord? What are the different types of intervertebral disc abnormalities that can occur? How can these issues relate to spinal stenosis?
-31 -Cervical, thoracic, lumbar, sacral, coccygeal nerves. -Intervertebral disc deterioration and herniation. -Disc deterioration and herniation can lead to spinal stenosis causes narrowing of the open spaces within your spine. This can put pressure on your spinal cord and the nerves.
What is the RMP value of a typical neuron? What is a threshold potential (TP)? What is the TP value for a typical neuron? What is the peak amplitude (in mV) of a typical neuron?
-70 mV. A threshold potential, which must be achieved in the axon hillock, is the potential at which the neuron will fire an action potential. -60 mV. +30 mV.
Can you draw a spinal reflex arc? What are the three neurons involved? How do they communicate with one another? What does ipsilateral mean? Contralateral?
-Afferent, inter and motor neuron. -They communicate through the neurotransmitters that are released in the synaptic clefts between them. -During an ipsilateral reflex, the response occurs on the side of the body that is stimulated. -Contralateral: opposite side.
What are the anatomical components of the peripheral nervous system (PNS)? What is the functional organization of the PNS? In other words, can you schematically explain the organization of the efferent division (somatic nervous system (SNS) and autonomic nervous system (ANS)) and the afferent division of the PNS?
-Cranial and spinal nerves. -There are two divisions of the PNS: *Afferent. Sensory (somatosensory, special senses and visceral senses). *Efferent. Somatic (skeletal muscle). Autonomic (cardiac, smooth muscle, glands and adipose). ----Sympathetic, parasympathetic and enteric
Sensory information enters the afferent division of the PNS. What are exteroceptors? What type of information do they send to the CNS? What are proprioceptors? What type of information do they send to the CNS? What are interoceptors? What type of information do they send to the CNS?
-Exteroceptors are sensory receptors that receive external stimuli. Special and somatic senses. -Gustatory, visual, olfactory, auditory, equilibrioception, pain, temperature, pressure, etc. -Proprioceptors are sensors that provide information about joint angle, muscle length, and muscle tension, which is integrated to give information about the position of the limb in space. -Interoceptors are receptors that receive stimuli from internal organs. Visceral sense, as in stomach or heart pain, for example.
If you were to stand straight and look straight ahead, where would most light entering your pupil light fall on your retina? What is the visual axis (i.e., principal optical axis)? What is the optic disc? Why is it also known as the blind spot? Can you find your blind spot?
-Fovea centralis. -The visual axis is an imaginary straight line that passes through both the center of the pupil and lands on the center of the fovea centralis. -The optic disc optic is the point of exit for ganglion cell axons leaving the eye. There are no photoreceptors in this area. Therefore, is known as the blind spot. -Use the diagram in the slides to find your blind spot.
Do tactile receptors undergo receptor or generator potentials? The receptor portion of one of these sensory neurons is literally a modification of what portion of the neuron? What happens to the membrane of the receptor as a result of receiving stimulus? Which ion enters the neuron to generate an AP? Where does this first AP arise? Where is tactile sense processed in the brain?
-Generator. -Dendrite. -Mechanically-gated ion channels open. -Na+. -Initial segment of the axon. -Somatosensory cortex.
Where is aqueous humor located? Vitreous humor? What are the functions of these humors? What is glaucoma?
-In the anterior chamber of the eye. -In the posterior chamber of the eye. -The aqueous humor plays an essential role in nourishing the cornea and the lens by supplying nutrition such as amino acids and glucose. It also maintains intraocular pressure. The vitreous humor (or body) allows the light to pass through the lens to the retina and helps to keep the eye in its round shape. -Glaucoma is the term applied to a group of eye diseases that gradually result in loss of vision by permanently damaging the optic nerve. This disease can occur due to high pressure in the eye due to an overaccumulation of fluid (aqueous humor).
The wall of the eye is composed of three layers of tissue. The outermost, fibrous layer is known as the _____________________ . The innermost layer is composed of the cells responsible for vision. This layer is called the ______________________ . The layer between these two is a very vascular layer that provides nourishment to the back of the eye. This layer is called the _____________________.
-sclera (outermost) - retina (innermost) - choroid (in between)
The sensory organ of audition is the organ of Corti. In the semicircular canals, the sensory organs are the ________________ while in the saccule and utricle the sensory organs are known as _____________________________.
-semicircular canals sensory organ = crista ampularis - saccule & utrucle sensory organ = macula
As epidermal stem cells continuously divide to produce new keratinocytes, the existing keratinocytes of the stratum basale are continuously displaced and pushed up through the layers of the epidermis until it sloughs off in a process known as desquamation. Approximately how long does it take for a single keratinocyte to go through this whole process?
1 month ( 30-40 days)
Once a nerve impulse is generated at the initial segment of the axon, it will continue down the entire length of the axon. Place the events below in the correct order for what happens next. Action potential arrives at the terminal knobs (axon terminals) Ca2+ ions flood into the terminal knobs neurotransmitters bind to their receptors (some diffuses out of the cleft; some is broken down) ions flow into/out of the postsynaptic cell causing a depolarization or hyperpolarization (depends on the channel and the ions that are flowing) neurotransmitter is released into the synaptic cleft receptors (ligand-gated ion channels in this case) open Local depolarization from the action potential causes voltage-gated Ca2+ channels to open Ca2+ ions cause synaptic vesicles to fuse with the plasma membrane
1. Action potential arrives at the terminal knobs (axon terminals) 2. Local depolarization from the action potential causes voltage-gated Ca2+ channels to open 3. Ca2+ ions flood into terminal knobs 4. Ca2+ ions cause synaptic vesicles to fuse with the plasma membrane 5. neurotransmitter is released into the synaptic cleft 6. neurotransmitters bind to their receptors (some diffuses out of the cleft; some is broken down) 7. receptors (ligand-gated ion channels in this case) open 8. ions flow into/out of the postsynaptic cell causing a depolarization or hyperpolarization (depends on the channel and the ions that are flowing)
Match the G protein type to its pathway below. inhibits adenylate cyclase leading to decreased cAMP levels in the cell and ultimately decreased phosphorylation of proteins activates adenylate cyclase leading to increased cAMP levels in the cell and ultimately increased phosphorylation of proteins activates phospholipase C (PLC) leading to increased levels of DAG and IP3ultimately leads to higher levels of intracellular Ca2+and/or increased phosphorylation of proteins
1. Gs - activates adenylate cyclase leading to increased cAMP levels in the cell and ultimately increased phosphorylation of proteins 2. Gi -inhibits adenylate cyclase leading to decreased cAMP levels in the cell and ultimately decreased phosphorylation of proteins 3. Gq -activates phospholipase C (PLC) leading to increased levels of DAG and IP3ultimately leads to higher levels of intracellular Ca2+and/or increased phosphorylation of proteins
Imagine that you are mid-conversation in the kitchen cooking dinner and while looking away from the stove you accidentally touch the hot pan. You immediately withdraw your hand and wince in pain. Place the events of what just took place in your nervous system in the correct order.
1. thermal nociceptors in your hand respond to the noxious stimulus 2. action potentials are sent afferently from the hand to the spinal cord 3. the sensory neuron synapses with an interneuron in the spinal cord 4. action potentials are generated in the interneuron 5. the interneuron synapses with a motor neuron 6. action potentials are generated in the motor neuron and travel efferently 7. the motor neuron communicates (through a neuromuscular junction) with your biceps muscle 8. biceps contracts and withdraws hand from the stimulus 9. the sensation of pain is processed in the somatosensory cortex of your brain
Match the basic descriptions below to the correct terms. 1.tonic receptors 2.phasic receptors receptors that adapt to stimuli rapidly; they will only respond to changes in stimuli receptors that adapt to stimuli at a slow rate or not at all; they will respond to a stimulus the entire time a stimulus is present.
1. tonic receptors- receptors that adapt to stimuli at a slow rate or not at all; they will respond to a stimulus the entire time a stimulus is present. 2. receptors that adapt to stimuli rapidly; they will only respond to changes in stimuli
Place the following events of phototransduction in the correct order. cGMP PDE is activated by transducin ligand-gated Na+ channels begin to close the rod cell hyperpolarizes (because K+ leak channels are always open) the concentration of cGMP decreases transudcin (G protein) is activated retinal changes conformation from cis to trans trans retinal dissociated from opsin molecule a photon of light is absorbed by rhodopsin decrease in amount of neurotransmitter released from the rod cell
1.a photon of light is absorbed by rhodopsin 2.retinal changes conformation from cis to trans 3.trans retinal dissociated from opsin molecule 4. transudcin (G protein) is activated 5.cGMP PDE is activated by transducin 6.the concentration of cGMP decreases 7.ligand-gated Na+ channels begin to close 8.the rod cell hyperpolarizes (because K+ leak channels are always open) 9.decrease in amount of neurotransmitter released from the rod cell
Match each analgesic mechanism below to the drug that acts through that mechanism. blocks voltage-gated sodium channels blocks the formation of prostaglandins works in the central nervous system to block transmission blocks the release of histamines reduces the amount of substance P
1.aspirin -blocks the formation of prostaglandins 2.NSAIDs - blocks the release of histamines 3.capsaicin - reduces the amount of substance P 4.lidocaine (and other local anesthetics) -blocks voltage-gated sodium channels 5.morphine (and other opiates) - works in the central nervous system to block transmission
Match each sensation below to the receptor type responsible for that sensation. 1.mechanoreceptors 2.chemoreceptors 3.photoreceptors 4.nociceptors 5.thermoreceptors 6.osmoreceptors hot and cold (thermoesthesia) pain (nociception) sight (vision) smell (olfaction) tactile sense (touch, pressure, vibration) changes in solute concentrations taste (gustation) hearing (audition)
1.mechanoreceptors -tactile sense (touch, pressure, vibration) -hearing (audition) 2.chemoreceptors -smell (olfaction) -taste (gustation) 3.photoreceptors -sight (vision) 4.nociceptors -pain (nociception) 5.thermoreceptors -hot and cold (thermoesthesia) 6.osmoreceptors -changes in solute concentrations
Match each condition on the right to its description on the left. 1.myopia 2.hyperopia 3.presbyopia 4.astigmatism 5.cataracts multiple focal points are formed due to different radii of curvature on the two axes of the cornea caused by a loss of elasticity in the lens with age clouding of parts of the lens leading to scattering of light passing through eye is too short; can be corrected with a converging lens to bring the focal point forward eye is too long; can be corrected with a diverging lens to move the focal point back
1.myopia -eye is too long; can be corrected with a diverging lens to move the focal point back 2.hyperopia - eye is too short; can be corrected with a converging lens to bring the focal point forward 3.presbyopia - caused by a loss of elasticity in the lens with age 4.astigmatism - multiple focal points are formed due to different radii of curvature on the two axes of the cornea 5.cataracts - clouding of parts of the lens leading to scattering of light passing through
Match the receptor below to it's description. 1.nicotinic receptor (nAChR) 2.muscarinic receptor (mAChR) 3.adrenergic receptor 4.GABAA receptor 5.GABAB receptor 6.AMPA receptor 7.NMDA receptor an ionotropic receptor; ligand-gated chloride channel; binds GABA an ionotropic receptor; binds ACh an ionotropic receptor; ligand-gated sodium channel; binds glutamate a metabotropic receptor; binds ACh an ionotropic receptor; ligand-gated and voltage gated Ca++ channel; binds glutamate a metabotropic receptor; binds GABA a metabotropic receptor; binds NE; α and β subtypes
1.nicotinic receptor (nAChR) - an ionotropic receptor; binds ACh 2.muscarinic receptor (mAChR)- a metabotropic receptor; binds ACh 3.adrenergic receptor - a metabotropic receptor; binds NE; α and β subtypes 4.GABAA receptor - a metabotropic receptor; binds GABA 5.GABAB receptor- an ionotropic receptor; ligand-gated chloride channel; binds GABA 6.AMPA receptor - an ionotropic receptor; ligand-gated sodium channel; binds glutamate 7.NMDA receptor - an ionotropic receptor; ligand-gated and voltage gated Ca++ channel; binds glutamate
Match the descriptions below to the correct layer of the dermis. 1.papillary layer 2.reticular layer -contains Meissner's corpuscles -primary site of most accessory organs (sebaceous glands, sweat glands, hair follicles, smooth muscle) -composed of more densely packed connective tissue -contains Pacinian corpuscles -interdigitates with the epidermis -closest to the epidermis -composed of loosely packed connective tissue -primary site of skin inflammation
1.papillary layer -contains Meissner's corpuscles -interdigitates with the epidermis -closest to the epidermis -composed of loosely packed connective tissue -primary site of skin inflammation 2. reticular layer -contains Pacinian corpuscles -primary site of most accessory organs (sebaceous glands, sweat glands, hair follicles, smooth muscle) -composed of more densely packed connective tissue
Place the following events for the first few steps of sound transduction in the correct order. the stapes transfers the energy to the perilymph of the vestibular duct through the oval window (like a plunger creating waves) waves in the perilymph begin to move the basilar membrane causing bending of hair cells sound waves enter the ear and strike the tympanic membrane causing it to vibrate the vibrational energy is transferred to the auditory ossicles - malleus, incus and finally the stapes.
1.sound waves enter the ear and strike the tympanic membrane causing it to vibrate 2.the vibrational energy is transferred to the auditory ossicles - malleus, incus and finally the stapes. 3. the stapes transfers the energy to the perilymph of the vestibular duct through the oval window (like a plunger creating waves) 4.waves in the perilymph begin to move the basilar membrane causing bending of hair cells
Match the description below to the correct malignant epidermal tumor below. 1.squamous cell carcinoma 2.basal cell carcinoma 3.melanoma -curable most of the time, but can metastasize -can arise from preexisting moles -second most common skin cancer -most deadly form of skin cancer (least curable) -rarely lethal and almost 100% curable -most common skin cancer
1.squamous cell carcinoma -curable most of the time, but can metastasize -second most common skin cancer 2.basal cell carcinoma -rarely lethal and almost 100% curable -most common skin cancer 3.melanoma -can arise from preexisting moles -most deadly form of skin cancer (least curable)
Match the expected dermal coloration to each of the conditions/situations described below. NOTE: some conditions are described more than once 1.yellow 2.blue 3.red -decreased concentration of oxyhemoglobin -poor hepatic (liver) function -dermal vasodilation due to embarrassment -accumulation of bilirubin in the blood -inflammatory response in the dermis -poor blood oxygenation
1.yellow -poor hepatic (liver) function -accumulation of bilirubin in the blood 2.blue -decreased concentration of oxyhemoglobin -poor blood oxygenation 3.red -dermal vasodilation due to embarrassment -inflammatory response in the dermis
The inner ear has a bony labyrinth and a membranous labyrinth. What are the three fluid-filled chambers of the cochlea? What are the fluids that each chamber contains? What are the three membranes associated with these chambers? What is the general function of the cochlea?
3 fluid-filled chambers (scala vestibuli (vestibular duct), scala media (cochlear duct) and scala tympani (tympanic duct)). Vestibuli and tympani (perilymph); media (endolymph). 3 membranes (vestibular, tectorial and basilar). Cochlea: produces nerve impulses in response to sound vibrations.
How long does it take a keratinocyte produced in the stratum germanium to be sloughed off the surface of the epidermis?
30 to 40 days
Let say you are looking at a snellen chart from a distance of 20 feet and can only read down to the 20/50 line. What is the maximum distance a person with 20/20 vision could stand from the chart and still be able to read that same line? 20 feet 40 feet 50 feet 100 feet
50 feet
What is the Snellen chart? What does 20/20 vision literally mean? 20/40? If the Snellen chart reveals that your visual acuity is 20/20, does this mean you have perfect vision?
A Snellen chart is an eye chart that can be used to measure visual acuity. 20/20 vision is considered "normal" vision. You can read at 20 feet a letter that most human beings should be able to read at 20 feet. If your visual acuity is 20/40, you are myopic. No, it just means perfect visual acuity. Perfect visual acuity doesn't mean perfect vision.
What is a depolarization? How can it be achieved? What is a hyperpolarization? How can it be achieved? What is a repolarization? How does this term relate to depolarization, hyperpolarization and resting membrane potential?
A depolarization is a decrease in membrane potential. The membrane potential is becoming less negative or more positive. This can occur by Na+ or Ca2+ entering the cell. Hyperpolarization is an increase in membrane potential. The membrane potential is becoming more negative. This can occur by Cl- ions entering the cell or K+ ions exiting the cell. Repolarization is returning to RMP after a depolarization. A neuron becomes depolarized, fires an AP, is repolarized, reaches RMP and is hyperpolarized shortly.
Can you explain what a generator potential is? Receptor potential? How do the two differ from one another? What structural class of neurons to these potentials occur in?
A generator potential occurs at the end of a neuron that has ligand- or mechanically-gated channels that cause voltage-gated channels to open in the spike initiation zone, thus creating action potentials. A receptor potential involves two cells, a receptor cell that generates a graded potential which releases a neurotransmitter on a sensory neuron which generates an action potential. These types of potentials occur in sensory neurons.
What is a semicircular canal? Ampulla? What is the function of a crista ampularis? How is this involved in the detection of head movements? How does the function of the crista ampularis relate to that of the organ of Corti?
A half-circular ring structure emanating from the vestibule. Bulged regions at the base of a semicircular canal. Detect the movement of the head (turning right and left, tilting right and left and nodding forwards and backwards). The cupula of the crista ampularis functions like the tectorial membrane in the organ of Corti.
In a disease such as multiple sclerosis where the immune system attacks myelin-synthesizing cells, which property or properties of neurons would be affected? How so?
Action potential conduction. In demyelinating disorders, there is damage to the myelin sheath and the axolemma since the immune system attacks these cells/membranes (autoimmune disease). Current will leak out of the axon and result in a short in the signal (i.e., a drop in action potential propagation).
What is the difference between albinism and vitiligo?
Albinism is an inherited condition caused by a genetic mutation (homozygous recessive). In vitiligo the melanocytes die for reasons that are not completely clear (likely an autoimmune response).
You are looking at a red ball. Which colors (wavelengths) of visible light are absorbed by the ball? Reflected? What does it mean the reflected photons are pixels of the image of the ball that forms on your retina?
All but red. Red. Photons reflect form every point of an object. So, the photons reveal not only the color or an object, but also its shape, photon by photon (or pixel by pixel).
In which portion(s) of a neuron does a resting membrane potential (RMP) exist? In which portion(s) of a neuron do graded (local) potentials occur? In which portion(s) of a neuron do action potentials occur?
All. Cell body, dendrites, internodes and terminal knobs. Nodes of Ranvier.
Action potential (AP) propagation along a myelinated neuron can be described as a series of successively regenerated APs linked by a series of successively regenerated graded potentials. Starting with a neuron reaching threshold in the axon hillock, can you provide a more detailed explanation of how an AP arises in the initial segment and then how the signal is propagated along a neuron? Is the same AP that is generated in the initial segment the signal that is propagated along the entire axon?
An AP arises in the initial segment when enough Na+ comes into the cell to bring it from -70 mV to -60mV. Here depolarization happens and this activates voltage-gated Na+ channels. Na+ flows in until the cell reaches +30 mV, where voltage-gated Na+ channels inactivate and voltage-gated K+ channels open. K+ leaves the cell until it reaches -90 mV, where voltage-gated K+ channels close and the cell returns to its normal state. This process repeats itself as AP propagation continues.
What is an astigmatism? Cataract? LASIK?
Astigmatism is a defect in the eye or in a lens caused by a deviation from the spherical curvature. Cataract: the lens of the eye accumulates pigments and becomes progressively opaque. LASIK: laser eye surgery or laser vision correction. Essentially, it is a procedure where the cornea is reshaped with a laser to change the way it bends light rays.
What are the two regions of the spike initiation zone of a neuron? What types of channels are located in each area? What type of potentials occurs in each area?
Axon hillock + initial segment of axon = spike initiation zone. The axon hillock has voltage-gated Na+ channels. The initial segment has voltage-gated Na+ channels and voltage-gated K+ channels. The axon hillock undergoes graded potentials and the initial segment undergoes action potentials.
If the ciliary muscles of the eye are relaxed, which receptor must be activated? What neurotransmitter(s) is binding to the receptor?
B2 receptors. Norepinephrine.
Can you draw out and label a typical motor neuron? What are dendritic spines? What is a soma? What is a nerve fiber? What are synaptic knobs?
Be able to draw out/label a motor neuron here. Dendritic spines- Elevations on dendrites where presynaptic neurons form a synapse. Soma- The cell body of a neuron. Nerve fiber- An axon. Synaptic knobs -The terminal ends of axons where neurotransmitters are stored and released.
Thinking anatomically, can you explain why smell is the only special sense that does not enter the brain by relaying through the thalamus?
Because the primary neurons enter the brain through tiny holes in the floor of the cranium and synapse with the secondary neurons in the olfactory bulbs at the base of the brain.
Of the three structural classes of neurons, which are sensory? Motor? Which conduct information afferently? Efferently? What percentage of all neurons are interneurons? Where are they located?
Bipolar: sensory afferent neurons (special senses). Unipolar: sensory afferent neurons (somatic senses). Multipolar: motor efferent neurons. 99% of all CNS neurons are interneurons.
Hair and nails emerge from hair and nail roots. Both hair roots and nail roots contain what type of cells? Do hair and nails desquamate?
Both hair and nail roots contain basale cells (stem cells). No
How is it that brain cancer is fairly common, yet like muscle (myocytes) and fat cells (adipocytes), neurons do not mitotically divide? How does chemotherapy work?
Brain cancer is typically caused by glial cells not neurons. Glial cells rapidly divide in the brain and they are more abundant, thus cancer may occur. Chemotherapy (e.g., taxol) works by targeting dividing cells (mitotic spindle apparatus) and halting cell division.
What portion(s) of a neuron can other neurons form synapses with? What is an excitatory postsynaptic potential (EPSP)? An inhibitory postsynaptic potential (IPSP)? In general, what types of potentials are EPSPs and IPSPs?
Cell body and dendrites. A depolarization. A hyperpolarization. Graded (local) potentials.
I like to think of dendrites and the cell body of a neuron as AM receivers and the axon as an FM transmitter. Can you explain my rationale for this comparison based on AM/FM radio waves and neuron function?
Dendrites and the cell body are like AM receivers since they receive sensory information and the amplitude of the graded potentials is modulated. The axon is like an FM transmitter since it transmits the information efferently and the frequency of this information is what is modulated.
What type of tissue is the reticular layer? What are some important organs found in this layer of the dermis?
Dense connective tissue. Sweat and sebaceous glands, hair follicles, smooth and skeletal muscle and Pacinian corpuscles.
What are the differences between erythema, dermatitis and rosacea?
Dermatitis is a dilatation of blood vessels in the papillary layer of the dermis. Erythema is a dilatation of blood vessels in the dermis. In rosacea, the blood vessels are chronically dilated.
Where is the ink or a tattoo deposited in someone's skin? When a tattoo fades over time is this due to years of desquamation?
Dermis No
The internodes of an axon are a defined length. What is the reason they evolved to be they length that they are? What would happen if they were shorter? Longer?
Diffusion is distance limited. If the nodes were any further apart, the graded potentials in the internodes would be too weak to reach the nodes. (See above.) The AP initiated in the initial segment could not be regenerated along the axon.
A person's eyeglass prescription is -2.5. What are the units of this prescription? Is this a prescription for negative or positive diopters? Can diopters be converted into Snellen chart numbers?
Diopters. Negative. No.
Which MAP transports recycled vesicles from the axon terminal knob to the soma? Is this in the positive or negative direction? Which MAP transports secretory vesicles from the soma to the terminal knob? Is this in the positive or negative direction? Which of the three components of the cytoskeleton do these MAPs "walk" along?
Dynein (-). Kinesin (+). Microtubules.
What are the components of the externa ear? Middle ear? Inner ear? What anatomical structure separates the external ear from the middle ear?
External ear: Auricle (or pinna). Auditory canal. Middle ear: Eardrum inner layer. Cavity (also called the tympanic cavity). ardrum outer layer (also called the tympanic membrane). Ossicles. Inner ear: Cochlea. Vestibule. Semicircular canals. Tympanic cavity.
(T/F) First degree burns are the most serious and damaging types of burns.
False
(T/F) The integument (skin) is an avascular organ.
False
(T/F) UVA light is more energetic than UVB light, thus UVA light has a longer wavelength than UVB light.
False
(T/F) Vellus hair is coarse hair.
False
T/F One taste receptor cell can be activated by all the different tastes.
False
T/F Referred pain is the process by which we experience the withdrawal reflex.
False
T/F Unmyelinated nerve fibers conduct action potentials faster than myelinated nerve fibers.
False
T/F LASIK corrects visual defects by altering the shape of the lens, thereby altering the bending of light entering the eye.
False LASIK reshapes the cornea
(T/F) HPV is commonly known as herpes.
False (HSV = Herpes)
Which parts of your body have the ability to discern between two separate pin pricks in very close proximity to one another? What does this ability tell you about the size of the nociceptive receptive fields in these regions of the body?
Finger tips and toes. Receptor fields are smaller in the hands and feet.
What are the five different tastes we can perceive? What is/are the tastants(s) for each of these different tastes? Each taste cell uses a single receptor. As tastants have varied signaling mechanisms, do they also trigger the release of different neurotransmitters from the receptor?
Five different tastes: Bitter: coffee, beer, unsweetened cocoa, earwax Sweet: monosaccharides Umami: glutamate Sour: protons Salt: Na+ No, they all result in the release of glutamate from the taste receptor cell.
Which of the following statements is true? one example of a GABA receptor is a voltage-gated chloride channel GABA is the most abundant inhibitory neuron in the central nervous system GABA is an excitatory neurotransmitter GABA causes EPSPs in postsynaptic neurons
GABA is the most abundant inhibitory neuron in the central nervous system
What are the three layers of the eyeball and what composes each layer. Which layer is most visceral? Parietal? Which layer contains photoreceptors? Which layer forms the cornea? Which layer forms the ciliary body? Which layers forms the iris?
Layers of the eyeball: Sclera: thick connective tissue; forms the "white" of the eye and the cornea of the eye. Choroid: vascular tissue; forms the ciliary body and iris. Retina: photoreceptors (rods and cones), bipolar cells and ganglion cells.
During a minor hand surgery, a local anesthetic (e.g., lidocaine) is used to numb the patient's hand. What is the mechanism by which this drug works?
Lidocaine inhibits voltage-gated Na+ channels. Neurons are still activated, but the voltage-gated Na+ channels can't open, so there is no APs and therefore no pain signal reaching the brain. Therefore, the perception of pain never occurs in the brain.
What type of channels are involved in EPSPs? Neurotransmitters? Ions? What type of channels are involved in IPSPs? Neurotransmitters? Ions?
Ligand-gated channels. Glutamate. Na+ or Ca2+. Ligand-gated channels. GABA. Cl-.
What type of tissue is the papillary layer of the dermis? What are some important organs found in this layer of the dermis?
Loose connective tissue. Capillary loops and mechanoreceptors (Meissner's corpuscles).
Suppose the suspensory ligaments are loose, which receptor must be activated in the ciliary muscle? Which neurotransmitter is causing this response?
M3. Acetylcholine.
You are creating a human-like android. You want to create an android that can react, move and think faster than yourself. How would you construct neurons for your android so that they propagate APs with a greater velocity than your own neurons?
Make the nodes of Ranvier closer together.
synthesize and secrete the pigment that gives color to our skin
Melanocytes
a single-celled tactile sensory receptor
Merkel Cells
Sweat glands can be classified as either: Merocrine (eccrine) Ceruminous Apocrine Sebaceous
Merocrine (eccrine) Apocrine
What is the sensory organ of audition? What are all of the cells and membranes that make up the organ of Corti? Where is it specifically located?
Organ of Corti. Tectorial membrane, outer hair cells, basilar membrane, inner hair cells, support cells. Cochlea.
Which of the following is not located in the papillary layer of the dermis: blood vessels Pacinian courpuscles collagen fibers dermal papilla
Pacinian courpuscles
What glial cell in the PNS has a similar function to the astrocyte in the CNS? What is a node of Ranvier? Are they found in the CNS and PNS?
Satellite cells. The region of an axon between myelinated regions (internodes). Yes.
Skin is referred to as soft keratin, but hair and nails are referred to as hard keratin. Why? What are the functions of a hair follicle? The arrector-pili reflex is considered to be a vestigial reflex. That is, it once had a physiological purpose, but that purpose does not exist anymore, but the reflex still does. What was the function of this reflex in distant humans? What are goosebumps? How do they relate to this reflex?
Skin is soft keratin since it desquamates and the cells are not compacted. Hair and nails are hard keratin since the keratinocytes are heavily compacted without desquamating. A hair follicle is physiologically used for protection, sensation, and insulation. The hair protects us from injuries to our head, it aides in the proprioception of our bodies in space by sensation in the hair follicles, and insulates us. The arrector-pilli reflex had the function of forming air pockets for thermal insulation in distant humans. Goosebumps are the result of this reflex.
The phenomenon of referred pain is thought exist as the result of "cross-talk between neurons." Where is it believed that this cross-talk occurs? Can you use this information to explain how an individual can experience pain in their arm when they are having chest pain due to a heart attack?
Spinal cord gray mater. When a person is having a heart attack the pain fibers in the heart and hand go to the spinal cord and they converge (cross talk) and the pain fibers from the heart can induce action potentials in the pain fibers coming from the arm.
mitotically active cells that continuously create and replace the most abundant cells of the epidermis
Stem Cells
What other cells are located in the epidermis? In which stratum are the cells you identified located?
Stem cells = stratum germinativum; melanocytes = stratum germinativum; Merkel cells = stratum germinativum; Langerhans' cells = stratum spinosum.
Select all the statements below that are true. Hair cells have stereocilia on their apical borders that give them their name Deflection of the basilar membrane relative to the tectorial membrane results in the bending of stereocilia (and subsequent chemical sound transduction) Stereocilia are embedded in the tectorial membrane There are three rows of outer hair cells and one row on inner hair cells Outer hair cells are responsible for the actual perception of sound. Stereocilia are motile structures supported by microtubules
Stereocilia are embedded in the tectorial membrane There are three rows of outer hair cells and one row on inner hair cells Deflection of the basilar membrane relative to the tectorial membrane results in the bending of stereocilia (and subsequent chemical sound transduction) Hair cells have stereocilia on their apical borders that give them their name
What are the important functions of subcutaneous fat? Is liposuction a means of permanent fat loss? Why is the hypodermis the desirable site for subcutaneous injections, such as insulin shots?
Subcutaneous fat is an energy reserve, shock absorber, and thermal blanket. Liposuction is not a permanent solution for fat loss. Fat cells will always be present therefore sucking the fat out will not ultimately be a complete fat loss solution. Hypodermis is desirable for subcutaneous injections because there isn't really anything to 'hit' or damage here and the subcutaneous plexus quickly picks up the injected drug here as well.
There are myriad nociceptive stimuli. What are some of these triggers for pain? If you had a lesion on your arm, what medications could you take to reduce the activity of prostaglandins? Histamine? Substance P? What's another name for endogenous morphine? Exogenous morphine? Does nociceptive information travel to the brain contralaterally or ipsilaterally?
Substance P, histamine and prostaglandins. Prostaglandins: aspirin. Histamine: NSAIDs. Substance P: capsaicin. Opiates. Morphine. Contralaterally.
What are the five different types of special senses? Based on your list, would you expect these senses to enter the nervous system at the level of the spinal cord or brain?
Taste (gustation), smell (olfaction), sight (vision), hearing (audition) and balance/equilibrium (equilibrioception). Brain.
What kind of Na+ channels are present in membrane discs? How are these channels regulated? What role do these Na+ channels play in transduction?
The Na+ channels are regulated by cGMP. They are open when cGMP levels are high and binds to them. They cause the photoreceptor cells to depolarize.
What are the two divisions of the CNS? The PNS? In which division would sensory receptors be appropriately categorized? What is your rationale?
The brain and the spinal cord. Cranial nerves and spinal nerves. PNS. Sensory organs are the most peripheral extensions of sensory neurons.
How does the "brain" of a neuron work? In other words, can you explain how temporal and spatial summation affect the threshold potential? Where does an action potential (AP) first occur in a neuron? What are the events that lead up to an AP occurring? If a postsynaptic cell synapses with 32 different EPSPs totaling 42 mV, and one IPSP of -32 mV, would the initial segment of the axon fire an AP? Why or why not?
The brain of a neuron is a calculator that does addition. It adds incoming + charge to incoming - charge. Temporal summation is when one presynaptic neuron is fired repeatedly over time. Spatial summation is when several presynaptic neurons fire simultaneously. In either case, many ions accumulate in the postsynaptic cell. Positive charge pushes K+ towards the axon hillock. Negative charge draws K+ away from the axon hillock. The initial segment of the axon. If the current reaching the axon hillock changes the membrane potential there to -60 mV, current will spread to the initial segment and open voltage-gated Na+ channels at -60 mV. An action potential will then ensue. Yes.
If a cell at rest is -70 mV, what happens when Na+ enters it? K+ leaves it? Chloride enters it? If a cell goes from -70 mV to -60 mV is that a reduction or increase in membrane potential? Why? What is the TMP when a cell is at 0 mV?
The cell becomes more +, or depolarized. The cell becomes more -, or hyperpolarized. The cell becomes more -, or hyperpolarized. Reduction; the cell is becoming less negative, so the polarity is being reduced. At 0 mV, there is no polarity across the cell membrane.
Graded potentials are also referred to as local potentials. Why are these potentials referred to as "graded" potentials? "Local" potentials? What does it mean that the magnitude (or amplitude) of a graded potential is variable? What does it mean that the change in membrane potential is directly proportional to the size of the stimulus? What does it mean that graded potentials are distance-limited?
The change in membrane potential is directly proportional to the magnitude of the stimulus. They are also called local potentials because they only occur over small regions of the plasma membrane. If there is a greater stimulus (i.e., more ions entering the cell), there will be a greater change in membrane potential. Therefore, the change in membrane potential is directly proportional to the stimulus. They are distance limited because diffusion is distance limited.
Select all the statements below that are false. The depolarization in the hair cell is known as a generator potential. Synaptic vesicles in the hair cell fuse with the plasma membrane due to an influx of Ca++ ions through voltage-gated calcium channels. The first (and tallest) of the stereocilia is known as a kinocilium. Once the mechanically-gated K+ channels open, K+ rushes out of the cell causing rapid depolarization
The depolarization in the hair cell is known as a generator potential. false bc its known as a "receptor potential" Once the mechanically-gated K+ channels open, K+ rushes out of the cell causing rapid depolarization false bc K+ rushes into cell
What is an equilibrium potential? What is the equilibrium potential value for Na+? For K+? How do these equilibrium potentials relate to the RMP? In other words, how did we experimentally determine that K+ is the ion primarily responsible for the establishment of a RMP?
The equilibrium potential is the membrane potential at which an ion is in equilibrium across the plasma membrane. Na+ = +60 mV. K+ = -90 mV. If the only ions across the cell membrane are K+ ions, the resultant membrane potential will be -90 mV, very close to the actual membrane potential of the neuron (-70 mV).
Stimuli can be sensed to varying degrees. Information regarding varying degrees of intensity (e.g., visualizing a dim white screen vs. a bright white screen) is coded in the form of varying AP frequencies. What is responsible for generating these differences in AP frequency? In other words, AP frequency is directly proportional to?
The frequency at which presynaptic neurons cause EPSPs on that neuron.
What does it mean that action potentials are variable in frequency? Fixed in magnitude? Can you compare and contrast the major differences between graded potentials and action potentials?
The frequency of APs along an axon is a major way in which information in coded. In general, a strong stimulus would have a greater AP frequency than a weak one. The amplitude of an AP is fixed for a specific neuron. Graded potentials may be depolarizing or hyperpolarizing depending on the stimuli, whereas APs are always depolarizing. In graded potentials, the amplitude is proportional to the stimuli, whereas in APs the amplitude is fixed.
What type of tissue(s) is the hypodermis? Is the hypodermis a layer of skin?
The hypodermis is loose connective tissue. No. It is a layer of tissue beneath skin.
Which of the following statements is more accurate? -The skin is also known as the integumentary system. -The integumentary system is composed of skin and and all the accessory organs.
The integumentary system is composed of skin and and all the accessory organs.
What are kinocilia? Are they motile structures? What are they supported by? Microtubules? Microfilaments? How do they interact with stereocilia via the tip-link mechanism? How does all of this relate to the process of hearing?
The kinocilium is the tallest of the stereocilia of a hair cell. No. Microtubules. Stereocilia and the kinocilium are connected by small connective tissue fibers. When the stereocilia are pushed towards the kinocilium, the fibers pull open mechanically-gated K+ channels in the shorter stereocilia. Endolymph is K+ rich. K+ enters the hair cell and depolarizes it. As a result, it releases neurotransmitters which activate neurons of the cochlear nerve that send the signal to the brain to be processed.
What is the relationship between the lens, the ciliary body and suspensory ligaments?
The lens is attached to the ciliary body via the suspensory ligaments.
Which of the following is NOT an acceptable definition for an equilibrium potential.
The membrane potential at which the chemical and electrical gradients of a given ion are driving movement of that ion in the same direction.
What are the most typical type of sweat glands? Where do their ducts open up into? What is the function of apocrine glands? Where are they located. Where do their ducts open?
The most typical sweat gland type is the eccrine gland. Eccrine gland ducts open onto the surface of the skin (a sweat pore) to cause evaporation for a cooling effect. Apocrine glands open up into hair follicles and are used to produce oily substances to excrete from the body. These are located in places such as the armpits or pubic areas. These secretions are odorless, but bacteria in these regions metabolize these secretions creating an odor. This is our natural body odor. Some argue that that this odor is attractive to the opposite sex (possibly containing pheromones).
What is the name of the glands that produce your natural skin moisturizer? Are eccrine glands found in the palms of your hands? Do your hands get oily from sebum? Why or why not?
The name of the gland producing natural skin moisturizer: Sebaceous gland Yes. Do your hands ever sweat? Sebum is the waxy/oily substance that is excreted from sebaceous glands. Therefore, the palms of the hands will not be oily from sebum since the palms do not contain sebaceous glands.
What is the function of the oval window of the vestibular duct? What is the function of the round window of the tympanic duct?
The oval window connects the middle and inner ear, through which sound vibrations of the stapes are transmitted. Movements of the oval and round window result in the basial membrane bouncing up and down.
Which of the following statements is false regarding the axon hillock? The net effect on the axon hillock of all EPSPs and IPSPs occurring across a neuron's cell body and dendrites determines what that neuron's response will be. The axon hillock is part of the spike initiation one (trigger zone). The plasma membrane of the axon hillock region contains ligand-gated sodium channels. The axon hillock is the last portion of the cell body.
The plasma membrane of the axon hillock region contains ligand-gated sodium channels.
The refractive index of the cornea is 1.38 while that of water is 1.33. If the two indices are so similar, why don't humans have clear vision underwater? How do swimming goggles help improve your underwater vision?
The problem is that they are too similar, so light rays don't converge much. This causes the focal point to form behind the retina. It is sort of like being hyperopic. Restores the air-corneal interface.
Which of the following statements is false regarding the refractory period of an action potential? The refractory period makes it so action potentials can only travel one way down the axon of a neuron. During the absolute refractory period, there can be no new action potentials fired. This is the reason you cannot sum action potentials. The refractory period of an action potential in a neuron is longer than the refractory period of an action potential in a cardiac muscle cell (cardiomyocyte). During the relative refractory, period a sufficiently large stimulus could cause another action potential to fire.
The refractory period of an action potential in a neuron is longer than the refractory period of an action potential in a cardiac muscle cell (cardiomyocyte).
Thick skin has five strata and thin has four, but this is not the primary reason why thick skin is so much thicker than thin skin. What is the primary reason?
The stratum corneum is much thicker in the thick skin that in the thin skin.
When is the triad of near reflex employed? What is lens accommodation? What is the state of the ciliary body, suspensory ligaments and lens when an object is more than 20 feet away? Less than 20 feet away?
The triad of near reflex is employed in response to focusing on a near object (closer than 20 ft. from the eye). Lens accommodation is the process by which the eye increases its converging power by making the lens more convex. More than 20 feet away:Ciliary muscles are relaxed, suspensory ligaments are taut and the lens is flattened out. Less than 20 feet away:Ciliary muscles are contracted, suspensory ligaments are loose and the lens is bulged (or very convex).
Which receptors would inform you of an ice cube that was just placed on your arm? The taste of a cup of coffee? The pain of stepping on a nail?
Thermoreceptors. Chemoreceptors. Nociceptors and mechanoreceptors.
What is the function of a macula? What is a utricle? A saccule? How are each of these involved in the detection of head movements? How does the function of the macula relate to that of the organ of Corti?
They detect linear and horizontal acceleration and deceleration and head tilt. Regions of the vestibule that contain maculae. The utricle and saccule are at a 90 degree angle to one another. The utricle is in the horizontal plane so it detects horizontal acceleration and deceleration and head tilt. The saccule is in the vertical plane so it detects linear acceleration and deceleration. The otolith membrane of the macula functions like the tectorial membrane in the organ of Corti.
Are nociceptors tonic or phasic receptors? When you put on your shirt/top/blouse in the mooring you can feel it on your skin, however, several hours later the feeling is "gone." Based on this fact, are tactile receptors tonic or phasic?
Tonic (slowly adapting). Phasic (quickly adapting).
When light hits rhodopsin, retinal is converted into the trans or cis conformation? What does it mean when your retina is "bleached out?" After light exposure, how is retinal converted back to its original conformation?
Trans. When exposed to light, there is a conformational change that causes opsin to dissociate from retinal, resulting in bleaching. A bleached rhodopsin molecule cannot be activated by light and therefore the rod cell is inactive. The process is mediated by the pigmented epithelial cells at the back of the retina.
(T/F) Freckles can be inherited from your parents.
True
(T/F) In terms of the change in membrane potential, a graded potential can be either positive or negative.
True
(T/F) The primary function of melanin is to protect epidermal cells' DNA from UV damage.
True
(T/F) Vellus hair is shorter than terminal hair.
True
T/F A photon of light with higher energy has a shorter wavelength than a photon of light with lower energy.
True
T/F All G Protein-coupled receptors (GPCR) are metabotropic receptors.
True
T/F An action potential first arises in the initial segment of the axon.
True
T/F As the eyes converge for the near reflex, the angle between the two visual axes becomes more obtuse (a larger angle).
True
T/F Different frequencies of sound will resonate at different points along the basilar membrane.
True
T/F In order for a clear image to be formed, the focal point of all the refraction that happens in the eye must be on the retinal surface,
True
T/F Interneurons are the most abundant type of neuron in your body
True
T/F Light will bend when entering a new medium at an angle. The amount it bends is proportional to the difference in refractive index of the two media.
True
T/F The greater the curvature of a lens (more rounded it is) the greater focal power it has.
True
T/F The negative or positive number associated with the power of a lens (in diopters) is an indication of where the focal point is. If the focal point of a lens is in front of the lens (an imaginary focal point) then the number is negative. If the focal point is behind the lens (a real focal point) then it will be a positive number.
True
T/F While the reason the the kinocilium and stereocilia of the hair cells move differs, the tip link mechanism is identical to that of audition.
True
What are the three different types of cone cells? What are their photoreceptor pigments collectively referred to as?
Types of cone cells: Blue. Green. Red. Photopsins (iodopsins).
What are the major differences between UVA and UVB? For example, which one penetrates deeper into skin? Is the one that penetrates deeper more carcinogenic (i.e., cancer causing)?
UVA penetrates deeper into the skin that UVB. However, UVB has a higher energy (i.e., shorter wavelength).
Which sensory organ is involved in detecting linear, horizontal acceleration in a speeding car for example? Linear, vertical deceleration retuning to earth in a space shuttle for example?
Utricle. Saccule
What channels are involved in an AP? At which voltages (in mV) do they open? Close? What are the three conformations of the voltage-gated sodium channel?
Voltage-gated Na+ channels and voltage-gated K+ channels. -60 mV: voltage-gated Na+ channels. +30mV: voltage-gated K+ channels. Three conformations of the voltage-gated Na+ channel are open (-60 mV), closed (-70 mV), and inactivated (+30 mV).
During depolarization in an AP, what channel is open and what channel is closed? During repolarization in an AP, what channel is open and what channel is closed? What are the conformations of the two channels at -70 mV? At + 30 mV?
Voltage-gated Na+ channels are open and voltage-gated K+ channels are closed. Voltage-gated K+ channels are open and voltage-gated Na+ channels are closed (actually, they are inactivated). -70 mV: voltage-gated Na+ channels are closed and voltage-gated K+ channels are closed. +30 mV: voltage-gated Na+ channels are inactivated and voltage-gated K+ channels are open.
What is the difference between a whitehead and a blackhead? What is the technical term for a pimple?
Whiteheads contain dirt, debris, bacteria, etc. that haven't been exposed to the atmosphere, while with blackheads this material is oxidized and turns black in color. Pustule.
Why is it important that the heart's AP frequency is about 1 AP per 200 ms versus skeletal muscle, which has a frequency of about 1 AP per 5 ms?
With a greater AP frequency, muscle cells can summate muscle tension forming what is known as a tetanus, or a sustained contraction. Heart cell AP frequency is markedly decreased, making it impossible for the summation of muscle tension. Therefore, the heart cannot undergo a sustained contraction.
Why do wrinkles form? There are really two major reasons. One involves the sun and another fibroblasts. Can you elaborate? Why do scars form? How do they form? Will they form if the skin is cut with a knife down into the stratum spinosum?
Wrinkles form due to aging where hormones and UV radiation damage the collagen and elastic fibers of the skin. Scars form from a deposition of collagen serving as a skin "patch" following an injury. Fibroblasts synthesize collagen to fill in the gap of the epidermis where the injury is. No. These cells can be regenerated.
Tanning salons maintain the safety of their tanning beds due to the lack of UVB. Are they misinforming the public?
Yes, heavy exposure to UVA, as in a tanning bed (~10x), can also lead to severe damage to the skin and skin cancer.
What is the most common type of skin cancer? What type of cells are responsible for this cancer? What is the most dangerous form of skin cancer? What type of cells are responsible for this cancer? Are all tumors cancerous? Why or why not?
a. Basal cell carcinoma. b. Stratum basale cells are responsible of basal cell carcinoma. c. Melanoma. d. Melanocytes are the cells responsible of melanoma. e. No, some tumors can be benign.
What are the differences in the quantities of pigments in red hair versus blonde and brunette? What causes some hair to be kinky, or wavy? Why is gray hair white in color?
a. Blonde hair: a lot of pheomelanin Black/ Brown hair: a lot of eumelanin Red hair: relatively equal amounts of pheomelanin and eumelanin b. Curly or wavy hair is a result from the hair shaft being more elliptically shaped compared to straight hair which is round in its shape. c. Gray hair is the absence of pigment, therefore it is white in its color since white is the absence of pigment.
What is cholecalciferol? Where is it made? What is its function? What is calcidiol? Where is it made? What is its function? What is calcitriol? Where is it made? What is its function?
a. Cholecalciferol is vitamin D3. b. In the skin. c. Cholecalciferol is used to make calcidiol. d. Calcidiol is made in the live from cholecalciferol. e. Calcitriol is made in the kidney from calcidiol. f. Calcitriol is important for calcium absorption.
What does it mean that the epidermis is avascular? Virtually all cells of the human body are within 20 µm of a capillary. Do some of the cells of the epidermis fly in the face of this general rule? a. It does not have blood vessels. b. Yes.
a. It does not have blood vessels. b. Yes.
What type of tissue is the epidermis? What germ layer is it derived from?
a. Keratinized stratified squamous epithelium b. Ectoderm
What is rickets? How does this disease develop? How does rickets differ from osteomalacia?
a. Rickets is the softening and weakening of bones in children due to too much collagen and not enough hydroxyapatite. b. Rickets is developed due to vitamin D deficiency. Vitamin D is required for calcium absorption. Calcium is a major component of the bone, therefore, in its absent the bone will be softer (i.e., less hydroxyapatite). c. Osteomalacia is the adult form of rickets.
Why are skin tags potentially dangerous to remove? A nevus is an accumulation of what type of epidermal cells? The moles you are born with are more likely to become malignant than the ones you develop throughout life? What does malignant mean? How does this term differ from benign? How does it relate to cancer?
a. Skin tags are potentially dangerous to remove because they contain dermis and therefore it can cause bleeding and be very painful. b. Melanocytes. c. Yes. d. Malignant are cells that are most likely to grow out of control and invade other tissue (i.e., metastasis). e. Benign cells are not generally harmful and cannot invade nearby tissues. f. Malignant tumors are cancerous (i.e., can spread).
A friend explains to you that multiple sclerosis is analogous to having a phone charging cord that has a broken coating and is frayed. He also explains how some electricity from the outlet is lost through these frayed spots on its way to charge the phone. In other words, there is a short in the wire. How do you compare this to a neuron that is damaged due to multiple sclerosis?
a. This is analogous to MS since the myelin sheath is attacked by the immune system. The myelin sheath acts as the rubber coating to a wire, and when this sheath is attacked by the immune system is breaks down over time. Without this sheath, information/current (K+) will leak out of our cells, thus creating a 'short' in our wires.
What is the primary pigment responsible for skin color? How is this pigment made? Where is it made? Where is it primarily located?
a.Eumelanin. b. Eumelanin is made by the oxidation of the amino acid tyrosine by tyrosinase. c. Eumelanin is made in the keratinocytes of the stratum spinosum. d. Eumelanin is located in the stratum spinosum.
An _______________________ is a ligand that binds to a receptor and activates it upon binding.
agonist
In terms of light being focused/refracted in the eye. Where does light bend the most? cornea-aqueous humor interface aqueous humor-lens interface lens-vitreous humor interface air-cornea interface
air-cornea interface
In the previous question regarding touching a hot stove, one step was left out. How does the information about the hot stove get to the brain in order for us to feel pain? -an axon collateral branching from the interneuron in the spinal cord sends the signal to the brain -an axon collateral branching from the sensory neuron bypasses the interneurons of the spinal cord and runs directly to the brain -magic -the motor neuron has two axons: one which travels to the muscle, and one which send the signal to the brain
an axon collateral branching from the interneuron in the spinal cord sends the signal to the brain
An _____________________________ is a ligand that binds to a receptor but does not activate it upon binding.
antagonist
What is the most apical stratum of the epidermis? Visceral? Which layer is not present in thin skin?
apical- Stratum corneum. visceral- Stratum germinativum (or basale). only in thick skin- Stratum lucidum.
Choose all that apply. Which of the following structures are directly associated with a hair follicle? apocrine gland eccrine (merocrine) gland mammary glands sensory nerve fibers Pacinian corpuscles blood supply (capillaries) Meissner's corpuscles sebaceous gland arrector pili
apocrine gland sensory nerve fibers blood supply (capillaries) sebaceous gland arrector pili
Which are the two regions of a neuron that make up the spike initiation zone? axon hillock synaptic cleft initial segment of the axon axon terminals
axon hillock initial segment of the axon
The organ of Corti rests on which of the following. basilar membrane tectorial membrane cochlear duct vestibular membrane
basilar membrane
Which of the following statements is correct: benign tumors are not cancerous skin color is primarily the result of the quantity of melanocytes UVA penetrates deeper in skin and therefore is responsible for direct DNA damage a "beauty mark" is clinically known as a verruca
benign tumors are not cancerous
[Almost] all of the special senses involve the use of afferent ____________ neurons. This is in contrast to the somatic senses which employ afferent _________ neurons. bipolar; (pseudo)unipolar bipolar; multipolar (pseudo)unipolar; bipolar multipolar; bipolar
bipolar; (pseudo)unipolar
If you were to remove a healthy lens from someone's eye. What would the natural conformation be? evenly thickness (like a disc of glass) bulged in the middle; narrower near the edges (like a magnifying glass) a perfect sphere donut shaped (with a hole in the center)
bulged in the middle; narrower near the edges (like a magnifying glass)
Which of the following associations are incorrect?: yellow sciera ( white of the eye) : jaundice redness of skin due to inflammation : dermatitis cyanosis: blue skin hue due to poor oxygenation of blood chronic (long-term) skin redness : erythema
chronic (long-term) skin redness: erythema
When viewing an object that is near, the ciliary body is _____________ and the lens is _______________. This is due to the release of norepinephrine from the __________________ nervous system. contracted; stretched (flattened out); parasympathetic relaxed; stretched (flattened out); sympathetic contracted; bulged; parasympathetic relaxed; bulged; sympathetic
contracted; bulged; parasympathetic
Which of the following correlation is incorrect: internal lining of the viscera- endoderm sensory neurons- ectoderm arrector pili muscle - mesoderm dermis of the skin - ectoderm
demis of the skin- ectoderm
Match the terms below to their definitions. positive deviation of the TMP from RMP TMP returning to RMP following a positive deviation from RMP negative deviation of the TMP from RMP
depolarization: positive deviation of the TMP from RMP repolarization: TMP returning to RMP following a positive deviation from RMP hyperpolarization: negative deviation of the TMP from RMP
From the choices below, choose ALL that are considered layers of the skin. skeletal muscle dermis epidermis hypodermis
dermis epidermis
Cerumen is commonly known as ________.
earwax
Which epidermal pigment is the primary determinant of skin color? eumelanin carotene pheomelanin
eumelanin
EPSP stands for _____________ post synaptic potential.
excitatory
T/F If a neuron is transferring information to another neuron, we call this a neuroeffector junction.
false
T/F Trans-retinal will spontaneously revert to its cis form after a short time.
false
During the formation of a scar, cells known as______________deposit collagen fibers at the dermal/epidermal border to form a "patch" in the skin"
fibroblasts
Which of the following is NOT a function of the hypodermis? thermal insulation filtration storage of energy reserves shock absorption
filtiration
An area of skin that has an increased amount of melanin within the keratinocytes without an increase in melanocytes is known as a:
freckle / age spot
An action potential is a brief depolarization of the transmembrane potential that is variable in ________________
frequency
Which of the following cells of the retina actually undergo an action potential? photoreceptor cells amacrine cells ganglion cells bipolar cells
ganglion cells
In the sense of touch, an action potential results from a ______________________ potential in the sensory neuron.
generator
If a person has high tyrosinase activity, they probably: are making a lot of vitamin D are not making a lot of vitamin D have dark colored skin have light colored skin
have dark colored skin
The condition known as _________________________ occurs when light rays entering the eye would focus at a point behind the retina, but instead hits the retina before it has focused.
hyperopia
If a person's eyeglass prescription is: +2.00 + 1.25 x 120 You can deduce that this person is: myopic with an astigmatism hyperopic with an astigmatism myopic without an astigmatism hyperopic without an astigmatism
hyperopic with an astigmatism
Which of the following statements is true? walking from a bright sunny day into a dim lit room, your rods can immediately take over and begin sending meaningful signals to the brain your cones allow you to distinguish shapes in dim lit scenarios walking on a moonlit night, your cones are highly activated in bright light, your rods are basically useless because all of the rhodopsin is bleached
in bright light, your rods are basically useless because all of the rhodopsin is bleached
IPSP stands for _______________ post synaptic potential.
inhibitory
Spinal nerves exit the CNS through the structure labeled "A" in the above image. This structure is known as: intervertebral disc spinous process vertebral foramen intervertebral foramen
intervertebral foramen
the most abundant cells of the epidermis; named for the strong, insoluble, fibrous protein which they produce
keratinocytes
Which of the following fibers would conduct action potentials the fastest? large diameter, unmyelinated axons small diameter, unmyelinated axons small diameter, myelinated axons large diameter, myelinated axons
large diameter, myelinated axons
Consider a tactile receptor. For an excitatory stimulus (touching something with your hand, for instance), the greater the strength of the stimulus, the ______________ the generator potential will be in the receptor. This would lead to ______________ action potential frequency in the neuron and ultimately a ______________ amount of neurotransmitter being released. smaller; decreased; lesser larger; increased; greater smaller; increased; lesser larger; decreased; greater
larger; increased; greater
A graded potential can be initiated by the opening of which types of channels. leak channels ligand-gated ion channels voltage-gated ion channels mechanically-gated ions channels
ligand-gated ion channels mechanically-gated ions channels
A graded potential is a change in the transmembrane potential that is variable in ________________
magnitude
The pigmented epithelium is located at the very back of the retina and contains granules of _____________________________ in order to prevent the scattering of light that has passed through the rest of the retinal layers.
melanin
Cytocrine secretion is carried out by which cells of the epidermis: melanocytes stem cells keratinocytes Merkel cells
melanocytes
From the options below, choose ALL of the epidermal cells that exclusively reside in the stratum basale. melanocytes keratinocytes stem cells Merkel cells Langerhans cells
melanocytes stem cells Merkel cells
The mechanoreceptors located in the epidermis are called ________________. Merkel cells Pacinian corpuscles Meissner's corpuscles Langerhans cells
merkel cells
Which are the three things included in the "triad of near reflex?" miosis convergence of the visual axes lens accomodation mydriasis
miosis convergence of the visual axes lens accomodation
The condition known as ________________________ occurs when light rays entering the eye focus at a point in front of the retina.
myopia
An accumulation of melanocytes in an area of the skin could be referred to as which of the following? verucca acrochordon nevus plaque
nevus (mole)
Imagine the following scenario: 1. You are studying a cell with RMP = -90 mV.2. You have the ability to open all of the gated potassium channels in the plasma membrane of that cell with the flip of a switch If you were to flip that switch and measure the net flow of potassium ions across the plasma membrane, which of the following best describes what you would observe.
no net flow of potassium ions
Somatic senses include: nociception audition tactile senses vision proprioception peripheral thermoreceptors
nociception tactile senses peripheral thermoreceptors proprioception
The portion of the mucosa lining the interior of your nasal cavity that contains all the neurons responsible for the sense of smell is called the _________________________________
olfactory epithelium
Which of the following statements is true? glutamate is the most abundant excitatory neurotransmitter in the peripheral nervous system glutamate is an inhibitory neurotrasmitter one example of a glutamate receptor is a ligand-gated sodium channel glutamate causes EPSPs in presynaptic neurons
one example of a glutamate receptor is a ligand-gated sodium channel
The primary site of skin inflammation is the ______________ which is composed of _________________
papillary layer of the dermis loose connective tissue
Light rays entering the eye from a distant object (>20 feet away) are said to be essentially ________________________ to each other. While light rays entering the eye from a nearer object (<20 feet away) are still _____________________ from one another
parallel diverging
A person with blonde, wavy hair will have more ________________ than _________________ in their hair shafts and those hair shafts will be __________-shaped. pheomelanin; eumelanin; oval pheomelanin; eumelanin; circle eumelanin; pheomelanin; oval eumelanin; pheomelanin; circle
pheomelanin; eumelanin; oval
Where rod cells have photopigments called rhodopsin, cones have photopigments called _________________________ that respond to various wavelengths of light.
photopsins
The process of a photon being converted into a meaningful physiological signal is called: phototransduction transducin refraction reflection
phototransduction
The tip link mechanism of the hair cells of the ear is an amazing and quite unique physiological construct. It involves the opening of mechanically-gated __________________________ channels via a physical linkage from one stereocilia to the next in a domino-like fashion.
potassium
Place the contributors of a neuron's resting membrane potential (RMP) in order from largest contribution smallest contribution.
potassium leak channels sodium/potassium pump anionic molecules (DNA/RNA and cytosolic proteins)
Select all the statments that are true for a rod cell of a person who is in a completely dark room. cGMP is unbound from the Na+ channels (relative to light scenarios) potassium leak channels are open retinal is in the trans conformation transducin is associated with rhodopsin (not activated) there is a higher concentration of cGMP that if there was light involved retinal is bound to the opsin molecule ligand-gated Na+ channels are open
potassium leak channels are open ligand-gated Na+ channels are open transducin is associated with rhodopsin (not activated) retinal is bound to the opsin molecule there is a higher concentration of cGMP that if there was light involved
When someone says they have a pimple, they should really be saying they have a __________. cyst pustule nodule papule
pustule
Imagine running the edge of a quarter along your calf. Then run that same edge on your finger or thumb. The reason you can feel the ridges of the quarter when running it along your finger, but not when you run it along your calf is because there are more _______________ in our hands leading to a greater __________________. -receptive fields; discriminative ability -discriminative abilities; receptive field
receptive fields; discriminative ability
Which color of light below has the lowest energy? red violet yellow green
red
The bending of light as it passes from one medium to another is a phenomenon known as __________________
refraction
When viewing an object that is far away, the ciliary body is _____________ and the lens is _______________. This is due to the release of norepinephrine from the __________________ nervous system. contracted; stretched (flattened out); parasympathetic relaxed; stretched (flattened out); sympathetic contracted; bulged; parasympathetic relaxed; bulged; sympathetic
relaxed; stretched (flattened out); sympathetic
The afferent division of the PNS carries _________________________ information while the efferent division carries motor information.
sensory
Evaluate the validity of the following two statements: 1. Neither hair nor nails undergo the process of desquamation. 2. Hair and nails are both forms of soft keratin. statement 1 is true; statement 2 is false. statement 1 is false; statement 2 is true. both statements are true both statements are false
statement 1 is true; statement 2 is false.
Which of the following layers of the epidermis is responsible for the physical difference in thickness between thin skin and thick skin. stratum germinativum (basale) stratum corneum stratum lucidum stratum spinosum stratum granulosum
stratum corneum
Which of the following layers of the epidermis is found only in thick skin? stratum germinativum (basale) stratum granulosum stratum lucidum stratum corneum stratum spinosum
stratum lucidum
If a neuron is transferring information to another neuron, we call this a
synapse
Which correlation below is correct? the apex of the basilar membrane is narrow and rigid allowing for the perception of low frequencies the base of the basilar membrane is narrow and rigid allowing for the perception of low frequencies the apex of the basilar membrane is narrow and rigid allowing for the perception of high frequencies the base of the basilar membrane is narrow and rigid allowing for the perception of high frequencies
the base of the basilar membrane is narrow and rigid allowing for the perception of high frequencies
The main reason the skin on the soles of your feet is so much thicker than the skin on your ankles is because:
the stratum corneum on the soles of your feet is much thicker than it is on your ankles
If the resting membrane potential of a cell were +50 mV, which of the following inferences could you plausibly make?
there are more sodium leak channels than potassium leak channels present in the plasma membrane of the cell
The enzyme that converts tyrosine to melanin is called
tyrosinase
Imagine you run into a person on the street who has darker colored skin than you. Which of the following factors affecting skin color would most likely be INCREASED in this individual? Select ALL that apply. number of melanocytes tyrosinase activity melanosome size lysosomal activity melanosome distribution
tyrosinase activity melanosome size melanosome distribution
Melanin is derived from which of the following amino acids? valine methionine lysine tyrosine
tyrosine
Most sensory neurons are
unipolar
Which color of light below has the shortest wavelength? red violet yellow green
violet
The special senses include: equilibrioception vision proprioception gustation nociception audition tactile senses olfaction
vision gustation audition olfaction equilibrioception
Assume we are dealing with white light for all incident light. An object's appearance in color is based on what light is reflected off the surface of that object into your eye, So an object that is pure blue absorbs green and red light (and all other wavelengths), while blue light is reflected off the surface. Referring to the color mixing wheel above, what color would an object that absorbs everything but green and red light be? green blue red yellow
yellow
Once a nerve impulse (action potential) reaches the axon terminal of a presynaptic neuron, that information is transmitted to the postsynaptic neuron in one of two ways. A(n)__________________________ synapse involves direct transmission of ions from presynaptic neuron to postsynaptic neuron via gap junctions. A(n) __________________________ synapse involves the transmission of information via diffusion of neurotransmitter across a synaptic cleft. Previous PageNext Page
-electrical -chemical
Choose all that apply. The hypodermis contains: dense connective tissue loose connective tissue vasculature adipose tissue
-loose connective tissue -vasculature -adipose tissue
Can you explain the processes that takes place in membrane discs of your rods or cones during light vs. dark? What would happen to your photopigments? Transducin? cGMP levels? How much neurotransmitter is being released? Which retinal cells have receptors for the released neurotransmitters?
In darkness, rhodopsin is inactive, cGMP levels are high, open Na+ channels (internally gated by the ligand cGMP), action potentials are generated and neurotransmitters are released. In light, photons activate rhodopsin, rhodopsin activates transducin, transducin activates a cGMP phosphodiesterase (PDE), the PDE decreases cGMP, the Na+ channels close, the cell hyperpolarizes and less neurotransmitter is released. Bipolar cells.
What are the three layers of cells of the retina? Which layer of cells process the photons (i.e., are the photoreceptor cells)? What is the macula of the retina? Fovea centralis?
Layers of retina: Innermost (closest to the vitreous body) - ganglion cell layer. Middle - bipolar cell layer. Rearmost - photoreceptor cell layer (rod and cone cell layer. The macula of the retina is an indentation in the retina off-center from the optic disc. The fovea centralis is a region of the retina in the center of the macula that has the highest concentration of cone photoreceptor cells. The visual axis normally falls on this location.
an immunologically active cell that presents antigens to other cells of the immune system (an APC)
Langerhans cells
Which type of graded potentials do taste receptors undergo? How many cells are involved in the peripheral processing of gustatory information? In what cell are APs generated?
Receptor potentials. The taste receptor cell and the bipolar sensory neuron. The bipolar sensory neuron.
For a patient with hyper-neuronal activity (e.g., anxiety or PTSD), what could you inhibit/block to stop their neurons from generating graded potentials, thereby preventing their neurons from firing (i.e., undergoing action potentials)?
Receptors in the neuron that, when opened, lead to EPSPs.
How is sound transduced through the ear (sequentially discuss all structures of the external, middle and inner ear in your description)?
Refer to slide 50. Put this into your own words.
What is refraction? What is a refractive index? What is the refractive index of air? Water? The cornea? The lens? If light passes from a medium with a refractive index of 2.0 into a medium with a refractive index of 1.0, what will happen to the light rays?
Refraction: bending of light rays as they pass through different refractive media. A number that reflects the degree to which a particular medium bends light rays. Larger numbers bend light more than smaller numbers. 1.00. 1.33. 1.38. 1.41. They will diverge. If light comes from a medium with a lower refractive index and enters a medium with a higher refractive index, then the light rays will converge.
What pigment is found in membrane discs of rods? Cones? What are the two structural components of a photopigment? Based on what you know about proteins and membranes, what type of protein would rhodopsin/photopsin be classified as?
Rhodopsin. Iodopsins (photopsins). Opsin (protein) and retinal. An integral membrane protein.
What type of conduction occurs in myelinated nerve fibers? Unmyelinated? What are the relative speeds of conduction? Which is faster, myelinated or unmyelinated? Nerve fibers are much like electrical wires. Current in electrical wires is generated by the flow of electrons. What is flowing in nerve fibers that creates the current of your neurons?
Saltatory (100 m/s). Continuous (1 m/s). K+.
Match the type of action potential propagation below to the associated fiber type. 1. myelinated 2. unmyelinated saltatory conduction continuous conduction
Saltatory conduction- myelinated continuos conduction- unmyelinated
Select all the statements below which are true. -almost immediately after the formation of a spinal nerve, it ramifies (splits) into the dorsal and ventral rami -a spinal nerve is formed from the merger of the dorsal and ventral roots -the cell bodies of motor neurons are located in the ventral root ganglia -all sensory information enters the spinal cord dorsally -a collection of neuron cell bodies in the periphery is known as a ganglia -the cell bodies of sensory neurons are located in the ventral root ganglia
-almost immediately after the formation of a spinal nerve, it ramifies (splits) into the dorsal and ventral rami -a spinal nerve is formed from the merger of the dorsal and ventral roots -all sensory information enters the spinal cord dorsally -a collection of neuron cell bodies in the periphery is known as a ganglia
Match the descriptions below to some of the structures of the eye. portion of the retina with the highest concentration of cones fibrous structure that helps focus light onto the retina (interestingly, it is not the structure of highest focal power) indented portion of the retina directly on the optical axis; contains the fovea ring of muscle that can control the shape of the lens; continuous with the choroid filled with vitreous humor; serves as internal hydrostatic skeleton for the eye connect the lens to the ciliary body; hold the lens in place commonly referred to as the blind spot; contains no photoreceptor cells; location where all the nerves exit the eye poteriorly hole in the middle of the iris through which light passes before reaching the lens filled with aqueous humor rings of pigments muscle tissue that change the amount of light being let into the eye
-Macula lutea- indented portion of the retina directly on the optical axis; contains the fovea -lens- fibrous structure that helps focus light onto the retina (interestingly, it is not the structure of highest focal power) -posterior chamber- filled with vitreous humor; serves as internal hydrostatic skeleton for the eye cilary body- ring of muscle that can control the shape of the lens; continuous with the choroid -fovea (centralis)- portion of the retina with the highest concentration of cones -suspensory ligaments- connect the lens to the ciliary body; hold the lens in place -Optic disc -commonly referred to as the blind spot; contains no photoreceptor cells; location where all the nerves exit the eye poteriorly -pupil- hole in the middle of the iris through which light passes before reaching the lens -anterior chamber -filled with aqueous humor -Iris- rings of pigments muscle tissue that change the amount of light being let into the eye
What are mechanoreceptors? What are some general examples? What are the three examples of tactile receptors in the skin? Which receptors detect a gentle touch? The rumble of an earth quake? Someone pressing down firmly on your skin?
-Mechanoreceptors respond to mechanical stimuli. -Tactile receptors, baroreceptors and proprioceptors. -Meissner's corpuscles and Merkel cells. -Meissner's and Pacinian corpuscles. -Pacinian corpuscles.
Choose ALL of the following statements that are CORRECT Melanosomes are degraded through lysosomal activity Keratinocytes create melanosomes and deliver them to melanocytes A melanosome is derived from the golgi apparatus/ER of a melanocyte A melanosome is derived from the nuclei of melanocytes Keratinocytes store and degrade melanosomes Melanocytes excrete melanosomes in a process known and cytocrine secretion
-Melanosomes are degraded through lysosomal activity -A melanosome is derived from the golgi apparatus/ER of a melanocyte -Keratinocytes store and degrade melanosomes -Melanocytes excrete melanosomes in a process known and cytocrine secretion
Can you explain the ABCDEs of melanoma? In other words, what are the signs that your mole might be transforming into cancer?
-The signs that a mole is transforming to cancer are changes in asymmetry (A), border (B), color (C), diameter (D) and if the mole is evolves (E) over time. A: Asymmetrical B: Border are uneven C: It has more colors D: Increases in diameter E: There are multiple changes
How many pairs of cranial nerves are there? Are these nerves mixed? In other words, do all cranial nerves contain both sensory and motor nerve fibers?
-There are 12 pairs of cranial nerves -Yes, some, but not all, are mixed. Cranial nerves 1, 2, and 8 are sensory. Cranial nerves 3, 4, 6, 1 and 12 are motor. Cranial nerves 5, 7, 9, and 10 are sensory and motor.
What is a ventral root composed of? A dorsal root? A dorsal root ganglion? A ventral ramus? A dorsal ramus? Sympathetic chain ganglia? What two components of the PNS combine to form a spinal nerve?
-Ventral rood is composed of motor neurons. -Dorsal root is composed of sensory neurons. -Dorsal root ganglion contains the cells body of unipolar neurons. -Ventral ramus is the anterior division of a spinal nerve. -Dorsal ramus is the posterior division of a spinal nerve. -Sympathetic chain ganglia are paired bundle of nerve fibers (and aggregations of nerve cell bodies - ganglia) that run from the base of the skull to the coccyx. They are part of the autonomic nervous system. -Ventral and dorsal roots.
Place the following molecules in order from earliest stage to latest stage in the production of the active form of vitamin D3. cholecalciferol (transported in the blood) a cholesterol derivative in the skin (7- dehydrocholesterol) a product of the liver (calcidiol) a product of the kidney (calcitriol)
-a cholesterol derivative in the skin (7- dehydrocholesterol) -cholecalciferol (transported in the blood) -a product of the liver (calcidiol) -a product of the kidney (calcitriol)
The ________________________division of the PNS sends all sensory stimuli to the CNS while the ______________________ division of the PNS delivers motor commands from the CNS to the periphery.
-afferent -efferent
For each of the structures below, determine the portion of the ear to which it belongs. external acoustic meatus (ear canal) semicircular canals cochlea auditory tube (eustachian tube) auditory ossicles tympanic membrane auricle (pinna)
1. external ear - external acoustic meatus (ear canal) & auricle (pinna) 2.middle ear -auditory tube (eustachian tube), auditory ossicles & tympanic membrane 3.inner ear - semicircular canals & cochlea
Match each molecule below to the taste modality it will elicit. 1.sweet 2.sour 3.salty 4.bitter 5.umami sodium ions quinine or raw cocoa MSG (glutamate) sucrose (glucose, lactose) hydrogen ion (proton)
1. sweet - sucrose (glucose, lactose) 2.sour - hydrogen ion (proton) 3. salty - sodium ions 4. bitter - quinine or raw cocoa 5. umami - MSG (glutamate)
If an individual has an eyeball that is shorter than normal, which refractive defect would they likely have? Where does the focal point form in this condition? Which type of lenses are used to correct for this refractive defect?
Hyperopia. Behind the retina. Convex, or converging lenses.
Match the neurotransmitter below to the appropriate synapse. 1.acetylcholine (ACh) 2.norepinephrine (NE) 3.γ-aminobutyric acid (GABA) 4.glutamate (Glu) cholinergic synapse glutamatergic synapse adrenergic synapse GABAergic synapse
Cholinergic synapse - acetylcholine (ACh) Glutamatergic synapse - glutamate (Glu) Aderenergic synapse- norepinephrine (NE) GABAergic synapse - y-aminobuyric acid (GABA)
In reference to rods and cones, what does it literally mean that cones are responsible for color vision? Rods for black and white vision? Since rods are not responsible for color vision, would you expect them to be more sensitive in the light or dark?
Cones are responsible for color vision as they contain iodopsins that absorb different wavelengths of light (so there are red, blue and green cones). Cones function best in relatively bright light, as opposed to rod cells, which work better in dim light.
What is convergence? How would you compare eye motions during convergence for an object more than 20 feet away? Less than 20 feet away?
Convergence is the ability of the eye to focuses light at a focal point. It can also be considered the bending of light rays towards the visual axis. More than 20 feet away:Ciliary muscles are relaxed, suspensory ligaments are taut and the lens is flattened out. Less than 20 feet away:Ciliary muscles are contracted, suspensory ligaments are loose and the lens is bulged (or very convex).
The human lens is concave or convex? Does it converge or diverge light rays? What do converging and diverging mean in reference to the visual axis? What is the focal length? Focal point? A diopter is a unit of converging or diverging power? Which structure of the eye plays the most important role in focusing light on the retina?
Convex. Converge. Converge = towards the visual axis and diverge = away from the visual axis. The distance between the center of the lens and the focal point. Where the light rays converge after passing through the lens. Converging. Cornea (it has the highest converging power).
What are the two sensory organs of equilibrioception? Where are each located and what are their general functions?
Crista ampularis and macula. A crista ampularis is located at the base of each semicircular canal in the ampulla region. Detect the movement of the head (turning right and left, tilting right and left and nodding forwards and backwards). Maculae are located in the utricle and saccule of the vestibule. They detect linear and horizontal acceleration and deceleration and head tilt.
Which sensory organ is involved in detecting your head nodding yes?
Crista ampularis.
What is cyanosis? What underlying diseases does this condition indicate? Is blood ever blue in the human body?
Cyanosis refers to bluish discoloration of skin. Poor blood supply. Lung or heart problem. No. The veins carrier less oxygen (deoxyhemoglobin) than the arteries, therefore, the veins absorb more red light and reflect blue.
In phototransduction, electromagnetic radiation gets transduced into electrical impulses. Which retinal cells are responsible for firing action potentials? Which cells have axons that comprise the optic nerve?
Ganglion cells. Ganglion cells.
Which of the following statements regarding generator and receptor potentials is false? Generator potentials and receptor potentials are two specific types of graded potentials. Receptor potentials are so named because they utilize a separate receptor cell. Action potentials can be initiated by both receptor and generator potentials. Generator and receptor potentials are observed in motor (efferent) neurons.
Generator and receptor potentials are observed in motor (efferent) neurons.
The human papilloma virus (HPV) is very common in young, sexually active individuals. What are genital warts? Why are they potentially dangerous, especially for females?
Genital warts are an infection caused by the human papillomavirus (HPV). Genital warts are correlated with cervical cancer in females.
Which region of the cortex of your brain determines if something is sour? In which region of the cortex of your brain do you determine if you like the taste of sour or not?
Gustatory cortex. Frontal cortex.
Often, after blood is drawn from your body, you are left with what appears as a bruise, or hematoma? What is a hematoma?
Hematoma is blood that leaks outside of damaged blood vessels.
Epidermal ridges and dermal papillae increase the surface area for attachment of the epidermis to the dermis. What are the structures that lag the epidermis down to the dermis?
Hemidesmosomes.
Can you explain the process of light adaption? That is, what happens in your eyes as you walk out of a movie theater into the bright light on a sunny afternoon? Can you explain the process of dark adaption (e.g., the previous scenario reversed)? What is the most realistic reason why most pirates wore a patch over one eye?
In light adaptation, the bright light momentarily dazzles us and all we see is white light because the sensitivity of the receptors is set to dim light. Rods and cones are both stimulated and large amounts of the photopigments are broken down instantaneously. This adaptation occurs in two ways: the sensitivity of the retina decreases dramatically and retinal neurons undergo rapid adaptation inhibiting rod function and favoring the cone system. The entire process occurs in a matter of a few minutes. In dark adaption, blackness is seen because our cones cease functioning in low intensity light. Also, all the rod pigments have been bleached out due to the bright light and the rods are initially nonfunctional. Once in the dark, rhodopsin regenerates and the sensitivity of the retina increases over time. During these adaptation process, reflexive changes occur in the pupil size. The entire process occurs over a period of up to 30 minutes. To keep one eye always dark adapted. Without a dark-adapted eye (the patch eye), going below the deck would be a challenge due to the darkness. Sliding the patch to the other eye reveals a dark-adapted eye which allows the pirate to navigate quickly under the deck of the ship.
Where are voltage-gated Na+ and K+ channels found in myelinated axons versus unmyelinated? What other protein must be present in the axolemma for AP formation and propagation?
In myelinated axons, they are found in the nodes of Ranvier. In unmyelinated axons, they occur continuously down the axon. The Na+/K+ pump.
Intuition suggests that people with dark-colored skin have more pigment-producing cells (i.e., melanocytes) than people with light-colored skin. Can you explain the real difference between dark skin and light skin?
In the dark skin, there is an increase in tyrosinase activity, melanosome size and distribution. There is also a decrease melanosome degradation. In light skin is the opposite.
What is the function of the inner hair cells of the organ of Corti? Outer hair cells? These hair cells contain stereocilia. Are these motile structures? What are they supported by? Microtubules? Microfilaments?
Inner hair cells: fire nerve impulses to the brain in response to distortion of the basilar membrane. Outer hair cells: they push the tectorial membrane and they selectively amplify the vibration of the basilar membrane. No. Stereocilia are basically long microvilli. Microfilaments.
What anatomical structure connects the middle ear to the throat (pharynx)? Why does this connection exist?
Internal auditory canal. To balance the pressures on either side of the tympanic membrane.
What are the ways in which the image formed on your retina is different than the object itself?
Inverted (up and down and right to left) and a fraction of the actual size of the object.
What is jaundice? How does this condition relate to a premature infant? A person with hepatitis B?
Jaundice is a condition where bilirubin (a yellow pigment) builds up in the tissues. Bilirubin is a degradation byproduct of hemoglobin metabolism. Hepatitis B and premature infants can develop jaundice. The reason is because when hemoglobin is broken down it releases heme, heme is converted to bilirubin (yellow color) in the liver and is secreted in the urine or feces. In premature infants and in persons with hepatitis B, the liver is not working property and the bilirubin will stay in the body and turn your eyes yellow.
What is the primary mechanism responsible for establishing a RMP? Hypothetically, how would your cell's RMP be affected if this mechanism went off-line (i.e., stopped working)?
K+ leak channels. If K+ leak channels stopped working, the RMP would be very positive as the K+ would build up in the cell via the action of the Na+/K+ pump.
What is the most abundant intracellular cation? What is the most abundant extracellular cation? What cation has the steepest concentration gradient across the plasma membrane? Why is it crucial that there is a 1 mOsm difference in plasma solute concentration between our blood plasma and interstitial fluid?
K+. Na+. Ca2+. It is crucial to have this difference in plasma solute concentration between our blood plasma and IF so that water will go into our blood stream to keep blood volume and blood pressure up.
What is the most abundant cell in the epidermis of your skin?
Keratinocyte.
If you were being chased by a bear in the woods, would your eyes undergo miosis or mydriasis? Which part of the ANS is elicited?
Mydriasis. Sympathetic.
Comparing a neuron (specifically the axon portion) to the charging cord for you cell phone, what biological material surrounding and axon would be analogous to the plastic/rubber coating surrounding the wire of the cord itself? What is the purpose of this material surrounding axons in humans?
Myelin sheath surrounds our 'wires' (axons). It insulates the neurons and increases action potential velocity.
If an individual has an eyeball that is longer than normal, which refractive defect would they likely have? Where does the focal point form in this condition? Which type of lenses are used to correct for this refractive defect?
Myopia. In front of the retina. Concave, or diverging lenses.
What is the conformation of the basilar membrane at the base of the cochlea? Apex?
Narrow, but thick. Broad, but thin.
Can a cell fire a second AP after threshold has been met but the TMP has not yet reached 30 mV? Why or why not? What about during the relative refractory period? Why or why not?
No, because voltage-gated Na+ channels would already be open from the first AP. Potentially, yes, but the stimulus would have to be greater than normal as the cell is hyperpolarized during this period.
If you touched a hot stove with your hand, you would reflexively remove your hand from the stove. Does the brain regulate this muscle activity required to remove your hand? Do you sense the pain before or after your hand is withdrawn?
No. The pain is perceived in the brain after the hand is withdrawn.
Elephants can hear sound frequencies of 15 Hz. Can humans hear these frequencies? Where would sounds with a frequency of 19,000 Hz deform the basilar membrane? 20 Hz?
No. Humans can hear down to about 20 Hz. Sounds w/ a frequency of 19,000 Hz deform at the Base. Sounds w/ frequency of 20 Hz deform at the Apex.
Hypothetically, if a cell's TMP was 0 mV, what would happen to its TMP if both voltage gated Na+ and K+ channels were blocked and incapable of opening? Could threshold be met?
No. Threshold would not be met since the cell would not be able to depolarize.
What are the two primary functions of the papillary plexus of capillaries?
Nourishment of tissues and temperature regulation through vasoconstriction and vasodilation.
Can you list a few drugs that would cause miosis? What receptors are responsible for miosis? Neurotransmitter? Can you list a few drugs that would cause mydriasis? What receptors are responsible for mydriasis? Neurotransmitter(s)?
Opiates (such as heroin or morphine) and other central nervous system depressants such as benzodiazepines and barbiturates will give you small pupils while under the influence of the drug. M3. Acetylcholine. Stimulant drugs like cocaine, amphetamines, methamphetamines and ecstasy will give you big pupils - along with cannabis (marijuana) - and hallucinogenic drugs like LSD and ketamine. alpha 1. Noradrenaline.
How do partial-thickness burns differ from full-thickness burns? Is there typically scarring following first degree burns? Why so/why not? Why do severe second degree burns and third degree burns often require skin grafting?
Partial thickness burns are 1st and 2nd degree burns and don't go all the way through the skin and hypodermis. -1st degree burns have no scarring since they do not penetrate deep enough, 2nd degree do have scarring since they go down to the dermis. Full thickness burns are 3rd degree burns and goes all the way to the subcutaneous layer, damaging things in the hypodermis even as far as muscle and bone. Skin grafting is required since the damage to the skin is so deep that the skin will not be able to repair itself.
How are freckles fundamentally different from age spots? Why are freckles more visible when you take a picture of skin with a camera that filters out all light except ultraviolet (UV)?
People with freckles have a genetic predisposition for them. Age spots develop due to environmental factors, such as decades of sun exposure. UV reflects melanin so you can see the pigments in the face.
Are odorant receptors phasic or tonic? Can you justify your choice by explaining why we add mercaptan to natural gas?
Phasic. Mercaptan is a sulfur-containing compound and is a component of garlic. We add it to natural gas so we can smell it since natural gas is odorless.
What is the difference between pitch and loudness? What are the units for each?
Pitch is determined by the frequency at which sound waves vibrate. Loudness is the amplitude of the waves. Pitch: hertz. Loudness: decibel.
An elderly person's vision has gotten increasingly worse over the last decade. They were informed by their ophthalmologist that the elasticity of their lenses has markedly decreased and decades of light bombarding their lenses induced the generation of pigments in them. What visual defect(s) does this person have? Can you explain each of the conditions to better support your answer? Is this person a good candidate for LASIK surgery? Why or why not?
Presbyopia and cataracts. Presbyopia is the loss if elasticity of the lens over time and therefore lens accommodation is impaired. Cataracts result from the buildup of pigments in the eye. Potentially. Reshaping the cornea could help with the farsightedness due to presbyopia. However, it will not help the cataracts.
What is presbyopia? How does the amplitude of accommodation of the lens change over time?
Presbyopia is a disease caused by loss of elasticity of the lens of the eye. The amplitude of accommodation decreases with age as a result of a decrease in the elasticity of the lens. As a result, the lens cannot bulge as much during lens accommodation and so the person is essentially farsighted.
What are the three components of a synapse? The synaptic cleft is nothing more than what? How is information transferred from the presynaptic cell to the postsynaptic cell?
Presynaptic cell - synaptic cleft - postsynaptic cell. Extracellular fluid (space). In the form of neurotransmitters.
What is the difference between eczema and psoriasis?
Psoriasis is an autoimmune disease that leads to abnormal keratinocytes proliferation. The etiology of eczema is unknown. Eczema is characterized by inflammation, swelling and redness, while in psoriasis you have patches of red, itchy and scaly skin.
What is miosis? Mydriasis? What are the muscles of the iris that control the diameter of the pupil? Which dilate it? Which constrict it? The pupil is not an anatomical structure. How can it be likened to a black hole of the universe?
Pupillary constriction. Pupillary dilation. Pupillary constrictor (sphincter) muscles and pupillary dilator (radial) muscles. Pupillary constrictor (sphincter) muscles. Pupillary dilator (radial) muscles. All light enters the pupil, but none exits it. That is why it appears black.