BIO 319 FINAL
canaliculi
allows osteocytes in lacunae to interact with each other
What extracellular component of bone endows it with tensile strength?
collagen fibers
suprachiasmatic nucleus
controls sleep and waking up
concentric lamellae
found within osteons; go around outermost portion of bone
The corneal cells do not have a direct blood supply; what is their workaround for this?
it receives nutrients via diffusion from the tear fluid at the outside and the aqueous humour at the inside and also from neurotrophins supplied by nerve fibers that innervate it.
taste (gustatory) cortex
responsible for the perception of taste
Haversian (Central) canals
surround blood vessels & nerve fibers, communicate w/ Volkmann's canals - allow blood vessels, usually very tiny artery and tiny veins, to MOVE UP AND DOWN canal.
What is a synostosis (synostoses) and what two joint types discussed in class can mature into it.
- As you age it thins into a boney seam - suture - skull
For graded potentials explain the terms "dying out locally"
- Graded potentials response is directly proportional to the stimulus - Amplitude diminishes as graded potential travel away from the initial site - "die out" - For ex: if you have a small stimulus you will have a small response, a greater stimulus a greater response
diencephalon
"in between brain" - epithalmus, hypothalamus, thalmus
What happens to skeletal muscle that is deprived of its interaction with a controlling neuron? Can this reach the point of no return?
- In skeletal muscle, lack of innervation causes severe alterations like functional impairment and followed by complete degeneration - yes
What is the role of titin and how does it factor into the extensibility of muscle along with muscle compressibility?
- titin binds calcium at specific sites, thereby increasing its stiffness - ensures that myosin occupies the central position in the sarcomere. It also provides passive tension when the muscle is relaxed.
Are there different types of cones and if so, how many and how have they been historically classified? Does each of the cone types "specialize" in picking up on part of the visible electromagnetic spectrum? Explain.
Blue Cones: pick up blue colors and some green, can see the lowest wavelength Red Cones: pick up green, yellow and red colors, can see the high wavelengths Green Cones: pick up green, yellow and red.
Why is a resting membrane potential of a muscle cell important?
Excitable cells have to have them because it is a baseline platform to launch an action potential.
What is the "resting and digesting" part of the nervous system AND What is the "fight or flight" part of the nervous system
REST AND DIGEST: parasympathetic nervous system FIGHT OR FLIGHT: sympathetic nervous system
If you were to define both "Anatomy" and "Physiology" using one common word, what would that word be for each term?
- ANATOMY: structure - PHYSIOLOGY: function
myofilament
The contractile proteins, actin and myosin, of muscle cells
unipolar neuron
Usually only found in invertebrate species - a single axon.
ventral root
contains axons of MOTOR neurons
circumferential lamellae
goes around entire circumference of diaphysis
pupil
produced by the muscles of the iris
What parts of the head-cycling account for the beginning of the relaxation of the muscle twitch to when it is fully relaxed?
- Hydrolisis of ATP - Recovery stroke
I also discussed the brain regions first affected at the beginning of both Parkinson's disease and Alzheimer's disease and how the diseases progress in each case, which you are also responsible for knowing.
- In Alzheimer's disease, as neurons are injured and die throughout the brain, connections between networks of neurons may break down, and many brain regions begin to shrink. By the final stages of Alzheimer's, this process—called brain atrophy—is widespread, causing significant loss of brain volume.
Can reflex arcs also inform the brain of what is going on? Can the brain "return the favor" in feeding back to influence a reflex arc?
- In a reflex action, the brain plays no part. The spinal cord, which reacts without thinking about how to respond to stimuli, is in charge of these automatic actions. It elicits no meaningful response in the brain. - Spinal reflexes are strongly influenced by control centers within the brain. Axons descend from numerous centers within the brainstem and the cerebral cortex and synapse primarily on the spinal interneurons, with some direct input to the motor neurons.
During complete tetanus,...is ATP being expended....must calcium remain high....must the controlling neuron keep firing?
- In complete tetanus, the sarcomeres do NOT continue to shorten since they are maximally contracted. - Myosin head cycling still occurs to hold the thin filament in position: the myosin heads bind and unbind the thin filament - ATP is required for the myosin heads to be able to unbind from the myosin head binding sites. - To have myosin head cycling still occurring, need the neuron to keep firing so that continuous action potentials occur, and for Ca levels to remain high so that the myosin head binding sites remain open
In the absence of another action potential that causes an immediate subsequent burst of calcium, what happens to the re-charged myosin heads in high energy position? Do these heads reform cross-bridges or no? Explain how your answer leads to relaxation.
- In the absence of another action potential, the sarcomere will relax and the titin (spring) will push back the z discs. - The myosin head cycle can only occur when an action potential has provided a voltage to open voltage calcium channels of terminal cisternae and the calcium has flooded the sarcoplasm - Therefore, the recharged myosin head in the high energy position will not reform a cross bridge unless there is another action potential.
How is our course an "integrative" approach?
- Integrative means that various aspects of both anatomy and physiology are linked/coordinated together -combining form and function to create a whole - Relating structure and function together - you can't study structure without function
How might acetylcholinesterase inhibitors that are less potent be used for the good?
- Mild acetylcholinesterase inhibitors can be used to treat diseases where the body doesn't make enough acetylcholine - The acetylcholinesterase inhibitor [INHIBITOR OF AN INHIBITOR] stimulates acetylcholine production - Can also be used as insecticides: insects can't breathe so they die; not toxic to humans/dogs
Know the tunics their anatomical characteristics and physiological roles along with their order from superficial to deep and vice versa.
(1) the fibrous tunic (cornea and sclera) (2) the vascular tunic (iris, ciliary body, and choroid) (3) the neuroectodermal (nervous) tunic (retina).
Know the comparison contrast of graded potentials vs action potentials
- Action potentials are all-or-none (digital) events - Graded potentials are not: strength of stimulus determines size of response - Action pitentials Do not die out locally in time & space: self propagate down the cell without decrement - Graded potential do die out locally in time & space - Action Potentials Have a minimal threshold: need to depolarize above -55mV - Graded potentials do not: strength of stimulus determines size of response - Action potentials Occur in excitable cells only - Graded potentials occur in all cells - Action Potentials Cannot summate - Graded potentials can
What factor(s) influence how fast an action potential can travel and how, to the extent discussed in class do these factors exert their effects?
- Axon diameter - internode distance - myelin sheath thickness
What is BOTOX ® and what is its medical usage(s)?
- BOTOX is botulinum toxin administered cosmetically to lightly poison the muscle so that the face relaxes and frown lines and wrinkles disappear - potential problem with botox: slippery slope of lightly paralyzing the muscle or having paralysis of the facial muscles, making it hard to have facial expression
Are all axons, myelinated
- No; they can be either myelinated or unmyelinated - enclosed in a myelin sheath.
What allows the initial upswing (depolarization) and when, how and why does it end?
- Depolarization is caused by the V-gated sodium channels opening and letting sodium into the cell, thus making the inside of the cell more positive (membrane potential becomes positive) - It ends when the V-gated sodium channels close
Are there ways to boost the functioning of noradrenergic and or serotonergic neurons? .
- Exercise can increase production of these neurotransmitters. - Prozac (SSRI: selective serotonin reuptake inhibitors) can increase production of serotonin - wellbutrin can increase production of norepinephrine
What are some common examples of where/when electrical synapses are important?
- For example, certain hormone-secreting neurons within the mammalian hypothalamus are connected by electrical synapses. - Examples of electrical synapses in mammalial brain include the cortical GABAergic interneuronal system
Where are each of these hormones produced, what are their target(s) and what might happen if they were not produced in sufficient amounts or their target tissue was incompetent to respond?
- GH: produced in pituitary gland and then secreted into blood stream. It is then sent to the receptors on the liver. - IGF-1: Produced in the liver receptors. The receptors change GH to IGF-1. The target tissue is the E-Plate and stimulate the mitosis of the chondrocytes Gonadal Sec Hormones: - Precursor: cholesterol - secreted from Pituitary gland and Cause growth at puberty, but also cause closure of the epiphyseal plates and the cessation of growth later.
gouty
- uric acid crystallizes in the metatarsal phalangeal joint of big toe - prominent in males - want to cut things out that are high in uric acid. sardeens, chopped liver
What molecule dampens /diminishes the brittleness of bone?
-collagen -Analogy steal cables being the collagen
How many pairs of cranial nerves? How many pairs of spinal cord nerves?
12 31
About how long does an action potential last on a given location of sarcolemma?
About 1 ms
median aperture
An opening in the roof of the fourth ventricle that connects to the subarachnoid space
What name describes the calcium phosphate salt component of bone?
Inorganic matrix: hydroxyapatite (calcium phosphate salt) - makes bones hard( crystallizes)
In the classical (admittedly oversimplified) model, be able to predict if a neuron undergoing a combination of temporal/spatial summation at a given point in time is likely to fire an action potential or not as discussed in slide 11-8.
LOOK AT SLIDE
osteoarthritis
- PANNUS: is extra growth of a joint that causes pain - OSTEOPHYTES: development of bone spurs and bulges - thinning of hyaline cartilage - thins unevenly losing the slick surface - genetic component - You want to use the joint and keep active with the joint
Which organ(s) participate in the synthesis of each of these hormones?
- Parathyroid Gland: makes PTH and secretes it when calcium in blood is low - Liver & kidneys: calcitorial - Thyroid Gland: Calcitonin
What 3 transmembrane proteins establish a resting membrane potential?
- Potassium leakage channel (more importance) - sodium leakage channel - sodium-potassium pump
How does summation occur and what is its overall significance?
- Summation creates a stronger, more sustained event (twitch) - increase the frequency of the stimuli so that the APs occur more rapidly one after another - The first AP causes the first twitch - The second AP starts stimulating the second twitch before the first twitch is even over (still in its relaxation phase), causing the second twitch to start "on the shoulders" of the first twitch and have a greater contraction - If keep doing this, the next twitches will also "stand on the shoulders" of the previous twitch
What part of the head cycling accounts for the increase in tension throughout the contraction period? How are the myosin heads behaving at the apex (highest point) of a twitch?
- The cross bridge formation - The period of twitch contraction corresponds to the beginning of the power stroke to the end of the power stroke, we are at the apex when the power stroke ends. - right AFTER the power stroke, the descent of the bell curve is cross bridge release due to high enough concentrations of ATP causing the release of the cross bridge.
Know the similarities and differences between the sensory nervous system pathways, autonomic system pathways and somatic nervous system pathways to the extent discussed in class.
- The somatic nervous system has sensory & motor pathways - autonomic nervous system only has motor pathways. - Both somatic and autonomic nervous systems are two components of the peripheral nervous system.
What are cholinergic circuits linked to in the functioning of the brain?
- There's a lot of circuits in the brain that are responsible for memories and thinking are cholinergic circuits - Cholinergic circuits: circuits where acetylcholine is secreted from one neuron to the next
Know all parts of a typical synovial joint, how they come together to make a synovial joint and how they work together to allow a synovial joint to function:
- Two long bones coming together such that their hyaline cartilage can make contact with one another. - Smooth surface (no friction) - Ex: Interphalangeal joints - Synovial fluid: Inside the joint capsule - DIATHROTIC JOINTS
What is proprioception in general and specifically how do synovial joints contribute to it.
- You get nervous feedback that comes from every joint about the stretch and compression of that joint that gets integrated by your brain to get consciously realized - Overall ability to ascertain how your body is positioning in space or how it is moving in space - Stretch receptors in joint that has a relationship with the nerve endings - Ear: information about how your head is positioned in space
What is a nerve in general? Anatomically, what is a nerve composed of?
- a whitish fiber or bundle of fibers that transmits impulses of sensation to the brain or spinal cord, and impulses from these to the muscles and organs. - Axons, cord-like groups of fibers in the center of your nerve. Dendrites, branches that carry electrical impulses. Endoneurium, a layer of connective tissue surrounding axons.
osteon
- cylindrical vascular tunnels formed by an osteoclast-rich tissue - located in compact bone - strengthens bone, influx of nutrients of bone, waste removals
What effect does depolarization have on the sarcolemma that borders the motor end plate? What two sarcolemma transmembrane proteins allow this to take place?
- depolarization effects voltage channels on the sarcolemma - voltage gated sodium channels and ligand gated sodium channels
Know the depolarization, repolarization and after hyperpolarization phases of an action potential and what drives their occurrence.
- depolarization: Na influx - repolarization: low closing of sodium channels and the opening of voltage-gated potassium channels - hyperpolarization: potassium channels are slow to open and close, and thus the cell polarizes itself beyond its usual membrane potentia
Axons from what retinal cell converge to form the optic nerve? What is is this convergence point at the back of the eye called? What general class of neuron is this (from the last question)?
- ganglion cells - optic disk - sensory neurons
precentral gyrus (primary motor cortex)
- goes straight from brain to motor neurons in spine (inhibitory and excitatory) somatic - gets instructions from premotor cortex
What roles do these play in the positive feedback that is central to giving birth?
- hypothalamus receives the signal from the stretch receptors and produces oxytocin for birth - oxytocin is released into the blood via the pituitary gland
Where is the hypothalamus located? What is its relationship to the pituitary gland?
- in brain above the pituitary gland - hypothalamus is the control center for the entire body that sends signals to the pituitary gland to release hormones
terminal cisterns(cisternae)
- in the sarcoplasmic reticulum - pour calcium when action potential is close to them due to the T-tubule being against the cisterns.
What is the difference between various amounts of intermediate tetanus vs. full blown tetanus? which of these do we keep our muscle fibers in most of the time to do most productive movements throughout the day?
- incomplete tetanus: longer, more powerful contraction than a twitch but not maximally contracting the muscles -We make most of our movements through incomplete tetanus - complete tetanus: have the highest frequency & tension possible because the sarcomere has maximally contracted
In a number of instances, we have seen a common theme of "first cartilage, then bone". Aside from the healing process of a break, what other instances have we discussed this theme?
- long bones being hyaline cartilage before birth.
Which tissue type is by far the most prevalent in making up these "pre-bone" structures or "bone models" that will eventually become bone?
- mesenchymal tissue - cartilage model
Does the human skeleton start out bony? If not, what two tissues compose the structures that will become bone?
- no -fibrous membranes (FB) & hyaline cartilage (LB)
What is Wolff's law and what does it say about bone growth throughout life and its relationship to bone use?
- our bones become thicker and stronger over time to resist forces placed upon them and thinner and weaker if there are no forces to act against. - bone is a use it or lose it structure
periosteum
- outer, double-layered connective tissue membrane with ligaments and tendons attached to bone though the periosteum - blood vessels and nerve pathways - the periosteum is where bone grows in diameter
Define bone remodeling and be able to recognize examples of it.
- over a period of time, bone can remodel itself for your overall behalf - breaking a bone; growth
Recognize examples of variables mentioned in class that are homeostatically regulated?
- pH: blood has to be 7.4-7.8 below 7 is death - Blood glucose: when body doesn't make enough insulin so the blood glucose levels are over what it should - body Temperature: 98.6. 100=fever. 102.103= really sick - blood gas: once there is a depression of oxygen signals get sent. ignoring it makes it more and more uncomfortable - blood pressure: 120/80. the pressure that is concurrent with your heart. the pressure is going to fall the while your heart relaxes
Which leakage channel has the greater impact on establishing the resting membrane potential and why?
- potassium leakage channel: 2 K+ in, 2 K+ out. - Passes K+ against its concentration gradient out of the cell Bc there is higher K+ inside the cell. - At the same time, other potassium channels push K+ inside the cell bc of the electrical gradient - Create an equilibrium potential (the electrical gradient that cancels out the chemical/concentration gradient) of -90mV
primary motor homunculus
- precentral gyrus. - represents a map of brain areas dedicated to MOTOR processing (percice control = more space/fine grain control) for different anatomical divisions of the body. - handles signals coming from the premotor area of the frontal lobes
Be able to recognize the difference between primary ossification and secondary ossification, which comes first and where each occurs.
- primary ossification becomes first in embryonic development - the first place where the bone formation begins in the axle of a long bone or in the body of an irregular bone - secondary ossification is after birth - the area of ossification that appears after the primary center of ossification at the epiphysis of edges of bones
What is a myogram? Under what circumstances might an electromyogram be the only option and why? When can you use force tensions myograms?
- record of information of muscle activity ELECTROMYOGRAMS: Electromyograms are used to measure the electrical activity of muscles in humans because it is noninvasive (can measure their activity without having to dissect the muscle) FORCE-TENSION: Force-tension myograms, however, require the muscle to be dissected
Describe/understand the experimental setup for measuring the resting membrane potential in terms of the equipment used.
- reference electrode is on the outside and set to zero - other electrode insisted inside cell - Measuring the voltage difference between what is on the inside compared to the reference - This is because voltage has no absolute value, so it is measured by comparing values.
You should be familiar with the following terms: synarthroses, diarthroses, amphiarthroses, along with their singular and adjectival forms.
- synarthroses (sis): immovable joints - diarthroses (sis): freely movable joints - amphiarthroses (sis): slightly movable joints
How is the activation of the voltage-gated sodium channels and v-gated potassium channels function like "a cascade of falling dominoes'? Specifically, what role do the v-gated sodium channels play in orchestrating the action potential (AP)? Specifically, what role does the v-gated potassium channels play in producing the action potential (AP)? Does the AP "move"?
- the flip in polarity as Na ions rush into the cell causes the action potential to propagate or move down the neuron. - As it flips, the potassium channels right behind it flip it back to continue the action potential down the neuron. - The activation of these transmembrane proteins acts like a cascade of falling dominoes. - Yes, the actin
Define "set point" in the context of negative feedback? Can set points vary? If so, example(s)?
- the hypothalamus can adjust the set point of the BP to elevate because physiology changes have to happen - set points have to change but they also have to be able to be reversed - Yes, set points can be adjusted. For example, if you run on a treadmill, your blood pressure will rise, so receptors will tell your brain which will tell your skeletal muscle that it needs more oxygen and glucose faster, so then your brain will raise the set point to sustain energy during your workout.
Know the common general elements of a chemical synapse?
- the presynaptic element (such as an axon terminal) - a synaptic cleft - a neurotransmitter - postsynaptic element (such as a dendritic spine).
What is summation and how does it apply to twitches?
- the process of adding up postsynaptic potentials and responding to their net effect - Twitches can summate: twitches blend into each other to create a stronger contraction - increased frequency of stimuli causes the next twitch "stands on the shoulders" of the previous twitch
How does the creation of multiple head-cycling's change the geometry of the sarcomere?
- the sarcomere become shorter and shorter with each successive head cycle. - As the z discs are pulled closer towards the center of the sarcomere, the H zone appears to disappear, and will look completely gone once the muscle is fully contracted. - The A-band does not change at all
Understand how anatomy and physiology are different subjects but are "joined at the hip".
- they are very related to each other and also influence each other. - The steering wheel analogy: a wheel that is purposely placed in front of you to spin and then the spin matched to whether you want to go right or left. it is in a specific place and the structure mates its function. - Form follows function; processes, structures and functions are all interwoven-Structure implies function - Physiology is explainable only in terms of the underlying anatomy -You can't FUNCTION without STRUCTURE, and vise versa. It is impossible to understand physiology without developing an understanding of anatomy; physiology is explainable only in terms of the underlying anatomy. You cannot have anatomy without physiology and vice versa
Perforating (Volkmann's) canals
- transmit blood vessels from periosteum into bone - communicate w/ Haversian canals, provide nutrients for osteons - allow blood vessels to perforate or go inside the bone
thalamus
- your body's information relay station. - All information from your body's senses (except smell) must be processed through your thalamus before being sent to your brain's cerebral cortex for interpretation - plays a role in sleep, wakefulness, consciousness, learning and memory
Describe the two classes of secretions osteoclasts secrete to dissolve bone.
-acid -collagenase
What is curare, where does it come from and who first discovered a use for it? What was that use?
-it is a poison of the synapse and a acetylcholine antagonist - creates competition for keyholes, blocking good keys from turning the lock and so the muscle cannot receive the message - curare acts as an antagonist because it replaces acetylcholine as a key and so the muscle can't get the signal from the neuron -paralytic neurotoxin that has the same effect as BOTOX -First discovered by South Americans who found it in plants and made it into a paste and put it on spear tips which helps with hunting. The animal would get weak and then they could easily get dinner. -it is not toxic if you eat it as the gut inactivates it, it is toxic when it gets into the bloodstream
Rank the 3 hormones involved from most important physiologically to least important.
-most critical: PTH -mid: Calcitonin -least important: calcitorial
Know the common anatomy of all serous membranes and what general function they all have in common and the basic anatomical characteristics they all share.
-parietal pericardium: outer membrane -visceral pericardium: inner sac -pericardial cavity containing pericardial fluid: space between both sacs -lining the contents and inner walls of body cavities, which secrete serous fluid to allow lubricated sliding movements between opposing surfaces. --Pericardium Heart --Pleurae Lungs --Peritoneum Abdominopelvic cavity
Know all the steps of head -cycling, how and when is the energy in ATP imparted to the cycle?
1) Exposure of the active sites: Ca binds to troponins→ tropomyosins move→ myosin head binding sites are exposed - Myosin heads are in the high energy position (upright) 2) Cross-bridge formation: myosin heads bind to the myosin head binding site - Myosin heads still in the high energy position 3) Power Stroke: energy form the myosin head is used to move the myosin heads, they pull the thin filaments towards the center of the sarcomere - Myosin heads are in the low energy position 4) Cross-bridge release: myosin heads unbind from the myosin head binding sites so that they can bind to ATP -Myosin heads are in the low energy position 5) Hydrolisis of ATP: myosin head hydrolyses the ATP that it's bound to and release energy - after the power stroke, ATP binds to the myosin heads and the cross bridge is detached. -Myosin heads are in the low energy position 6) Recovery stroke: ADP is used to return myosin heads to the high energy position - Can repeat the whole cycle if the neuron released multiple APs since the calcium is gone
Name 4 types of bone cells (one is actually a "bone-precursor cell") and know their physiological roles and location as per class discussion. Where are each of these cells typically found doing their job?
1. Osteoblasts: BUILDS NEW BONE, remodel existing bone, they secrete collagen and organic matrix 2. Osteocytes: Bone maintaining cells, FOUND IN LACUNAE 3. Osteoclasts: Bone destroying cells, break down bone and REABSORBS BONE 4. Osteoprogenitors: undergo mitosis to become osteoblasts; BONE-PRECURSOR CELL
corpus callosum
2 way street, colossal body - communication b/w right and left brain - controls tone of voice
What is the frequency range of the human ear?
20 Hz to 20,000 Hz
What is the wavelength range of the electromagnetic spectrum that is perceivable by humans?
400-700 nm
choroid plexus
A highly vascular portion of the lining of the ventricles that secretes cerebrospinal fluid.
What characteristics does an electrical potential have to have in order to be considered "graded"?
A stimulus causes ion channels to open, increasing the permeability of the membrane to Na+, K+, Cl- Increased permeability of the membrane to Na results in depolarization. Depolarizing graded potentials can combine (summate) to cause an action potential Increased permeability of the membrane to K+ or Cl- results in hyperpolarization The size of the graded potential is proportional to the strength of the stimulus. Thus, a graded potential produced in response to several stimuli is larger than one produced in response to a single stimulus Graded potentials can also summate. Graded potentials magnitude decreases as they spread over the plasma membrane. Graded potentials cannot be measured a few millimeters from the point of stimulation
Describe the key shape of an action potential
A wave that goes up, stops, then goes back down
achondroplasia and cretinism
ACHONDROPLASIA: - the E Plate wont respond to the hormones properly. The E Plate undergoes limited mitosis and you will see shortening of LONG BONES. CRETINISM: - TH is known to develop and grow the brain: toddler stage -most serious form of dwarfism -diminished stature and irreversible brain damage -wind up being incredibly disabled -test thyroid hormone when baby is bone. if it is detached than you can do thyroid hormone replacement
afferent neurons AND efferent neurons
AFFERENT: sensory neurons that receive sensory input and transmit the info the CNS from the effector EFFERENT: motor neurons/Nerve cells that conduct impulses away from the central nervous system to the effector organs to initiate the action
Know all surface anatomy terms gone over in lecture.
ANTERIOR -frontal region: forehead -Cervical: 7 bones in the neck -Thorax: chest -Pectoral: working out the pecs -Mental: chin -Antecubital region: bend in the elbow -manuse: hand -feomral: femur -dorsum: top of food -Patellar: kneecap POSTERIOR -olecranon: point of elbow -Dorsum: back of hand -Popliteal region: hollow behind knee -Calcaneal: heel -plantar: sole of food
To the extent discussed in class, know the different types of glial cells and their respective physiological roles?
ASTROCYTES: regulate blood flow, and transfer mitochondria to neurons, and supply the building blocks of neurotransmitters, which fuel neuronal metabolism OLIGONDENDROCYTES: the myelinating glia of the central nervous system. Myelination of axons allows rapid saltatory conduction of nerve impulses and contributes to axonal integrity MICROGLIAL: regulate brain development primarily through two routes: the release of diffusible factors and phagocytosis EPENDYMAL: ciliated-epithelial glial cells that develop from radial glia along the surface of the ventricles of the brain and the spinal canal. They play a critical role in cerebrospinal fluid homeostasis, brain metabolism, and the clearance of waste from the brain
Where are the autonomic motor neurons located within the spinal cord? Specifically, where are somatic motor neurons located within the gray matter of the spinal cord?
AUTONOMIC: lateral horn SOMATIC: ventral horn
the trigger zone
AXON HOLLOCK activates and initiates the propagation of the action potential of the cell through voltage gated channels inside the cell
Once an action potential is initiated, what are its characteristics?
Action potentials: are all or none (digital) events, very fast, exclusive to excitable cells, once they start they will self-propagate all the way down to the end of the cell cannot summate
Is there a famous disease in which the neurons of these circuits start getting sick and begin dying? is there a type of drug that can be used to gently boost the functioning of these circuits and allow these neurons to function a little longer than they otherwise would? How would this type of drug work in doing this?
Alzheimer's disease: causes memory loss, ability to form thought, destroys neurons in brain, eventually causes death - Acetylcholinesterase inhibitor (an inhibitor of an inhibitor) can be used to boost the production of acetylcholine. This would allow acetylcholine to remain longer in the synapse (its scarcity is what causes the problem).
How is an action potential channeled into the cell and how does it also keep going down the sarcolemma after encountering such a channel?
An AP is channeled into the cell through T tubules Some of the AP can go down the T tubule and some of the AP can continue down the sarcolemma to the next T tubule
How is it possible that calcium that spiked so quickly can also diminish so quickly before another head cycling is allowed? What effect would this "vacuuming up of calcium back into the sarcoplasmic reticulum" have on the possibility of a subsequent head cycling?
Because the Ca++ pumps in the terminal cisterns remove Ca++ from the sarcoplasm - The lack of calcium prevents a subsequent head cycling from occurring - Calcium is needed so that the myosin head binding sites are exposed and myosin can bind
bipolar neuron
Bipolar neurons have two extensions extending from the cell body. - At the end of one side is the axon, and the dendrites are on the other side. - These types of neurons are mostly found in the retina of the eye, can also be found in parts of the nervous system that help the nose and ear function.
cervical and lumbar enlargement
CERVICAL: supplies nerves to the shoulder and upper limbs LUMBAR: nerves of pelvis and lower limbs
Also know what defines cartilaginous joints (synchondroses, symphyses) along with specific examples of these that I went over.
CH: - Bones joined by cartilage with the absence of a joint cavity - Ex: acetabulum (synarthrotic catalogus joint) SYNCHONDROSES - synarthrotic - A bar or plate of hyaline cartilage unites the bones - All are synarthrotic - Ex of synchondroses: first rib joint to the spinal column and manubrium SYMPHYSES - amphiarthrotic - Bones covered with intervening fibrocartilage pad - Ex: pubic symphysis:Mostly fibrocartilage - Ex: intervertebral disk- Shock absorber: if you didn't have it it would be painful every time you took a step
Know the initialisms CNS and PNS and what they stand for?
Central Nervous System Peripheral Nervous System
What is the name of the part of the inner ear that the stapes vibrates against? Is the cochlea fluid filled?
Cochlea, fluid filled
broca's area
Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.
anatomy of a neuron
DENDRITES: receive the info for the neuron AXON: where electrical impulses from the neuron travel away to be received by other neurons SOMA: to maintain the cell and to keep the neuron functioning efficiently
Know all body cavities and know which organs exist in each cavity to the extent to the extent I had you read about in Chapter 1.
DORSAL - cranial cavity: brain - vertebral canal: spinal cord VENTRAL - thoracic cavity: (1)pleural cavitites: on lung (2)mediastinum: heart, thymus, trachea, esophagus - abdominalpelvic cavity: (1)abdominal: digestive organs, liver, speen (2)pelvic: bladder, urethra, rectum, large intestine, reproductive organs
Can depolarizations be graded potentials? Can hyperpolarization's be graded potentials?
Depending on the stimulus, graded potential can be depolarizing or hyperpolarizing Depolarization is the movement of resting membrane potential toward zero (moves in positive direction from resting membrane potential -70mV). Hyperpolarization is the movement of resting membrane potential further away from zero (moves in negative direction from -70mV)
regarding, Parkinson's I discussed possible therapies including administration of dopamine and L-dopa? Why does dopamine administration not work?
Dopamine from a medication or injection can't penetrate the blood-brain barrier.
What portion(s) of the sarcomere change during contraction?
During muscle contraction, the I band/H zone is reduced in size as the overlap between the thick and thin filaments increases. The Z-lines come together, and so the sarcomere shortens as well.
What are the basic characteristics of muscle fibers (e.g., understand how the terms excitable, contractile, extensible and elastic apply to muscle cells)?
EXCITABLE: respond to chemical and mechanical stimuli by generating organized movement of electrical charge across membranes CONTRACTILE: shortening EXTENSIBLE: tolerate stretching ELASTIC: snap back into position after stretch
What structure/tissue must be present for long bone to grow lengthwise?
Epiphyseal plate
Where are bipolar neurons in the retina and what is their role?
Found in the bipolar layer which is the third layer from the front of the eye, these provide the main pathways from photoreceptors to ganglion cells,
Know the initialisms GH, IGF-1 and the name of the hormones they represent.
GH: growth hormone (somatotropin) IGF-1: Insulin-like Growth Factor -1 - secreted by the liver to the E-plate
hippocampus & substantia nigra
HIPPOCAMPUS: Alzeihmer's begins here (short term memory loss) SUBSTANTIA NIGRA: where Parkinson's disease begins in the basal nuclei BASAL NUCLEI: encapsulated group of neurons
What is the overall main physiological effect of each of these hormones (e.g. Either hypercalcemic or hypocalcemic)?
HYPOCALCEMIC: calcitonin HYPECALCEMIC: calcitorial/PTH
Why is using the Nernst equation insufficient for precisely calculating the actual resting membrane potential?
How the cell potential really depends on concentration! - The Nernst equation accurately predicts cell potentials only when the equilibrium quotient term Q is expressed in activities
What is an autoimmune disease?
Immune system attacking itself - RHEUMATOID ARTHRITIS
Also know which nerves are transmitted sequentially, at least in part, by the jugular foramen, superior orbital fissure, and internal acoustic meatus. Know the anatomical significance of this.
JUGULAR FORAMEN: - Glossopharyngeal Nerve IX - Vagus Nerve X - Accessory Nerve XI SUPERIOR ORBITAL FISSURE: - Oculomotor Nerve III - Trochlear Nerve IV - Trigeminal Nerve V - Abducens nerve VI INTERNAL ACOUSTIC MEATUS - Facial Nerve VII - Vestibulochlear Nerve VIII
How is loudness and frequency encoded to the brain?
LOUDNESS: Loudness is based on how much the hair cells move, the more vibration, the louder something is and vice versa FREQUENCY: Hair cells are vibrated based on frequency, the higher the frequency, the closer to the oval window and the lower the frequency, the closer to the apex or middle of cochlea
plural form of Lacuna Trabecula Lamella Epiphysis canaliculus
Lacunae trabeculae lamellae epiphyses (sis-single, ses- plural → also goes for bone joints like synarthrosis) canaliculi
Know, from a gross anatomical perspective, where compact and spongy bone are found in both long bones (including differences in the proportions of spongy and compact bone in epiphyses vs. diaphysis) and flat bones.
Long bones: compact bone out outside, spongy bone on inside - Longer than they are wide - Diaphysis has at least one epiphysis - Ex: upper and lower limb- like femur Short bones: like a sandwich with compact as top and bottom and spongy bone in the middle - Kind of boxy - Ex: carpals and tarsals
How does a ligament differ with a muscle in terms of elasticity and extensibility and why are these differences important?
MUSCLES - extensible and elastic LIGAMENTS - not extensible nor elastic
How does it strikingly different from negative feedback both in how it works and its purpose?
Negative feedback is lessening a stimulus back to normal, where the positive feedback is continuing to increase and increase until there is sudden collapse causing the cycle to break
In repeated head-cycling, what has to continue happening to keep sarcoplasmic calcium levels high?
Neuron needs to fire multiple action potentials
the purposes of this class, how do resting membrane potentials and action potentials of neurons compare with resting membrane potentials and action potentials of muscle cells?
Neuron resting membrane potential: -70 mV Muscle resting membrane potential: -85 mV Neuron AP and muscle AP are the same thing
Why do you think it is important that the v-gated sodium channels activate at an offset in time compared to the v-gated potassium channels?
Opening the V-gated potassium channels at the same time as the V-gated sodium channels would counteract eachother and no action potential would be initiated
post and pre membrane vocab
POSTSYNAPTIC MEMBRANE: The specialized membrane on the surface of the cell that receives information by responding to neurotransmitter from a presynaptic neuron. POSTSYNAPTIC CELL: the cell that receives the NT PRESYNAPTIC MEMBRANE: the specialized membrane of the axon terminal of the neuron that transmits information by releasing neurotransmitter PRESYNAPTIC CELL: facilitate the rapid release of chemical neurotrans- mitter in response to electrical impulses
What is an equilibrium potential of a given ion, and what equation can be used to calculate it?
POTASSIUM: -90mV SODIUM: +60mV term used to specify the membrane potential that exactly counterbalances the chemical gradient so that the two gradients are in "equilibrium" with one another? - Nernst equation
Also, what are the target(s) of each of these hormones and what specific physiological effect does each of these hormones have on their respective targets.
PTH: bone & kidneys - PTH stimulates osteoclites to break down bone and release Ca2+ into the blood. - In Kidneys, PTH increases Ca2+ reabsorption from the urine. PTH also stimulates active vitamin D formation Calcitonin: Kidney - it shifts the balance from osteoblast and osteoclast to favor osteoblast. pulling calcium out of the blood and pulling it into the bone (hypocalcemic). - calcitonin interacts with the kidney to put more calcium into the urine = lowering the levels in the blood. - calcitonin inhibits osteoclast, which allows for enhanced osteoblast uptake of Ca2+ from the blood to deposit into bone
Know the major cell types imbedded within the retina and know their relative position from most deep to most superficial and vice versa, with most superficial defined as the cells closest to encountering an incoming photon.
Photoreceptor cells (deepest) Bipolar neurons (middle) Ganglion cells (superficial)
Define positive feedback.
Positive feedback is when an unusual event occurs, in which you want the variable to keep changing more and more to achieve goal- Ex: giving birth→ the uterus will gradually contract while in labor and it will get stronger and more frequent as it goes on until you finally give birth, then the force of contraction will die down.
What then causes the repolarization? Specifically, what ion and ion channel orchestrates the repolarization?
Repolarization is caused by the V-gated potassium channels opening and letting potassium out of the cell, thus returning the membrane potential to its resting value
Functionally, compare/ contrast rods and cones.
Rods: used for very dim light and allows you to see things in black and white and very blurry, very sensitive Cones: less sensitive which allows us to see color
What is serotonin, norepinephrine, and dopamine derived from?
SEROTONIN: the amino acid tryptophan NOREPINEPHRINE/DOPAMINE: derived from tyrosine
What is the differences between somatic motor pathways vs autonomic motor pathways
SOMATIC motor pathways are consciously controlled, meaning the movements are made while consciously controlling them. These are located in the ventral horn AUTONOMIC motor pathways are "automatically" controlled. resting and digesting & fight or flight are controlled by these motor pathways. lateral horn? or autonomic ganglion
How does SSRI work and how do reuptake inhibitors work in general to boost the levels of "mood maintaining" neurotransmitters?
SSRIs work by blocking reuptake, meaning more serotonin is available to pass further messages between nearby nerve cells.
Know the defining characteristics of fibrous joints and their subclassifications: sutures, syndesmoses, and gomphoses along with specific examples I went over.
SUTURES - unique to skull (22 bones) - Dense fibrous CT between flat bones of skull thins as skull grows - Dense irregular connective tissue unites the fontanelles into sutures - 4th decade (30s) skull bones become united into welded seams SYNTESMOSES - bones connected by short ligaments of dense CT allows minimal movement to no movement- ex: radioulnar syndesmosis GOMPHOSES - peg-in-socket fibrous joint (teeth only) - Always a joint between a tooth and the mandible or maxilla connected to bone by periodontal ligaments - Partially calcified ligaments - Teeth are held very securely to the gums - Bacteria can get between bone and tooth and can erode ligaments. Pockets of bacteria can cause tooth loss
What two ion channels conduct their respective ions in accordance with the ion gradients established by the sodium potassium pump? For each ion, what is the direction of the gradient and how does this relate to the difference of concentrations on either side of the membrane?
Sodium & Potassium ion channels - There's higher K+ outside the cell, so pump pushes K+ against its concentration gradient into the cell - There's higher Na+ inside the cell, so pump pushes Na+ against its concentration gradient out of the cell
Know the terms hyperplasia, hypertrophy and apoptosis and how they apply to the epiphyseal plate.
THE ZONE OF RESERVE CARTILAGE: what you have here is osteochondral progenitor cells that are capable of being osteochondral progenitor cell or a chondroblast. ZONE OF PROLIFERATION/ZONE OF GROWTH/ZONE OF HYPERPLASIA: chondorcytes mature and enlarege and mitosis (hyperplasia) ZONE OF HYPERTROPHY: going through mitosis is here in this zone. these cells are going to hypertrophy (getting bigger) ZONE OF CALCIFICATION: killing themselves. Still taking up space. then it gets pushed down to what is called the ossification zone (apoptosis) ZONE OF OSSIFICATION/OSTEOGENIC ZONE: you have osteoblast and osteoclast and they are from the diaphysis invading this area here and they are cooperating to put down new material onto the dead material. they are building a new bone city on top of a cartilage graveyard. - Hypertrophy: the volume of the cell gets bigger adding to the tissue. cells are not changing in number but increasing in volume.
What is another term for cisterns?
Terminal cisternae
Anatomically what must be present in a long bone for it to be classified as a juvenile bone and why? After this is gone, what forms in its place signifying that it is now an adult bone?
The E-plate must be present and it is deemed juvenile bone because the long bone can still grow. E-line
How does the development of skeletal muscle lead to formation of up to dozens of nuclei per cell?
The fusion of multiple myoblast
Why do you think there is always a latent or lag period for a twitch?
The latent period is the period between the time that you stimulate the action potential and the time that you see a force being generated.
How is the bony labyrinth positioned with respect to the membranous labyrinth? Which of these two contains the hair cells?
The membranous labyrinth (contains hair cells) is housed within the bony labyrinth
Brain cancer is a dreaded disease. Do most brain cancers originate from neurons? If not, why not? Which cells do they originate from and why not from neurons?
The most common primary brain tumors are called gliomas, which originate in the glial tissue. Neurons do not undergo mitosis and so rarely become cancerous as they do not duplicate themselves
multipolar neuron
These neurons have a single axon and symmetrical dendrites that extend from it. This is the most common form of neuron in the central nervous system.
What are a few global common characteristics of neurotransmitters? How is the neurotransmitter signal abolished for each of the neurotransmitters, if discussed?
They're small molecules that can be rapidly synthesized and removed from the synapse - Get rid of neurotransmitters with secondary active transport through NT-gated channels: symport NT with Na++ back into the presynaptic cell
Are individual twitches digital events? What does "digital" mean in this context?
Twitches are digital events (happen all the way or dont happen at all)
What other phenomenon have you learned about in this class that can undergo summation?
Twitches produced in muscles and graded potentials produced in neurons
Understand how/ways in which cranial nerves V and VII complement one another?
V also has sensory from anterior two-thirds of tongue
choroid
Vascular tunic, very vascularized, helps supply blood to both the sclera and retina
What is the prominence and significance of H20 in the body?
Water is the most abundant molecule in the body and water is about 66% of your body weight.
white matter
Whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths.
bone marrow
YELLOW MARROW: -adults -produce cartilage, fat, bone RED MARROW: -kids -in growing bone
Will fatigue eventually set in? What will be the result when this fatigue happens?
Yes fatigue will set in, you can only last so long when you make a maximal contraction and you will have to give out. - Neurons can only fire so many times before getting tired, synapses only have so much acetylcholine they can release before wearing out - you cannot keep opening Ca++ voltage channels forever because you will eventually loose the Ca++ gradient - You will loose ability to keep Ca++ high in sarcoplasm before you run out of ATP - When Ca++ cannot be kept high anymore, sarcomere relaxes
For each band or zone, which (thick/thin filaments) are present in that 100% position? Know the basic structure of myosin and its relationship to the thick filament.
Z disk: - Thin - Spring-like protein that attaches the end of the thick filament to the z-disk. M line: - thick I band: - Thin A band: - Thick and Thin H-zone: - Thick
ganglion
a collection of neuron cell bodies located outside the CNS
Understand/know the arrangement of troponin complex/tropomyosin/and actin polymers and their arrangement in the assemblage of the thin filament.
actin polymers: - Aggregation of actin protein which grows an actin strand - Two actin strands are wound around each other (pearl necklace) tropomyosin: - Dimer: 2 threads of polypeptides wound to make a string - They attach one after the other that move up and down the entire length of the thin filament - Another tropomyosin that moves along the other strand - 2 strands that are faithful to one strand each - Blocks the myosin head binding sites Troponin: - Trimer - Regularly occurs every 90 nm - Bolts the tropomyosin to the actin
What is a muscle action potential or muscle potential?
action voltage (wave)
Can graded potential be experienced by all cells or just excitable cells
all cells
Do myosin heads cycle synchronously or asynchronously?
asynchronous - myosin heads attach at different times. If they all attached at once, then when they let go, the sarcomere would just spring back - since they attach at different times, they are able to continue contracting while keeping a grip on the thin filament.
What are barbiturates and how do they affect GABAnergic synapses?
barbiturates are extremely powerful drugs enhance GABA-mediated chloride currents by binding to the GABA-A receptor and increasing the duration of the Cl- channel opening
hat is the rationale for the numbering of the cranial nerves?
based on the order in which they emerge from the brain and brainstem, from front to back
Understand also how cranial nerves 7 and 9 complement one another.
both a sense of taste
medulla oblongata (mylencephalon)
bottom most part of the brainstem, a key conduit for nerve signals to and from your body, helps control vital processes like your heartbeat, breathing and blood pressure and throwing up/swallowing, sneezing
What other cytoplasmically soluble factor is necessary for head-cyling progress to the recovery stroke?
calcium
How does the calcium interact with the myofilaments?
calcium binds to troponin C subunit that then moves the tropomyosin fibers out of the way to reveal the myosin head binding sites on the G actin of the thin filaments.
What tiny structures allow osteocytes to contact one another and share interstitial fluid?
canaliculi
spongy bone
cancellous bone/woven bone/trabecular bone: contains trabeculae and bone marrow
cornea
clear layer that sits on the most anterior part of your eye, and has a lot of nerve endings, dome shape helps wavelengths pass through it, then through the pupil
hypothalamus
commander of autonomic nervous system, controls nuclei of pons & medulla oblongata, has nuclei that control fundamental functions such as thirst, hunger, sleep and sex drive (emotional)
cortical bone
compact bone: The outer hard portion of bone
dorsal root ganglion
contains the cell bodies of sensory neurons that bring information from the periphery to the spinal cord
What is the anatomical relationship between muscle fascicles, muscle fibers, myofibrils and sarcomeres
cylinders within cylinders: - thick and thin filaments make ups the sarcomeres - sarcomeres make up myofibrils - myofibrils make up muscle fibers/cells - muscle fibers make up muscle fascicles - muscle fascicles make up muscles
all the lobes of the cortex
damage to the frontal lobe can cause personality changes & change in reasoning & logical thinking (judgment), language issues. parietal lobes control spatial reasoning
Ideally, the goal of negative feedback is to ___________ the signal to ___________.
decrease, zero
central sulcus
delimits the boundary between motor and the sensory cortices, as well as the boundary between the frontal and parietal lobes
Cerebellum (Metencephalon)
dendrites packed in, auto-pilot of brain - Little cerebrum
Can neuronal membranes be hyperpolarized? What about depolarized? Which of these must be great enough at the trigger zone in order to get a neuron to fire?
depolarized (excitatory); hyperpolarized (inhibitory) - depolarized
the tree meninges
dura mater (most superficial) arachnoid mater pia mater (deepest)
Is the spinal cord also surrounded by meninges? If so, which? What about cerebrospinal fluid?
dura, arachoid, pia - has cerebrospinal fluid
trabecula(e)
each of a series or group of partitions formed by bands of connective tissue, especially a plate of the calcareous tissue forming cancellous bone. - trabecula/trabeculae is one of the beams of spongy bone (the threads of a sponge)
What is the tapetum lucidum and what is its function? Do humans have the tapetum lucidum?
enables animals to see in dimmer light than would otherwise be possible, humans do not have them
System-wise, which system is famous for being behind (controlling and enforcing) negative feedback?
endocrine and nervous
What are the 4 major tissue types? Can each of these 4 major tissue types be classified into sub-classifications? If so, which of the 4 are especially complex in this regard?
epithelial, connective, muscle, nervous - MUSCULAR AND CONNECTIVE
What is muscle cell contraction predicated upon?
excitation
Are EPSPs and IPSPs postsynaptic events? Can they summate with each other? If so, how so? Can they cancel each other out? If so, how so?
excitatory (or EPSPs) if they increase the likelihood of a postsynaptic action potential occurring, and inhibitory (or IPSPs) if they decrease this likelihood Neurotransmitter effects last several times longer than presynaptic impulses, and thereby allow summation of effect
What does EPSP stand for? Is it depolarizing?
excitatory postsynaptic potentials yes, it is a temporary depolarization of postsynaptic membrane
filum terminale
fibrous extension of the pia mater; anchors the spinal cord to the coccyx
sclera
fibrous tunic, surround the eye then becomes clear when it reaches the cornea
What kind of ion would you have to inject into the cell to get a hyperpolarization? .....a depolarization?
for hyperpolarization: potassium for depolarization: sodium
ciliary body
found behind the iris and includes the ring-shaped muscle that changes the shape of the lens when the eye focuses. It also makes the clear fluid that fills the space between the cornea and the iris.
Can axon that are severed heal? If so, which cells are critical to this and what medical intervention must be made to facilitate this? Is there a difference between oligodendrocytes and Schwann cells in facilitating? If so, specify?
glial cells: - Schwann cells in the PNS - Oligodendrocytes in the CNS
hat is the name of the cells in the inner ear that transduce the vibration into an action potential that the brain can understand and why are they called "hair cells"?
hair cells
brain ventricles
hollow, sole function is to produce and secrete cerebrospinal fluid to protect and maintain your central nervous system
crossover of the pyramidal tracts
how left brain controls right side of body and vice versa
What extracellular component of bone endows it with compressive strength?
hydroxyapatite
What does IPSP stand for? Is it hyperpolarizing?
inhibitory postsynaptic potentials temporary hyperpolarization of postsynaptic membrane
Why is negative feedback called negative feedback? What are the 4 components that all negative feedback systems have?
it is called NF because any deviation is considered negative. Pushing the deviation back in the opposite direction is considered negative - signal: invoke a series of steps that is going to diminish the signal and make it smaller (back to zero) - receptor: influenced by one thing only and gives information to the controller - controller: brain is going to make a decision and stimulate an effector - effector: begins to work until the controller shuts it off.
Wernicke's area
lateralized to left parietal lobe, decodes language for understanding, sends info to prefrontal cortex, dictionary of brain, auditory & reading
Each of the tissue types can be considered_____________ of identical cells.
lumps or sheets
arachnoid villus (granulation)
microscopic herniations of the arachnoid membrane that penetrate the overlying dura and invaginate through the walls of the superior sagittal sinus and other venous structures.
brain stem
midbrain, pons, medulla oblongata
retina
nervous tunic, light comes in and is focused by the cornea, then the lens, then the retina
How does its synthesis blur the distinction between the nervous system and the endocrine system? Would you say that all hormones are necessarily synthesized by organs classically classified as endocrine organs? Explain.
oxytocin synthesis and release uses both the nervous system and the endocrine system no, oxytocin is synthesized by the hypothalamus
Telencephalon (cerebrum)
part of the brain which attributes motor function to the body - Initiates and coordinates movement and regulates temperature
Pons (metencephalon) bridge
part of your brainstem, a structure that links your brain to your spinal cord, handles unconscious processes and jobs, such as your sleep-wake cycle and breathing.
insula
plays a role in a variety of homeostatic functions related to basic survival needs, such as taste, visceral sensation, and autonomic control
What is the physiological significance of such an are that responds to a noxious stimulus?
polysynaptic reflex that facilitates the withdrawal of an affected body region in response to noxious stimulation.
Can you think of a ligand gated ion channel or channels that would have a hyperpolarizing effect?
potassium & chloride channel
pyramidal tracts
provides voluntary control of muscular movements, consists of two distinct pathways, the corticonuclear tract and the corticospinal tract. - The corticospinal tract carries motor signals from the primary motor cortex in the brain, down the spinal cord, to the muscles of the trunk and limbs
prefrontal cortex
rational brain, gives orders
Know the basic components of how spinal reflex arc works that includes the presence of at least one interneuron.
reflex arc consists of these five steps in order -sensor -sensory neuron -control center -motor neuron -muscle. These five parts work as a relay team to take information up from the sensor to the spinal cord or brain and back down to the muscles.
What is the difference between the relative and absolute refractory periods?
relative: after firing when a neuron will not fire again no matter how strong the incoming message may be absolute: period after AP in which neuron cannot generate another action potential because Na+ channels are innactive
Which of these is "the atomic unit" of contraction?
sacromeres
midbrain (mesencephalon)
serves important functions in motor movement, particularly movements of the eye, and in auditory and visual processing
What is another name of a skeletal muscle cell?
skeletal muscle fiber
What is the epidural space, is it also present in the brain? What is the clinical significance of the epidural space?
space between dura mater and skull - Inferior to the L1/L2 IVD, anesthesia can be injected into the epidural space, bathing the spinal nerve roots, with little danger of lesioning the spinal cord
interstitial lamellae
spaces between osteons
sarcoplasmic reticulum
specialized endoplasmic reticulum of muscle cells - stores calcium
Where do the cell bodies of unipolar sensory neurons congregate?
spinal and cranial nerve ganglia
conus medullaris function
stabilize the spinal cord
dorsal root
the SENSORY branch of each spinal nerve
endosteum
the connective tissue membrane lining the inner cavities of bone
What limits the ability to grow the length of long bones throughout life?
the fusion of the E-plate to make an E-line, meaning growth is finished and the bone is no longer juvenile
In "thumb nail sketch" terms, why/how does the epiphyseal plate stay relatively the same thickness throughout long bone growth?
the rate of cartilage growth on the epiphyseal side of the plate is equal to the rate of cartilage replacement by bone on the diaphyseal side of the plate.
Diaphysis
the shaft of long bone;walls = compact bone
Epiphysis
the very tip of bone, mostly made of spongy bone
visual cortex
to receive, segment, and integrate visual information
longitudianl fissure
to separate the brain into two hemispheres, left and right.
iris
two of them, can dilate or constrict which is controlled by the cranial nerve
What mechanism does the middle ear use to amplify vibration? I can think of two mechanisms.
vibrations travel down the external auditory canal and strike the eardrum (tympanic membrane)
amygdala
visual & auditory, funnels info through it & if it sees or hears something scary, initiates fight or flight
epiphyseal plate
what allows us to grow; made up of hyaline cartilage
epiphyseal line
when epiphyseal plate starts thinning into welded epiphysis then you have an epiphyseal line (means you can't grow anymore)
auditory cortex
where language decoding begins from ear to wernicke's area
Can a person with a healthy skeleton increase the thickness of bones throughout life?
working out
What portion(s) stay the same?
A-band and filaments
What is a chemical synapse and how is an NMJ such a synapse?
- When you have the release of the chemical synapses the muscle is induced to create its own action potential which moves down the muscle cell membrane in both directions. - Gap between the axon and sarcolemma which neurotransmitters are released from - synapse
Based on the difference in this autonomic response, how might your somatic responses differ?
- Somatic responses are solely based on skeletal muscle contraction. - The autonomic system, however, targets cardiac and smooth muscle, as well as glandular tissue.
Regarding action potentials understand the details of how a voltage gated sodium channel is activated and how it is inactivated?
- Voltage-gated sodium channels activate when the membrane is depolarized and close on deactive/repolarization - inactivation, which leaves the channel refractory,
Might a mild acetylcholinesterase inhibitor be useful as a component of treatment for this disease?
- mild acetylcholinesterase inhibitor can be used medicinally to make more acetylcholine because you have less channels - there more of a chance that ACh can bind to the channels before the antibodies
What is sympathetic/parasympathetic tone?
SYMPATHETIC: Control of BP even at rest and vascular system is entirely innervated by sympathetic fibers: keeps vessels in a continual state of partial constriction PARASYMPATHETIC: normally dominates heart, smooth muscle of digestive and urinary tract organs and activates most glands: slows heart beat, dictates normally activity levels of digestive and urinary tracts
how myelinating cells interact with an axon of a neuron.
Schwann cells cover most of the surface of all axons in peripheral nerves. Axons and these glial cells are not only in intimate physical contact but also in constant and dynamic communication, each one influencing and regulating the development, function, and maintenance of the other
What is the order of transmission through the ossicles from the tympanic membrane to the oval window?
The malleus is vibrated, this vibrates the incus which vibrates the stapes. - The stapes then vibrates the tympanic membrane which vibrates the oval window when frequency of sound is encoded to the brain.
Exactly how do the myofilaments slide past one another and how does this lead to the shortening of the sarcomere from repeated head cycling.
The myosin heads in the power stroke pull the thin filaments towards the center of the sarcomere dragging the Z discs
What are uses of barbiturates and what can an overdose cause?
mostly used for treatment of seizures and anesthesia Symptoms typically include difficulty thinking, poor coordination, decreased level of consciousness, and a decreased effort to breathe (respiratory depression). if there is too much, can lead to death
primary somatosensory homunculus
represents a map of brain areas dedicated to SENSORY processing for different anatomical divisions of the body. Located in the postcentral gyrus. sensitive parts of body are bigger in map.
What are the serotonin secreting neurons (serotonergic neurons), Dopamine secreting neurons (Dopaminergic neurons) and Norepinephrine (Adrenergic neurons) famous for maintaining?
responsible for regulating our moods
cerebral cortex
responsible for the higher-level processes of the human brain, including language, memory, reasoning, thought, learning, decision-making, emotion, intelligence and personality
Define histology. Can histology be defined as a sub-classification of anatomy?
study of tissues (groups of cells) - Yes, tissues are an organ and tissues and cells are apart of almost all of the structures in anatomy
lens
will thicken as you get close to someone and moves towards them and thin as you move away from them within 12 feet
Can hyperpolarization's partially or completely cancel out the effects of depolarizations?
yes, that is how you get back to resting membrane potential
In general, for a diarthrotic joint, what is the relationship between joint stability and joint flexibility?
joint flexibility = less joint stability
rheumatoid arthritis
- AUTOIMMUNE DISEASE - attacks the synovial membrane - White blood cells initiate attack and synoviocyte accumulation/synovial membrane is not functioning correctly. -Joint falls apart and gets destroyed and is incapable of any kind of movement - Ankylosis: frozen joint/joints fused together - cortisone: suppresses immune system which can help manage flair ups -Methotrexate (anti-cancer drug) that prevents the cytochind message to be processed by the secondary immune response
What effect might you expect a powerful acetylcholinesterase inhibitor to have on neuromuscular physiology?
- Acetylcholinesterase inhibitors inhibit acetylcholinesterase - it stimulates the production of acetylcholine. - Potent acetylcholinesterase inhibitors can cause death since they cause the body to go into uncontrollable full body contractions and the person would not be able to breathe and would uncontrollably defecate, vomit, and choke on their own saliva.
Why is the presence and activity of acetylcholinesterase every bit as important as acetylcholine release in the first place?
- Acetylcholinesterase prevents acetylcholine from keeping channels open longer than they should, and allows the body to control over muscle contraction. - Uncontrolled muscle contractions cause convulsions because uncontrolled acetylcholine caused motor end plate to continuously be depolarized and create continuous action potentials down the muscle cell
Specifically, what events comprise the latent period and in what order do they occur?
- Action potential starts at Time 0, but we do not see the moving of tension until 5 ms later - Once you excite the sarcolemma, it takes a certain amount of time for the action potential to move down sarcolemma, down the T Tubules initiating Ca++ voltage channels in the terminal cisternae, pouring Ca++ into the sarcoplasm, Ca++ binding to troponin, troponin undergoes shape change and pulls tropomyosin out of the way of active site, myosin heads bind and you have formed the cross bridge at the end of the latent period.(now we are right at the end of the latent period, just before start of contraction)
How do calcium pumps and voltage activated calcium channels of the terminal cisterns work together to modulate sarcoplasmic calcium ion concentrations during and after an action potential is conducted down a T-tubule?
- An action potential activates the V-gated Ca++ channels release Ca++ into the sarcoplasm - and Ca++ PUMPS (always on) bring in Ca++ back into the terminal cisterns. The Ca++ levels in the sarcoplasm drop. Troponin drags tropomyosin back over the myosin head binding sites and titins push the Z discs back to the resting positions (muscles relax).
For the nutrients mentioned, understand why a lack of any of these things would negatively affect (or positively affect as in "lack of stress" on bone growth)?
- Calcium could be negative for bone growth if there is lack - cortisol would be positive for bone growth if there is lack (stress hormone) - vitamin D is negative for bone growth if there is lack - vitamin C is negative for bone growth if there is lack (the creation of collagen)
What "pump" is imbedded within the membrane of the terminal cisterns and what role does it play in the regulation of sarcoplasmic calcium?
- Calcium pump - sucks the calcium from the sarcoplasm and back into the terminal cisterns
Understand the basic difference between endochondral ossification and intermembranous ossification in terms of where they occur and which is most common.
- EO: Process of transforming cartilage into bone. skeleton/ long bones ossified from cartilaginous precursor. - IO: bone develops from a fibrous membrane. bones of skull and clavicle ossified directly from embryonic mesenchyme precursor.
For a given muscle, what is the epimysium, perimysium and endomysium and where are they located?
- EPIMYSIUM: outer connective tissue that enshouds the MUSCLE - PERIMYSIUM: surrounds FASICLES - ENDOMYSIUM: surrounds muscle FIBERS/cells
On what part of the cell are EPSPs and or IPSPs physiologically relevant?
- EPSP: between a given synapse on a postsynaptic cell and the trigger zone - IPSP: between a trigger zone and an axon terminal
Compare and contrast chemical vs. electrical synapses? Which is overwhelming more common in the nervous system?
- Electrical synapses allow for direct, passive current flow between neurons through channels called gap junctions that link the two neurons together. Synapses are fast and bidirectional - Chemical synapses have more space between neurons, which is called a synaptic cleft. Synapses are slower and generally unidirectional. MORE COMMON IN THE NERVOUS SYSTEM
How does gross anatomy differ from histology and be able to define each.
- GROSS ANATOMY: study of structures that can be viewed without a microscope; can be approached systemically or regionally; can be viewed by the naked eye; "large" and is a subcategory of anatomy. - HISTOLOGY: study of tissues (groups of cells). Can't be seen with the naked eye and needs high tech equipment
During muscle contraction, is the typical fiber more apt to fatigue via running low on ATP first, or running low on sarcoplasmic calcium first?
- It is better for calcium to run out than ATP. - When you run out of Ca++ you are forced to relax, no continuation of head cycling - If your ATP gets below critical threshold, thick filament will be STUCK/ FUSED to thin filaments.
Understand the basic global functions of muscle (e.g., Movement, Posture, Joint Stability and Thermogenesis)
- MOVEMENT: produce tension to move things, pulling, squeezing - POSTURE: Baseline tension exerted at all times - JOINT STABILITY: constant tension holds joints together - THERMOGENESIS: heater
What does a professional histologist need (supplies/chemicals) in order to start doing histology?
- Microtome to make ultra thin sections - A high quality light microscope that magnifies specimens up to 1000x with good resolution - broad array of solutions and stains so that the microscope slide can be optimally visualized
is there an autoimmune disease that can "demyelinate" myelinated axons? If so, what disease, what type of glial cell is specifically attacked and what can be the effects?
- Multiple sclerosis (MS) - oligodendrocytes are damaged - impairment of learning and memory, Messages that pass along a demyelinated nerve become delayed or blocked
What is the role of the sodium potassium pump (another name for this?) in establishing and maintaining the resting membrane potential and which ions and how many of each does it pump across the cell membrane? What provides energy for this pump?
- Na⁺/K⁺-ATPase - Higher K+ inside the cell than outside, and higher Na+ outside the cell than inside - Pump loads 3 Na+ into the sodium binding sites and pushes them out of the cell - Then, the other side of the pump binds 2 K+ and pushes them into the cell - 3 Na+ out, 2 K+ in: outside of the cell becomes more positive so the pump is not enough to balance the charge difference - The pump requires energy (ATP) to complete 1 cycle
How are serotonin and norepinephrine "cleared from the synapse"?
- Norepinephrine action is terminated by reuptake into the presynaptic terminal via NET - Action of catecholamines and indolamines on target cells is terminated much more slowly than those of acetylcholine; they are removed from synaptic cleft by reuptake.
Can a postsynaptic cell in one context be a presynaptic cell in another context?
- Note that these designations are relative to a particular synapse—most neurons are both presynaptic and postsynaptic.
For each cranial nerve, know the name and the number and the foramina(foramen) that transmit(s) the nerve.
- Olfactory Nerve I: cribriform plate (special sense of smell) * Inability to smell - Optic Nerve II: optic foramen (special sense of sight) * blindness on the affected side - Oculomotor Nerve III: superior orbital fissure (motor to eye muscles) * pupil dilation/double vision - Trochlear Nerve IV: superior orbital fissure (motor to one eye muscle) * differculty moving the eye inferiory and laterally - Trigeminal Nerve V: superior orbital fissure, foramen rotundum, foramen ovale (senosry from scalp) * trigeminal neuralgia - Abducens nerve VI: superior orbital fissure (motor to one eye muscle) * eye deviates medially - Facial Nerve VII: internal auditory canal, stylomastoid foramen (sense of taste) * facial palsy - Vestibulochlear Nerve VIII: internal auditory canal (special sense of hearing) * loss of hearing and balance - Glossopharyngeal Nerve IX: jugular foramen (sense of taste posterior one-third of tonge) * differculty swallowing - Vagus Nerve X: jugular foramen * differculty swalling and or hoarseness - Accessory Nerve XI: foramen magnum, jugular foamen * differculty elevating the scapula - Hypoglossal Nerve XII: hypoglossal canal
Where is thyroid hormone produced and what might happen if it was not produced in sufficient amounts, especially immediately after birth through young childhood? I can think of two things.
- Produced in the thyroid gland - development of Cretinism: Low thyroid hormone during early infancy/toddler stage-short stature/profound cognitive deficit. - diminish sature - irreversible brain damage - most serious form of dwarfism
For the positive feedback integral for the human female to give birth, what is (are) the signal, the controller, effector, and the receptor(s)?
- Receptors: stretch receptors and nerve pulses in uterus - controller: brain/ purtuitary gland - effector: contractions smooth muscle tissue - variable: contraction force of uterine smooth muscle
Define the regional and systemic approaches to gross anatomy. What about blending these approaches? Are regional and systemic approaches subcategories of gross?
- Regional approaches is based on the regional placement on the body - systemic approaches is based on system to system. - it is possible to blend these approaches. Within each region, all systems are studied simultaneously. - SUBCATEGORY OF GROSS ANATOMY
In basic terms, what is the impact of genetics, stress, nutrients (protein, calcium, etc. in the diet, vitamin D, vitamin C) on bone growth?
- Size and shape of a bone determined genetically but can be modified and influenced by nutrition and hormones - Stress: adrenal gland (cortisol): stressed hormone bad: too much can stunt your growth and suppress your immune system - Nutrition: Lack of calcium, protein and other nutrients during growth and development can cause bones to be small—also the negative effects of stress - Vitamin D: (What is a vitamin) Promotes absorption of calcium from intestines Ingested or made (which is why it is considered a nutritional Component but also a hormone (see slide 7-7) - Vitamin C: Necessary for collagen synthesis by osteoblasts Scurvy caused by inadequate vitamin C
What happens to the bands of a sarcomere when a sarcomere is fully contracted and why can it not shorten any further?
- When you maximally contract a sarcomere to about a third of its resting length you are done because you have pushed the two z-disk maximally close to each other - spring is maximally compressed.
Know pathways mediated by sensory from the surface of the body to the spinal cord.
- When you touch something with the end of your finger, you activate a Merkel cell - The Merkel cell communicates with the nerve ending that it's intimate with, causing an AP, the AP travels up the finger, arm, and shoulder to the spinal cord dorsal root (incoming sensory info ALWAYS comes through the dorsal root) - Info can then be sent to the brain so it can decode what you're feeling (can sometimes bypass the brain and info is sent directly to the motor neuron)
Can the degree of rigor mortis be measured by experts? If so, might this be useful under certain circumstances? Explain.
- Yes the degree of rigor mortis can be used as a benchmark to measure time of death - if the human body is still stuck in a frozen position then they will know the individual has died within 24 hours. - If the body is already decomposing you will be past the 24 hour mark. - Instruments can calibrate and determine an accurate time of death.
t-tubules, triad
- area formed from terminal cistern of one sarcomere, T tubule, and terminal cistern of neighboring sarcomere - When an action potential hits a T-tubule some potential goes down the T-tubule and some will still run through the sarcolemma until it reaches the next T-tubule.
In a relaxed sarcomere, how is tropomyosin positioned with respect to the myosin head binding sites on actin and what puts in this position?
- blocks binding sites - one end jelly bean of troponin
Understand the basics of how bone reacts to a break (fracture) and the pathway it takes in healing.
- breaking a long bone in half will cause a lot of blood clasing a hematoma formation - reduction from doctors: closed reduction or an open reduction where they put in screws and (surgery) - osteocondroprogenter cells/fibroblast/chondroblast cells that put together a fibrocartilage bridge the unites the two broken ends - once you have the cartilage in place the osteoblast start developing woven bone replacing the cartilage. - the woven bone gets made into compact bone by osteoclast and osteoblast contributions.
What does an AP moving down the t-tubules induce in the terminal cisterns? And afterwards, what happens to the calcium concentration in the sarcoplasm?
- causes the terminal cisterns to pour fourth calcium into the sarcoplasm where it will bind to troponin. - Terminal cisterns have 2000 times the amount of calcium as the rest of the sarcolemma, so they act as an amplification of the signals. - Afterward, the calcium concentration in the sarcoplasm increases exponentially.
What is clostridium botulinum and how is the poison it produces relevant to the NMJ? How toxic is botulinum toxin compared to other chemical toxins?
- clostridium botulinum is a bacteria that produces the botulinum toxin and thrives in environments with little to no oxygen - the toxin is extremely small dose to be lethal and it inhibits exocytosis of vesicles -very specific: goes to NMJ and blocks ability of synapse to release ACh from vesicles in the neuron to the synaptic cleft - botulinum toxin is extremely toxic (one of the most toxic)
Lamealle
- concentric ring of solid bone matrix in osteon - osteocytes are between them
sarcoplasm
- cytoplasm of a muscle cell - critical role in muscle contraction
What is GABA and what is it derived from? What type of ligand gated ion channel on the post synaptic membrane is GABA and glycine often matched with?
- derived from glutamate - GABA is gamma aminobutyric acid. - It is an agonist molecule that can bind to ligand-gated channel and open them wider - It is often matched with Cl- channels. It will hyperpolarize the postsynaptic membrane
Is there another equation that can be used to calculate this resting membrane potential? If so, what is the name of this equation and why is it better than the Nernst equation?
- goldmans equation - This equation that is essentially an expansion of the Nernst equation and weights other ions proportionally to their permeability and individual equilibrium potential
How has a resting sarcomere changed after multiple head-cyclings until a sarcomere is maximally contracted? What limits the extent of contraction of a sarcomere?
- if a muscle fiber stretches so much that filaments do not overlap, the myosin heads have nothing to attach to and cannot generate tension. - If the sarcomeres are so compressed and cramped that the z discs touch the thick myofilaments, and the thin filaments touch and interfere with one another, little or no further shortening can occur.
pituitary dwarfism
- if the pituitary gland does not secrete as much GH it will be detrimental to the growth. - A person who has it has complete body proportionality - lack of GH
osteomalacia
- in adults -low in vitamin D and calcium -the cells are fine and in balance but the osteoblast do not have enough to work with when it comes to hardening the bone -wind up making soft bone making the weight baring bones bend due to body weight.
rickets
- in kids -low in vitamin D and calcium -the cells are fine and in balance but the osteoblast do not have enough to work with when it comes to hardening the bone -wind up making soft bone making the weight baring bones bend due to body weight.
For positive feedback, the purpose is to continually_____________ the signal, whereas in negative feedback the purpose is to______________ the signal back to the ______________.
- increase - decrease, zero
is one EPSP on a postsynaptic cell induced by a depolarization enough to drive the trigger zone of a postsynaptic cell to threshold? If not, how can summation drive the trigger zone of a postsynaptic cell to threshold?
- multiple presynaptic inputs must create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential. - During this summation, multiple neurons in close proximity fire at the same time, bringing the postsynaptic cell to threshold.
sarcolemma
- muscle cell membrane - transits neural excitatory that leads to muscle contraction
What is sarin and why is it so terrible?
- nerve gas that is an acetylcholinesterase inhibitor and causes uncontrollable full body contractions; chemical weapon - End up not being able to breathe, and uncontrollably defecating, vomiting, and choking on your own saliva
Are rods and cones dispersed equally over the surface of the retina? If not, describe the pattern of the retina? how might your explanation support the phenomenon that peripheral vision increases in dim light?
- no - rods all over the place, tiny spot of cones behind the optic disk (PERIPHERAL VISION IN DIM LIGHT)
Is a nerve that controls skeletal muscle truly a "one way street"? If not, why not?
- no two way street sends information to spinal cord and spinal cord sends information to skeletal muscle
postcentral gyrus (primary somatosensory cortex)
- notices nice feelings (velvet) or hurt (cut on razor blade) and how to react to that - processing afferent somatosensory input and contributes to the integration of sensory and motor signals necessary for skilled movement
What is proprioception? Be able to apply this term correctly to any nerves that may give proprioceptive feedback.
- oculomotor nerve III - Trochlear Nerve IV - Trigeminal Nerve V - Abducens Nerve VI - Facial Nerve VII - Glossopharyngeal Nerve IX - Vagus Nerve X - Hypoglossal Nerve XII
Which nerves discussed in class are entirely afferent?
- olfactory I - Optic II - vestibulochlear VIII
What is the signal and what is the variable? Are the terms "signal" and "variable" identical in meaning? If not, do they relate to one another and if so, how so?
- signal is a change in variable - not identical but the signal is a change in variable
lacunae
- small cavity in osteon containing osteocyte - provides passageways
What are the two types of summation and how do each of them work?
- spatial: involves simultaneous signals coming from multiple presynaptic neurons being received by a single postsynaptic neuron. - temporal: involves a single presynaptic neuron rapid-firing signals to a postsynaptic neuron
What is rigor mortis? what accounts for the development of rigor mortis after death?
- stiffening of muscles after death. - Caused by shortage of ATP: myosin can't unbind from the myosin head binding sites on the thin filament
How is it a "rolling wave of depolarization/repolarization"? Describe how the v-gated sodium channels and the v-gated potassium channels work in tandem to construct an action potential.
- the AP continues to be propagated down the sarcolemma - opened by depolarization, allowing more sodium to enter the cell. The pump is inactivated when the sodium channels are automatically blocked - repolarization is when v-gated potassium channels are open
How does the AP interact with the T-tubules? The T-tubules are effectively involutions of what?
- the action potential moves down the sarcolemma to the T tubules which stimulate the terminal cisterns - voltage change travels down t tubules where it interacts with terminal cisterns which have voltage gated calcium channels that open to allow calcium ions to enter to bind troponin sarcolemma
Define summation insofar as graded potentials are concerned?
- the additive effect of several electrical impulses on a neuromuscular junction. - Individually the stimuli cannot evoke a response, but collectively they can generate a response.
can this terrible toxin be prepared in a way that makes it a useful medical drug?
- when someone has a stroke, blockage disables ability for motor neurons to get signals (arm goes under spastic paralysis) - they were able to make botulinum a useful medical drug by taking a tiny dose to the specific area right in the muscle, poisoning the synapse and cause partial paralysis so that the person can relax their arm -is used as botox to partially paralyze muscles and get rid of wrinkles
Know how the following parts of the synapse or synaptic events interact during the activation and deactivation of a synapse and the order of this interaction: Action potential down a neuron, voltage gated calcium channel, acetylcholine, synaptic cleft, motor end-plate, acetylcholine gated sodium channel, acetylcholinesterase, acetylcholine diffusion
-an action potential travels down a neuron and reaches the presynaptic terminal, causing voltage-gated calcium channels to open up and cause a huge influx of calcium into the neuron -the dramatic spike of calcium will have a reaction with vesicles that contain a neurotransmitter called acetylcholine and the vesicles will perform exocytosis of the acetylcholine from the presynaptic terminal into the synaptic cleft -the acetylcholine will interact with structures on the motor end plate incredibly fast; wave of acetylcholine will interact with ligand-gated channels. the ACh with diffuse and 2 will insert to the binding site and unlocks the gate, which allows sodium to move into postsynaptic cell. This is called the acetylcholine gated sodium channel -the sodium is then flowing into the postsynaptic cell causing depolarization to occur, and if depolarization passes a threshold, an action potential is generated along the postsynaptic membrane. this action potential then catches fire causing a chain reaction and it moves down the sarcolemma -ACh then unbinds from the ligand-gated Na+ channels, which then close and the enzyme acetylcholinesterase then removes ACh from the synaptic cleft by breaking it down into acetic acid and choline. acetic acid diffuses away but choline is taking with Na+ into the presynaptic terminal where it can be recycled to become ACh.
What is myasthenia gravis, what type of disease is it, and what goes wrong when one has this disease?
-myasthenia gravis is an autoimmune disease -for myasthenia gravis, the immune system attacks ACh gated sodium channels -cells react by getting rid of channel -inability to keep eyelids open
Are most cells of the brain neurons? If not, what type of cell is 50-100 times more abundant then neurons?
-no, glial cells - star-shaped glial cells called astrocytes are the most abundant cell in the brain
What is the refractory period and what is its significance on questions about whether action potentials can summate, whether they can split in half and go in opposite directions, and whether an action potential can undergo backward reflection after reaching the axon terminal?
-refractory period: is the time in which a nerve cell is unable to fire an action potential - Summation is not possible with action potentials (due to the all-or-none nature, and the presence of refractory periods) - no backward reflection; refractory period helps impart directionality to an action potential?
Know how anatomy and physiology can be investigated from atoms, molecules, cells,.....all the way to the organism itself.
1. Chemical level: atoms combined to form molecules 2. Cell level: those molecules form organelles (such as nucleus & mitochondria) that make up cells in our body 3. Tissue level: similar cells & surrounding material make up tissue (such as smooth muscle tissue) 4. Organ level: different tissues combine to form organs, like the urinary bladder - Organ- structure that's composed of at least 2 tissues and has a specific function. Ex → urinary bladder has epithelial tissue (innermost), connective tissue (to provide rigidity), and smooth muscle tissue 5. Organ system level: organs (urinary bladder) make up organ system - Urinary system consists of the bladder, kidney, ureter, urethra and they all have a specific function to help excrete urine.6. Organism level: organ systems make up an organism
Know the four major categories of macromolecules. Atoms of what 4 elements are spectacularly overrepresented in the makeup of these macromolecules.
Carbohydrates, lipids, proteins, nucleic acids C, O, H, N
superior sagittal sinus
A venous sinus located in the midline just dorsal to the corpus callosum, between the two cerebral hemispheres.
Does the underperformance of the secretion of noradrenergic, dopaminergic and or serotonergic neurons correlate to a clinical condition or conditions?
CLINICAL DEPRESSION: This occurs when there is a chemical imbalance caused by the lack of serotonin or norepinephrine in the presynaptic cell.
What is (are) the components of the central nervous system and what are the components of the peripheral nervous system?
CNS: Spinal cord and brain PNS: autonomic, sympathetic, parasympathetic, somatic
What initiates cross bridge formation?
Ca++ binds to troponins & they move the tropomyosins, leaving the myosin head binding sites exposed
In basic terms, what induces calcium ion to spike and what affect does it have on the way the myofilaments interact and why?
Depolarization of the sarcolemma caused by nerve stimulation causes calcium ions to be released from the sarcoplasmic reticulum
Know relative size of skeletal muscle cells and how they are formed from myoblasts.
Each fascicle is a bundle of muscle fibers less than 1 cm long and up to 0.1mm wide formed by fusion of multiple myoblast in embryo
gigantism and acromegaly
GIGANTISM: -make too much hormone -when you become over tall you have enlarged organs that do not work well -tumor in pituitary gland which makes too much hormone (pituitary adenoma) ACROMEGALY: you can develop apromagaic features but still be a normal height:if you are an adult
gyrus (gyri) and sulcus (sulci)
GYRUS: help to increase the surface area of the cerebral cortex and form brain divisions SULCUS: another name for a groove in the cerebral cortex. Each gyrus is surrounded by sulci, help to increase the surface area of the cerebral cortex and form brain divisions
What is the relationship between homeostasis and negative feedback?
Negative feedback occurs when the body is not at homeostasis, so the body performs actions to get the body back into homeostasis; Homeostasis related to negative feedback in order to "bring back to set point"
Can action potentials in either type of excitable cell blend together or summate?
Neither type of action potential can summate (blend together)
What does the term NMJ stand for?
Neuromuscular junction: synapse w/ skeletal muscle and a neuron
What mechanism(s) allow a long bone to grow wider and why is this important?
ONE: one to make the medullary cavity wider TWO: have to make the compact bone thicker - osteoblast working together with osteoclast - osteoclast activity with the inner surface of the bone - At the same time making the diaphyseal will thicker: osteoblast; at all times you are growing the bone wider - inside osteoclast activity and outside osteoblast activity: the osteoblast activity on the outer surface is greater than the osteoclast activity on the inside. HAVE TO BE OUT OF BALANCE: YOU GET TO THICKEN THE BONE
Know the components of the outer, middle, and inner ear to the extent discussed in class. Know the scientific names and the common names of all parts (the technical names of the ear drum and the technical and common names of the 3 ear bones (ossicles).
OSSICLES: 1. Malleus (C: Mallet (hammer): amplifies sound 2. Incus (C: Anvil): malleus vibrates against the incus 3. Stapes (C: Stirrup): smallest bone in the body, incus vibrates against the stapes IN ORDER EAR DRUM - tympanic membrane
osteoporosis
OSTEOPOROSIS: - osteoclast and osteoblast become out of balance. osteoblast have trouble keeping with the osteoclast; not having enough vitamin D/calcium is making it worse - sudden braking of bones - In woman: is is more prominent in women because estrogen stimulate osteoblast activity, so when estrogen is lowered like menopause. woman just do not have the hormone support their whole life.
In general, how are osteoblasts and osteoclasts opposite yet complementary?
Osteoblasts are bone making cells while osteoclasts are bone destroying cells.
What role does oxytocin and peripheral nerves play?
Oxytocin causes the uterine smooth muscles to contract; peripheral nerves tell hypothalamus to produce oxytocin
Regarding the hormone oxytocin, what is striking about its synthesis and its release?
Oxytocin is produced in the hypothalamus and is secreted into the bloodstream by the posterior pituitary gland
What cells directly receive the photons?
Photoreceptor Cells, these are the deepest, and contain the cones and rods
Define tissues, organ, and organ systems
TISSUE: A tissue is a group of cells, in close proximity, organized to perform one or more specific functions. ORGAN: structure made up of at least two tissues with a specific function ORGAN SYSTEM: an organ is one of the parts of a confederation of organs completing a system
How is the circulatory system and the nervous system invested in bone and what soft tissue structure(s) facilitate this? What is the significance of this investment?
The periosteum is the scaffolding for blood vessels and nerves to enter the bone.
Know the order in which cells of the retina synaptically activate each other upon light stimulus.
When light hits the retina, it stimulates photoreceptors, creating an electrical signal that is conveyed through other neurons of the retina to the optic nerve, and then on to the brain.
What affect do ligand gated sodium channels have on postsynaptic membranes/cells?
a resulting conformational change opens the ion channels, which leads to a flow of ions across the cell membrane.
In general terms, define a hormone as per the classical definition of a hormone.
a substance/organic molecule produced by glands with internal secretion, which serve to carry signals through the blood stream to target receptors.
On the other hand, are all acetylcholinesterase inhibitors equally potent and therefore terribly poisonous?
no they aren't all equally as potent & no they aren't all illegal weapons of war
What is the role of the sodium/potassium pump play in allowing an AP?
opened by depolarization, allowing more sodium to enter the cell. The pump is inactivated when the sodium channels are automatically blocked by inactivation goes soon after they open.
cerebrospinal fluid
permeates & circulates in lateral ventricles, leaks into third ventricle, leaks into fourth ventricle, leaks around spinal cord in spinal column, fills space b/w brain and skull. - The brain does this to neutralize ionic charges and insulate the brain from rattling in the skull. meningitis can be diagnosed by looking at CSF through a microscope
lateralized areas
the view that functions are performed by distinct regions of the brain
What is necessary to induce two or more head-cycling's one right after another?
there needs to be enough calcium to bind to the troponin polypeptide so the the tropomyosin chain is moved, and the G actin active sites remain exposed
Which of these is a muscle cell organelle?
thin and thick filaments
