Exam 1 study guide_Final Flashcards
Define physiology.
The study of body functions (mechanisms of action, cause and effect sequences of physical and chemical processes)
List and describe the levels of organization in the body.
- Chemical – atoms (C, H, O, N) and molecules (protein, carbs, fat, nucleic acids)
- Cellular
- Tissue
- Organ
- Body System
- Organism
Define cells.
smallest entities capable of carrying out life processes (body’s structural and functional building blocks)
Define tissues.
groups of cells that have a similar structure and act together to perform a specific function.
Define organs.
two or more types of tissue that act together to perform functions
Define Body system
collection of organs that perform related functions, interact to accomplish a common activity essential for survival of whole body
Name the four primary types of tissue and give an example of each.
- Epithelial – cells specialized for exchanging material (epithelial sheets and secretory glands)
- Connective - few cells within abundance of extracellular material (loose connective tissue, tendons, bone)
- Muscle – specialized cells for contracting (smooth, cardiac, skeletal)
- Nervous – specialized cells for initiating and transmitting electrical impulses (brain, spinal cord)
What are Glands?
Epithelial tissue derivatives specialized for secreting
What are the two types of glands?
Exocrine – secrete through ducts to the outside of the body (or cavity to outside (eg. sweat, digestive juices); Endocrine – release hormones into blood (eg. Pancreas secretes insulin)
Define secretion.
When stimulated, release of specific products from a cell that were produced in the cell
Distinguish among external environment, internal environment, intracellular fluid, extracellular fluid, plasma, and interstitial fluid.
external environment – outside body
internal environment – inside body (ECF)
intracellular fluid – fluid within cell
extracellular fluid – fluid outside of cells
plasma – fluid portion of blood
interstitial fluid – fluid that bathes all cells
Define homeostasis.
Maintenance of a dynamic steady state in the internal environment (essential for each cell’s survival and each cell contributes)
List factors that must be homeostatically maintained
Concentration of: nutrients, O2 and CO2, waste products, water, salts (and other electrolytes); pH; volume and pressure; temperature
Define negative feedback.
A change in a control variable triggers a response that drives a change in the opposite direction of initial change (opposes change)
Define positive feedback.
A change in a control variable triggers a response that drives the variable in the same direction (amplifies change)
Define feedforward mechanism
Respond in anticipation of a change in a regulated variable
Compare negative feedback and positive feedback.
Opposes change vs. amplifies change
What is a specialized cell function?
Function essential for survival of the organism
What are the basic functions performed by each cell?
- Obtain O2 and nutrients
- Energy generating chemical reactions
- Eliminate wastes
- Make proteins and other cell components
- Control movement of materials between cell and environment
- Move material throughout
- Responding to the environment
- reproduction
Explain the difference between basic cell functions and specialized cell functions and indicate in what way each of these categories of functions is essential for life in a multicellular organism.
Specialized cell functions are essential for the survival of the organism; basic cell functions essential for the survival of the cell
Jennifer R. has the “stomach flu” that is going around campus and has been vomiting profusely for the past 24 hours. Not only has she been unable to keep down fluids or food, but she also has lost the acidic digestive juices secreted by the stomach that are normally reabsorbed back into the blood farther down the digestive tract. In what ways might this condition threaten to disrupt homeostatically maintained factors? What factors are moved away from normal by her profuse vomiting? What body systems respond to resist these changes?
Fluid loss = low plasma volume;
acid loss effect pH
Urinary system reduces water and acid eliminated
Respiratory system adjusts rate of CO2 removal
Circulatory system maintains blood pressure despite fluid loss
Nervous and endocrine regulate response
Considering the nature of negative-feedback control and the function of the respiratory system, what effect do you predict that a decrease in CO2in the internal environment would have on how rapidly and deeply a person breathes?
Slow shallow breaths allows CO2 to accumulate to normal levels
State the principles of the cell theory.
- Cell smallest structural and functional unit capable of carrying out life processes
- Cell function depends on structural properties
- Building block of organism
- Organism’s structure and function depends on collective structure and function properties of its cells
- New cells arise from preexisting cells
- Therefore cells of all organisms similar in structure and function
State the functions of DNA.
(1) Genetic blueprint during cell replication and (2) directing protein synthesis
What are the different types of RNA?
Messenger (transcribes DNA code); Ribosomal (part of ribosome that reads mRNA and translates into protein); Transfer (delivers amino acids to protein under construction)
Define genome.
all genetic info coded in a single (and complete) set of DNA
Define proteome.
Complete set of all proteins possible from genes in genome
Distinguish between the rough ER and smooth ER structurally and functionally.
Rough: flattened interconnected sacs studded with ribosomes – makes proteins for secretion and membrane construction
Smooth: interconnected tubules, no ribosomes – packages proteins in transport vesicles
List the stages of cellular respiration, and state where each is accomplished.
Glycolysis (cytosol) = 2 ATP
Citric acid cycle (mitochondria matrix) = 2 ATP
Oxidative phosphorylation (mitochondrial inner membrane) = 28 ATP
Compare the amount of ATP produced from one glucose molecule in anaerobic and aerobic conditions.
Aerobic = 32 (assuming full efficiency); Anaerobic = 2 (only glycolysis, pyruvate converted to lactate)
List the three general categories of activities associated with cytosol.
(1) Intermediary metabolism, (2) ribosomal protein synthesis, and (3) protein storage
Define intermediary metabolism.
The large collective set of chemical reactions inside cell that involve small organic molecules (simple sugars, amino acids, and fatty acids)
List the three types of cytoskeletal elements and state one function of each.
Microtubules (vesicle transport, cilia and flagella, mitotic spindle); Microfilaments (cell contractile systems); Intermediate filaments (resist stresses)
Compare exocytosis and endocytosis.
Exocytosis: secretory vesicle fuses with plasma membrane, releases contents to exterior, and becomes part of membrane. Endocytosis: extracellular material enclosed in plasma membrane that pinches off as an endocytic vesicle
Definesecretion.
Release a specific product made by the cell to the exterior
What are the three ways endocytosis can be accomplished?
Pinocytosis, receptor-mediated endocytosis, and phagocytosis
Define pinocytosis.
Nonselective. ECF taken up and retrieve plasma membrane added by exocytosis
Define receptor-mediated endocytosis.
Highly-selective, import specific large molecules
Define phagocytosis.
“cell eating” large, multi-molecular particles take up (performed by only a few specialized cells – white blood cells)
Kevin S. and his wife have been trying to have a baby for the past 3 years. On seeking the help of a fertility specialist, Kevin learned that he has a hereditary form of male sterility involving nonmotile sperm. His condition can be traced to defects in the cytoskeletal components of the sperm’s flagella. As a result of this finding, the physician suspected that Kevin also has a long history of recurrent respiratory tract disease. Kevin confirmed that indeed he has had colds, bronchitis, and influenza more frequently than his friends. Why would the physician suspect that Kevin probably had a history of frequent respiratory disease based on his diagnosis of sterility from nonmotile sperm?
Same defective microtubules are in respiratory cilia; therefore, unable to clear mucus and inhaled particles
The poison cyanide acts by binding irreversibly to one component of the electron transport system, blocking its action. As a result, the entire electron-transport process comes to a screeching halt, and the cells lose more than 94% of their ATP-producing capacity. Considering the types of cell activities that depend on energy expenditure, what would be the consequences of cyanide poisoning?
Cells can’t make new components, transport nutrients across membranes, or perform mechanical work. Organs will shutdown.
List the specialized functions of the different types of membrane proteins.
- Channels – allow water soluble substances to pass
- Carrier/transport molecules – transfer specific substances
- Docking-marker acceptors – bind docking-markers of vesicles
- Membrane bound enzymes – control chemical reactions
- Receptors – bind extracellular chemical messengers
- Cell adhesion molecules – fix to other cells or connective tissue
- Self-recognition glycoproteins (recognize cells of same type)
Describe the extracellular matrix.
Mesh of fibrous proteins embedded in a watery gel-like substance (interstitial fluid) of complex carbohydrates
List the three types of specialized cell junctions and indicate their primary role.
Desmosomes – “spot rivets” anchor adjacent but non-touching cells
Tight junctions – bind firmly at points of direct contact to seal off passage between cells
Gap junctions – cells linked by tunnels of connexon (allow passage of small molecules and ions)
Distinguish between passive and active forces that produce movement of substances across the plasma membrane.
Passive does not require energy; active requires cell to expend energy in transport
Describe what causes the carrier to change shape to expose binding sites for passengers to opposite sides of the membrane in facilitated diffusion, primary active transport, and secondary active transport.
Phosphorylation (binding of phosphate group from splitting ATP) causes carrier to change shape
Describe the relative contributions of K+and Na+to the resting membrane potential.
Pumps more Na out of cell than K into cell but K more permeable and will move back down concentration gradient (back out of cell) making out even more positive
What two properties of a particle influence whether it can permeate the plasma membrane?
Lipid solubility and size (surface area and molecular weight), [and charge]
Colostrum, the first milk that a mother produces, contains an abundance of antibodies, large protein molecules. These maternal antibodies help protect breast-fed infants from infections until the babies are capable of producing their own antibodies. By what means would you suspect these maternal antibodies are transported across the cells lining a newborn’s digestive tract into the bloodstream?
Vesicular transport. Endocytosis into intestinal lining, exocytosis into interstitial fluid
When William H. was helping victims after a devastating earthquake in a region not prepared to swiftly set up adequate temporary shelter, he developed severe diarrhea. He was diagnosed as having cholera, a disease transmitted through unsanitary water supplies contaminated by fecal material from infected individuals. The toxin produced by cholera bacteria causes Cl-channels in the luminal membranes of the intestinal cells to stay open, thereby increasing the secretion of Cl-from the cells into the intestinal tract lumen. By what mechanisms would Na+andwater be secreted into the lumen in conjunction with Cl2 secretion? How does this secretory response account for the severe diarrhea that is characteristic of cholera?
Cl- secretion creates electrical gradient, and Na+ follows, thus lumen more salty and water follows via osmosis. Toxin keeps Cl- channels from closing
Describe the three conformations of a voltage-gated Na+channel and indicate the membrane potential at which each of these conformations exists.
(1) Closed but capable of opening(activation gate closed, inactivation gate open); (2) open/activated (both gates open); (3) closed and not capable of opening (activation gate open, inactivation gate closed)
Distinguish between temporal summation and spatial summation.
Temporal: Excitatory postsynaptic Potential (EPSP) from a single presynaptic input occurring so close they add together; Spatial: adding EPSPs from several presynaptic inputs occurring at same time
Describe the permeability changes and ion fluxes that occur during action potential.
Na activation gate opens at threshold, Na rushes into cell – depolarization to +30 mV; Na inactivation gate closes and K activation gate opens and K rushes out (repolarization to hyperpolarization); Na/K pump restores gradients during refractory period
Compare contiguous conduction and saltatory conduction.
Contiguous: spread of action potential along every patch of membrane down length of axon; Saltatory: myelinated fiber, impulse jumps node to node
Compare the events at excitatory and inhibitory synapses.
Excitatory: nonspecific cation channels allow both Na and K movement but Na has electrical and concentration gradients in its favor, K only has concentration gradient; therefore, more Na moves into cell making it more positive and closer to threshold. Inhibitory: increases permeability of subsynaptic membrane to K+ (or Cl- depending on synapse), K moves out making hyperpolarized (more negative) and less likely to fire
Define signal transduction.
Process by which incoming signals (instructions from extracellular chemical messengers) are conveyed to target cell; transfer of signal into cell for execution.
List and describe the type of intercellular communication.
Direct (gap junctions, transient direct linkup); Indirect: (Paracrine, neurotransmitter, hormone, neurohormone)
Describe the sequence of events in the cAMP second messenger pathways.
Players
• Receptor
• G protein
• Adenylate cyclase (amplifier enzyme)
• cAMP
• Protein kinase A (phosphorylates a protein)
Turning on:
• Ligand (lipophobic) binds to receptor
• G-protein activated
1. GDP falls off, GTP added, and alpha subunit slides over to adenylate cyclase
• Adenylate cyclase converts ATP to cAMP
• cAMP activates Protein kinase A
• Protein kinase A phosphorylates a protein
• Response inside cell
Turing off
• Ligand falls off receptor
• Deactivate G-protein by hydrolyze GTP back to GDP + phosphate
• Phosphodiesterase (PDE) breaks down second messengers (ie. lowers cAMP levels in ICF)
• Phosphatase - enzyme that will de-phosphorylates protein
Describe the sequence of events in the Ca2+second messenger pathway.
Players
• Receptor
• G protein
• Phospholipase C (PLC) - amplifier enzyme
• cAMP
• Protein kinase A (phosphorylates a protein)
Turning on:
• Ligand (lipophobic) binds to receptor
• G-protein activated
1. GDP falls off, GTP added, and alpha subunit slides over to PLC
• PLC converts PIP2 (phospholipid) to IP3 (phospholipid)
• IP3 binds to a channel on the ER membrane
• Channel opens and Ca released into cytoplasm
• Ca produces a direct response inside cell, or Ca binds to Calmodulin
• Calmodulin activates a Protein kinase which phosphorylates a protein to produce a response in the cell
Turning off: same as cAMP, DAG, Ca
Explain how the cascading effect of hormonal pathwaysamplifies the response.
Each step activates more molecules than were in previous step leading to exponential amounts of activated enzyme products
Compare the nervous and endocrine systems.
Bothe maintain regulatory systems. Nervous: rapid responses (specificity depends on proximity to target organ); Endocrine: regulates activities that require duration rather than speed (specificity depends on specialization of target cell receptors)
Assume presynaptic excitatory neuron A terminates on a postsynaptic cell near the axon hillock and presynaptic excitatory neuron B terminates on the same postsynaptic cell on a dendrite located on the side of the cell body opposite the axon hillock. Explain why rapid firing of presynaptic neuron A could bring the postsynaptic neuron to threshold through temporal summation, thus initiating an action potential, whereas firing of presynaptic neuron B at the same frequency and the same magnitude of EPSPs may not bring the postsynaptic neuron to threshold.
Axon hillock is the region of lowest threshold. Graded potentials fade quickly, and B had farther to travel therefore A will be of greater strength.
Discuss the function of cerebrospinal fluid.
Surrounds and cushions the brain; exchange material with brain interstitial fluid
Explain by what means the blood-brain barrier anatomically prevents transport between the cells that form the walls of brain capillaries and physiologically restricts transport through these cells.
The endothelial cells surrounding the brain capillaries are linked by tight junctions. Only lipid-soluble substances can get through and highly selective membrane bound receptors carry glucose, amino acids, and ions through
State the functions of Broca’s area and Wernicke’s area.
Wernicke’s area: speech understanding; Broca’s area: speech formation
What regions comprise the basal nuclei and what are their function.
Grey matter around thalamus (caudate nucleus, putamen, globus pallidus, claustrum): inhibit muscle tone, purposeful motor activity/suppressing useless movement, monitor and coordinate slow sustained contractions
Describe how the thalamus serves as a sensory relay station.
All sensory input synapses in thalamus on way to cortex
What is the function of the hypothalamus?
Integrate homeostatic functions and links autonomic nervous system and endocrine system. Controls: body temp, thirst and urine output, food intake, anterior pituitary hormone secretion (makes posterior pituitary hormones), contractions and milk ejection, and is a major autonomic nervous system coordinating center (smoothe muscle, cardiac muscle, and exocrine glands, emotional and behavioral patterns, sleep-wake cycle
What is the function of the limbic system?
Emotions, behavior patterns, motivation, learning, and memory
Define long-term potentiation.
Connection gets stronger the more often it is used (increased use at preexisting synapse leads to enhanced ability of presynaptic neuron to excite postsynaptic neuron
State the functions of the three parts of the cerebellum.
Vestibulocerebellum: maintain balance and control eye movement; Spinocerebellum: enhances muscle tone and coordinates skilled, voluntary movements; Cerebrocerebellum: planning and initiating voluntary activity by providing input to cortical motor areas, stores procedural memories
List the functions of the brain stem.
origin of majority of cranial nerves
- Cardiovascular, respiratory, and digestive control
- muscle reflex involved with equilibrium and posture
- Receive and integrate synaptic input from spinal cord – activate cerebral cortex
- sleep-wake cycle
Discuss the location and functions of the three neural systems that play a role in the sleep-wake cycle.
. Arousal system (Brain stem and commanded by hypothalamus)
- slow-wave sleep center (hypothalamus)
- paradoxical sleep center (brain stem) – REM sleep-on neurons
Julio D., who had recently retired, was enjoying an afternoon of playing golf when suddenly he experienced a severe head- ache and dizziness. These symptoms were quickly followed by numbness and partial paralysis on the upper right side of his body, accompanied by an inability to speak. After being rushed to the emergency room, Julio was diagnosed as having suffered a stroke. Given the observed neurological impairment, what areas of his brain were affected?
Left side somatosensory cortex and primary motor cortex (areas for upper body) and Broca’s areas
The hormone insulin enhances the carrier-mediated transport of glucose into most of the body’s cells but not into brain cells. The uptake of glucose from the blood by neurons does not depend on insulin. Knowing the brain’s need for a continuous supply of blood-borne glucose, predict the effect that insulin excess would have on the brain.
Blood glucose drops because too much is getting stored in cells and not enough is getting to the brain
Discuss what types of neuronal cell bodies are located in the dorsal, ventral, and lateral horns of the spinal cord.
Dorsal horn: cell bodied of interneurons (afferent neuron terminate on them); ventral horn: cell bodies of efferent motor neurons supplying skeletal muscles; lateral horn: cell bodies of autonomic nerve fibers (to cardiac muscle, smooth muscle, and exocrine glands
Explain how light absorption by a photopigment leads to a hyperpolarizing receptor potential.
cGMP keeps Na channels open in absence of stimulus (light), leads to “dark current” and release of glutamate; Light reduces cGMP concentration, Na leak stopped leading to hyperpolarization and decrease in neurotransmitter release
Compare rod and cone vision.
Rods – indistinct gray vision at night; cones – sharp color vision during day
Compare the mechanisms for pitch, loudness, and timbre discrimination.
Pitch: frequency of vibrations, greater frequency = higher pitch; Loudness (intensity): depends on amplitude of sound waves (pressure diff. between high pressure region of compression and low-pressure region of refraction); Timbre (quality): depends on overtones, additional superimposed frequencies on fundamental pitch/tone
Compare tonic and phasic receptors.
Tonic receptors: do not adapt or slowly adapt to sustained stimulation; Phasic: rapidly adapt (relay intensity rather than status quo)
Explain how acuity is influenced by receptive field size and lateral inhibition.
Smaller receptive field (region of response) = greater acuity [more receptors in an area]; lateral inhibition (activated signal pathway inhibits pathways next to it) = sharpen contrast and localize stimulus
List the different types of sensory receptors and their function.
Photoreceptors – visible light
Mechanoreceptors – mechanical energy (muscle stretch receptors, sound waves in ear, blood pressure)
Thermoreceptors – heat and cold
Osmoreceptors – changes of concentrations of solutes in ECF
Chemoreceptors – taste, smell, O2 and CO2 concentrations
Nociceptors – pain (tissue damage: cutting and burning)
Describe how sensory transduction occurs from stimulation to generation of an axon potential
Stimuli causes graded potential (receptor potential) which trigger action potential
Suzanne J. complained to her physician of bouts of dizziness. The physician asked her whether by “dizziness” she meant a feeling of lightheadedness, as if she were going to faint (a condition known as syncope), or a feeling that she or surrounding objects in the room were spinning around (a condition known as vertigo). Why is this distinction important in the differential diagnosis of her condition? What are some possible causes of each of these symptoms?
Syncope – inadequate delivery of O2 and glucose to brain; Vertigo – disfunction of vestibular apparatus
A patient complains of not being able to see the right half of the visual field with either eye. At what point in the patient’s visual pathway does the defect lie?
Left optic tract or optic radiation
List the five established primary tastes and the stimuli that evoke each of these taste sensations.
Salty – (directly affect membrane channels) Na+ channels
Sour – (directly affect membrane channels) H= blocks K+ channels
Sweet – (second messenger) cAMP to block K+ channels
Bitter – (second messenger) gustducin G-protein, second-messenger pathway similar to vision G-protein transduction
Umami – (second messenger) glutamate binds to GPCR
Discuss the relationship of the adrenal medulla to the autonomic nervous system.
Modified sympathetic ganglion, does not give rise to post-ganglionic fibers, but secretes catecholamine hormones
Discuss the role of ACh and of AChE at a neuromuscular junction.
ACh = neurotransmitter; AChE = turns off by inactivating ACh
Distinguish between preganglionic and postganglionic fibers.
Autonomic nerve pathway 2-neuron chain. Preganglionic fiber: axon of first neuron, cell body in CNS; Postganglionic fiber: axon of second neuron, innervates effector organ
What is the advantage of dual innervation of many organs by both branches of the autonomic nervous system?
Permits precise control over organ’s activity
Distinguish among the following types of receptors in terms of mechanism of action and effect at the effector organ: nicotinic receptors, muscarinic receptors,α1receptors,α2receptors,β1receptors, andβ2 receptors.
nicotinic receptors – excitatory (ACh preganglionic fibers and motor neurons) opens nonspecific cation receptor channels
muscarinic receptors – excitatory (ACh form parasym. Post-synaptic fibers) activates G-protein-coupled receptors
α1receptors – excitatory or inhibitory (NE) activates IP3-Ca second-messenger pathway
α2 receptors – inhibitory (NE) inhibits cAMP
β1 receptors – excitatory (E and NE) activates cAMP
β2 receptors – inhibitory (E) activates cAMP
What regions of the CNS regulate autonomic output?
Lateral horn of thoracic and lumbar spinal cord (sympathetic) and brain and sacral spinal cord (parasympathetic)
Describe the sequence of events that occurs at a neuromuscular junction.
Action potential opens Ca2+ channels of terminal button, acetylcholine released into synaptic cleft by exocytosis, binds to receptor opens nonspecific cation channel (more Na in than K out); local current in muscle cell opens adjacent voltage-gated Na channels, Na enters triggering an action potential; Ach destroyed ending muscle cell’s response
Compare the central and peripheral nervous systems and function of both.
CNS controls muscles and glands by transmitting signals; PNS relays signals and brings back feedback signals
The venom of certain poisonous snakes containsα-bungarotoxin, which binds tenaciously to ACh receptor sites on the motor end-plate membrane. What would the resultant symptoms be?
Skeletal muscle paralysis; can’t contract diaphragm and breath = death
List and describe the methods of membrane transport. Indicate what types of substances are transported by each method, and state whether each means of transport is passive or active and unassisted or assisted.
- Simple diffusion (conc. Or electrical Gradients) – passive
- Facilitated (Carrier mediated) diffusion – passive (down conc. grad.) large and hydrophilic molecules
- Active transport (carrier mediated) – active (against gradients)
- Primary: energy directly required
- Secondary: couples cotransporter with a pump (pump sets up gradient to drive cotransporter)
