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Human Physiology
BIO 2301 Exam 1 LATEST 2025 SUMMER-
AUTUMN CSCC GRADED A (ANSWERED)
The following beaker of solution is .15 M of NaCl. how many osmoles are in the solution .3 Osmoles Which of the following will cause a neurotransmitter to be released from a neuron voltage gated channels allow calcium to enter the presynaptic axon terminal simple diffusion is "simple" because particles moving need no assistance or helpers to get across the membrane due to the fact that these particles are usually polar, large, and lipid insoluble. false regulation of blood glucose level is an example of negative feedback mechanism how would osmolarity of a solution change if water, but not solutes, was added? the osmolarity would decrease
Human Physiology what is the normal osmolarity of plasma 300 mOsm or .3 M Which receptors can Acetylcholine bind to? muscarinic receptors & nicotinic When is Ach excitatory? nicotinic receptors Stimulation causes skeletal muscle contraction. Also found in many parts of the CNS, where they are important in cognitive function and behavior. When is Ach inhibitory? stimulation of muscarinic receptors cause heart rate to decrease, increase peristalsis along the digestive tract and miosis (constriction) of the pupil. muscarinic receptors G protein receptor located within the target organ of the parasympathetic postganglionic fibers such as the heart, digestive tract, and iris.
Human Physiology This neurotransmitter generally has an excitatory effect on pathways that control muscles and an inhibitory effect on pathways that mediate sensation. Activity is lowest during sleep. Also function in the regulation of food uptake, reproductive behavior and mood and anxiety. Dopamine As a chemical messenger, _______ is similar to adrenaline. __________ affects brain processes that control movement, emotional response, and ability to experience pleasure and pain. Glutamate Excitatory neurotransmitter that helps to shape the processes of learning and memory; categorized as an amino acid neurotransmitter. Substance P Neuropeptide (string of amino acids) is an important mediator of pain signals. endorphins/enkephalins act as natural opiates, analgesics or euphorics, reducing our perception of pain under certain stressful conditions. ex. second wind, runners high, Histamine
Human Physiology an organic nitrogenous compound involved in local immune responses, as well as regulating physiological function in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. involved in the inflammatory response Epinephrine plays a role in emotional behavior, alertness, blood pressure regulation and the biological clock (hormone release) The movement of particles across a cell membrane during simple diffusion is driven by differences in concentration across the membrane. True A person is given an IV of distilled water. What will happen to his red blood cells? hemolysis A solution of glucose that is 0.3 M is iso-osmolar and isotonic. true The effect of oxytocin on parturition or labor is an example of: positive feedback mechanism
Human Physiology Which of the following is an adrenergic receptor which is involved with dilating the blood vessels of the heart (coronary blood vessels)? beta Which type of Na+ channel is primarily found along the axon? Voltage gated This portion of the nervous system includes the brain and spinal cord. CNS The projections from a neuron that are usually highly branched are the: Dendrites This division of the nervous system is largely voluntary. somatic Which of the following neurotransmitters is involved in neural processes which make pain? Substance P
Human Physiology A current that causes a resting membrane potential of - 70 mv to go to - 90 mv is described as: Hyperpolarizing An IPSP or EPSP occurs on which part of a neuron? Dendrite Which of the following receptors is directly involved in causing skeletal muscle contraction? Nicotinic Receptors for the neurotransmiter secreted by a neuron are often found on the axon terminals of the presynatpic cell in order to facilitate which of the following? increase reuptake and recycling of neurotransmitters Schwann cells form myelin sheaths around the large nerve fibers in: Peripheral nervous system Flexible structure that allows for precise focus of light on the retina. Lens
Human Physiology During a neurological exam, touching the cornea of the left eye causes only the left eye to blink. Touching the cornea of the right eye causes only the left eye to blink. Which of the following is consistent with these signs? damage to CN VII on the right Which is more WORK for the eye, looking at a close object (reading this question) or looking at a far object(mountain range)? Close This type of receptor responds to harmful stimuli that produce pain: Nociceptors Is your sympathetic division part of the sensory or motor division of the PNS? Motor If one were to have a portion of their left somatosensory cortex affected by a stroke, it would be expected that they would have loss of feeling on the left side of their body? False Presbyopia is due to:
Human Physiology Loss of elasticity of the lens Contains only cones: Fovea Centralis The average pitch range for hearing is: 20 - 20,000 Hz Receptors for color vision and bright light. Cones Positive feedback Not very common in the body - the result or response will enhance or exaggerate the original stimulus so that the activity or output is accelerated. The body moves away from the normal set point. example of positive feedback
- Baby presses on cervix
Human Physiology passive transport movement of materials across a membrane that requires no expenditure of energy influence of polarity Recall, polarity simply relates to the number of polar bonds contained within a molecule, or that a molecule contains polar bonds or ionizing bonds. If all the bonds in a molecule are electrically neutral, then it is called nonpolar. solubility In order to dissolve in water, a substance must be electrically attracted to water molecules. hydrophilic Molecules having a number of polar bonds and/ or ionized groups will dissolve in water. said to be "water loving". Hydrophobic Molecules composed predominantly of carbon and hydrogen are insoluble in water since their electrically neutral covalent bonds are not attracted to water molecules. These molecules are "water fearing". When you mix hydrophobic molecules with water, 2 phases occur, as in oil and water
Human Physiology Amphipathic molecules that have a polar or ionized region at one end and a non polar region at the opposite end. When mixed with water, amphipathic molecules form cluster, with their polar regions at the surface of the cluster where they are attracted to the surround water molecules. The non polar ends are oriented toward the interior of the cluster. ex. phospholipids Diffusion Movement from a region of high concentration to a low concentration. active processes moves solutes against the concentration or electrochemical gradient (from low concentration to higher concentration). Utilizes ATP for energy simple diffusion thru the lipid portion of the membrane can be achieved by small lipid soluble molecules, such as fat, oxygen, carbon dioxide, alcohol. Describe what drives the direction of simple diffusion
Human Physiology Pinocytosis cell drinking - plasma membrane surrounds droplets of fluid with dissolved molecules. Can be fluid only or adsorptive, which takes in molecules bound to specific proteins along with the extracellular fluid osmosis net diffusion of water across a membrane osmolarity is a measurement of the number of solute particles within a solution: Example, glucose solution: glucose is the solute, water is the solvent. calculate osmolarity 1.0 mole/L or 1M sucrose = 1 osmol/L or 1 Osm 1.0 mole/L or 1 M NaCl = 2 osmol/L or 2 Osm 1.0 mole/L or 1 M MgCl2= 3 osmol/L or 3 Osm tonicity is the ability of a solution to change the shape or tone of cells by altering their internal water volume.
Human Physiology isotonic solution that causes no change Hypotonic solution that causes the cell to swell and burst (hemolyze) water will enter the cell (ie: cell in 200 mOsm nonpenetrating solution) Hypertonic solution that causes the cell to shrink (crenate) water will leave the cell (ie: cell in a 400 mOsm nonpenetrating solution Nonpenetrating solutes: solutes that cannot permeate the cell membrane, cannot pass thru. Sodium, Potassium and Chloride are examples of nonpenetrating simply because while they do enter or leave the cell thru diffusion, they are also pumped thru by active transport as if diffusion never happened. Dendrites The receiving end of the neuron contains receptors to neurotransmitters that cause either an EPSP or IPSP to be conducted toward the nerve cell body.
Human Physiology Axon terminal, a.k.a. synaptic knobs or boutons: The neurotransmitters are synthesized, stored and released from the axon terminals. When the impulse reaches axonal terminals it causes neurotransmitters, stored in vesicles at the terminal, to be released into the extracellular space Synapse or Synaptic cleft: The space between the ending of one neuron and either another neuron or muscle. The neurotransmitter diffuses across this space. The neuron before the synapse is called the Presynaptic neuron and the neuron that is after or receives in the synapse is the postsynaptic neuron. presynaptic neurons: the neuron carrying the impulse toward the synapse postsynaptic neurons neurons leading away from the synapse resting membrane potential Measured at - 70mV RMP must be in place in order to generate a graded potential or an action potential or current that allows for cell to cell communication.
Human Physiology Why is the Na/K pump so important? transports sodium out of the cell and potassium back in If the change in membrane potential is toward the positive, it is called ex. - 70mV to - 50mV depolarization If the change in membrane potential is toward the negative, it is called ex. - 70 to - 90mV Hyperpolarization As the sodium entry declines, the voltage gated potassium channels open and potassium rushed out of the cell. The cell interior becomes less positive (more negative) and the membrane potential moves toward the resting level. repolarization phase Graded Potentials This is a change in the membrane potential that is short-lived and occurs in a small area or over a short distance.
