SCB 204 Midterm Review Topics PDF

SCB 204 MIDTERM REVIEW TOPICS 1. Define the terms: Nerve, Ganglia, Nuclei, Tracts 2. Local channels and its characteristics. 3. Blood Brain Barrier SCB 204 MIDTERM REVIEW TOPICS 4. Refractory periods, types, and characteristics of each type. Refractory Period: Time the membran...

SCB 204 MIDTERM REVIEW TOPICS 1. Define the terms: Nerve, Ganglia, Nuclei, Tracts 2. Local channels and its characteristics. 3. Blood Brain Barrier SCB 204 MIDTERM REVIEW TOPICS 4. Refractory periods, types, and characteristics of each type. Refractory Period: Time the membrane cannot be stimulated to fire another action potential. Divided into an absolute refractory period and a relative refractory period. SCB 204 MIDTERM REVIEW TOPICS Absolute Refractory Period: No additional stimulation no matter how strong is able to produce an additional action potential. Relative Refractory Period: Only a stronger than normal stimulus will produce an action potential. 5. Types of synapses and their respective characteristics.  Neuronal synapses may be: SCB 204 MIDTERM REVIEW TOPICS o 3 types of neuronal synapses: axodendritic, axosomatic and axoaxonic. o Electrical: Important for programmed behaviors such as breathing o Chemical: Majority of synapses in nervous system More efficient and unidirectional. Electrical signal is converted into a controlled chemical signal with no loss of strength. Chemical synapses are slower with a 0.5 ms synaptic delay. Presynaptic neuron has synaptic vesicles with neurotransmitters. Synapse separated by a 20-50 nm synaptic cleft. SCB 204 MIDTERM REVIEW TOPICS Postsynaptic neuron has receptors for neurotransmitters. Receptors are usually linked directly or indirectly to ion channels. Signal can vary in size. 6. Receptors, their types, and characteristics. 2 types: Ionotropic and Metabotropic Receptors SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 7. Excitatory/Inhibitory post synaptic potentials Excitatory: - A small local depolarization that moves membrane potential of postsynaptic neuron closer to threshold. - Results from opening of Na+ and Ca2+ channels allowing positive charges into postsynaptic neuron. SCB 204 MIDTERM REVIEW TOPICS Inhibitory: - Small local hyperpolarization moves membrane potential of postsynaptic neuron farther away from threshold. -Results from either opening of K+ or Cl- channels. SCB 204 MIDTERM REVIEW TOPICS 8. Types of Circuits, characteristics, and examples. Neural Circuits: Patterns of synaptic connection between neuronal pools. How pools are connected determines the function of the circuit. 2 basic types of neural circuits: diverging and converging. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 9. Examples of Ascending/descending tracts. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 10.Structure of spinal cord, its horns, and their functions. SCB 204 MIDTERM REVIEW TOPICS Spinal meninges: Continuous with meninges of brain. 3 layers: 1. Outer dura mater. 2. Middle arachnoid mater. 3. Inner pia mater. 1. Epidural space:  Exists between dura mater and vertebral foramen.  Filled with veins and adipose tissue to cushion and protect spinal cord. 2. Subdural space. Only a potential space since dura mater and arachnoid mater stick to one another. 3. Subarachnoid space. Lies between arachnoid mater and pia mater and filled with cerebral spinal fluid (CSF). Site for lumbar puncture or spinal tap to remove CSF. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 11.What is reflex and its components and characteristics. REFLEX: Protective programmed automatic responses to stimuli Composed of a sequence of steps known as a reflex arc. Begins with a sensory stimulus and ends with a rapid motor response. SCB 204 MIDTERM REVIEW TOPICS 12.Golgi tendon reflex. Golgi Tendon Reflex: Monitors tension generated by a muscle contraction Polysynaptic reflex protects muscles and tendons from damage Causes muscle relaxation. An increase of tension causes Golgi tendon organs to inhibit contracting muscles with simultaneous activation of antagonist muscles. SCB 204 MIDTERM REVIEW TOPICS 13.Brain lobes and their respective functions. SCB 204 MIDTERM REVIEW TOPICS 14.Limbic system and functions. SCB 204 MIDTERM REVIEW TOPICS 15.Features/functions of Association, Projection and Commissural fibers. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 16.Pathways of sensory/motor neurons. SCB 204 MIDTERM REVIEW TOPICS 17.Receptors of sympathetic/parasympathetic nervous system. SCB 204 MIDTERM REVIEW TOPICS Adrenergic Receptors Types and Locations: 1. Alpha-1 (α1) Receptors: o Found in smooth muscle cells of blood vessels (skin, gastrointestinal organs, kidneys), arrector pili muscles, uterus (during pregnancy), and genitourinary organs. 2. Alpha-2 (α2) Receptors: o Located in preganglionic sympathetic neurons and certain sympathetic target cells (pancreas, adipose tissue). 3. Beta-1 (β1) Receptors: o Present in cardiac muscle cells, kidney cells, and adipose tissue. 4. Beta-2 (β2) Receptors: o Found in smooth muscle cells of airways (bronchioles), skeletal muscle fibers, urinary bladder, blood vessels serving skeletal muscles, liver, pancreas, and salivary glands. SCB 204 MIDTERM REVIEW TOPICS 5. Beta-3 (β3) Receptors: o Located in adipose tissue and smooth muscle cells of the digestive tract. Functions:  α2 Receptors: Hyperpolarize preganglionic neurons, reducing ACh release and dampening sympathetic response (negative feedback).  β1 Receptors: Increase heart rate and force of contraction.  β2 Receptors: Relax smooth muscles (e.g., bronchodilation).  β3 Receptors: Involved in lipolysis in adipose tissue. Cholinergic Receptors Types and Locations: 1. Muscarinic Receptors: o Found on sweat glands and parasympathetic target cells. 2. Nicotinic Receptors: o Located in membranes of all postganglionic neurons and adrenal medulla cells. Functions:  Muscarinic Receptors: Mediate parasympathetic effects (e.g., gland secretion).  Nicotinic Receptors: Excite postganglionic neurons and adrenal medulla cells. Summary  Adrenergic receptors (α and β types) respond to norepinephrine and epinephrine, affecting various organs and tissues.  Cholinergic receptors (muscarinic and nicotinic) respond to acetylcholine, influencing para sympathetic activities and postganglionic neuron excitation. SCB 204 MIDTERM REVIEW TOPICS 18.Sympathetic/Parasympathetic nervous system. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 19. Diseases: Tay Sachs’s disease: Deficiency of enzyme hexosamindase-A which results in buildup of gangliosides around nerve cells in the brain. Gangliosides inhibit nerve conduction producing blindness, loss of coordination and dementia. Disease causes death by age 3. SCB 204 MIDTERM REVIEW TOPICS Alzheimer’s disease: Most common form of dementia and early signs are memory loss and forgetfulness. Characterized by neurofibrillary tangles, senile plaques and degeneration of cortical neurons and synaptic connections. Most numerous in the cortical association areas and the hippocampus. Results in impairment of attention, language skills, critical thinking, visual-spatial abilities and changes in personality. Lou Gehrig’s disease: Amyotrophic lateral sclerosis (ALS) degenerates the cell bodies of α- motor neurons in anterior horn of spinal cord and upper motor neurons of the cerebral cortex. Produces muscle weakness and death occurs within 5 years. Huntington’s disease: Exaggerated unwanted movements. Flailing of the limbs (chorea). Hereditary. SCB 204 MIDTERM REVIEW TOPICS 20. Brain waves: Alpha: (note: I could not find this definition in the ppts or textbook, this is according to google) Alpha waves are a type of brain wave that are associated with relaxation, alertness, and creativity: Beta: are low in amplitude and high frequency occur when awake and engaged in mental activity. Theta: are normal in children and drowsy or sleeping adults. Delta: are in awake infants and adults during deep sleep. 21. Slowly/Rapidly adapting receptors and their functions: Name Function Type Location Merkel Cells Detect form & Slow Epidermal texture adapting ridges Ruffini Detect stretch Slow Dermis, Corpuscles & movement adapting Hypodermis, & ligaments SCB 204 MIDTERM REVIEW TOPICS Tactile Discriminative Rapidly Dermal Corpuscles touch stimuli Adapting Papillae but not as fine as merkel cells Lamellated Deep Pressure Rapidly Hypodermis Corpuscles & vibration Adapting stimuli 22. Two-point discrimination.  Means of measuring the size of receptive fields.  It is the minimum distance a subject can feel 2 distinct points. SCB 204 MIDTERM REVIEW TOPICS 23. Photoreceptors and their relations with light/dark. Cones: Color Rods: Dark 24. Mechanism of activation of photoreceptors. 1. Light Absorption: SCB 204 MIDTERM REVIEW TOPICS  Photon Interaction: When light hits the photoreceptor, it is absorbed by rhodopsin, a pigment in the rod cells.  Cis to Trans Conversion: This causes the retinal part of rhodopsin to change from a bent shape (cis-retinal) to a straightened form (trans- retinal), leading to the separation of retinal from opsin. 2. Activation of Transducin and PDE:  Chemical Reactions: The unbound opsin changes shape, triggering a series of chemical reactions.  Transducin Activation: This starts with the activation of the G- protein transducin.  PDE Activation: Transducin then activates phosphodiesterase (PDE). 3. Closing of Sodium Channels:  cGMP Conversion: PDE catalyzes the conversion of cyclic guanosine monophosphate (cGMP) to GMP.  Channel Closure: With less cGMP available, sodium ion channels close, reducing sodium influx. 4. Hyperpolarization: SCB 204 MIDTERM REVIEW TOPICS  Membrane Potential: The photoreceptor membrane potential becomes more negative, leading to hyperpolarization. 5. Signal Transmission:  Glutamate Release: In the dark, photoreceptors release glutamate, inhibiting bipolar cells. In light, hyperpolarization stops glutamate release, allowing bipolar cells to depolarize and transmit signals to retinal ganglion cells, which then send action potentials to the brain. This process is essential for converting light into electrical signals that the brain can interpret, enabling vision. SCB 204 MIDTERM REVIEW TOPICS 25. Refractive errors and corrective lenses. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 26. Relation of ion channels with bending of stereocilia at organ of corti. 27. Stimulation of Saccule/Utricle receptors. Overview: The utricle and saccule are parts of the vestibular system in the inner ear that help monitor static equilibrium and linear acceleration. They contain specialized structures called maculae, which house the receptor cells responsible for detecting head position and movement. SCB 204 MIDTERM REVIEW TOPICS Key Components: 1. Maculae: Located in the utricle and saccule, these structures contain hair cells with stereocilia and a kinocilium. 2. Otolithic Membrane: A gelatinous layer containing calcium carbonate crystals (otoliths) that increase its density. Mechanism of Stimulation:  Orientation of Hair Cells: o Utricle: Stereocilia are oriented vertically. o Saccule: Stereocilia are oriented horizontally.  Head Movement: o Tilting Head: Gravity pulls on the otolithic membrane, bending the stereocilia. o Linear Acceleration: Inertia causes the otolithic membrane to lag behind, bending the stereocilia. Response to Bending:  Toward Kinocilium: Depolarization occurs, increasing glutamate release and action potentials in the vestibular nerve.  Away from Kinocilium: Hyperpolarization occurs, decreasing glutamate release and action potentials. Function:  Static Equilibrium: Detects head tilting.  Linear Acceleration: Senses changes in movement, such as starting or stopping in a car. Summary: The utricle and saccule detect head position and linear acceleration by bending stereocilia in response to movement, altering neurotransmitter release and nerve activity to inform the brain about balance and orientation. SCB 204 MIDTERM REVIEW TOPICS 28. Action potentials in ampulla. 29. Decussation of fibers. Decussate: the action of crossing, especially fiber nerves, often found in the form of X. SCB 204 MIDTERM REVIEW TOPICS Tract: Corticospinal Most fibers decussates at Medullary pyramids in medulla oblongata Spinalothalmatic 2nd order neuron decussates in spinal cord and travels up the Spinothamatic Tract Fasciculus gracilis 2nd order neuron decussates at Medulla oblongata REFER TO PICTURE IN “9. Examples of Ascending/descending tracts.” 30. Cranial nerves: sensory, motor, and mixed. SCB 204 MIDTERM REVIEW TOPICS Name 1,2,8 Sensory 3,4,6,11,12 Motor 5,7, 9, & 10 Both SCB 204 MIDTERM REVIEW TOPICS 31. Thalamus as a relay station with sensory pathways. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 32. Sweet. Salt, umami, and bitter tastes sensations. SCB 204 MIDTERM REVIEW TOPICS 33. Characteristics of endocrine systems. 34. Merocrine/Endocrine/Paracrine/Autocrine secretions. Merocrine?? SCB 204 MIDTERM REVIEW TOPICS 35. Neuroendocrine organs:  Secondary neuroendocrine organs (secrete neurohormones).  Hypothalamus.  Pineal gland. (melatonin)  Adrenal medulla. (NE & E)  Posterior pituitary gland. 36. Types of hormones and mechanisms of actions. SCB 204 MIDTERM REVIEW TOPICS 37. Type of regulation utilized by Insulin/Glucagon. Blood Glucose Regulation SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 38. Hormones with relations to feedback mechanisms. 39. Secretion of hormones from Hypothalamus/Pituitary and other endocrine glands SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 40. Functions of each hormone. o To understand the functions of each hormone, let's break them down based on their roles in metabolic and fluid homeostasis. o Metabolic Homeostasis Insulin o Function: Lowers blood glucose levels by facilitating the uptake of glucose into cells and promoting its storage as glycogen in the liver. Glucagon o Function: Raises blood glucose levels by stimulating the conversion of glycogen to glucose in the liver. Thyroid Hormones (T3 and T4) o Function: Increase metabolic rate, enhance protein synthesis, and regulate long-term energy balance. o Fluid Homeostasis Antidiuretic Hormone (ADH) o Function: Promotes water reabsorption in the kidneys, reducing urine output and helping to maintain blood pressure. Aldosterone SCB 204 MIDTERM REVIEW TOPICS o Function: Increases sodium reabsorption in the kidneys, which leads to water retention, thereby increasing blood volume and pressure. Atrial Natriuretic Peptide (ANP) o Function: Reduces blood volume and pressure by promoting sodium and water excretion in the kidneys. o Key Points Insulin and Glucagon: Work antagonistically to maintain blood glucose levels. Thyroid Hormones: Regulate overall metabolic rate. ADH and Aldosterone: Work to retain water and maintain blood pressure. ANP: Acts to reduce blood volume and pressure. o These hormones interact in complex ways to maintain the body's internal balance, ensuring that both energy and fluid levels are kept within optimal ranges. 41. Regulation of secretion of hormones. SCB 204 MIDTERM REVIEW TOPICS Regulation of Hormone Secretion Hormone secretion is regulated through three main types of stimuli: hormonal, humoral, and neural. Let's break these down: 1. Hormonal Stimuli: o Endocrine cells can increase or decrease their secretion in response to other hormones. o Example: The hypothalamus releases growth hormone-releasing hormone (GHRH) to stimulate the anterior pituitary gland to secrete growth hormone (GH). Conversely, somatostatin from the hypothalamus inhibits GH secretion. 2. Humoral Stimuli: o Endocrine cells respond to changes in the concentration of certain ions or compounds in the blood or extracellular fluid. o Example: Elevated blood glucose levels trigger pancreatic cells to release insulin. 3. Neural Stimuli: o Some endocrine cells respond to signals from the nervous system. o Example: Sympathetic neurons stimulate the adrenal medulla to release epinephrine and norepinephrine. Negative Feedback Loops Hormone secretion is generally regulated by negative feedback loops, which function as follows: 1. Stimulus: A physiological variable deviates from its normal range. 2. Receptor: Endocrine cells detect this deviation. 3. Control Center: The same endocrine cells act as the control center, adjusting hormone secretion. 4. Effector/Response: The hormone triggers a response in target cells to return the variable to its normal range. 5. Homeostatic Range: Once normal conditions are restored, hormone secretion is adjusted back to normal levels. This system ensures that hormone levels remain balanced, maintaining homeostasis in the body. 42. 1st/2nd/3rd tires of hormone secretion regulation for each specific hormone SCB 204 MIDTERM REVIEW TOPICS 43. Adrenal cortex, layers, and respective secretion. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 44. Functions of cortisol/Aldosterone. SCB 204 MIDTERM REVIEW TOPICS 45. Mechanism of production of Thyroid hormone. SCB 204 MIDTERM REVIEW TOPICS SCB 204 MIDTERM REVIEW TOPICS 46. T3/T4. 47. Hypothyroidism and Hyperthyroidism. SCB 204 MIDTERM REVIEW TOPICS Hypothyroidism Hyperthyroidism Due to iodine deficiency Common is Graves disease due to production of abnormal and destruction of thyroid proteins from immune system gland (Hashimoto’s that mimic TSH. thyroiditis). Symptoms: weight loss, heat Symptoms: weight gain, intolerance, increased blood cold intolerance, slow heart pressure and disruption in heart rate, hypotension and rhythm. goiter. Enlargement of thyroid Treatment: iodine or gland (goiter). thyroid hormone Treatment: drugs that supplements. inhibit T3 and T4 production or removal/destruction of thyroid gland. SCB 204 MIDTERM REVIEW TOPICS 48. Homeostasis of calcium levels. Calcitonin: ↓ blood [Ca2+] due to hypercalcemia by inhibiting osteoclast cells. SCB 204 MIDTERM REVIEW TOPICS 49. Function of Insulin/Glucagon/ Somatostatin. Maintains Blood sugar levels 50. Functions of Thymopoietin, Leptin, Erythropoietin, Atrial Natriuretic Factor. Name Function Thymopoietin Paracrine signals to assist T lymphocyte maturation. Leptin Induces satiety and prevents overeating. Erythropoietin Acts on red bone marrow to stimulate development of erythrocytes. Atrial Natriuretic Factor Vasodilates blood vessels. In kidney causes natriuresis – excretion of Na+ and water. Both vasodilation and natriuresis ↓ blood pressure.