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MCB 32
Full Class
Question | Answer |
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Epithelial Tissue | Continuous layer of cells separating fluids and vessels |
Exocrine Glands | Epithelial glands which secrete product to external enviroment |
Endocrine Glands | Epithelial glands which secrete hormones into the blood stream |
Apical and Basolateral | Two distinct sides of the cell (Apical faces lumen; basolateral faces outside) |
Desmosomes | Hold cells together under stress |
Catabolic Reaction | Breaking down of larger molecules into smaller ones |
Anabolic Reaction | Production of larger molecules |
Allosteric Regulation | Activation/inhibition of enzyme by changing its shape |
Primary Transport | Uses ATP to transport substances |
Secondary Transport | Couples flow of one substance down its concentration gradient to another going up its gradient |
Paracrine | Diffuses locally and acts on a neighboring cell |
Metabotropic receptors | Receptors which function through a second messenger |
Posterior Pituitary | Extension of neural tissue; produces vasopressin and oxytocin |
Anterior Pituitary | Endocrine gland; prolactin and other hormones (ACTH) |
Vasopressin (ADH) | regulates water balance in the body |
Oxytocin | Milk, contractions, bonding (pregnancy stuff) |
Tropic Hormones | Regulates release of other hormones |
Cortisol Pathway | CRH (hypothalamus) stimulates anterior pituitary to produce ACTH; stimulates adrenal cortex to produce cortisol (steroid); which inhibits past pathways |
Addison's Disease | Hypoglycemia caused by hyposecretion of cortisol |
Cushing's Syndrome | Hyperglycemia and fatigue caused by hypersecretion of cortisol |
Insulin | Released by beta cells in the pancreas; increases reuptake of glucose into cells |
Glucagon | Released by alpha cells in the pancreas; stimulates breakdown of glycogen, lipids, and amino acids to produce glucose |
Temporal Summation | Two postsynaptic graded potentials from one synapse in rapid succession can summate |
Spatial Summation | Two postsynaptic graded potentials from nearby synapses around the same time can summate |
Glutamate | Main excitatory neurotransmitter in CNS |
GABA | Most common inhibitory neurotransmitter in CNS |
Afferent Neurons | Send signals towards the CNS |
Efferent Neurons | Send signals away from CNS |
Interneurons | Process signals in CNS |
White Matter | Clusters of myelinated axons in spinal cord |
Grey Matter | Cell bodies and dendrites |
Ganglion | Collection of cell bodies in periphery (i.e. in spinal cord) |
Nucleus | A ganglion in the CNS |
Meninges | Connective tissue membranes between outer bones and CNS |
Astrocytes | Glia cells involved in the blood-brain barrier |
Brainstem | Connects to spinal cord: Made up of Midbrain, Pons, and Medulla |
Midbrain | Controls eye movement, sleep, etc. |
Pons | Relay between cerebellum and cerebrum, etc. |
Medulla | Controls blood pressure, breathing, etc. |
Cerebellum | Involved in motor coordination and balance |
Forebrain | Largest part of brain |
Diencephalon | Under cortex, made up of Thalamus and Hypothalamus |
Thalamus | Relay system for sensory info |
Hypothalamus | Regulates homeostasis, links endocrine and neural systems |
Cerebrum | Made up of Cerebral Cortex and Basal Ganglia |
Cerebral Cortex | Outermost part of brain, divided into 4 lobes |
Frontal Lobe | Reasoning, motor skills, language |
Parietal Lobe | Kinesthetics, pain, somatosensory cortex |
Temporal Lobe | Hearing, memory, speech |
Occipital Lobe | Vision, colors, word recognition |
Limbic System | Learning, memory formation, emotions |
Nociceptors | Receptors involved with pain and discomfort |
Receptive Field | Area over which a stimulus will produce a response in a specific neuron |
Gate-control Theory | Touch and pain can interact in terms of reception |
Autonomic Nervous System | Controls subconscious functions of the body |
Parasympathetic Nervous System | Controls the body at rest (metabolism, etc) |
Sympathetic Nervous System | Prepares body for stress; danger. |
Preganglionic Neuron | Connect CNS to autonomic ganglion |
Postganglionic Neuron | Connect to target tissue |
Sympathetic Chain | Ganglia linked parallel to spinal cord; causes widespread sympathetic effect |
Vagus Nerve | Contains most of the cranial preganglionic nerves |
ANS Sympathetic Neurotransmission | ACh targets nicotinic receptors; followed by Norepinephrine binding adrenergic receptors |
ANS Parasympathetic Neurotransmission | ACh targets nicotinic receptors; followed by ACh targetting muscarinic receptors |
Varicosities | “boutons;” enlargements in axon where synapses connect to targets (motor end plate) |
Effect of Cocaine | Blocks reuptake of Norepinephrine; continually triggers sympathetic systems |
Adrenal Medulla | Sympathetic neuroendocrine tissue; “modified sympathetic ganglion”; secretes epinephrine |
Chromaffin Cells | Secrete epinephrine into blood; causes general alarm signal |
Somatic Motor System | Consciously controls skeletal muscle; only one neuron between system and muscle fibers |
Motor Unit | Collection of a motor neuron plus all the associated muscle fibers |
Neuromuscular Junction | Synapse between motor neuron and muscle fiber |
Curare | Natural toxin native in South America; antagonist of ACh receptors |
Botulinum Toxin | Cleaves a motor neuron protein involved in vesicle release; which paralyzes muscles |
Nerve Gases | Inhibit acetylcholinesterase; i.e. sarin |
Reflex | Automatic involuntary spinal cord action in response to a sensory stimulus; doesn't use brain |
Muscle Spindle | Senses lengthening of muscle and sends signal to the spinal cord; may in turn (through SC) activate counteracting muscle |
Monosynaptic Reflex | Muscle circuit involving only one synapse |
Patellar Stretch Reflex | Patellar tendon is tapped; knee jerks automatically |
Skeletal Muscle Tissue | Striated; attached to bones and controls movement (somatic peripheral system) |
Cardiac Muscle Tissue | Striated; runs heart. Controlled by autonomic system and hormones |
Smooth Muscle Tissue | Smooth; involved in organs/tubes/motion. Controlled by autonomic system and hormones. |
Tendons | Connect muscles to bones. Made out of collagen |
Fascicles | Bundles of muscle fibers |
Sarcolemma | Muscle fiber membrane |
Sarcoplasm | Muscle fiber cytoplasm |
Sarcoplasmic Reticulum | Muscle fiber ER |
Sarcomere | A unit of actin and myosin – actually contracts muscle fibers |
Myofibril | A repeating arrangement of muscle fibers and proteins |
T-tubules | Long tubes in sarcolemma; conducts action potential to center of muscle fiber |
Actin | Remember – composed of two F-actin fibers wrapped around each other |
Inactivation of muscle | Tropomyosin wraps around actin and prevents myosin binding; troponin positions tropomyosin – on or off, by situation |
Crossbridges | Where myosin heads bind actin |
Sliding filament model | Myosin heads walk along actin filaments; bringing sarcomere ends closer together |
Excitation-contraction coupling | Motor neuron releases ACh onto muscle, opening Na channels and depolarizing muscle. AP travels down T-tubule into interior; causes Ca2+ channel opening in SR. Ca floods cytoplasm and activates troponin; allowing contraction |
Twitch | When a muscle cell responds to a single AP |
Summation (muscular) | Occurs if a muscle fiber is stimulated continually – Ca2+ won't be pumped back into SR |
Tetanus | Muscle doesn't relax at all – sustained maximal contraction |
Recruitment | As more motor units are recruited, the muscle will generate much larger force |
Muscle Fiber Types | Slow Oxidative (Type I); Fast Oxidative (Type IIA); Fast Glycolytic (Type IIB) |
Type I Muscle Fiber | Slow Oxidative – Red due to stored oxygen in myoglobin; small and fatigue resistant |
Type IIA Muscle Fiber | Fast Oxidative – Red due to stored oxygen in myoglobin; medium sized and fatigues moderately |
Type IIB Muscle Fiber | Fast Glycolytic – White due to lack of myoglobin; large and fatigues quickly |
Flexor | Muscle responsible for bringing bones closer |
Extensor | Muscle responsible for moving bones away from each other |
Proprioceptors | Sensory neurons in muscle |
Golgi tendon organ | Proprioceptor wrapped around connective tissue in tendon – helps protect from muscle tear/damage |
Portal System | Dumps blood from one capillary directly into another without it being redistributed by the heart |
Diffusion | Random movement of molecules in solution. Only effective over short distances |
Bulk Flow | Circulatory system's transfer of blood to capillaries in tissues |
Diffusional Exchange | Transfer of gases and nutrients in capillaries (short distances, large surface area) |
Pulmonary Circulation | Carries blood to lungs to be oxygenated; brings this back to heart |
Systemic Circulation | Carries oxygenated blood to other parts of the body, brings deoxygenated blood back |
Arteries | Large branching vessels that conduct blood away from the heart; elastic smooth muscle can withstand high pressure |
Atherosclerosis | Depositing of plaque in arteries; can lead to ruptures |
Veins | Large converging vessels that conduct blood to the heart; then flexible walls leave resistance relatively low |
Arterioles | Use variable pressure to control blood pressure (total flow remains the same) |
Blood flow, by vessel | Heart > Arteries > Arterioles > Capillaries > Venules > Veins |
Series Arrangement | Whole CV system. LH > systemic > RH > Pulmonary > LH |
Parallel Arrangement | Both pulmonary and systemic circuits run in parallel branches; allows independent regulation |
Poisseuille's Law | Flow is equal to the pressure difference divided by the resistance (NOT absolute P) |
Total Blood Flow | 5 L/min (both circuits) |
Resistance | Dependent on viscosity, length, and radius; first two are ignored. Resistance is inversely proportional to radius |
Aorta | Main artery, provides oxygenated blood to systemic circulation. Comes from left ventricle |
Systole | Valves close, heart contracts and empties, generating pressure |
Diastole | Valves open, heart relaxes and fills |
Cardiac Output | Equal to stroke volume multiplied by heart beat rate (may increase up to 5x when exercising) |
Cardiac Muscle | Mononucleated and branched with intercalated disks |
Gap Junctions | Provide electrical continuity between cells |
Pacemaker cell | Measures action potentials in order to measure heart contraction frequency |
Cardiac refractory period | Extra long (almost as long as the twitch) which helps prevent tetanus |
Continual circulatory flow | Arterial pressure from stretching is used to drive blood when ventricular pressure is zero |
Single-unit smooth muscle | Gap junctions allow contraction as a single unit |
Multi-unit smooth muscle | Fewer gap junctions; independent contractions allow precise control of multiple units |
Muscle contractions (Fastest > Slowest) | Skeletal > Cardiac > Smooth |
Hypertension | High blood pressure due to increased resistance; Heart must contract harder |
Effects of exercise | CO is increased 4-fold, increasing pressure and thus a drop in resistance |
Capillary Sphincter | When relaxed, allows nutrients/waste to travel between capillaries and tissue cells |
Fluid Capillary Transport | Depends on osmotic pressure and blood pressure |
Lymphatic System | Collects excess tissue fluid; returns it to blood in the veins |
Swollen feet, ankles or other body parts | Caused by blocked lymphatics or circulation |
Distribution of blood by volume | 60% in veins, 15% in arteries, 12 in pulmonary blood vessels, 8% in heart, 5% in capillaries |
Skeletal Muscle Pump | Valves which assure one-way flow from lower extremities to the heart |
Sympathetic Nerves | Use (nor)/epinephrine to increase blood pressure, stroke volume, and cardiac output |
Parasympathetic Nerves | Use acetylcholine to slow APs and heart rate; little effect on ventricle contractions |
Valsalva Maneuver | (Anti-homeostasis) Forceful exhalation against a closed airway; reduces blood flow (veins/brain), CO |
Starling Curve | Changes in end-diastolic volume (increased venous return) increases stroke volume |
Autonomic Arteriole Regulation | Sympathetic nerves constrict most arterioles to increase blood flow to others |
Metabolic Arteriole Regulation | Constricts or dilates arterioles to regulate metabolic activity (also capillaries) |
Circulatory Homeostasis | During exercise, muscle/respiratory pumps increase venous return to maintain homeostasis |
Arterial Baroreceptors | Detect changes in arterial pressure (through AP frequency) and send to CV control center |
HBR | Heart Rate |
SV | Stroke Volume |
CO | Cardiac Output (HBR * SV) |
TPR | Total Peripheral Resistance |
MAP | Mean Arterial Pressure (CO * TPR) |
Fick's Law of Diffusion | Flux of solute is proportional to Area * Concentration / Distance |
Bulk Flow | Refers to the blood circulation and breathing; dependent on differences in pressure and vessel resistance |
Cystic Fibrosis | Lack of a protein regulating mucus etc; leads to trouble breathing, digestive problems, sweat etc. |
Pleural sacs/fluid | Attach lung to the chest wall; facilitating air flow in and out of lung |
Respiratory Inspiration | Diaphragm contracts, ribs and chest (thoracic cavity) expand; drawing in air |
Respiratory Expiration | Diaphragm relaxes; ribs and chest (thoracic cavity) contract; expelling air |
Pneumothorax | Seal of chest cavity is broken; lungs aren't bound by pleural fluid so they gradually collapse |
Boyle's Law | P1V1 = P2V2 (explains how air flows into and out of lungs) |
O2 Distribution | About 20% is used, the rest is kept in storage (excess capacity) |
Pulmonary Capillaries | Located in walls of alveoli; large alveolar surface area and thin membrane allow exchange within 1 second |
Pneumonia | Excess fluid in alveoli increases distance and decreases diffusion; results in less O2 to blood and tissues |
Forces Opposing Muscle Work in Breathing | Tissue resistance of chest wall; Airway resistance; compliance of lungs (∆V/∆P) |
Surface Tension | Tension of water in alveoli increases work of breathing |
Surfactant | Compound that lowers surface tension and pressure, making breathing easier (useful for babies/sick people) |
Hemoglobin | Protein in red blood cells that binds and transports O2 (high affinity for CO => toxicity); 4 hemes and 4 globins each |
Hemoglobin effects on diffusion | Hb-bound O2 is different from free O2, so bound O2 increases O2 release, vice versa and etc. |
Bicarbonate ion | HCO3-, method of transporting CO2 in the plasma. Released by pancreas in response to acid from stomach |
S-shaped Hb Curve | Allows maintenance of homeostatic O2 levels, despite acidity/temperature/etc. (increases binding) |
Red hands/extremities | May be due to cold or CO poisoning; bound Hb is visibly red |
Hematocrit | Percentage of RBC per blood volume; proportional to O2/CO2 capacity |
Erythropoietin (epo) | Increases/involved in RBC production |
Blood Doping | Transfusion of RBC or epo to increase hematocrit and thus O2 capacity |
Carbonic Anhydrase | Catalyzes the reaction between CO2 and HCO3-; similar effects to Hb |
Functions of the Urinary System | Regulate plasma composition; remove waste products/toxins from bloodstream |
Nitrogenous Wastes | Ammonia (soluble, toxic); Uric acid (insoluble); Urea (soluble, non-toxic) |
Kidney Functions | Filter blood, reabsorb nutrients and >99% of water; secrete and excrete toxins in urine |
Kidney Dialysis | Removal of waste by diffusion equilibration across dialysis membrane |
Ureters | Transport urine from kidneys to bladder |
Bladder | Stores urine |
Urethra | Excrete urine from bladder to outside of the body |
Nephron | Functional unit of the kidney: Consists of Bowman's capsule, its associated tubules, and a loop of Henle |
Afferent Arteriole | Carries blood to the glomerulus |
Efferent Arteriole | Carries blood away from the glomerulus |
Renal Corpuscle | The unit consisting of Bowman's capsule and glomerulus; first step of filtration |
Bowman's Capsule | First step in filtration of blood to urine; contains glomerulus enclosed in a sac |
Glomerulus | A cluster of capillaries that carry out the first step of filtration, filtrate passes through Bowman's to the DCT |
Proximal Convoluted Tubule (PCT) | Reabsorbs all nutrients, most ions and water; some toxin secretion (all passive/obligatory) |
Loop of Henle | Connects PCT to DCT; maintains osmotic pressure in the nephron |
Vasa Recta | Straight capillaries that run parallel to the loop of Henle; allow reabsorption of ions and urea |
Distal Convoluted Tubule (DCT) | Reabsorbs ions and water; secretes toxins, urea, and excess ions |
Aldosterone | Regulates reabsorption of Na and Cl ions in the DCT |
Mechanism of Aldosterone | Increases number of Na/K pumps on basolateral membrane; opens channels on apical membrane |
Production of Aldosterone | JGA granular cells secrete renin ---> converts angiotensinogen to angiotensin → triggers aldosterone |
ADH | Anti-diuretic hormone; regulates reabsorption of water by opening aquaporins in principal cells |
Regulation of ADH Release | Increased osmolarity or reduced blood pressure/volume stimulate release from hypothalamus |
Collecting Duct | Final step of kidney reabsorption/secretion; passes urine on to the ureter |
Renal Arteries | Carry oxygenated blood to kidney where it is continually filtered; receives about 20% of CO at rest |
Peritubular Capillaries | Blood vessels along nephrons; allow reabsorption and secretion using gradients |
Juxtaglomerular Apparatus (JGA) | Regulates tubule and nephron functions |
Podocytes | Located in outer layer of glomerulus; provide selectivity through filtration (retain plasma proteins and RBCs) |
Glomerular Filtration Forces | Primarily capillary pressure (hydrostatic and osmotic); less so Bowman's capsule pressures |
Rate of Filtration (Bowman's) | Highly regulated; can be significantly affected by small changes in glomerular capillary pressure |
Formula for Excretion | Filtration - resabsorption + secretion |
Formula for Urine Volume | Glomerular Filtration - reabsorption + secretion |
Water Distribution in the Body | 66%/33% split (28 liters in intracellular fluid; 14 liters in extracellular fluid) |
Hyper/Hyponatremia | High/low plasma concentration of sodium ions |
Proportion of Sodium Reabsorption | 70% in PCT; 30% in DCT |
ACE Inhibitors | Molecules that inhibit enzymes involved in the production of aldosterone; may reduce hypertension, etc. |
GI Pathway | Mouth > Pharynx > Esophagus > Stomach > Small Intestine > Colon/Large Intestine > Rectum > Anus |
GI Motility | Smooth muscle contractions in GI tract helps push the food from one end to another |
Layers of the GI Tract Wall | Mucosa, Submucosa, Muscularis Externa, Serosa |
Mucosa | Made up of epithelial cells and connective tissue |
Submucosa | Made up of connective tissue, blood vessels, and elements of the enteric (intestinal) nervous system |
Muscularis Externa | Made up of circular and longitudinal smooth muscle |
Serosa | Made of solely connective tissue |
Accessory Glands of GI Tract | Salivary glands, liver, gallbladder, and pancreas |
Long vs Short Reflexes | Long reflexes occur through CNS while short reflexes occur locally in the GI tract |
Cephalic Phase | Mental stimuli through CNS; thoughts of food which stimulate production of saliva, acid, mucus, and pepsinogen |
Gastric Phase | Stomach stimuli; food in stomach stimulates long&short reflexes involving gastrin, secretes acid and pepsinogen |
Intestinal Phase | Small intestinal stimuli; fat and protein stimulate long/short reflexes with CCK and secretin, stimulate secretions |
Lysozyme | Enzyme in saliva that destroys bacteria |
Salivary Amylase | Enzyme in saliva that breaks down starch |
Secreting Cells in Gastric Pits | Neck cells, chief cells, parietal cells, G cells |
Neck Cells | Secrete mucus |
Chief Cells | Secrete pepsinogen |
Parietal Cells | Secrete acid |
G Cells | Secrete gastrin into the bloodstream |
Acid Reflux (Heart Burn) | Stomach acid flows backwards into esophagus due to weakness/relaxing of lower esophageal sphincter |
Gastroesophageal Reflux Disease (GERD) | Frequent acid reflux; can be caused by obesity, pregnancy, smoking, medications |
Ulcers | Erosions of GI tract lining; caused by acid/pepsin breaking down lining (can be caused by aspirin or infection) |
Chyme | Partially digested food mixed with gastric juices (yum) |
Duodenum | First portion of small intestine; where pancreatic enzymes and bile carry out most of digestion |
Villi | Extensions which give the small intestine more surface area for absorption; each has capillaries and lacteals |
Lacteals | Part of the lymphatic system; take up fat for reabsorption |
Enterocytes | Epithelial cells of the small intestine; contains/covered by brush border |
Brush Border | Microvilli that cover enterocytes, increase surface area to aid in absorption |
Secretin | Triggered by HCl release; causes secretion of pancreatic bicarbonate |
Cholecystokinin (CCK) | Triggered by proteins and fat in intestine; causes secretion of pancreatic enzymes |
Carbohydrate Transport | Sugar transporters in the apical membrane of enterocytes use Na gradient to pump monomers into cell |
Zymogens | Proteins/peptides are secreted as this inactive form (until the duodenum); i.e. trypsinogen or pepsinogen |
Trypsin | Active form of protease which cleaves/activates zymogens |
Hepatic Portal Vein | Bring amino acids and sugars to liver for detoxification on the way to the heart |
Bile | Made by liver and stored in gallbladder; made of amphiphilic bile salts and other waste products to be eliminated |
Emulsification | Bile helps break down fat globules into smaller droplets |
Gallstones | Painful byproduct of excess cholesterol or insufficient bile |
Chylomicrons | Packages of digested fatty acids; released via exocytosis and drained into blood through lacteals |
Foxglove Digitalis | Blocks Na/K pump, causes increased urine excretion (too much can be fatal) |
Diabetes Mellitus | Disease characterized by high blood sugar; often related to insulin problems |
Type I Diabetes | Autoimmune; damage to beta cells causes low insulin lvels (5-10% of cases) |
Type II Diabetes | Specific cells develop resistance to insulin (90-95% of cases); often related to obesity |