Exam 2: Circulatory and Other Systems PDF

# Exam 2 ## Circulatory System * **No circulatory:** Aquatic invertebrates * **Closed:** Vertebrates, Cephalopods, Annelids * Diffusion through skin * Heart contractions * High blood pressure drives fluid movement. * Muscular pump. * Vessels connected. * **Systematic heart:** B...

# Exam 2 ## Circulatory System * **No circulatory:** Aquatic invertebrates * **Closed:** Vertebrates, Cephalopods, Annelids * Diffusion through skin * Heart contractions * High blood pressure drives fluid movement. * Muscular pump. * Vessels connected. * **Systematic heart:** Blood to body tissue. * **Branchial heart:** Blood to lungs. * **Arteries:** Blood to heart. * **Veins:** Blood away from heart * **Differences:** Arteries are thicker endothelium, have elastic fibers (be ABP), smoother. Small veins have valves (unidirectional flow) * Cells connecting are thin for gas exchange and diffusion. * **Open:** No blood vessels * Pumps into hemocoel (unoxygenated). * Sends blood to tissues, open spaces, bathes. * **Vessel Dilation:** Controlled by ANS. * Changes lumen size, changes blood flow in areas. * **(Vaso)constriction:** Reduces blood flow. * **Dilation:** Increases blood flow ## Microcirculation * **Through capillaries:** (vessel walls) - Basal lamina/endothelium * **Supply:** Changes amount of blood (WBCs, hormones, waste, nutrients, thermoregulation, BP). Must have blood. * **Diffusion** * **Super small:** Susceptible to BP changes - Bad when sick * **Can obstruct blood flow.** ## Oxygen Unloading * **Hemoglobin** releases oxygen around tissues with low $O_2$ partial pressure. * **Increases release** as need increases. ## Cardiac Cycle * **Ventricles fill with blood.** * **Atria contract**(at end of ventricular diastole) completes ventricular filling. * **Ventricles contract:** Atrioventricular valves close - Pressure builds until aortic & pulmonary open. * **Blood pumped out of ventricles** into aorta & pulmonary arteries. * **Ventricles relax,** pressure in ventricles, pressure in aorta/pulmonary, so they close ## Series Circulatory plan ***2-chambered:** * **Gills** → **Heart** → **Systematic Tissues** * **Oxygenated** ***4-chambered** * **Lungs** → **Left side of heart** → **Systematic tissues** * **Right side of heart** → **Right side** * **Right side moves deoxy to lungs** - Left side - **Systemic tissues** → **Right side** * **Unoxygenated** ## Digestive System * **Ingesting small organisms** * **Suspension feeding:** Brought into organism, broken down and digested. * **Symbiosis:** Food obtained from microbial symbionts. * **Bulk feeder:** Whole animal/chunks. * **Deposit:** Pick up food waste (worms). ## Foods with building blocks * **Calcium:** Skeleton. * **Amino acids:** Proteins, energy. * **Fatty acids:** Membranes, energy. * **Nucleic acids:** Break chem bonds. ## Essential nutrients: * **Calcium.** * **Phosphorus:** ATP, nucleic acid formation, bone. * **Sodium:** H2O balance, nervous and muscular function. * **Potassium:** Nervous and muscular function. * **Shifts with exercise.** ## BMR * **Resting metabolic rate.** ## Macromoles: Carbohydrates ## Proteins * **OH, NH2, etc** ## Fatty Lipids * **OH, etc** ## Nucleic acids * **-O-P-O-** * **OH, etc** ## Metabolic Rate * **↑:** More food consumption + BMR. * **Higher aerobic respiration** = + BMR. * **Birds:** Large initial investment and speed = +Energy. * **Smaller animals:** Need more food / gram of body weight. * **BMR lowest** in big animals ## Division of Labor: * **Cells Specialized** for particular function * **Tissue:** Similar cells. * **Organ:** Or more tissues - Defined function. ## Simple Epithelium * **One celled thin sheet** * **Enables solute movement.** * **Lines digestive tract, absorbs nutrients & produces digestive enzymes.** ## Size of epithelial lining lumen * **Bigger:** More flow, digestion/absorption. ## Midgut * **Gets partially digested food, recieves enzymes & continues digestion.** ## Peristalsis * **Movement of tract to propel food thru.** ## Circulatory system delivers nutrients to **Systemic tissues** ## Herbivores * **Long intestine** for storage. ## Vertebrates * **Short intestine** ## Gizzard * **Less developed organism's, breaks up food.** ## Crop/Stomach * **Digest & store.** ## No Vertebrae has enzymes to digest **cellulose** * **Have microbes to** ## Glucose Homostasis * **Alpha cells:** Glucagon. * **Beta cells:** Insulin. * **Negative feedback.** * **Down gradient:** High to low. ## Neurons/Action Potential ### Nervous System * **Sensory input:** Receptors. * **Integration:** Thoughts, decisions, memories, sensations. * **Motor output:** Effector organs (activates via stimulation). ### Neuron Structure * **Cell body:** Organelles * **Dendrites:** Receptive * **Axon:** Variable size * **Axon terminals:** Surface area. * **Neurotransmitter synthesis** ### If dendrite gets strong enough excitement, generates action potential ### Axon terminals * **Store neurotransmitters** (in synaptic vesicles) * **Vary in #** * **Are excitable** - Allow release. ### Synaptic gap * **Neurotransmitters diffuse across to reach excitable** ### Resting membrane potential * **Ions unevenly placed** - Separated by gradients. * **More K on inside than Na, vice versa for outside** * **Requires energy to seperate (voltage)**. * **Voltage determines open/close of channels.** ### Ions flow down gradients, creates a current. * **Current:** Flow of ions, release of potential energy. ## Na+ into cell = **depolarized, EXCITED** ## RMP ### Negative potential? At rest. * **Na+ high outside** * **K+ higher inside** * **High to low (down gradient).** 1. **Na+/K+ pump** - from inside. * **3 Na+ enter** - energy comes, changes pump to open out. * **Releases Na outside** * **3 K+ enter** - Pi leaves & channel changes to open. outside (more K+ inside). 2. **Permeability** * **Leaky channels:** Allow ions to go where they want. * **K+ has most leak channels** - Always changing to * **K+ goes outside** (high to low conc.) * **Looses more K+, looses + charge = Negative potential** ### Member Gated Channels: * **Ligand:** Chemical messenger binds & opens gate. * **Voltage:** Current opens pump/gate → AP. ### Neurotransmitters = ligand. ### Na has activation gate: * **At rest this blocks channel.** * **Voltage unlocks.** * **Inactivation gate - slowly closes, blocks channel.** * **Then switches so active is closed & inactive is open, cycle repeats.** ### Charges vary by strength ## Graded Potentials * **Generated by ligand-gated** * **(neurochemical messenger binds to stimulus)** * **Gate opens it by other neuron.** * **Na+ goes down gradient (in), looses strength, gets weaker as it moves.** * **Fizzles out, meds enough to reach axon (multiple can happen at once) - creates AP.** ### Membrane Potential * **All or nothing** * **Changes = signals** **1. Grande activates action potential.** **2. Action potential** * **Long distance signaling** * **Constant strength** ## Action Potential ### Summation potential - all graded. * **If strong enough, changes in membrane potential don't weaken with distance.** 1. **Resting State** 2. **Depolarization:** Makes more positive. * **All VG Na+ channels open** 3. **Repolarization:** * **VG Na+ channels inactivated** * **VG K+ channels open** - flow out. 4. **Hyperpolarization:** * **K+ open longer than needed** * **Then Na+ & K+ rest.** ## AP Propogation * **Myleninated fibers** - prevent Na+ from leaking. * **Separates ionic attraction across membrane.** * **More glial = higher transduction - faster AP.** * **Increases conduction velocity** * **Ca reacts with synaptic vesicles** - releases & diffuses into target cell. ## Sensory Systems * **Receptor cells transform stimuli into electric signals** **1. Transduction:** Conversion of energy to one form or another. * **Receptor cells:** Stimulated by light (into chemical energy) - transduction **2. Transmission:** Energy relayed to integrative parts of NS (brain, ganglia). ### Sensory receptors * **More SA= more receptors/sensations.** * **In/directly generates graded** (receptor) potential. * **Different sensory proteins** * **Ionotrophic:** Receptor protein is ion channel. * **Metabotropic:** Receptor protein relays signal thru a protein to a channel (a protein activates 2ndary & then opens) ### Stimulus Detection * **Signals relayed to appropriate processing region** * **Neurons extend from receptor to processing.** ## Muscle Stretch * **Stretch receptors:** Mechanoreceptors * **Usually ionotropic** * **Muscle spindle:** Detect lengthening. * **Neurons transmit AP to NS** * **Frequency dependent on degree of stretch** * **Stimulates motor neurons to increase muscle contraction.** ## Olfaction * **Metabotrophic receptor** * **Odorants:** Chemical/molecules can cause olfactory response - **Chemoreceptors** ### Olfactory Epithelium: * **Nasal cavity** - Mucus coated. * **Mucus surrounds dendrites** traps receptors, affects other chemicals. * **AP** to olfactory bulb - olfactory nerve brain. ## Auditory * **Mechanoreceptors** * **Sound waves:** Electric signals. * **Hearing organ:** thin membrane - moves with sound. * **High frequency:** High pitch. * **Different pitches move different points of basilar membrane** to make different pitches. ### Organ of Corti * **Hair cells w/ sterocillia** move - **Neurotransmitters** released - AP. * **AP:** Cochlear nerve → brain. ## Vision * **Photoreceptors:** Sensitive to light - **Hyperpolarize neurons** * **Opsin** absorbs light (11-Cis-retinal) - Vitamin A * **Opsin absorbs light, changes shape.** → activates G-protein - **Graded potential** * **Signal processing:** Light absorbed → cornea → pupil → lense → retina absorbs → processed by integrating neurons (photoreceptors). * **Rods/cones** * **Rods:** Light * **Cones:** Color * **Humans = 3 cones** - goes to ganglion, AP axons send to brain. ## Humans can't use: * **Electromagnetic wavelength 400-700 nm** * **Electric fields** ## Nervous Systems * **Functions, neurons, organs, structures** * **Centralization:** nerves cluster together to form CNS. * **Cephalization:** Sensory organs congregate at anterior creates head region - evolution: many sensory organs anterior, coordinated responses. ## Neuron classes: * **Sensory/afferent** * **Interneurons:** recieves & relays to motor. * **Motor/efferant:** Sends to structures. ## Nerve net * **Dorsal axons:** Brain, spinal, nerves * **Simple NS:** Brain, ganglia ## Peripheral NS - Part of * **Afferant:** Recieves sensory - Skin, skeletal muscles, joints. - Visceral * **Efferant:** Motor - Activates muscles/gland * **Somatic system:** Motor nerve fibers * **Voluntary** * **Autonomic:** Smooth muscle, heart rate, endocrine glands * **Involuntary.** Reproductive organs. **1. Sympathetic:** Alertness, heart rate, BP. * **Exercise, stress, anger, fight or flight.** **2. Parasympathetic:** Reduced energy usage - **relaxes** * **Body maintenance, waste removal - Digestion.** **3. Enteric** * **Digestive tract** ## Neurons: * **Sensory, motor, interneurons** * **Polysynaptic:** Multiple synapses. * **1. Receptor** * **2. Sensory neuron** * **(Goes to interneuron)** * **3. Integration Center** * **4. Motor neuron ** * **Longer** * **5. Effector** * **Response.** ## Muscular System * **Sacromere:** Makes contractions. * **Structures:** Multinucleate. * **T-tubules** * **Sarcoplasmic reticulum:** Stores calcium. * **Myoglobin:** Transports O2, stores some for when needed. * **Glycosomes:** Stored energy, packets of glucose chains - can breakdown and use. ## Sarcomere * **S=time** * **Contains:** Actin (thin) 3 Myosin (thick) * **Titin:** Anchors myosin, elastic, connects to ends of thick. - Pulls inward (shortens) when contracted. ## Excitation: * **Muscle cell excited by AP** generated. * **Contraction:** Electrical excitation leads to contraction. * **Contractions:** Coordinated by neuron. * **Generated by Ach.** * **Motor neuron stimulates AP** → goes to axon terminal → **Mial vesicles** * **Vesicles released and diffuse across synaptic gap** * **Ach binds to channels for Na+ to flow in (not at rest).** * **Positive electric current, excites (electrical signal).** ## AP signal: * **Spreads across membrane.** * **T-tubule allows travel of AP deep into cell.** * **T-tubule protein excited by AP, releases Ca, opens channels for Ca to go into cytoplasm.** ## Reflex Arc * **Neurons:** Sensory, motor, interneurons. * **Polysynaptic:** Multiple synapses. * **1. Receptor.** * **2. Sensory neuron** * **(Goes to interneuron)** * **3. Integration Center** * **4. Motor neuron** * **Longer.** * **5. Effector** * **Response** ## Muscular System * **Sacromere:** Makes contractions. * **Structures:** Multinucleate. * **T-tubules.** * **Sarcoplasmic reticulum:** Stores calcium. * **Myoglobin:** Transports O2, stores some for when needed. * **Glycosomes:** Stored energy, packets of glucose chains - can break down and use. ## Sarcomere * **S=time** * **Contains:** Actin (thin) 3 Myosin (thick). * **Titin:** Anchors myosin, elastic, connects to ends of thick. - Pulls inward (shortens) when contracted. ## Excitation: * **Muscle cell excited by AP** generated. * **Contraction:** Electrical excitation leads to contraction. * **Contractions:** Coordinated by neuron. * **Generated by Ach.** * **Motor neuron stimulates AP** → goes to axon terminal → **Mial vesicles** * **Vesicles released and diffuse across synaptic gap** * **Ach binds to channels for Na+ to flow in (not at rest).** * **Positive electric current, excites (electrical signal).** ## AP signal: * **Spreads across membrane.** * **T-tubule allows travel of AP deep into cell.** * **T-tubule protein excited by AP, releases Ca, opens channels for Ca to go into cytoplasm.** ## *(Check book marks)* ## Muscle Contraction * **Thick filaments attach & pull thin (myosin) to center.** ### Sliding Filament 1. **Ca2+ released by sarcoplasmic membrane.** 2. **Ca2+ binds to troponin** - changes shape. 3. **Troponin untwists tropomyosin** - uncovers myosin binding sites. 4. **Allows myosin cross bridge cycle**. ### Muscle Contraction * **Cross bridge:** Underlies sliding. * **Makes bond possible** 1. **ATP binds to myosin (myosin = low energy now).** 2. **ATP hydrolysis** → ADP+Pi - now activated conformation. (Can bind to filament.) 3. **Myosin binds to active site** (cross bridge). 4. **ADP+Pi removed.** 5. **Myosin changes** - creates power stroke - **Puts sarcomere to middle, removes Pi, shoots forward (schooches along towards M-line)**. ### Lo restarts cycle to end: 1. **Neuron stops communicating with muscle cell.** 2. **Ca2+ transported into SR.** 3. **Troponin retwists tropomyosin** (hides bonding heads). 4. **Creates resting conformation.** ## Exoskeleton * **Pulls on interior surface.** * **Apodeme:** Projects into body, muscles attach here. * **Catch muscle:** Structure closer to main body. ## Hydrostatic skeleton * **Uses fluid from body cavity to move** * **2 layers of muscle** - contract at different times to slide. ## Contraction ATP * **Need for:** Cross bridge movement. * **K+ and Na+ pump regulates charge.** ## Production: * **Immediate.** - Creatine phosphate stored, when bond broken = ATP * **Glycolytic:** Glycosis - CC 30 * **Oxidative:** Not sustained. ## Skeletal Fiber types: * **Slow oxidative:** Marathon - resist high endurance - thin. * **Fast oxidative:** Relan - moderate exercise - thick. ## Fast glycolytic: * **Powerlifting, sprinting. Intense / Powerful movements.** - Few capillaries. ## Endurance: * **Fast glycolytic/oxidative** ## Skeletal System * **Endoskeleton:** Bone, cartilage, bone cartilage bank - regulates calcium. * **Exoskeleton:** * **Molting:** Allow growth for exoskeleton. * **Vulnerable during molting.** ## Bone cells * **Osteoblasts:** Deposit new bone. * **Osteocytes:** Osteoblasts surrounded by bone. * **Osteoclasts:** Dissolve bone. * **Ca to ECF** ## Bone: * **Membranous:** Forms on CT membrane. * **Cartilage:** First cartilage - thin. * **Ossifies to bones.** * **Compact.** ## Bone growth: * **At growth plate, interstitial (inside) - grows** * **Cancellous:** Holes. * **Haversian canal:** For blood vessels * **Spongey:** No haversian. ## Innate immunity * **Genetically programmed** * **Nonspecific** - First line of defense. * **Physical barriers, toxic molecules.** * **Relatively quick response with inflammation** * **Protection** against Pathogens **1. Recognition phase:** Recognize pathogen. **2. Activation phase:** Mobilization of cells/molecules to help. **3. Effector phase:** Invader is destroyed. ## Innate defenses: * **Physical/chemical barriers** * **Amoebocytes:** Cells for pathogen destroying. ## Toll-Like Receptors: * **Mostly active during recognition/activation** * **Participate in innate defense** (type of PRR). * **Vertebrates:** TLR binds to FER bacteria (recognition). * **Protein kinase cascade:** One activates another until defensive protein TF. * **Transcription factor changes.** * **TF enters nucleus & binds to promoters.** * **Genes encoding defensive proteins are creaated.** ## Cell Types WBC: * **WBC/lucocytes:** Large cells, ingest pathogens (phagocytosis) - adaptive/innate immunity → T & B cells * **PAMP (Pathogen Associated Molecular Pattern):** Recognition. ## WBC = 2nd line of defense * **Basophiles:** Release histamine & inflammation. * **Eosinophiles:** Kill antibody-coated parasites. ## When WBC are activated (pathogen gets close to blood) ### Mammalian Defense - Lymphatic system * **Lymphoid tissues** * **Blood plasma** * **Lymph:** Fluid derived. ## Fluid pushed out of capillaries bc ↑ pressure. * **When leaving, usually blood takes back up** ## Lymph nodes: * **Have dead ends, circulate up to heart & then transports.** * **Contain WBC to detect pathogens & respond.** ## First Line of Defense * **External surfaces:** PA, skin, mucus membranes (secrete mucus), * **Defensins:** protein/peptide insert into pathogen cells - kills cell by disrupting gradient. * **Toxic to bacteria** * **Doesn't kill our own.** ## Bad Line - activate WBCs * **TLR (toll-like receptor) is PRR (pattern recognition receptor).** * **TLR binds to PAMP (pathogen associated molecular patterns) - recognize PAMPs.** * **PAMP creates downstream, signal transduction pathway.** * **PAMP allows defense** ## Inflammation * **To isolate area & recruit WBCs - P responders** * **Helper responders:** Tumor necrosis factor, prostaglandins, histamine. * **Prostaglandins:** Help initiation of inflammatory response. * **Histamine:** Increase blood vessel permeability. * More WBCs & molecules. * **Damaged tissue recruits histamine (for diffusion)** * **Vessels become leaky & dilated.** * **Blood plasma & phagocytes mac to infected tissue via vessels.** * **Phagocytes engulf bacteria.** * **Heal with WBCs.** * **Histamine & signaling stop - no more calling phagocytes** ## Humoral Immunity ### Innate * **Complement system** * **Extracellular** * **Antibodies:** Specific to pathogen - **B cells circulate**. ### Natural Active * **Produce antibody, natural exposure (prodvas antibodies)** ### Artificial Active * **Production of antibody via vaccine. (Antibodies)** ### Natural Passive * **Temporary immunity, Antibodies from other person - receives antibodies.** ### Artificial Passive * **Temporary, injection of immune serum.** ### Adaptive: * **Specificity** * **Diversity (lymphoctyes)** * **Memory** * **Distinguish between self & nonself.** * **DNA changes** ### B cells * **Produce antibodies (free-floating antigen binding).** * **#-cell activated by TH** * **Antigenic determinants:** Pattern on antigen immune system recognizes. * **Binds to antigen binding site** (one open for B cell, another for antigen - antigen). * **B-cell receptor** ### Memory 1. **Primary immune response:** Antibody T-cell production. 2. **Secondary immune response:** Rapid response - Infection with previously encountered pathogen. ### Memory 1. **Recognition:** B-cell makes antibody to bind to antigen. 2. **Activation:** T-cell stimulates B-cell to divide a bunch 3. **Primary response:** Some time cells become plasma cells (effector). * **Secrete same antibody as parent cell.** * **Potentially cells develop into non-secreting memory cells.** * **Divide at slow rate, keeps a clone** ### Recombination * **Takes any combination of segments from a gene** * **Shown on mRNA & allows for recombination** * **To get antibodies** * **Takes immunoglobulin genes** ## Antibodies * **Can:** Activate complement system. * **Antibodies become activated** when binding antigens to pathogen surfaces. * **Activates complement proteins** * **Creates protein structure to attack & lyse a cell** * **All coded in antibodies** * **Activation of effector cells** * **Attracts NK, phagocytes.** * **Helps neutralize antigen.** ## 1. Humoral, * **Enhances phagocytes** to clear microbes/damaged cells. * **Function:** Inflammation. * **Cell membrane attack.** * **Phagocytosis.** ## Pathway * **C3b (protein binds to pathogen)** * **Phagocyte recognition** * **Attracts phagocytes** * **C3b (a diff C-protein activates inflammation)**. * **Phagocytes attracted** * **C3b (protein inserts in pathogen menibrane)** * **Creates holes & dies** ## Adaptive - **Myosin = THICK** ## Cell Mediated immunity * **Requires cell contact** (for diffusion) * **T-cell** (T-lymphocytes / T cells) * **T-cells have surface receptors** (like B-cells) ## T-cell receptors: * **Not immunoglobulins but Glycoproteins** * **Similar to B:** Alpha chain. * **Beta chain:** Extends throughout membrane * **Constant region & variable region.** * **Only binds to antigens** when bound to MHC protein. ## MHC proteins: * **TH:** T-helper cells → Activates adaptive immune response * **TC:** T-cytotoxic cells → Death of all displaying antigen. ### Which T-cell? * **MHC Class 1:** Present on surface of all nucleated cells (non-specific). * **Display antigens/viral proteins stuck to MHC then T-cell lyses cells.** * **If replicated based on APC release/perforin** * **Antigen can be produced inside too.** * **MHC Class 2:** On B-cell surface, macrophages, dendritic. * **Present antigens to TH cells.** **1. APC takes up antigen** via phagocytosis. **2. Cell breaks antigen** into fragments. **3. Class II MHC protein binds to antigen fragment.** **4. MHC presents antigen** to TH. **More TH created and all release cytokins.** * **Communication with other cells. Stimulates to** - macrophages, B-cells, NK. ## Regulatory T-cells (Tregs) * **Have special receptor** * **Helps determine self/nonself** * **Mediates tolerance to self antigens** * **Recognize nonself antigens** * **Binds to self-antigens to tell TH or TC to not kill self.** * **Kill TC/TY instead of APC.** ## AIDS * **Kills TC/infects TH.** * **Activates TH, infects TH & dying.** * **TC kills TH** (cause TH infected). * **TH infected exponentially** * **Virus attacked, HIV+, low level remains** * **TC is going down** * **Dormant stage:** Low TC levels, no tell to help, low virus levels - virus grows again. ## Endocrine ## Why NS & endo? * **NS:** Fast, can end abruptly. * **Targets body region, uses neurons to signal** * **Endo:** Slow, broadcast, slower to end. * **Targets specific kinds of cells.** * **More efficient, uses hormones to signal.** ## NS & endo work together to maintain: * **Homeostasis** * **Coordination** * **Response to signals.** ## Extra ## Ficks Law: * **Rate of diffusion/SA is proportional to SA.** * **Doesn't apply between gas mixture & aqueous.** ## Endocrine system * **Autocrine signaling:** Acts on signaling cell. * **Paracrine signaling:** Acts on nearby cells. * **Endocrine signaling:** Uses circulatory system to transport ligands. * **Pheromone:** Chemicals that trigger behavioral response. ## Endocrine Glands * **Secretes into blood stream** * **No ducts** * **Intracellular effects** (changes internal physiology). * **High capillary density** * **Fenestrated** (has holes for hormones to diffuse) * **Cell-to-cell communication** ## Exocrine glands * **Ducts** * **Secretes onto epithelial surfaces** (straight onto glands. * **Extracellular effects** (digestion). * **Goes to all kinds of glands** ## Endocrine cells * **Neurosecretory:** Behave like neurons, release hormone (not NT). * **Neurohemal organ:** Neurons next to. * **Creates AP** from axon terminal. * **AP allows secretion** into capillaries & then target cells. * **Non-neural endocrine cells:** Epithelial endocrine cells. * **All secretes directly into capillary** ## Hormone Classes * **4-rings Steroids:** Made from cholesterol. * **Lor Zadron, monoamines:** Made from 1 or 2 AA (dopamine, adrenaline, TH). * **Linearish Peptides:** 3-200+ AA - Hypothalamus inhibitors. ### Transport: * **Monoamines/Peptides:** Diffuse directly across/travels through blood. * **Steroids/TH:** Uses transport proteins to circulate through blood. * **Creates stability & increases half-life.** ## Steroids * **Hydrophobic** * **Can diffuse through membrane** * **Gene activation** * **Most go straight to nucleous** * **To find hormone receptor.** 1. **Find receptors** 2. **Stimulate mRNA** 3. **Transcribe new protein** 4. **Protein releases effects.** ## Peptides * **Hydrophobic** * **Cannot diffuse through membrane.** * **Receptor on cell surface** * **Travels freely** * **Much faster** * **Uses air made proteins** 1. **Hormone receptor activates G-protein.** 2. **Activates adenylate cyclase** 3. **Adenylate cyclase makes cAMP** (from ATP). 4. **cAMP activates protein kinase** 5. **Protein kinase phosphorylates enzymes** & activates or deactivates. 6. **Activated enzymes catalyze metabolic reactions** - wide range of effects. ## Target Cells * **Function can change over time** * **Function can be different in individuals** * **Certain receptors determine for different hormones on target cells.** * **Diff cells have diff receptors** (leading to varied cellular responses when bound.) ## Hormone release * **Peptides/AA:** Fast, stored in vesicles. * **Steroids:** Slow, must synthesize. * **Transport protein** ## Hormone removal * **Target cells can degrade** * **Half-life** * **Liver/kidney can degrade.** * **Can be excreted** ## Portal System * **Veins start & end in capillaries.** - Blood bed to another. ## No major endocrine control ## Hypothalamus * **Involuntary - neurosecretory** * **Sex drive, stress response, hunger, thirst** ## Pituitary * **Connected to hypothalamus** * **Infundibulum** * **Connects hypo & pituitary** ## Anterior Pituitary * **Circulatory connection to hypothalamus** * **Lo neuro communication between neurons & neurosecretory.** * **Capillaries in infundibulum, down to anterior, reviving.** * **Neurosecretory from hypo secretes in 1st capillary bed.** * **Flow: Moves to 2nd capillary bed.** ## Hypophyseal portal system * **Anterior has endocrine cells** * **If receptor present, then secretes into blood to find target cells.** ## Control: Hypothalamus signaling * **Release hormones** - travel from hypo to tell Pit to release. * **Inhibiting hormone** - silence target cells in pituitary (doesn't release). * **Stimulation in waves** - **Tey** ## Tropins: Control other glands endocrine signals. * **Hormones:** ACTH, TSH, FSH, LH * **Act on non-endocrine:** GH (growth hormone), PRL (prolactin). ## Posterior Pituitary * **Made of nervous tissue, NOT a true gland.** * **Neuroendocrine cells** - neurosecretory cells in hypo have axons extending to posterior. * **Axon is transporter (not blood).** * **Hormones stored in nerve endings** * **When stimulated, releases.** ## Hormones: * **ADH, Oxytocin** ## Negative feedback * **Hypothalamus → GRH → Anterior Pituitary → CH/FSH → Thyroid → T4 → ActH → Cortisol.** ## Gland * **Pineal gland:** Melatonin, sleep cycle. * **Hypothalamus** * **Thyroid** * **Parathyroid:** 9 parathyroid. * **Thymus:** T cell * **Adrenal cortex** * **Pancreas** ## **TH helps w/ bone regulation.** ## Thyroid gland * **Endocrine gland - vascular tissue for transportations.** * **Brain regulates BMR.** * **TRH released by hypothalamus → anterior TSH → thyroid TH** * **Reduces BMR** * **More TH= more slowed-down BMR** ## Follicles: * **Follicular cells:** Filled w/ colloid. * **Secretes TH** * **Regulates BMR** * **Single larger of cells** * **Receives TSH, stimulates release of TH:** 1. **Stimulate follicular.** 2. **Take in colloid.** 3. **Chops colloid into 2 AA** * **If 3 iodines attached, T3** ## Colloid: Storage * **Contains T4 & iodine** ## Parafollicular endocrine cells * **Secretes calcitonin** - (increases bone formation) ## Disorders: Hypothyroidism * **Goiter: Super inflamed lymphade** * **Usually by? No iodine** * **More TSH** = more TG * **No TH** * **No iodine** → no TH → more TSH → Overstimulation of follicular. * **Colloid increases** ## Insect Development * **Development in steps:** * Growth by molting, shape changes. * **Development hormones:** 1. **PPTH (prothoracicotropic hormone):** Stored in neurosecretory cells. * **Targets prothoracic glands.** * **Allows ecdysone release.** 2. **Ecdysone:** Protein that allows exoskeleton molting. * Loosens connection/adhesion. 3. **Juvenile hormone (JH):** * Non-neural cells - steroids. * Released at each molting. * Decreases with molting. * Most mature stage after no JH - pupa (resting state). 4. **PPTH stays constant.** 5. **JH decrease** - becomes adult. # Interneurons: Bridge between sensory & motor. ## Sacromere: * **Actin:** Thin filament * **Myosin:** Thick * **Z-line:** Seperation between sacromeres (constant). * **A-band:** Thick filaments (stays constant) * **H-zone:** Only thick * **I-band:** Thin filaments only. * **M-line:** Center of sacromere. ## Where neuron meets muscle fibers * **Fluid w/ Ach** - that breaks down Ach (stops continuous stimuluation). * **Into synaptic cleft** (initiates implulse). * **Tor end plate** - Ach finds receptors. * **Sarcolemma** - goes down T-tubules. * **Reticulum** to release calcium. * **Calous myosin head binding, activates.** ## (cluster outside of CNS) ## Muscle/gland ## Produces interferons ## (Neuron recognition & response)