Exam 2 Circulatory & Digestive Systems PDF

# Exam 2 ## Circulatory System - **No circulatory:** aquatic invertebrates - **Closed:** vertebrates - Cephalopod 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 - Cephalopod 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 - Blood away from heart ## Veins - **Difference:** - **Artery:** thicker endothelium, has elastic fibers (bc ABP), smoother - **Small vein:** valve (unidirectional flow) - Cells connected are thin for gas exchange ## Open - No blood vessels - Pumps into hemocoel (unoxygenated) - Sends blood to tissues, open space, 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 carry blood - **Diffusion** - **Super small - susceptible to BP changes - bad when sick** - **Can obstruct blood flow** ## Oxygen Unloading - Hemoglobin releases oxygen around tissues w/ low O₂ partial pressure - Increases release as need increases ## Cardiac Cycle - Ventricles fill w/ blood - Atria contract (at end of ventricular diastole) - completes ventricular filling - Ventricles contract, atrioventricular 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 systematic tissues → right side - Unoxygenated ## Digestive System - Ingesting small organisms - **Suspension feeding:** brought into organism - broken down & digested - **Symbiosis:** food obtained from microbial symbionts - **Bulk feeder:** whole animal/chunks - **Deposit:** pick up food waste (worms) ## Foods w/ 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 & muscular function - **Potassium:** nervous & muscular function - Shifts w/ exercise ## BMR - Resting metabolic rate ## Macromolecules: Carbohydrates ## Proteins ## Fatty Lipids ## Nucleic ## Metabolic Rate - ↑ = more food consumption - Higher aerobic respiration = + BMR - **Birds:** large initial investment, & 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 func. ## Simple Epithelium - One-celled thin sheet - Enables solute movement - Lines digestive tract, absorbs nutrients to produces digestive enzymes ## Size of Epithelial Lining Lumen - Bigger = more flow, digestion/absorption ## Midgut - Gets partially digested food, receives enzymes continues digestion ## Peristalsis - Movement of tract to propel food thru ## Circulatory System Delivers - Nutrients to systematic tissues ## Herbivores - Long intestine for storage ## Vertebrates - Short intestine ## Gizzard - Less developed organisms, breaks up food ## Crop/Stomach - Digest & store - No vertebrae has enzymes to digest cellulose - Have microbes to ## Glucose Homeostasis - Alpha cells - glucagon - Beta cells - insulin - Negative feedback ## Neurons/Action Potential - **Nervous system** - **NS functions:** - **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 - 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 excite ## Resting Membrane Potential - Ions - unevenly placed - separated by gradients - More K on inside than Na, vice versa for outside - Requires energy to separate (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 - K+ higher inside, high low (down gradient) - Nat high outside - **RMP:** negative potential? - 1. Na+ K+ pump - 3 Na+ enter - from inside - Releases Na outside - Energy comes, changes pump to open out - 2 K+ enter, Pi leaves & channel changes to open - Inside, K+ released inside (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 low conc.) - Looses more K+, looses + charge = negative potential ## Member Gated Channels - **Ligand:** chemical messenger binds & opens gate - **Voltage:** current opens pumps/gate → AP ## Neurotransmitters = Lagand - **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 (stimulus) - 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, needs enough to reach axon - (Multiple can happen at once) → creates AP ## Membrane Potential - All or Nothing - Changes → signals - **1. Grade:** activates action potential - **2. Action potential:** - Long distance signaling - Constant strength ## Action Potential - **Summation potential:** all graded - Lo if strong enough: changes in membrane potential - Doesn't weaken w/ 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 Propagation - **Myelinated fibers:** prevent Na+ from leaking - Separates ionic attraction across membrane - More gial = higher transduction - faster AP. - Increases conduction velocity - **Ca reacts w/ synaptic vesicles:** releases & diffuses into target cell ## Sensory Systems - Receptor cells transform stimuli into electric signals - **Transduction:** - Conversion of energy to one form or another - **Receptor cells:** - **1. Graded potential (receptor potential):** - 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: - **1. Ionotropic:** receptor protein is ion channel - **2. Metabotropic:** receptor protein relays - Signal thru a protein to a channel - (A protein activates 2ndary & than open's) ## Stimulus Detection - Signals relayed to appropriate processing region - Neurons extend from receptor to processing ## Muscle Stretch - **Stretch receptors:** mechanoreceptors - Usually ionotropic - **Muscle spindles:** detect lengthening - Neurons transmit AP to NS. - Frequency dependent on degree of stretch. - Stimulates motor neurons to increase muscle contraction ## Olfaction - Metabotrophic receptor - **Odorants:** chemicals that 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 - makes w/ sound - High frequency = high pitch - Different pitches move diff points of basilar membrane to make - **Organ of Corti:** - Hair cells w/ sterocillia - move = neurotransmitters released - APA - 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 → lens → retina absorbs → processed by integrating neurons → goes to ganglion, AP axons send to brain - **Photoreceptors:** - **Rods:** light - **Cones:** color ## 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:** receives & relays to motor - **Motor/efferent:** sends to structure - **Nerve net:** - Dorsal axons → brain, spinal, nerves - Simple NS → brain, ganglia - **Peripheral NS:** - **Afferent:** receives sensory - **Somatic:** Skin, skeletal muscles, joints - **Visceral** - **Efferent:** motor - activates muscles/glands - **Somatic system:** - Motor nerve fibers - Voluntary - **Autonomic:** - Smooth muscle, heart rate - Endocrine glands - Involuntary - Reproductive organs - **ANS (autonomic):** dilation of vessels - **Sympathic:** alertness, heart rate, BP - Exercise, stress, anger, fight or flight - **Parasympathic:** reduced energy usage RELAXES - Body maintenance, waste removal - Digestion - **Enteric:** digestive tract ## Neurons: - Sensory, motor, interneurons - **Polysynaptic:** multiple synapses - 1. Receptor - 2. Sensory neuron - 3. Integration center - 4. Motor neuron - 5. Effector response (goes to inter neuron) - **Monosynaptic:** - 1 synapse between - Motor & sensory - No interneuron ## 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 & use ## Sarcomere - **Sz time** - Contains: **Actin (thin)** & **Myosin (thick)** - **Titin:** anchors myosin, elastic, connects to ends of thick - Pulls inward (shortens) when contacted. - **Excitation:** muscle cell excited AP generated - **Contraction:** electrical excitation leads to contraction - Coordinated by neuron ## Contractions - **1. Motor neuron stimulates AP** goes to axon terminal to **make vesicles** - **Vesicles released** & **diffuse** across synaptic gap - **Ach binds to channels** for Na+ to flow in (not at rest) - Ach **positives electric current** → **excites** (electrical signal) - **AP signal spreads:** 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 - Neurones: sensory, motor, interneurons - **Polysynaptic:** multiple synapses - 1. Receptor - 2. Sensory neuron - 3. Integration center (goes to inter neuron) - 4. Motor neuron (longer) - 5. Effector response - **Monosynaptic:** - 1 synapse between - Motor & sensory - No interneuron ## 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 & use - **Sz time** - Contains: **Actin (thin)** & **Myosin (thick)** - **Titin:** anchors myosin, elastic, connects to ends of thick - Pulls inward (shortens) when contacted. - **Excitation:** muscle cell excited AP generated - **Contraction:** electrical excitation leads to contraction - Coordinated by neuron ## Contractions - **1. Motor neuron stimulates AP** goes to axon terminal to **make vesicles** - **Vesicles released** & **diffuse** across synaptic gap - **Ach binds to channels** for Na+ to flow in (not at rest) - Ach **positives electric current** → **excites** (electrical signal) - **AP signal spreads:** 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 - **Sliding filament:** - **Thick filaments** attach & pull **thin** (myosin) - To center - **1. Ca2+ released** by sarcoplasmic membrane - **2. Ca2+ binds to troponin** - changes shape - **Troponin untwists tropomyosin** - uncovers myosin binding sites - Allows 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 - **Myosin now activated conformation** (can bind to filament) - **3. Myosin binds to active site (cross bridge)** - **4. ADP+Pi removed, myosin changes** - Creates power stroke → **puts sacromere to middle, removes Pi** - **Shoots forward (squooshes along)** toward M-line - **Lo restarts cycle to end:** - **1. Neuron stops communicating w/ muscle cell** - **2. Ca2+ transported into SR** - **3. Troponin retwist 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 diff times to slide ## Contraction ATP - **Need for:** - Cross bridge movement - K+ & 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:** relay, moderate exercise, thick ## Fast Glycolytic - Powerlifting, sprinting, intense/powerful movements, few capillaries ## Endurance - Fast glycolytic/oxidative ## Skeletal System - **Endoskeleton:** bone, cartilage, bone cartilage bank - regulate calcium - **Exoskeleton:** - **Molting:** allows 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** - **Cancellous** - **Holes** - **Haversian canal** - for blood vessels - **Spongey** - no haversian ## Innate Immunity - **Innate:** - Genetically programmed - Nonspecific - *First line of defense* - Physical barriers, toxic molecules - Relatively quick response - **Inflammation** - Protection againts pathogens - **1. Recognition phase:** recognize pathogen - **2. Activation phase:** mobilization of cells/molecules to help - **3. Effector phase:** invader is destroyed - **Physical/chemical barriers:** - Thick epithelial - Sweat - can deter bacterial pathogens - **Amoebocytes:** cells for pathogen destroying - **Adaptive:** - Targets specific pathogens - Antibodies made - Slow, long lived - Evolved in vertebrates - Creates memory ## Innate Defenses - **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 created. - **Cell types WBC:** - **WBC/leukocytes:** - Large cells, ingest pathogens - Phagocytosis - adaptive/innate immunity → TB cells ## WBC = 2nd Line of Defense - **Basophiles** - release histamine & inflammation - **Eosinophiles** - kill antibody coded 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 of pressure - When leaving usually blood takes back up - Lymph nodes - have dead ends, circulate up to heart & then transports - Have dead ends, WBCs to detect pathogens & respond. ## First Line of Defense - External surfaces: PA, skin - Mucus membranes (secrete mucus) - **Defensins:** protein/peptide insert into pathogen cell - kills cell by disrupting gradient - Toxic to bacteria - Doesn't kill our own ## Bad Line - Activate WBCs. - **TLR is PRR.** - **TLR binds to PAMP:** recognizes PAMPS - Creates downstream signal transduction pathway - PAMP allows defense ## Inflammation - To isolate area & recruit WBCs P responders - **Helper responders:** - **Tumor necrosis factor** - **Prostaglandins:** help initiation of inflammatory response - **Histamine:** increases blood vessel permeability - More WBCs & molecules - **1. Damaged tissue recruits histamine (for diffusion) - Vessels** become leaky & dilated - **Blood plasma & phagocytes** move to infected tissues via vessels - **Phagocytes engulf bacteria** - **Histamine & signaling stop** - no more calling phagocytes - **Heal w/ WBCs** ## Humoral Immunity - **INNATE(complement)** - **EXTRA-cellular** - Antibodies specific to pathogen - B-cell circulate - **Natural active:** produce antibody, natural exposure - **Artificial active:** production of antibody via VACCINE - **Natural passive:** temporary immunity, antibodies from other person - **Artificial passive:** temporary, injection of immune serum - **Adaptive:** - **Specificity:** - **Diversity (lymphocytes):** memory - **Distinguish between self & itself** ## Specificity - **B cells:** produce antibodies (free-floating antigen binding) - **T cells:** B lymphocytes - WBCs, produce antibodies - **Antigenic determinants:** pattern on antigen immune system recognizes - **B-cell activated** by TH - **Binds to antigen binding site** (one open for B cell, another for antigen) - **B-cell receptor** ## Memory - **1. Primary immune response:** antibody & T-cell production - **2. Secondary immune response:** rapid response - Infection w/ 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 sine 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 - **Con:** - **1. Activate Compliment 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. - **2. Activation of effector cells** - Attracts NK, phagocytes - Helps neutralize antigen ## 1. Humoral, Innate - Enhances phagocytes to clear microbes/damaged cells - **Func: inflammation:** - Cell membrane attack - Phagocytosis ## Pathway - **1. C-protein binds to pathogen (C3b)** - Phagocyte recognition - **2. A diff C-protein activates inflammation (C3b)** - Phagocytes attracted - **3. C-protein inserts in pathogen menibrane** - Creates holes & dies ## Adaptive - **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 (nonspecific) - Display antigens/viral proteins stuck to MHC then T-cell - If replicated, as binding to APC release/perforin - Lyses cells - **MHC Class 2:** on B-cell surface, macrophages, dendritic cells - Present antigens to TH cells - **1. APC takes up antigen** via phagocytosis - **2. Cell breaks antigen** into fragments. - **3. Class 11 MHC protein** binds to antigen fragment - **4. MHC presents antigen** to TH - **More TH created** and all **release cyotkins:** - Communication w/ other cells - Stimulates: - NK - Macrophages - B-cells - **Myosin = thick** ## Regulatory T-cells - **Tregs** - Have special receptor - Helps determine self/nonself - Mediates tolerance to self antigens - Binds to self-antigens to tell TH or TC to not kill self - All, kill TC/TY instead on APC - **Recognize nonself antigens** - **HIV is symptoms of AIDs** ## 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 TH is going down - Dormant stage - low TH 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 - Rate of diffusion 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:** use circulatory system to transport ligands - **Pheromone:** chemicals that trigger behavioral response ## Endocrine Glands - Secretes into blood stream - No ducts - Intracellular affects (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 Steriods:** made from cholesterol - **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 - **Steriods/TH:** uses transport proteins to circulate through blood - Creates stability & increases half-life ## Steriods - Hydrophobic - Can diffuse through membrane - Gene activation - Most go straight to nucleus - To find hormone receptor - **1. Find receptor** - **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 make 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 - **Steriods:** slow, most 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 - One bed to another ## No Major Endocrine Control - **Hypothalamus:** - Involuntary - neurosecretory - Hunger, thirst, sex drive, stress response - **Pituitary:** - Connected to hypothalamus - Infundibulum - Connects hypo & pituitary ## Anterior Pituitary - **Circulatory Connection** to hypothalamus - Neurosecretory neurons. - Capillaries only in infundibulum, communication between neurons & neurosecretory. - Flow: neurosecretory from hypo secretes in 1st capillary bed, 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 - **Tropins:** control other glands endocrine glands - **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:** - GnRH - CRH/FSH - Thyroid → - **Ant:** - GH - ACTH - Cortisol ## Gland - **Pineal gland:** melatonin, sleep cycle - **Hypothalamus** - **Thyroid** - **Parathyroid:** 4 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 - Before release: - 1. Stimulate follicular - 2. Take in colloid - 3. Chop 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 lymph node - Usually by: - No iodine - No TH - More TSH = more TG - No iodine → no TH → more TSH → overstimulation of follicular - More storage space - Colloid increases # Insect Development - Development in steps - Growth by molting, shape change ## Development Hormones: - **1. PPTIH:** prothoracicotropic hormone - Stored in neurosecretory cells - Target prothoracic glands - Allows ecdysone release - **2. Ecdysone:** - Protein that allows exoskeleton molting - Loosen connection/adhesion - **3. Juvenile hormone (JH):** - Non-neural cells (steroids) - Released at each molting - Decreases w/ molting, most mature stage after no JH - Allows pupa (resting state) - Becomes adult ## PPTH Stays Constant ## JH Decrease ## Interneurons - Bridge between sensing & motor ## Sacromere - **Actin:** thin filament - **Myosin:** thick - **Z-line:** separation between sacromeres (constant) - **A-band:** thick filaments (stays constant) - **H-zone:** only thick - **I-band:** thin filaments only - **M-line:** center of sacromere # Where Murin Meets Muscle Fibers - Fluid w/ Ach - That breaks down Ach (stops continuous stimulation - Into synaptic cleft (initiates impulse) - To end plate - Ach finds receptors - Sarcolemma, goes down T-tubules - Sarcoplasmic reticulum to release calcium - Calcium, myosin head binding, activates - Mylion (cluster outside of CNS) - Muscle/gland ## Produces Interferons - **Interferon recognition & response**