this unit covers chapters: 7,11,43,44,45

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This unit covers chapters: 7,11,43,44,45. Evolution. Pathway similarities suggest that ancestral signaling molecules evolved in prokaryotes and were modified later in eukaryotes The concentration of signaling molecules allows bacteria to sense local population density. - PowerPoint PPT Presentation


  • This unit covers chapters: 7,11,43,44,45

  • Evolution Pathway similarities suggest that ancestral signaling molecules evolved in prokaryotes and were modified later in eukaryotesThe concentration of signaling molecules allows bacteria to sense local population density

  • Cell Membrane structures that aid in communication Ch. 7Animal and plant cells have cell junctions that directly connect the cytoplasm of adjacent cellsTight JunctionsDesmosomesGap Junctions

  • Tight Junctions-prevent leakage of extra cellular fluid by making a tight seal around adjacent cells. Ex: skin cellsDesmosomes-acts like a rivet, attaching cells together. Ex: muscle cells, if a muscle tears then a desmosome has ruptured.Gap Junctions- in animals and Plasmodesmata in plants allows ions, amino acids, and sugars to transport between cells

  • Membrane Protein functionsTransportSignal TransductionCell to Cell recognitionIntercellular joiningAttachment to cytoskeleton

  • Feedback Positive Feedback Negative Feedback

    Which is an example is each:Temperature regulation _______________Lactation in mammals _________________Blood Clotting ______________________Secretion of Insulin __________________

  • SOOOOHow would you describe Positive Feedback?

    How would you describe Negative Feedback?

  • Chapter 11Cell Communication

  • Signal-Transduction PathwaySignal on a cells surface is converted into a specific cellular responseLocal signaling (short distance) - Paracrine (growth factors); Synaptic (neurotransmitters)Long distance - hormones

  • Stages of Cell Signaling3 steps:Reception: target cell detectionTransduction: single-step or series of changesResponse: triggering of a specific cellular response

  • Immunity and Cell CommunicationCh 43

  • Types of immune responsesHumoral immunityB cell activationProduction of antibodiesDefend against bacteria, toxins, and viruses free in the lymph and blood plasma

  • Cell-mediated immunityT cell activationBinds to and/or lyses cellsDefend against cells infected with bacteria, viruses, fungi, protozoa, and parasites; nonself interaction

  • Immunity in Health & DiseaseActive immunity/natural: conferred immunity by recovering from diseaseActive immunity/artificial: immunization and vaccination; produces a primary response

    Passive immunity: transfer of immunity from one individual to another natural: mother to fetus; breast milk artificial: rabies antibodies

  • The Inflammatory Response1- Tissue injury; release of chemical signals~ histamine (basophils/mast cells): causes Step 2... prostaglandins: increases blood flow & vessel permeability

    2/3- Dilation and increased permeability of capillary4- Phagocytosis of pathogens~ fever- leukocyte-released molecules increase body temperature

  • Nervous System and cell communicationCh 48

  • Parts of Neuron-Nervous System CellNeuron~ structural and functional unitCell body~ nucelus and organellesDendrites~ impulses from tips to neuronAxons~ impulses toward tipsMyelin sheath~ supporting, insulating layerSchwann cells~PNS support cellsSynaptic terminals~ neurotransmitter releaserSynapse~ neuron junctionNeurotransmitters- chemical messengers that pass information from transmitting to receiving neurons

  • Sensory Receptors~ dendrites receive stimulus and send to CNS which will relay to Effector cellsEffector cells~ muscle or gland cells that will produce a desired responseNerves~ bundles of neurons wrapped in connective tissueCentral nervous system (CNS)~ brain and spinal cordPeripheral nervous system (PNS)~ sensory and motor neurons

  • Sensory neuron: convey information to spinal cordMotor neurons: convey signals to effector cell (muscle or gland)

    Reflex: simple response; sensory to motor neurons.

  • Is typically -60 to -80 millivolts

  • Endocrine and cell communicationCh 45

  • Regulatory systemsHormone~ chemical signal secreted into body fluids (blood) communicating regulatory messagesTarget cells~ body cells that respond to hormonesEndocrine system/glands~ hormone secreting system/glands (ductless); Exocrine glands~ secrete chemicals (sweat, mucus, enzymes) through ductsNeurosecretory cells~ actual cells that secrete hormonesFeedback mechanisms ~ negative and positive

  • Mode of Action: Chemical Signaling1- Plasma membrane reception signal-transduction pathways (neurotransmitters, growth factors, most hormones) 2- Cell nucleus reception steroid hormones, thyroid hormones, some local regulators

  • Hypothalamus~regulates the pituitary gland

    Pituitary glandPineal glandThyroid glandParathyroid glandsThymusAdrenal glandsPancreasGonads -ovary, testis

  • Pineal-secretes serotonin which regulates the sleep/wake cyclesThyroid- regulates metabolism Parathyroid- control calcium level in bones and bloodThymus-secretes hormones that produce antibodiesAdrenal- secretes aldosterone and cortisol which creates a fight or flight response Gonads-secrete testosterone, esterogen, or progesteronePancreas- secretes Insulin and Glucagon to regulate blood sugar levels

  • Examples of Hormone RegulationPituitary: Regulates other glandsOxytocin:uterine and mammary gland cell contractionAntidiuretic (ADH):retention of water by kidneys

  • Pituitary Gland regulatesGrowth (GH)~bones Disorder: gigantism/dwarfism Prolactin (PRL)~mammary glands; milk production Follicle-stimulating (FSH) this causes the sex cells to finish meiosis and prepare for sexual reproduction

    Luteinizing (LH)~ovaries/testes- helps maintain levels of sex hormones in the body

  • Thyroid-stimulating (TSH)~ regulates metabolism

    Adrenocorticotropic (ACTH)~ aids in bodys response to stress Melanocyte-stimulating (MSH) has effects on skin pigmentation

    Endorphins~natural opiates; brain pain receptors

  • MSHInteresting fact about MSH : However, in many red headed people, and other people who do not tan well, there are variations in their hormone receptors, causing them to not respond to MSH in the blood.

  • The pancreas (organ)Hormones secretes by the pancreas to regulate Blood Sugarglucagon~ raises blood glucose levels insulin~ lowers blood glucose levels

  • Ch 44 ExcretoryWith focus on the Kidneys, Ureter, Bladder, and Urethrea

    Other organs involved in excretory would be skin and lungs

  • The Kidneys (organ)

  • Role of ADH When the brain detects dehydration it will secrete ADH.ADH will reduce amt of water in urine.Secretion stops when the blood volume returns to homeostasis.


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