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Cells and their components Cuchulainn Liam GentFormat: • MCQ! • Open questions! • Quick recaps! • Audience participation!Learning objectives: •and its microanatomyll is • How the cell maintains homeostasis and interacts with the environment • How cells become tissues Disclaimer: • You may not have been taught some of these things at this stage! • That is okay! • Most questions can be answered by an educational guess! • We learn more from mistakes than not! • All relevant information can be found in the slide notes! • I take no credit of any photos or diagrams used in this presentationQ1: Who is this? A. Charles Darwin B. Robert Koch C. Louis Pasteur D. Robert HookeQ1: Who is this? A. Charles Darwin B. Robert Koch C. Louis Pasteur D. Robert HookeWhat is a cell? • What does “cell” mean? • What is the broad definition of a cell? • What defines a eukaryotic cell? • How many do we have in the average human body? And what is the commonest cell type? • How many non-self cells?Q2: What does the cell membrane NOT contain? A. Phospholipids B. Chromatin C. Cholesterol D. Channel proteinsQ2: What does the cell membrane NOT contain? A. Phospholipids B. Chromatin C. Cholesterol D. Channel proteins EXTRA POINTS: Explain the image!The Plasma Membrane • Phospholipids! • Cholesterol! • Glycoproteins and glycolipids! • proteins!ialised transport EXTRA POINTS: • Etc… not completely accurate? model? How was this found out? Why is itQ3: How do ions MOSTL Y cross the membrane? A. Simple diffusion B. Channels C. Endocytosis D. Carrier proteinsQ3: How do ions MOSTL Y cross the membrane? A. Simple diffusion B. Channels C. Endocytosis D. Carrier proteinsMembrane transport • How do molecules cross membranes? • (a) Lipophilic, small, uncharged molecules • (b) Ions • (c) Larger, water-soluble moleculesExtra question: Which of these conditions do NOT involve a faulty channel protein? A. Cystic fibrosis B. syndromeal long QT C. Myasthenia GravisExtra question: Which of these conditions do NOT involve a faulty channel protein? A. Cystic fibrosis Involves mutation in chloride channel gene. Most genetic types of LQTS involve mutation in potassium or sodium channel B. Congenital long QT gene, or associated proteins. syndrome Immunologic abnormality against nicotinic Ach receptors (still ion channel, but is C. Myasthenia Gravis immune reaction against it, and not an inherently faulty channel)Q4: What is happening in the diagram? A. Phagocytosis B. Receptor mediated endocytosis C. Constitutive secretion D. PinocytosisQ4: What is happening in the diagram? A. Phagocytosis B. Receptor mediated endocytosis C. Constitutive secretion D. Pinocytosis cytoplasmic face of the vesicle? And what do they do? Transport by Vesicles • Endocytosis; • Phagocytosis • Pinocytosis • Receptor-mediated endocytosis (follow-up on next slide) EXTRA POINTS: What does vesicle mean? And what is the difference from a vacuole?EXTRA EXTRA POINTS: Who isolated Clathrin, and what does the word mean?Transport by Vesicles • Exocytosis; • Constitutive secretion • Regulated secretionQ5: What is chemical signalling from nerve to muscle an example of? A. Endocrine B. Paracrine C. AutocrineQ5: What is chemical signalling from nerve to muscle an example of? A. Endocrine B. Paracrine C. AutocrineSignal Reception & Transduction; how do cells communicate? • Autocrine EXTRA POINTS: What is juxtacrine signalling? • Paracrine • EndocrineQ6: What is the cause of pseudohypoparathyroidism? A. Growth hormone defect B. Parathyroid hormone defect C. Growth hormone receptor defect D. Parathyroid receptor defectQ6: What is the cause of pseudohypoparathyroidism? A. Growth hormone defect B. Parathyroid hormone defect C. Growth hormone receptor defect D. Parathyroid receptor defect tetany? How would you treat thise condition?Signal Reception & Transduction; how do cells communicate? • Channel-linked receptors • Enzymatic receptors • G-protein-coupled receptorsExtra question: What happens if the Ras signalling pathway is permanently switched on? A. You become stressed due to fight or flight signal B. Your cells stop dividing C. You develop acidosis D. You have uncontrolled cell proliferationExtra question: What happens if the Ras signalling pathway is permanently switched on? A. You become stressed due to fight or flight signal B. Your cells stop dividing C. You develop acidosis D. You have uncontrolled cell proliferation exactly?INTS: Meaning whatSignalling pathways: • Phosphorylation is key to activating signalling proteins. These are just examples of pathways along which signals are carried. Don’t get bogged down on the details too much. • binds adenylyl cyclase; increases cAMP; activating PKA; activates phosphorylase kinase; activates glycogen phosphorylase • phospholipid into DAG and inositol 1, 4, 5 triphosphate; latter opens Ca channels in the ER causing Ca increase in cytoplasm, which can have multiple effects • Ras pathway; ligand binds receptor tyrosine kinase; dimerization and kinase activation follows; binds RTK and activates Ras-activating protein, activating Ras; which starts a cascade ofor protein phosphorylation involving MAP kinases, changing protein activity and gene expression Membrane A B Organelles C Vesicle D Membrane Q7: What are the A structures labelled A? B A. Golgi B. Centrioles C C. Nuclei D. Mitochondria Vesicle D Q7: What are the structures labelled A? A. Golgi B. Centrioles C. Nuclei D. Mitochondria EXTRA POINTS: What cells might have many of these? What happens if they don’t work? Is it treatable? Q8: What is the structure below the mitochondria? A. Smooth endoplasmic reticulum B. Centrosome C. reticulumoplasmic D. Lysosomes Q8: What is the structure below the mitochondria? A. Smooth endoplasmic reticulum B. Centrosome C. reticulumoplasmic D. Lysosomes Endoplasmic reticulum • 2 types • Smooth • Makes lipids and steroid hormones • Drug detoxification • Rough • Dotted with ribosomes •export proteins for Q9: Which antibiotics target the bacterial ribosome? A. Streptomycin B. Tetracyclin C. Chloramphenicol EXTRA POINTS: if you can explain D. All of the above this picture! Q9: Which antibiotics target the bacterial ribosome? A. Streptomycin B. Doxycycline C. Chloramphenicol Aminoglycoside; binds 30S, bacEXTRA POINTS: Tetracyclines; binds 30S, bacteriostatic D. All of the above resistance Binds 50S, bacteriostatic develop? T o ponder; If ribosomes are required to make protein, but the ribosome itself is made of protein, how did proteins first form? Membrane Q10: Where Mitochondria are ribosomes made? sER & rER difficult B to visualise here** A. Golgi B. Nucleolus C C. Centrioles D. Lysosomes Vesicle D Membrane Q10: Where Mitochondria are ribosomes made? sER & rER difficult B to visualise here** A. Golgi B. Nucleolus C C. Centrioles D. Lysosomes Vesicle DNucleus and nucleolus • Nucleus: • Largest • Enveloped • Nuclear pores •(Chromosomes) • Contains nucleolus •nucleatedyour cell types areCentral dogma • DNA transcribed to RNA by RNA polymerase • RNA is processed; addition of and exons spliced togetherntrons • translated by ribosomes, who uses triplets of nucleotides (codons) to determine the amino acid used Membrane Mitochondria Q11: What is the function of the structure labelled C? B A. Cell movement B. Cell division C C. Respiration D. Protein export Vesicle NucleusQ11: What is the function of the structure labelled C? A. Cell movement B. Cell division C. Respiration D. Protein export Membrane Q12: What is Mitochondria the function of the structure labelled B? B A. Organisation of microtubules B. Breakdown of cell waste GA C. Produce ATP D. Excrete waste Vesicle Nucleus Membrane Q12: What is Mitochondria the function of the structure labelled B? B A. Organisation of microtubules B. Breakdown of cell waste GA C. Produce ATP D. Excrete waste Vesicle NucleusCytoskeleton • A network of protein filaments and motor moreeins allowing cell movement and • Composition: • Microfilaments; small, structural support and contractions • Intermediate filaments; support • Microtubules; larger, movement • Centrosome; organisation of the tubules, exists as a pair of centrioles, and are important in cell division • Motor proteins: Kinesis, dyneins, myosins Membrane That’ s Mitochondria the cell! Centrioles Not everything is labelled*** But cells come together and make tissues, that make up organs! GA Let’s explore that next… Vesicle NucleusQ12: What is NOT a type of epithelial tissue? A. Simple Squamous B. Transitional C. Reticular D. PseudostratifiedQ12: What is NOT a type of epithelial tissue? A. Simple Squamous B. Transitional C. Reticular (Found in lymph nodes) D. Pseudostratified Tissues: EXTRA POINTS: What is this a picture of?Q13: Where is simple squamous epithelium found? A. Bronchi, uterus, digestive tract B. Oesophagus, mouth, vagina C. Bladder, urethra, ureters D. Alveoli, blood vessels, lymphaticsQ13: Where is simple squamous epithelium found? Simple columnar; absorbs, and secretes A. Bronchi, uterus, digestive tract mucous and enzymes B. Oesophagus, mouth, vagina Stratified squamous: protects against abrasion C. Bladder, urethra, ureters Transitional: Allow urinary organs to expand stretch D. Alveoli, blood vessels, lymphatics Simple squamous: Allows materials to pass secretes lubricating substancestion, andForm fits function! • Epithelial tissue • Simple – single layer (absorption, secretion) • Squamous (flat) • Cuboidal • Columnar • Pseudostratified (respiratory tract) • Stratified – multiple (protection) • Squamous • Keratinised (dry) • Non-keratinised (moist) • TransitionalQ14: What is the most abundant tissue in the body? A. Muscle B. Connective C. Nervous D. EpithelialQ14: What is the most abundant tissue in the body? A. Muscle B. Connective C. Nervous D. Epithelial EXTRA POINTS: What is the tissue type in the above picture?Connective tissue •Types of connective tissue: Type out some! •Cells are embedded in ECM •Main functions: • Binding/structural support • Protection • Transport • InsulationConnective tissue •Types of connective tissue: Type out some! •Cells are embedded in ECM •Main functions: • Binding/structural support • Protection • Transport • InsulationQ15: What type of connective tissue does the arrow point to? A. Loose B. Adipose C. Reticular D. Dense E. Cartilage F. BoneQ15: What type of connective tissue does the arrow point to? A. Loose B. Adipose C. Reticular D. Dense E. Cartilage F. BoneQ16: What type of connective tissue does the arrow point to? A. Loose B. Adipose C. Reticular D. Dense E. Cartilage F. BoneQ16: What type of connective tissue does the arrow point to? A. Loose B. Adipose C. Reticular D. Dense E. Cartilage F. BoneQ17: What type of connective tissue does the arrow point to? A. Loose B. Adipose C. Reticular D. Dense E. Cartilage F. BoneQ17: What type of connective tissue does the arrow point to? A. Loose B. Adipose C. Reticular D. Dense E. Cartilage F. BoneQ18: Which are connective tissue diseases? A. Rheumatoid arthritis B. Systemic Lupus erythematosum C. Osteoarthritis D. All of the aboveQ18: Which are connective tissue diseases? A. Rheumatoid arthritis B. Systemic Lupus erythematosum C. Osteoarthritis D. All of the above Point being: Connective tissue is abundant, and many debilitating conditions affect it.Connective tissue summary: • Loose: most abundant; connects other tissues, e.g. under skin and between muscles. • Adipose: areolar matrix with adipocytes; white or brown tissue. • Reticular: lymphatic system, matrix of reticular fibres. • Dense: Fibrous or elastic; tendon, ligaments, periosteum vs blood vessels and lungs. • Cartilage: chondrocytes in collagen and proteoglycan matrix; hyaline, fibrocartilage and elastic fibrocartilage • Bone: Osteocytes embedded within a mineralised collagen matrix; contains osteoblasts, -clasts and -cytesQ19: Which statement is true? A. Cardiac is striated, skeletal is not B. Skeletal cells are mononucleated, cardiac are not C. Cardiac cells have intercalated discs D. Skeletal muscles are under involuntary controlQ19: Which statement is true? A. Cardiac is striated, skeletal is not B. Skeletal cells are mononucleated, cardiac are not C. Cardiac cells have intercalated discs D. Skeletal muscles are under involuntary controlMuscle tissue • Smooth: • Non-striated, involuntary, peristalsis, gut & ureter • Skeletal: • Striated, multinucleated, voluntary • Cardiac: • Striated, involuntary, mononucleated, intercalated discsExtra question: Why are skeletal muscle cells multinucleated? Write down your best guess in the chat, or turn on your microphone!Extra question: Why are skeletal muscle cells multinucleated? • Skeletal muscle cells are big! • Multiple nuclei mean multiple copies of genes, allowing large amounts of proteins and enzymes needed for contraction • To control long cells with many structural and functional units, a single nuclei might not cut it!Q20: Which of the following is true? A. Glial cells are excitable B. Neurones are supportive cells C. Glial cells are more numerous than neurons D. An oligodendrocyte is a type of neuronQ20: Which of the following is true? A. Glial cells are excitable B. Neurones are supportive cells C. Glial cells are more numerous than neurons D. An oligodendrocyte is a type of neuron Nervous tissue • Neurones • Excitable & initiate, receive and transmit information • within PNSs within CNS, axons found • Glial cells • Non-excitable, supportive, more numerous • Examples: astrocytes, oligodendrocytes, ependymal cells and microgliaQ21: Which junction mechanically attaches cells to adjacent cells or the ECM? A. Anchoring junctions B. Communicating junctions C. Occluding junctions D. T junctionsQ21: Which junction mechanically attaches cells to adjacent cells or the ECM? A. Anchoring junctions B. Communicating junctions C. Occluding junctions D. T junctionsCellular junctions For tissues to form, cells need to stick together. • Occluding: seal together, preventing leaks • Anchoring: mechanically attach cells to adjacent cells or the ECM • Some junctions involve actin filaments, and others intermediate filaments. • Communicating: control signals from one cell to another, most are linked via gap junctions Have a think about which junctions might be found where!Feedback Please take a minute now before you leave to fill in a quick feedback form: • https://app.medall.org/training/feedback/anonymous?organisati on=accessibility-in- medicine&keyword=f2b15912a9105ed6da140918 (I’ll post the link in the chat) AIMFacebook Page Give our Facebook page a like for updates and opportunities, just search @AIMEdinburghThank you for coming! Email: s1713373@ed.ac.uk Or accessibilityinmedicine@gmail.com Resources: Junqueira’s Basic Histology: Text and Atlas, 15e (online access via library)