l # 1 Introduction & Cells.pdf

Biology 143 Anatomy Instructor: Douglas Panton Biology 143 fall 2022  Topics of Anatomy Gross or macroscopic: structures examined without a microscope – Regional: studied area by area – Systemic: studied system by system – Surface: external form and relation to deeper...

Biology 143 Anatomy Instructor: Douglas Panton Biology 143 fall 2022  Topics of Anatomy Gross or macroscopic: structures examined without a microscope – Regional: studied area by area – Systemic: studied system by system – Surface: external form and relation to deeper structures as x-ray in anatomic imaging Microscopic: structures seen with the microscope – Cytology: cellular anatomy – Histology: study of tissues  Topics of Physiology Reveals dynamic nature of living things Considers operations of specific organ systems – Cell physiology: examines processes in cells – Neurophysiology: focuses on the nervous system – Cardiovascular: the heart and blood vessels Subjects That Encompass Both Anatomy and Physiology Pathology: structural and functional changes caused by disease Exercise Physiology: changes in structure and function caused by exercise Structural & Functional Organizations Chemical Level: interaction of atoms Cell Level: functional unit of life Tissue Level: group of similar cells and the materials surrounding them Organ Level: one or more tissues functioning together Organ System Level: group of organs functioning together Organism Level: any living thing. Organs of the Body Organ Systems of the Body Organ Systems of the Body (cont.)  Imaging Techniques Radiography Computed Tomography (CT) Dynamic Spatial Reconstruction (DSR) Digital Subtraction Angiography (DSA) Ultrasound (US) Magnetic Resonance Imaging (MRI) Positron Emission Tomography (PET)  Radiography: Shadowy negative of internal body structures  Computed Tomography (CT Scan): computer- analyzed composite of radiograph; shows slices of body. Dynamic Spatial Reconstruction (DSR): 3-D version of CT using multiple slices.  Digital Subtraction Angiography (DSA): comparison of radiographs with and without dye. Used in blood vessel studies.  Ultrasound (US): computer-analyzed sound waves bounced off a structure in the body.  Magnetic Resonance Imaging (MRI): uses magnetism and radio waves to look for varying alignment of protons in soft tissues.  Positron Emission Tomography (PET): uses radioactively-labeled glucose to calculate metabolic activity of cells.  Characteristics of Life Organization: condition in which there are specific relationships and functions Metabolism: all chemical reactions of the body Responsiveness: ability to sense changes and adjust Growth: increase in size and/or number of cells Development: changes in an organism over time – Differentiation: change from general to specific – Morphogenesis: change in shape of tissues, organs Reproduction: new cells or new organisms  Basic Structure of the Cell – Plasma membrane – Cytoplasm containing organelles – Nucleus Functions of the Cell – Basic unit of life – Protection and support through production and secretion of various kinds of molecules – Movement. Various kinds occur because of specialized proteins produced in the cell – Communication. Cells produce and receive electrical and chemical signals – Cell metabolism and energy release – Inheritance. Each cell contains DNA. Some cells are specialized to gametes for exchange during sexual intercourse  Plasma Separation of intracellular vs. extracellular materials Membrane Production of charge difference (membrane potential) across the membrane by regulation of intracellular and extracellular ion concentrations – Outside of membrane positively charged compared to inside because of gathering ions along outside and inside Glycocalyx: combinations of carbohydrates and lipids (glycolipids) and proteins (glycoproteins) on outer surface. Fluid-mosaic model Endocytosis Internalization of substances by formation of a vesicle Types – Phagocytosis – Pinocytosis – Receptor-mediated endocytosis  Exocytosis Accumulated vesicle secretions expelled from cell Examples – Secretion of digestive enzymes by pancreas – Secretion of mucous by salivary glands – Secretion of milk by mammary glands  Cytoplasm Cellular material outside nucleus but inside plasma membrane Composed of Cytosol, Cytoskeleton, Cytoplasmic Inclusions, Organelles Cytosol: fluid portion. Dissolved molecules (ions in water) and colloid (proteins in water) Cytoskeleton Supports the cell but has to allow for movements like changes in cell shape and movements of cilia – Microtubules: hollow, made of tubulin. Internal scaffold, transport, cell division – Microfilaments: actin. Structure, support for microvilli, contractility, movement – Intermediate filaments: mechanical strength Cytoplasmic inclusions: aggregates of chemicals such as lipid droplets, melanin  Organelles Small specialized structures with particular functions Most have membranes that separate interior of organelles from cytoplasm Related to specific structure and function of the cell Nucleus Membrane-bound Nucleoplasm, nucleolus and nuclear envelope Much of the DNA in a cell located here  Chromosome Structure Chromatin: DNA complexed with proteins (histones) During cell division, chromatin condenses into pairs of chromatids called chromosomes. Each pair of chromatids is joined by a centromere Centrioles and Spindle Fibers Located in centrosome: specialized zone near nucleus Center of microtubule formation Before cell division, centrioles divide, move to ends of cell and organize spindle fibers Cilia Appendages projecting from cell surfaces Capable of movement Moves materials over the cell surface  Flagella Similar to cilia but longer Usually only one per cell Move the cell itself in wave-like fashion Example: sperm cell Microvilli Extension of plasma membrane Increase the cell surface area Normally many on each cell One tenth to one twentieth size of cilia Do not move Ribosomes Sites of protein synthesis Composed of a large and a small subunit Types – Free – Attached (to endoplasmic reticulum) Endoplasmic Reticulum Types – Rough Has attached ribosomes Proteins produced and modified here – Smooth No attached ribosomes Manufactures lipids Cisternae: Interior spaces isolated from rest of cytoplasm Golgi Apparatus Modification, packaging, distribution of proteins and lipids for secretion or internal use Flattened membrane sacs stacked on each other Function of Golgi Apparatus Action of Lysosomes  Peroxisomes and Proteasomes Peroxisomes – Smaller than lysosomes – Contain enzymes to break down fatty acids and amino acids – Hydrogen peroxide is a by-product of breakdown Proteasomes – Consist of large protein complexes – Include several enzymes that break down and recycle proteins in cell Mitochondria Major site of ATP synthesis Membranes – Cristae: Infoldings of inner membrane – Matrix: Substance located in space formed by inner membrane Mitochondria increase in number when cell energy requirements increase. Mitochondria contain DNA that codes for some of the proteins needed for mitochondria production.