INTRODUCTION TO ANATOMY AND CELL BIOLOGY. THE CELL 1. Aims and scope of anatomy 2. Methods of morphological examination 3. Aims and scopes of cytology, histology and embryology 4. Methods for microscopic observations 5. The cell – basic structural and functional unit cellular organization and chemical composition cell membrane cell organelles – membranous and non-membranous Aims and scope of human anatomy Anatomy – knowledge of the structure of living things Gr. ἀνατοµία anatomia = to cut apart; from ἀνατέµνειν ana: separate, apart from, and temnein , to cut up, cut open human anatomy animal anatomy (zootomy) plant anatomy (phytotomy) Human anatomy: Aim: how is the human body organized? structure of living organism spatial organization of living matter Scope (mission): why it is so organized? regularity of the structure functional approach Prof. Dr. Nikolai Lazarov 2 Major anatomical disciplines Systemic anatomy Topographical (regional) anatomy Plastic anatomy Clinical (applied) anatomy Dynamic anatomy (functional anatomy of the locomotor apparatus) Comparative anatomy the study of phylogenesis (Gr. φυλή/φ ῦλον, phyle/phylon = "tribe, race" + genesis, “ creation”, from Gr."gignesthai" = "to be born") Embryology the study of ontogeny, ontogenesis (ontos, present participle of “to be” + genesis, “creation”) Anthropology – the study of human behavior (Gr. ἄνθρωπος, anthrōpos = "human") Morphology – the study of the form or shape of an organism (Gr. morphe, “ form”) = anatomy + cytology + histology + embryology NB: Morpheus (Gr: Μορφέας, Μορφεύς, "he who forms, shapes, moulds", from the Greek morphe) is the Greek god of dreams and sleep Prof. Dr. Nikolai Lazarov 3 Systemic anatomy Locomotor system (apparatus) – Osteology , scientific study of bones – Osteologia , Gr. os, ossis = bone Arthrology , study of articulations and ligaments – Arthrologia , Gr. arthros = joint Myology , specialized study of muscles – Myologia , Gr. myos = muscle Internal organs, viscera – Splanchnology alimentary system respiratory system urogenital system endocrine glands – endocrinology Cardiovascular system – Angiology Nerve system – Neuroanatomy sense organs and integument, skin Prof. Dr. Nikolai Lazarov 4 Methods of morphological investigations Dissection, Gr. anatemnein = separate HIC MORTUI VIVOS DOCENT Ink injection technology Corrosion method Plastination Graphic and plastic reconstruction Imaging anatomy: Roentgen anatomy X-ray computed tomography (CT) Magnetic resonance imaging (MRI) Microscopic techniques: Light microscopy Electron microscopy Experimental anatomy Prof. Dr. Nikolai Lazarov 5 Regional texture of the human body Parts of the body: head, caput neck, collum trunk, truncus thorax, thorax abdomen, abdomen pelvis, pelvis extremities (limbs) upper, membrum superius lower, membrum inferius Prof. Dr. Nikolai Lazarov 6 Major axes and planes in the human body Three main axes and planes: sagittal axis – anterior-posterior transversal axis – transverse longitudinal axis – superior-inferior sagittal plane – median section transversal plane – axial section frontal plane – coronal section Prof. Dr. Nikolai Lazarov 7 Spatial orientation in the human body Spatial terminology: (main axes of the human body ) frontal plane – frons,tis m. anterior,us = ventralis,e posterior,us = dorsalis,e sagittal plane – sagitta,ae f. medialis,e ↔ lateralis,e proximalis,e ↔ distalis,e median plane sinister ↔ dexter transversal (horizontal) plane superior,us = cranialis,e inferior,us =caudalis,e Prof. Dr. Nikolai Lazarov 8 Anatomical Nomenclature Nomina Anatomica End of 19 th century – over 50 000 anatomical terms 1895 – Basle Nomina Anatomica (BNA ): 5528 anatomical terms 1933 – Birmingham Revision (BR ) 1935 – Jena Nomina Anatomica (JNA ) 1955 – Parisiensia Nomina Anatomica (PNA, NA ): 5640 anatomical terms Revisions of Nomina Anatomica : 1960 – New York 1965 – Wiesbaden 1970 – Saint Petersburgs (formerly Leningrad) 1975 – Tokyo 1980 – Mexico City 1983 – last 5th edition of Nomina Anatomica 1985 – Nomina Histologica and Nomina Embryologica 1998 – Terminologia Anatomica (TA ) Prof. Dr. Nikolai Lazarov 9 Objective of cytology, histology and embryology Cytology – now Cell Biology: (Gr. κύτος, kytos, a hollow + logos, study) Histology: (Gr. ἱστός , histos, web or tissue + logos ) general histology special histology = microscopic anatomy of organs Embryology: (Gr. έµβρυον, embryon + logos ) general embryology (embryogenesis) special embryology (organogenesis) Prof. Dr. Nikolai Lazarov 10 Levels of organization Levels of organization: cell tissue organ organ system organism The cell: the basic structural and functional unit of all known living organisms the smallest unit of life – the building block of body Major cell abilities: reproduction by cell division the functioning of a cell depends upon its ability to extract and use chemical energy stored in organic molecules response to stimuli such as changes in temperature, pH or levels of nutrients cell contents are contained 11 within a cell surface membrane Prof. Dr. Nikolai Lazarov 11 The cell – evolutionary levels The biological universe consists of two cell types: Prokaryotic cells (Gr. πρό- (pro-) "before" + καρυόν (karyon) “nut or kernel", referring to the cell nucleus ) bacteria and archaea Eukaryotic cells – "true nucleus" (Gr. eυ- (eu), "good", "true") multicellular organisms internal compartmentalization Prof. Dr. Nikolai Lazarov 12 The cell – external morphology 200 different cell types that come in an astounding assortment of shapes and sizes: size – 5-200 µm small-sized – up to 10 µm medium-sized – 10-20 µm large-sized – > 20 µm shape – related to their function: spherical spindle-shaped squamous, cuboidal ... color: colorless pigmented Prof. Dr. Nikolai Lazarov 13 The cell – chemical composition essential elements: macroelements – 98-99% of the cell mass - C, N, O, H microelements – up to 0.000001% - Cu, Zn, Mg ultra trace elements – ≤0.000001% - Hg, Ag, U, Ra water – 70-80% exogenous – ⅔ endogenous – ⅓ inorganic molecules: free – ions bound with organic molecules organic compounds: carbohydrates lipids proteins 14 nucleic acids Prof. Dr. Nikolai Lazarov 14 Basic cellular architecture nucleus (Lat., nux, nut) cytoplasm (Gr. kytos , cell + plasma , thing formed) organelles (“little organs”) universal and specialized membranous (membrane-limited) nonmembranous cytoplasmic inclusions deposits of carbohydrates, lipids, and pigments cytosol (cytoplasmic matrix ) Prof. Dr. Nikolai Lazarov 15 Plasma (cell) membrane Plasma membrane , synonym: plasmalemma (Gr. lemma = 'husk') thickness – 8-10 nm (EM) asymmetrical Chemical composition: lipids – 20-40% phospholipids steroids (cholesterol) glycolipids – 2-10% proteins – ~50% hydrophobic – structural hydrophilic – receptors and enzymes >30 carbohydrates – 10% glycoproteins glycolipids glycocalyx 16 Prof. Dr. Nikolai Lazarov 16 Fluid mosaic model Lipid-protein mosaic model structural skeleton – phospholipid double layer globular proteins: Seymour integral membrane proteins, Jonathan Singer (single-pass and multi-pass (1924-) transmembrane proteins) peripheral proteins freeze-fracture: P-face (protoplasmic) Е-face (extracellular) Garth L. Nicolson (1943-) Prof. Dr. Nikolai Lazarov 17 Membrane proteins – structure and functions Membrane proteins: ~50% w/w in the plasmalemma synthesized in the rough endoplasm reticulum their molecules are completed in the Golgi apparatus transported in vesicles to the cell surface Functional categories: transport proteins structural proteins (membrane-anchored) receptor proteins enzymes Prof. Dr. Nikolai Lazarov 18 Cell coat (glycocalyx) First description – Yamada (1955) Synonym = glycolemma thickness – up to 100 nm renewal – 6-8 h PAS-positive Chemical composition: glycolipids cerebrosides gangliosides glycoproteins proteoglycans hyaluronic acid Functions : defense absorption immunologic role cell recognition cell adhesion Prof. Dr. Nikolai Lazarov 19 Cell surface modifications 4 types structural specializations: (Gr. mikros, small + Lat. villus, tuft of hair) Microvilli: cytoplasmic processes, 1 µm high;0.08 µm wide brush (striated) border core of actin filaments terminal web Basal cell surface folds: interdigitations Stereocilia: non-motile microvilli of unusual length ductus epididymis hair cells of the ear Cilia & Flagella Prof. Dr. Nikolai Lazarov 20 Intercellular junctions 3 types intercellular junctions: Barrier (impermeable) junctions: tight junction, zonula occludens occluding strip, fascia occludens occluding spot, macula occludens Adhering (anchoring) junctions: punctum adhaerens belt desmosome, zonula adhaerens spot desmosome, macula adhaerens (Gr. desmos, band + soma, body) Communicating junctions: gap junction, nexus synapse 21 Junctional complex Prof. Dr. Nikolai Lazarov 21 Membrane-limited organelles Endoplasmic reticulum Annulate lamellae Mitochondria Golgi apparatus Lysosomes Proteasomes Secretory vesicles Transport vesicles Peroxisomes Coated vesicles 22 Nucleus Prof. Dr. Nikolai Lazarov 22 Endoplasmic reticulum Endoplasmic reticulum: rough smooth rough endoplasmic reticulum protein synthesis 23 Prof. Dr. Nikolai Lazarov 23 Rough (granular) endoplasmic reticulum Structure: cisternae – 7-8 nm ribosomes Functions: protein synthesis and segregation: intracellular utilization extracellular export initial glycosylation