NSCI 5720 Organization & Cell Biology 2023 PDF

ORGANISATION & CELL BIOLOGY NSCI5720 VERTEBRATE ANATOMY & PHYSIOLOGY Understand the levels of organisation of organ systems Name the four types of tissues that make up the body OBJECTIVES Be able to name and identify the parts of the cell and its organelles Discuss the functions of the organelles Ex...

ORGANISATION & CELL BIOLOGY NSCI5720 VERTEBRATE ANATOMY & PHYSIOLOGY Understand the levels of organisation of organ systems Name the four types of tissues that make up the body OBJECTIVES Be able to name and identify the parts of the cell and its organelles Discuss the functions of the organelles Explain how the function of the cell may influence the structure/organelles within them LEVELS OF STRUCTURAL ORGANISATION In order to understand anatomy, we can break the body down into levels: Atomic – most simple level Molecular – groups of atoms come together to form molecules Cellular – smallest unit in the body that houses organelles required to function Tissue – group of similar cells that perform a similar function. 4 major types – nervous, connective tissue, muscle, epithelial tissue Organs – different types of tissues together form an organ Organ system – different organs work together to meet a body need eg. Respiratory system or cardiovascular system Organism – made up of all the systems working together LEVELS OF STRUCTURAL ORGANISATION What are some organ systems that you know? WHAT WE WILL BE DISCUSSING… Today’s lecture we will be discussing cells and how cells come together to form tissues, organs and organ systems Then for each body system we will discuss the anatomy and physiology each organ system CELLS Cells are the building blocks of all living things Cells are specialized for particular & important functions - take up nutrients, create energy, provide structure etc. The function of the cell will determine cell shape and structure and what organelles are predominant CELLS Despite all these different functions and shapes cells are made up of essentially the same structures Cell (plasma) membrane Nucleus Cytoplasm (containing organelles) We will go through each of these structures… CELL (PLASMA) MEMBRANE Semipermeable membrane around the cell → between the external environment and the cytoplasm of the cell Allows some molecules to pass, but blocks others Keeps electrolytes and molecules etc where they should be to maintain cellular function The plasma membrane contains proteins that act as ion channels, receptors, pumps --> when we give medications they act on these receptors CELL (PLASMA) MEMBRANE EXTENSIONS Cilia Like little mobile hairs that extend from the cell surface of a group of cells Lots of them extend from the exposed surface of the cell Act to move fluid, mucus, cell debris across a cell surface eg. lungs Flagella One larger extension on individual cells Propel cells allowing movement eg. sperm cell NUCLEUS Most cells contain a nucleus, but some do not eg. some mammalian erythrocytes (red blood cells, RBC) “Control centre” of the cell that contains genetic material – deoxyribonucleic acid (DNA) → cell division Three regions Nuclear membrane – same as plasma membrane Nucleolus – manufacture of ribosomes Chromatin - DNA that makes up chromosomes NUCLEUS - NUCLEAR MEMBRANE Semi-permeable membrane around the nucleus Contains selective pores that allow for the exchange of material between the nucleus and cytoplasm NUCLEUS - NUCLEOLUS Sites of ribosome production Ribosomes then migrate to the cytoplasm through nuclear pores into cytoplasm NUCLEUS - CHROMATIN Composed of DNA and protein Scattered throughout the nucleus Chromatin condenses to form chromosomes when the cell divides (mitosis & meiosis) CYTOPLASM Cytoplasm – the substance of the cell with organelles Made up of: Cytosol – viscous fluid Cytoskeleton – gives support and structure to cell and allows movement of organelles Organelles – “little organs” that have specialised functions Inclusions CYTOPLASM CYTOSKELETON Flexible, protein fibrils that can change with the needs of the cell Gives support and shape, enables movement, anchors organelles within the cytosol CYTOPLASMIC ORGANELLE MITOCHONDRIA Mitochondrion = singular “Powerhouse” of the cell → produces energy for cells to function Cellular (aerobic) respiration – the cell uses oxygen (O2) to break down glucose, producing adenosine triphosphate (ATP) = energy and carbon dioxide (CO2) as a waste product Cells that have high energy demands eg. muscle have higher concentrations of mitochondria in their cytoplasm CYTOPLASMIC ORGANELLES RIBOSOMES Made in the nucleolus, released through nuclear pores into the cytoplasm Found at two locations Free in the cytoplasm Attached to the rough endoplasmic reticulum Made up of protein and RNA Sites of protein synthesis → proteins are enzymes, chemical messengers etc (very important) CYTOPLASMIC ORGANELLES ENDOPLASMIC RETICULUM (ER) Series of folded membranes Two types of ER – smooth and rough Rough Endoplasmic Reticulum (RER) Studded with ribosomes (makes it “rough”) Production and modification of proteins – packages the proteins into vesicles to be transported to Golgi apparatus Smooth Endoplasmic Reticulum (SER) Not as common Manufactures lipids, phospholipids, and hormones and other substances needed by the body CYTOPLASMIC ORGANELLES - GOLGI APPARATUS/GOLGI BODY Receives proteins from the endoplasmic reticulum Golgi apparatus modifies and packages the proteins in vesicles Sends the vesicles to where they are needed – within the cell or to the extracellular space Also produces lysosymes – vesicles with digestive enzymes GOLGI APPARATUS/GOLGI BODY CYTOPLASMIC INCLUSIONS Vesicles, vacuoles, lipid droplets in the cytoplasm Vesicles, vacuoles – sac formed by a membrane that function in storage and transport. Difference depends on what they contain They form during any intracellular process where something is produced in one organelle and needs to be stored or transported elsewhere eg. secretion (exocytosis) or uptake (endocytosis) Lysosomes – type of vesicle that contains digestive enzymes that break down materials within the cell. Used to remove damaged organelles etc SO NOW WE UNDERSTAND CELL STRUCTURE…. WE CAN MOVE ONTO TISSUES TISSUES Four main types of tissues: Epithelial – Lining cells. Covers all internal (hollow organs, body cavities) and external body surfaces eg. skin, lining of blood vessels Muscle – smooth muscle (organs), cardiac (heart muscle), skeletal muscle (attached to bones) Nervous – brain, spinal cord and nerves Connective Tissue – connects, separates and supports other tissue types eg. fat, tendon, ligaments, tendons, fascia etc AND THEN… So a group of cells is called a tissue When a group of different tissues come together, what is this called? ORGANS Group of several types of tissues that come together to perform a function Heart – made up of cardiac muscle cells, nervous tissue, connective tissue in valves and pericardium (connective tissue layer around the heart), endothelial cells (type of endothelium) Other examples – liver, lungs, brain, stomach, intestines, pancreas, kidneys etc ORGAN SYSTEMS Group of organs that come together to perform one or more functions Example gastrointestinal system – stomach, small intestine, large intestine, pancreas, liver, gall bladder, vasculature etc There are 11 organ systems: Integumentary Nervous Skeletal Endocrine Muscular Cardiovascular Lymphatic Urinary Respiratory Reproductive systems Digestive ORGAN SYSTEMS IN THE BODY – WHAT TISSUE TYPES ARE THEY MADE UP OF? Integumentary Skeletal Muscular Nervous Endocrine Cardiovascular Lymphatic/Immune Respiratory Digestive ​Urinary Reproductive INTEGUMENTARY SYSTEM Tissues that line both internal and external body cavities Physical barrier between the external environment and the internal body Eg. Skin, mucosa, hair, feathers, scales, beaks Epithelium and connective tissues– skin Muscle – raises hairs (hackles) Nervous – sensation, pain, pressure etc SKELETAL & MUSCULAR SYSTEMS Provides form and support to the body and enable movement Bones, tendons, cartilage – connective tissues Skeletal muscle – shortening of the muscle pulls on connective tissue creating movement Nervous – muscle contraction is initiated by signals in nerves Bones also contain marrow (connective tissue) – blood cell production LYMPHATIC SYSTEM System of vessels and lymph nodes that are present in the tissues of the body Complementary to the circulation – returns fluid in the tissues to the circulation Vessels are lined with endothelium (type of epithelium) Lymph nodes and immune cells – connective tissue RESPIRATORY SYSTEM Organs involved in gas exchange – upper resp tract, lungs, muscles, protected by ribs Inhaling oxygen and transferring it to the blood Releasing carbon dioxide from the blood into the lungs to exhale Gas exchange – epithelium, connective tissue Smell – epithelium and nervous tissue Thermoregulation – endothelium and connective tissues Vocalisation – epithelium, nervous & connective tissues DIGESTIVE SYSTEM Mouth, oesophagus, stomach, small & large intestines, pancreas and liver Work together to breakdown food into small particles to be absorbed and used in the body as energy and building blocks etc Smooth muscle, nervous tissue, connective tissues and epithelium all involved in making up these organs NERVOUS SYSTEM Groups of neurons working together to control, regulate, and communicate with the different systems in the body Brain and spinal cord Special senses – eye, ear etc made up of nervous tissue, connective tissue, epithelium ENDOCRINE SYSTEM Group of glands that produce hormones that are released into the blood to have an effect on other organs Regulates growth, reproduction, energy, stress, metabolism etc Gland cells are made from epithelium Connective tissue supports the glands Ducts are lined with epithelium CARDIOVASCULAR SYSTEM Group of tissues that function to transport nutrients and oxygen to body tissues and remove carbon dioxide and waste products Work with the respiratory system to oxygenate blood Heart – cardiac muscle, connective tissue, nervous tissue and endothelium Veins, arteries, capillary beds – endothelium, connective tissue and smooth muscle URINARY SYSTEM Collection of organs that work together to eliminate waste products and clear toxins from the blood, they also maintain water homeostasis and electrolyte concentrations Kidneys – endothelium, connective tissues Ureters, bladder, urethra – tubes are all lined with epithlium, wall of the bladder contains smooth muscle REPRODUCTIVE SYSTEM Reproductive system produces sex hormones – behaviour and physical development Organs and glands involved in sexual reproduction – smooth muscle, connective tissues, nerves, epithelium ANY QUESTIONS?