Unit 1 Review: Histology and Embryology PDF

Unit 1 Review: Histology and Embryology What is histology? What is the function of a cell, and cells’ common characteristics? What is exocytosis, endocytosis, pinocytosis, phagocytosis? a)Pinocytosis: “cell drinking” b)Phagocytosis: “cell eating” 1) Exocytosis: expulsion of materials out...

Unit 1 Review: Histology and Embryology What is histology? What is the function of a cell, and cells’ common characteristics? What is exocytosis, endocytosis, pinocytosis, phagocytosis? a)Pinocytosis: “cell drinking” b)Phagocytosis: “cell eating” 1) Exocytosis: expulsion of materials out of the cell by fusing of a vesicle membrane with the cell membrane. 2) Endocytosis: uptake of materials into the cell (includes pinocytosis and phagocytosis): What are the cell organelles, their structure and function? (pg. 78) Cell membrane (plasma membrane) Cytoplasm Nucleus: - Nucleolus - Chromatin - Nucleoplasm - Nuclear envelope - Nuclear pores Endoplasmic Reticulum: (“highway system”) - Rough ER and Smooth ER Ribosomes (“protein factories”) Golgi Apparatus (“processing and packaging center”) Mitochondria (“powerhouse”, ATP) Lysosome (“sewer system”, created by Golgi Apparatus) Cytoskeleton: (“cell’s skeleton”) Microfilaments: Delicate, threadlike. Arranged in a meshwork. Cause various kinds of cellular movement. Microtubules: Thick, stiff. Form cell’s internal skeleton. Maintain the shape of the cell. Cilia, flagella, centrioles, mitotic spindle. Intermediate filaments: Various types of thicker, threadlike. microscopic structures within the cell. Involved with intercellular junctions and mitosis. Inclusions (hint: store lipids and melanin pigmentation). INTERCELLULAR JUNCTIONS: bonds between cells Tight junction: fuses cell membranes together (hint: “waterTIGHT” seal). Gap junction: tubular channels between cells. Desmosomes: attach adjacent cells to each other. Hemidesmosomes: attach cells to basement membrane. INTERCELLULAR JUNCTIONS: bonds between cells Basement membrane LIFE CYCLE OF A CELL: 1. Interphase (DNA is replicated, cell grows and forms new organelles) G1: the initial resting phase of cell growth. S: DNA replication (chromatin and centrosome replication) G2: the second resting phase of cell growth. 2. Mitosis (Cell Division) Prophase Metaphase Anaphase Telophase 3. Cytoplasmic Division – what is it? 4. Differentiation – what is it? Meiosis-occurs during the maturation of sex cells. What happens in each stage? What stage is this? What stage is this? What stage is this? What stage is this? UNIT 2: Basic Tissues Basic Tissues What are tissues? (hint: grouping of similar cells) 4 basic types of tissues: Epithelial Tissue: - forms protective coverings - function in secretion and sensory Connective Tissue: - provides support for softer body parts - bind structures together. Muscular Tissue: - producing body movements. Nerve Tissue: - conduct impulses that help control and coordinate body activities. 1) Epithelial Tissue Covers and lines both the external and internal body surfaces, including vessels and small cavities. Serves as a protective covering or lining. Involved in tissue absorption, secretion, sensory, and specialized functions (ciliated). Protects the more complex inner structures from physical, chemical and pathogenic attack, as well as dehydration and heat loss (acts as a barrier). Cells are tightly packed together. Epithelial cells are: Capable of rapid turnover: - what is Turn Over time and how many days for skin/oral cavity? Joined together by – desmosomes Epithelium is highly regenerative (deeper cells reproduce by mitosis) Epithelium is avascular, no own blood supply: - nutrition comes from the underlying connective tissue (very vascular). EPITHELIUM: review the diagrams for each type! Simple squamous epithelium Cells are flat, arranged in one layer. Function: covers connective tissue, performs a filtering function. Location: - pulmonary alveoli (lungs) - inner and middle ear - blood and lymphatic vessels (what is the term?) - heart - serous cavities. Simple Cuboidal Epithelium Cube-like cells (nucleolus in the center). Function: protection / covering for an organ, contributes to secretion. Location: - lines the ducts of various glands (Ex: salivary glands). Simple Columnar Epithelium Cells are rectangular. Function: protection, secretion/absorption. Has goblet cells. May be ciliated. Location: Non-ciliated: - Stomach - Large/small intestine - Lining of cervical canal Ciliated: - Uterus - Fallopian tubes - Small intra-pulmonary bronchi Pseudostratified columnar epithelium Crowded columnar cells. Nuclei are at different levels. Moistens, warms and cleans lining membranes. May be ciliated Location: - Upper respiratory tract including nasal cavity and paranasal sinuses. Stratified squamous NON- keratinized epithelium Many layers of cells on an irregular basal layer (“layered cake”). No layer of keratin. Kept moist from bodily secretions. Cells range in shape (from cuboidal to squamous cells). Location: - Buccal and alveolar mucosa - Ventral part of tongue (underneath) - Soft palate - Floor of the mouth - Sulcular epithelium - Esophagus - Cornea Stratified squamous KERATINIZED epithelium Located on dry or wet surfaces. Has a keratin layer for protection. Composed of 5 layers: - Stratum basale - Stratum spinosum - Stratum granulosum - Stratum lucidum (palms & soles, NOT in oral cavity) - Stratum corneum (dead, non- nucleated layer). Location: - Skin - Free gingiva (outside only) - Attached gingiva - Hard palate - Dorsal side of tongue - Lips Epidermis Dermis Hypodermis Transitional Epithelium Shape of the surface cells changes (undergoes transition) depending on the degree of stretch. Ranges between stratified non- keratinized squamous and columnar epithelium. Range from polyhedral to dome shaped, flat cells Cells are soft, pliable and loosely arranged Location: - Urinary bladder Basement membrane Thin, acellular structure. Located between the epithelium and connective tissue. 3 layers: 1. Lamina Lucida (clear layer) 2. Lamina Densa (dense layer) (1 & 2 make up BASAL LAMINA) 3. Reticular Lamina (collagen and reticular fibers) BASEMENT MEMBRANE 2) Connective Tissue Function varies depending on type: - connects, supports, protects, provides frameworks, fills spaces, stores fat, produces blood cells, provides protection against infection and helps repair tissues. Cells are some distance apart and have lots of matrix between them (fibers and intercellular substance). What are the major cell types found in connective tissue? Know the composition and location of connective tissue fibers: - Collagenous fibers (hint: collagen) - Elastic fibers (hint: elastin) - Reticular fibers (hint: reticulin) Location Function Structure 2) Connective Tissue Loose CT Forms thin membranes between organs and binds them together. Provides protective padding for the deeper structures. Intercellular space contain tissue fluids Location: ‒ beneath the skin ‒ between muscles. Adipose CT Stores fat. Protective cushion and heat insulator. Cells packed tightly together. Location: ‒ beneath the skin ‒ abdominal membranes ‒ oral cavity ‒ around the kidneys ‒ heart ‒ various joints. 2) Connective Tissue Fibrous CT Composed of strong collagenous fibers. Bind parts together. Location: - Tendons - Ligaments - Eyes - Skin Elastic CT Composed mainly of elastic fibers. Strength with elasticity. Location: - Walls of some hollow internal organs - Vocal cords Reticular CT Delicate network of interwoven reticular fibres forming a supportive framework. Location: - Blood vessels - Liver - Spleen - Lymphatic organs 2) Connective Tissue Connective Tissue: Cartilage Provides support/framework, decreases friction. Intercellular materials are composed collagen fibers and intercellular substance. Lacks direct blood supply, slow to heal. Perichondrium: - surrounds the cartilage - a fibrous connective tissue sheath containing blood vessels - chondroblasts lie internal to it (what are chondroblasts??). Cells of the cartilage: - Chondroblasts – produce matrix - Chondrocytes – maintain matrix What are the 3 main cartilage types and where are they located? - Hyaline - Elastic - Fibrocartilage Cartilage Connective Tissue: Bone Rigid connective tissue. Intercellular matrix contains mineral salts and collagen. Produces blood cells and stores calcium/other minerals. What are the bone cells and their function? - Osteogenic cells (stem cells) - Osteoblasts (bone-building) - Osteocytes (bone-maintaining) - they have their own sites in the bone - Osteoclasts (bone-crushing) Osteoid Periosteum Osteoblasts Newly mineralized bone Osteocyte in its lacuna Canaliculi Lamella Haversian canal Bone Architecture: Osteon Harversian canal Volkmann canal Lamella Lacuna Canaliculi Sharpey’s fibers Periosteum Ossification: what is it? Intramembranous: Formation of osteoid within 2 dense connective tissue sheets - Appositional growth - What bones are formed this way? Endochondral: - Formation of osteoid within a hyaline cartilage - Interstitial growth, then appositional - What bones are formed this way? Hema/o=blood Does not contain fibers Red and white blood cells in plasma – where are they made? Transports white blood cells to connective tissues. Blood cells: what is their function? - Red blood cells - Platelets - White blood cells (leukocytes): § Neutrophil (PMNs) § Eosinophil § Basophil § Monocytes § Lymphocytes § Mast cells CT: HEMATOPOETIC TISSUE 3) MUSCLE TISSUE Contractile tissue that moves parts attached to it. 1. Skeletal: Attached to the bone Controlled by conscious effort Cells are long/threadlike Striated, voluntary muscle 2. Smooth: Walls of hollow internal organs, glands, and linings of blood vessels. Non-striated, involuntary muscle 3. Cardiac: Found only in heart Cells are joined by intercalated discs Cells are arranged in branched, interconnecting networks Striated, involuntary muscle 4) Nerve tissue Found in the brain, spinal cord and peripheral nerves. Composition of a neuron: Dendrite: Impulses to the cell body. Axon: Impulses away from cell body. Body: Metabolic activity of the cell, no impulse transmission. What is this: - Nerve - Synapse - Ganglion - Afferent (sensory) nerve - Efferent (motor) nerve - Neuron and what is it’s function?