CBIO 2200 1nd Edition Lecture 7 Outline of Last Lecture I Classes of Epithelium and Cell Shape II Simple Epithelia III Stratified Epithelia IV Connective Tissue Functions V Adipose Tissue VI Cartilage Outline of Current Lecture I Bone Tissue Osseous Tissue II Fluid Connective Tissue Blood III Nervous Tissue excitable tissue IV Muscle Tissue excitable tissue V Cell Junctions VI Glands VII Membranes Current Lecture I Bone Tissue Osseous Tissue a Two forms of osseous tissue i Spongy bone 1 Characterized by trabeculae also called spicules These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute II III IV ii Compact bone 1 Composed of osteons rarely found in osteons 2 Osteon a Central canal Haversian canal b Concentric lamellae c Osteocytes mature osteoblasts in lacunae called osteocytes once trapped in lacunae d Canaliculi channels that allow osteocytes to communicate with each other e Periosteum connective tissue that covers bone Fluid Connective Tissue Blood a Plasma ground substance b Formed elements cells and cell fragments i Erythrocytes RBC ii Leukocytes WBC iii Platelets cell fragments help in forming clots Nervous Tissue Excitable Tissue a Excitability capable of responding to stimuli because of membrane potential b Membrane potential electrical charge difference voltage that occurs across the plasma membranes is the basis for their excitation i Negative charge within cell ii With positive charge leaking out negative proteins cannot move across membrane c Consists of i Neurons nerve cells ii Neuroglia glial support system immune cells provide nutrients iii Neuron Parts 1 Neurosoma cell body 2 Dendrites 3 Axon nerve fiber Muscle Tissue Excitable tissue a Excitability causes contraction of cell b Membrane potential c Skeletal cardiac and smooth muscle tissues d Skeletal muscle tissue attached to the bones with a few exceptions such as some face muscles i Skeletal muscle ii Contains multiple nuclei adjacent to up against plasma membrane iii Responsible for voluntary movements iv Striations because of arrangements of proteins e Cardiac muscle tissue i Myocytes or cardiocytes ii Contain one centrally located nucleus V VI iii Intercalated discs allows ions to pass quickly from cell to cell iv Striated and involuntary proteins are not as organized as in skeletal muscle muscle movements happens without you thinking v Tend to be branched f Smooth muscle tissue i Lacks striation and is involuntary ii Fusiform cells big in middle and taper off on ends iii One centrally located nucleus iv Visceral muscle in abdomen Cell Junctions a Connections between one cell and another blood cells and metastatic cancer cells do not have cell junctions b 4 types tight junctions desmosomes hemi desmosomes and gap junctions intercalated discs c Some allow for communication and some allow no communication d Tight junction continuous closure i Adjacent cells are linked by trans membrane cell adhesion proteins ii Does not allow molecules to come between them e Desmosomes non continuous closure i Patch that holds cells together ii Serves to keep cells from pulling apart resists mechanical stress iii Hook like J shaped proteins that hole cells together arise from cytoskeleton iv Do not allow material to pass between cells f Gap junction i Communicating junction formed by a ring like connexon looks like orange with sections ii Ions can pass between cells g Hemi desmosomes i Half desmosomes ii Only found on basal surface of cell iii Attaches cell to basement membrane iv Made of variety of proteins v When you do not have right components of proteins the connection will not be a proper connections will not connect to basement membrane disease called hemidesmosomal epidermolysis bullosa an autosomal heritable blistering disease Glands a A cell or organ that secretes a substance can be any type of substance b Secretion substance that will remain in body c Excretion substances that will leave the body d Glands are classified as endocrine or exocrine e Exocrine gland VII i Communicates with the surface via ducts f Endocrine glands do not have ducts release products directly into blood strem and do not communicate with surface g Some organs have both endocrine and exocrine functions i Liver gonads pancreas h Endocrine gland structure i Capsule around them divides glands into lobes ii Septa or trabeculae invagination of molecule 1 Further divide into lobules iii Stroma connective tissue framework of gland iv Parenchyma does the work of cell releases substance of gland v Simple unbranched vi Compound branched vii Shape of gland 1 Tubular simple duct and secretory part are continuous and have same diameter 2 Acinar compound dilated secretory parts have dilated sacs on the ends 3 Tubulo acinar compound secretory cells are both in duct parts and secretory parts i Glands classified by types of secretions i Serous gland secrete watery substance ii Mucous gland produces glycoprotein mucin combined with water make mucous iii Mixed gland secretes both watery substance as well as mucous secretion iv Cytogenic glands produce an actual cell males sperm females ovaries j Glands classify by their modes of secretion i Merocrine vesicles that go to plasma membrane merge with it and release contents into cell e g tear glands ii Aprocrine a product that is accumulated in vesicle and it is released from the cell iii Holocrine the whole cell degenerates accumulate oil until it degenerates e g oil gland like on scalp Membranes a Line body cavities and cover their viscera soft internal organs of the body i Cutaneous skin largest membrane stratified squamous epithelium ii Mucous line passages that open to the outside nose digestive tract urinary tract contain goblet cells three layers 1 Epithelium 2 Lamina propria contains blood vessels 3 Muscularis mucosa layer of smooth muscle iii Serous internal membrane line cavities organs etc made up of squamous cells areolar tissue and smooth muscle 1 Endothelium serous membrane in blood vessels 2 Mesothelium pericardium plural cavity lining peritoneum iv Synovial line joint cavities i e knee 1 Inner lining of fibrous layer of capsule and goes right up to articular cartilage but does not cover it 2 Connective tissue 3 Secretes synovial fluid