BIOL10002 Lecture Notes - Epithelium, Tight Junction, Neuroglia
Monday, March 19, 2018
BIOL10002: Lecture 10 - Tissues & Homeostasis
Types of Cells
-Fat cell
-Neuron: Conveys information from 1 cell to another
-Macrophage
-Smooth muscle
-Glial Cels : Support cells int he nervous system
Epithelial Tissue
-Generally occur in layers or sheets
-Lines blood vessels, various tubules & ducts (e.g. GI tract, blood vessels)
-Function:
•Create a barrier between you and the external environment — skin is the
largest organ in the body ; covers the whole of the body.
•May be involved in secretion and absorption
•May be involved in smell and taste (refer to nervous system
-Types:
•Squamous (flattened) e.g. on skin or lining of the cheeks
•Columnar (rectangular) e.g. Tightly packed (tight junctions prevent cells from
breaking apart & form such tight barrier) - can have cilia (lungs, intestine)
•Cuboidal (squarish) e.g. tightly packed around tubules , ducts (kidney, trachea
etc.)
-Polarize: To divide into different sides — in biology - Two sides of a columnar
epithelial cell are different (Basal & Apical) Apical faces the lumen
!1
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find more resources at oneclass.com
Monday, March 19, 2018
Muscle Tissues
-Generate force & movement
-Most abundant tissue in the body
-Muscle cells contain long filaments of myosin & actin — allow muscles to contract &
relax
-Types:
•Skeletal muscle (regular arrangement of cells) — regular arrangement of actin
& myosin filaments result in striped striated appearance (VOLUNTARY
CONTROL)
•Smooth (Irregular arrangement of cells in the muscle) Lack of striated
appearance. INVOLUNTARY CONTROL — GI tract (motility) ; blood
vessels(relaxation & contraction) — can be circular or longitudinal fiber
•Cardiac muscle — Branched cells form strong structural meshwork —
responsible for beating and contracting heart
Connective Tissue**
-Loose cells (fibroblast / stroma) Loosely embedded in extracellular matrix (Like a
fishnet!!)
-Extracellular Matrix (ECM)— fishnet — can be considered as a scaffold or meshwork
-Loose cells are capable of movement on their own, can travel through the ECM
-EXTRACELLULAR because proteins in the matrix are secreted by cells
-Composition and properties of the ECM is different in different connective
tissues(elastin & collagen)
•Collagen : Most common, long fibers that are strong and resistant to stretch,
provide structural strength to organ (rigid ECM) — not much movement for
Fibroblast — bone & skin
•Elastin : Long fibers can be stretched then recoil, abundant in tissues that can
regularly stretch — lungs, arteries
!2
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Neuron: conveys information from 1 cell to another. Glial cels : support cells int he nervous system. Lines blood vessels, various tubules & ducts (e. g. gi tract, blood vessels) Polarize: to divide into different sides in biology - two sides of a columnar epithelial cell are different (basal & apical) apical faces the lumen. Muscle cells contain long laments of myosin & actin allow muscles to contract & relax. Types: skeletal muscle (regular arrangement of cells) regular arrangement of actin. & myosin laments result in striped striated appearance (voluntary. Control: smooth (irregular arrangement of cells in the muscle) lack of striated appearance. Involuntary control gi tract (motility) ; blood vessels(relaxation & contraction) can be circular or longitudinal ber: cardiac muscle branched cells form strong structural meshwork responsible for beating and contracting heart. Loose cells ( broblast / stroma) loosely embedded in extracellular matrix (like a. Extracellular matrix (ecm) shnet can be considered as a scaffold or meshwork.
