Lecture 2 Flashcards
What are 2 different membranes found in the body?
Organs = tissue membrane (flat cells surrounded by loose connective tissues) Cells = cell membrane (phospholipid bilayer)
What is the difference between lumen and cytoplasm?
Hollow space within organs
interior of cells
What are the two fluid compartments of the body?
Intracellular fluid Extracellular fluid (plasma [fluid component of blood] and interstitial fluid [between cells and circulatory system])
What is the purpose of the cell membrane?
Forms protective barrier between internal/external environment
Regulation of communication
Structural support
Regulation of exchange
What is cytosol?
intracellular fluid
What is the cell membrane composed of?
Phospholipids
cholesterol (increased fluidity, decreased permeability)
carbohydrates (glycoprotein, glycolipid)
Proteins (transmembrane, peripheral [non-covalently bonded to either proteins or lipids], lipid anchored [covelently bonded])
Carbohydrates almost exclusively on ECF side, cannot remove transmembrane protein without disrupting the membrane
How are cells grouped together?
By the extracellular matrix and cell adhesion proteins
Describe the extracellular matrix
Composed of proteoglycans (proteins covalently bonded to long sugar molecules) and insoluble protein fibers`
List the 3 different cell junctions
Gap junctions, desmosomes, tight junctions
Describe the gap junction
uses connexin proteins
enables communication between cells
like a tunnel
can be opened/closed (regulated)
Describe the tight junction
Like a row of staples (creates little pockets)
makes barrier to movement between cells
uses claudin and occludin proteins
Describe desmosomes and hemi-desmosomes
Anchor cells to each other
provide strength during mechanical stress
uses cadherin proteins attached to plaque glycoproteins
failure of them leads to metastasized tumours
hemi-desmosomes attach cells to extracellular matrix
What are 5 types of epithelial tissue cells, and what are the functions
Broad: protect internal environment, regulate exchange
1) Exchange: rapid exchange (ex. capillaries, lungs)
2) Secretory: goblet cells
3) Protective: barrier between internal/external environment (ex. skin)
4) Ciliated: beat in rhythm to move materials (ex. mucus in airways)
5) Transporting: regulated movement
What is the difference between the apical and basolateral membranes?
Apical = facing lumen or external environment Basolateral = facing other cells or ECM or ECF
What are the 6 types of connective tissue and what are the functions?
Broad: provides support and barriers, has extensive extracellular matrix
Loose: elastic tissues, supportive (irregularly arranged)
Dense: strength and flexibility (tendons/ligaments) (parallel fibers)
Adipose: fat
Blood (no insoluble protein fibers in ECM)
Bone
Cartilage
