Summary Epithelial and Supportive tissue

Epitheel- en Steunweefsel
(BOOK)
Tissues
Interstitial fluid is the fluid between cells.
Cells > tissues > organs > organ systems
(the skin is an organ of the integumentary system, which protects against infection and helps
regulate body temperature)
There are four main types of animal tissues:
 Epithelial tissues are closely packed, often with tight junctions and they function as a barrier.
All epithelia are polarized (two different sides)  apical surface (lumen our outside of the
organ) and basal surface (‘inner site’).
o Stratified squamous epithelium
 Multi-layered
 Regenerates rapidly by division near the basal surface
o Pseudostratified columnar epithelium
 Single layer of cells varying in height and position of nuclei
 Can be ciliated (covered by cilia (trilhaar))
 Overgangsepitheel bekleed de binnenzijde van de blaas, en kan sterk van
vorm veranderen.
o Simple squamous epithelium
 Single layer of plate like cells
 Easy diffusion of nutrients and gases
o Simple columnar epithelium
 Large brick-shaped cells
 Places where secretion or active absorption is important
o Cuboidal epithelium
 Dice-shaped cells specialized for secretion
 Connective tissue consist of sparse populations of cells scattered through an extracellular
matrix. The matrix generally consists of a web of fibers embedded in a liquid, jellylike, or
solid foundation. Within the matrix there are fibroblasts (secrete fibre proteins) and
macrophages (engulf by phagocytosis). There are three main connective tissue fibers
collagenous fibers (strength and flexibility), reticular fibers (connect tissues) and elastic
fibers.
o Loose connective tissue
 Binds epithelia to underlying tissues and holds organs in place
 Includes all three types of fibers
o Fibrous connective tissue
 Dense with collagenous fibers
 Found in tendons and ligaments
o Bone
 Consists of repeating units called osteons
o Blood
 Plasma, red- and white blood cells (erythrocytes and leukocytes)
o Adipose tissue

,  Stores fat in adipose cells
 Each adipose cell contains a large fat droplet that can slink and grow

o Cartilage
 Collagenous fibers embedded in a rubbery protein-carbohydrate complex
(chondroitin sulfate). Chondrocytes secrete the collagen and chondroitin
sulfate
 Muscle
o Skeletal muscle
 Attached to bones by tendons
 Bundles of long cells with striations
o Smooth muscle
 Lacks striations
 Spindle shaped
o Cardiac muscle
 Striated like skeletal muscle
 Branched fibers that interconnect via intercalated disks  help synchronize
heart contraction




 Nervous
o Neurons
 Transmit nerve impulses
 Receives by dendrites and sends by axons
o Glia
 Isolate and support nervous cells (rigidity)