Study Question Six

• Q6. List all primary tissue types, their functions, special structural aspects, and the primary germ layer they came from.
• All primary tissue types

  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Functions of the EPITHELIAL tissue:

  • Protection. Protect exposed and internal surfaces from abrasion, dehydration, and destruction
  • Permeability. Relatively impermeable but can modify and regulate in response to stimuli
  • Sensation. Convey information to the nervous system as well as neuroepithelia which are specialized sensory epithelia
  • Secretion. Gland produce secretions such as enzymes, hormones, and mucus.
• Characteristics of the EPITHELIAL tissue:

  • Cellularity. Composed of cells bound tightly together by specialized junctions
  • Polarity. Epithelial cells have an apical surface facing lumen of a body cavity, and a basal surface attached to the underlying basement membrane
  • Attachment. Basal surface of typical epithelium is bound to a thin basement membrane, a complex structure produced by the epithelium and cells of the underlying connective tissue
  • Avascularity: Do not contain blood vessels
  • Sheets: Composed of a sheet of cells one or multiple
  • Regeneration: Stem cells used to divide and replace
• The EPITHELIAL tissue can be found in ectoderm, mesoderm, endoderm
• Functions of the CONNECTIVE tissue:

  • Framework. Support, surround and interconnect other tissue types
  • Transport. Fluids and dissolved materials
  • Protect. Delicate organs, defend
  • Store. Energy, especially in lipids
• Characteristics of the CONNECTIVE tissue:

  • Matrix. Extracellular fluid which surrounds cells
  • Fibers. Consist of three types which are collagen fibers, elastic fibers, reticular fibers
  • Cells. Consist of multiple types such as fibroblasts, chondrocytes, osteocytes, adipocytes, blood cells
  • Ground Substance. Gel material that fills the space between cells and fibers
• The CONNECTIVE tissue can be found in mesoderm
• Functions of the MUSCLE tissue:

  • Movement. Responsible for movement of the body and its parts
  • Heat Production. Muscle contractions generate heat, maintain body temperature
  • Circulation. Pumps blood throughout the body, helps regulate blood flow and pressure
• Characteristics of the MUSCLE tissue:

  • Fibers. Which vary by type
  • Cells. Which vary by type
  • Proteins. Which vary by type
• The MUSCLE tissue can be found in the mesoderm
• Functions of the NERVOUS tissue:

  • Signal Transmission. Transmitting electrical signals throughout the body. Neurons carry information
  • Coordination of Responses. Coordinates responses to stimuli by sensory information and generating motor responses
  • Control of Bodily Functions. Regulates bodily functions
  • Cognitive Functions. Higher functions such as thought, memory, emotion
• Characteristics of the NERVOUS tissue:

  • Neurons. Transmit electrical impulses along plasma membrane
  • Neuroglia. Supporting cells that support tissue, regulate composition of interstitial fluid, provide nutrients to neurons
  • Dendrites. Several branching processes that attach to cell body
  • Axon. Several branching processes that attach to cell body
• The NERVOUS tissue can be found in ectoderm