Vertebrate Body CH2

• Vertebrates

  • based on anatomy and embryology
  • contain -
  • Notochord(skeltal rod supporting the body)
  • deuterostomic(the anus forms before the mouth during embryonic development)
  • bilateral symmetry(right and left side are symmetrical)
  • gastrulation (embryo transforms from 1 dimesion to multicellular layers)
  • multicellular
• Embryonic development

  • The zygote cleaves (cut in half) forming 2,4,8,16 and so fourth blastomeres (cells of the blastula)
  • The Blastocoel is a hollow ball of cells

  
• Cleavage - spiral and determinate in protostomes

  Spiral - blastomeres divide at an angle to the polar axis

  • 45 degree angle from polar axis, creates spiral

  Cleavage -radial and indeterminate in dutersomomes

  Radial - blastomeres divide in parallel to the polar axis

  • In line with the lower cells
  • issues in embryonic development can arise macrolecithal eggs have big yolk sacs there can also be discord cleavage (squids)

  A) lungs

  B) heart

  C) skin

  D) cells in one area are specalized

  E) not detemined, can create twins

  F) lower cells bigger- yolk sac

  
• Gastrulation

  • the formation of the ectoderm and endoderm
  • gas bubble forms in cell and forms the gut

  
• Protostomes

  • Schizocoely - the mesoderm originates at the juncture of the endoderm and ectoderm

  
• Deuterostomes

  • Enterocoely - the mesoderm is derived from outpocketing of the archenteron

  A) not this

  
• • Schizocoely - the coelom directly opens up inside the mesodermal tissue
  • Enterocoely - the coelom is formed as the interior of the pouches as the mesoderm buds off the archenteron
• • Schizocoely - the coelom directly opens up inside the mesodermal tissue
  • Enterocoely - the coelom is formed as the interior of the pouches as the mesoderm buds off the archenteron
  • Both usually end in the same result

  
• Blastopore

  • becomes mouth in protostomes
  • becomes anus in deuterostomes

  
• Protostomes VS deuterostomes summed up

  • deuterostome characteristics are likely primitive
  • protostomes are likely derived

  
• Embryonic Origins of Adult tissues

  • Epithelial - Ectoderm - integument covering, Endoderm - digestive system lining, Mesoderm - coelom lining
  • Nervous - ectoderm (neuroectoderm)
  • Muscle - mainly mesoderm, some neuroectoderm
  • Connective - mainly mesoderm, some neuroectoderm
• Connective tissues

  • cells are loosely arranged in an extracellular matrix (liquid, jellylike, solid)
  • 4 types of connective tissue ------
  • Loose connective tissue
  • Dense connective tissue
  • Supporting connective tissue
  • Fluid connective tissue (blood)
• Loose connective tissue

  • packing material between organs or padding under the skin - randomly located and excrete stuff
  • Soft extracellular matrix
  • One variety - Adipose tissue is made up of cells with large fat droplets surrounded by a loose matrix of fibers and fluids
• Connective tissue

  • Dense connective tissue - tendons and ligaments that connect muscles, bones, and organs and contains many tough collagen fibers
  • fibrous extracellular matrix, provides connections
  • lots of molecules and are often arranged in a particular manner
• Connective tissues

  • Supporting connective tissues - firm extracellular matrix, bone and cartilage
  • provides structural support for the body and protective enclosures for the brain and neves
  • firm extracellular matrix, functions in structural support and protection
• Connective tissue

  • Fluid connective tissues - cells surrounded by a liquid extracellular matrix (blood, transports material throughout the body. Its extracellular matrix is plasma)
  • function is transport
• Nervous Tissue

  • Nerve cells (neurons) and several types of supporting cells
  • All neurons have projections that contact other cells, and there are usually many connected to form a network
  • comes from the neural tube
  • Short branching dendrites transmit electrical signals from other cells to the cell body
  • Long axons which carry electrical signals from the cell body to the other cells
• Muscle Tissue

  • was a key innovation in the evolution of animals, like nervous tissue it appears in no other lineage
  • function is movement
  • 3 types -------
  • Skeletal muscle
  • cardiac muscle
  • smooth muscle
• Skeletal muscle (actin and myosin)

  • long cells called muscle fibers
  • attaches to the bones of the skeleton and exerts a force on them when contracted
  • Responsible for most body movements (voluntary)
  • Encircles and controls the openings of the digestive and urinary tract
  • Sarcomere - contractile unit of muscle fibers (fast movements)
• Cardiac Muscle

  • the walls of the heart for pumping blood throughout the body
  • structurally similar to skeletal muscle but each cardiac muscle cell is physically and electrically connected to the other cardiac cells helping to transmit signals during a single heartbeat
• Smooth muscle -

  • lines walls of digestive tract and blood vessels (not fast)
  • cells are tapered at each end (spindle shaped)
  • controls many voluntary movements
• Epithelial Tissues (typically line the outside)

  • the epithelial tissues (epithelial) cover the outside of the body, line the surfaces of organs and form glands.
  • Organ - a structure that serves a specialized function and consists of several tissues
  • Gland - a group of cells that secrete specific molecules of solutions
• Epithelial Tissues

  • form layers of closely packed cells
  • Cells are sided (Polarized)
  • Apical side - faces away from the other tissues and toward the environment
  • Basolateral side - faces the animals interior and is connected to other tissues by a layer of fibers called basal lamina
• Body Cavities

  • Dorsal and Ventral
  • Ventral cavity physically divided in mammals by a diaphragm

  
• Body Divisions

  • Jawed vertebrate body is divided by a horizontal septum, epaxial and hypaxial divisions

  
• Body Regions

  
• Body planes

  
• Body Directions