Unit One

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Unit One

• From Cells to Organ Systems

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Levels of Organization

• All living things have a level of organization
  based on their specific composition
• A Prokaryotic organism is made of just one cell
• A Eukaryotic organism is made of millions to
  trillions of cells depending on the species to
  which the individual belongs
• Humans are, of course, Eukaryotic a person is
  composed of trillions of cells functioning in
  concert to enable the individual to live

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Levels of Organization

• Within a person, or any eukaryotic organism,
  there is a level of organization of structures
  which is as follows
• Atoms - - gt Molecules/Compounds - - gt Organelles
  - - gt Cells - - gt Tissue - - gt Organs - - gt Organ
  Systems - - gt Organism

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Epithelial Tissue

• Epithelial Tissue consist of layers of cells that
  cover and protect various surfaces and body
  cavities
• Glands are specialized Epithelial Tissues because
  they synthesize and secrete a fluid
• Exocrine Glands secrete fluid to the outside of
  the individual
• Endocrine Glands secrete a specific fluid known
  as a Hormone into the blood stream within the body

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Epithelial Tissue

• Epithelial Tissues are classified by shape and
  number of cell layers
• Simple Epithelium are composed of a single layer
  of cells
• Stratified Epithelium are composed of multiple
  layers of cells aka Strata

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Categories of Epithelial Tissue
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Connective Tissue

• Supports the softer organs of the body against
  gravity and connects parts of the body to each
  other
• Collagen Fibers made of protein, add
  strength/integrity to organs and are slightly
  flexible
• Cartilage is the transition tissue from which
  bone develops maintains the shape of certain
  body parts (nose) and protects/cushions joints

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Connective Tissue

• Bone specialized connective tissue that
  contains only a few living cells most of bone
  structure consists of hard mineral deposits of
  calcium and phosphate
• Blood consists of cells suspended in a fluid
  matrix called Plasma considered connective
  tissue because all blood cells are derived from
  earlier cells located within bone

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Connective Tissue

• Adipose Tissue highly specialized for fat
  storage located primarily under the skin where
  it serves as a layer of insulation and also forms
  a protective layer around internal organs

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Muscle Tissues

• Consist of specialized cells that are able to
  shorten and contract, resulting in movement
• Skeletal Muscle Tissue connects to tendons,
  which attach to bones it is voluntary muscle
  because we can exert conscious control over it
• Cardiac Muscle Tissue found only in the heart
  individual cells are much shorter than Skeletal
  Muscle cells and this tissue is considered
  involuntary because the heart beats on its own

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Muscle Tissue

• Smooth Muscle Tissue surrounds hollow organs
  and tubes (blood vessels, digestive tract,
  uterus, bladder) these cells are much smaller
  than Skeletal Muscle cells and it is involuntary
  like Cardiac Muscle

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Nervous Tissue

• Consists primarily of cells that are specialized
  for generating and transmitting electrical
  impulses throughout the body
• Neurons are those specialized cells that transmit
  electrical impulses
• Glial Cells are found in Nervous tissue but do
  not transmit electrical impulses their role is
  to surround and protect neurons and also supply
  them with nutrients

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Organs Organ Systems

• Organ structure composed of two or more tissue
  types that perform a specific function or
  multiple functions
• Organ System a group of organs that serve a
  broader function that is vital to the
  organism/species

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Body Position/Direction
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The Skin

• The Skin aka Integumentary System has many
  functions protect from dehydration, defense
  against microorganismal infection, regulation of
  body temperature, and aids in some sensory
  perception (touch, vibration, pain etc.)
• Skin consists of the Epidermis (outer layer of
  cells) and the Dermis (inner layer of connective
  tissue)
• Melanocytes located near the base of the
  epidermis and produce a dark brown pigment known
  as Melanin (protects against UV Rays)

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The Skin
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Eukaryotic Species Homeostasis

• Humans, who are Eukaryotic, must keep their
  bodies in a state of dynamic equilibrium where
  fluid amounts are always in flux but do not
  fluctuate greatly
• Maintaining the bodys dynamic equilibrium is
  known as Homeostasis
• Water levels - Nutrient levels
• Internal Temperature - Hormone levels