Tissues, Organ Systems, and Homeostasis

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Tissues, Organ Systems, and Homeostasis

• Starr/Taggarts
• Biology
• The Unity and Diversity of Life, 9e
• Chapter 33

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Key Concepts

• The cells of most animals interact at three
  levels of organization tissues, organs and organ
  systems
• Four types of tissues are seen in most animals
  epithelial, connective, muscle and nervous
  tissues
• Cells engage in metabolic activities

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Key Concepts

• The bodys internal environment consists of
  fluids outside of cells
• Stability in the internal environment is
  maintained by cells, tissues, organs and organ
  systems
• Homeostasis is the stable environment maintained
  for normal operation of an organism

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INTEGUMENTARY SYSTEM
MUSCULAR SYSTEM
SKELETAL SYSTEM
NERVOUS SYSTEM
ENDOCRINE SYSTEM
CIRCULATORY SYSTEM
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LYMPHATIC SYSTEM
RESPIRATORY SYSTEM
DIGESTIVE SYSTEM
URINARY SYSTEM
REPRODUCTION SYSTEM
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Epithelial Tissues

• Free surface faces body fluid or environment
• Simple epithelium
• Layer of single cells
• Lines cavities, ducts, tubes
• Stratified epithelium
• Two or more layers
• Functions in protection

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Cell-to-Cell Contacts

• Tight junctions
• Prevent leaks between cells
• Adhering junctions
• Cement cells together
• Gap junctions
• Help cells communicate
• Intercellular connections
• Connection of cytoplasm

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Glandular Epithelium

• Exocrine
• Mucus
• Saliva
• Earwax
• Milk
• Oil
• Digestive enzymes
• Endocrine
• Secrete hormones

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Connective Tissue

• Soft Connective Tissue
• Loose
• Dense, irregular
• Dense, regular

• Specialized Connective Tissue
• Cartilage
• Bone
• Adipose tissue
• Blood

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Loose connective tissue
Dense, irregular connective tissue
Dense, regular connective tissue
collagenous fiber
collagenous fibers
collagenous fibers
fibroblast
elastic fiber
fibroblast
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Specialized Connective Tissues

• Cartilage
• Cushions
• Bone formation
• Bone
• Spongy and compact
• Adipose tissue
• Fat
• Blood
• Transport

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Adipose tissue
Bone
Cartilage
compact bone tissue
ground substance with very fine collagen fibers
nucleus
blood vessel
cartilage cell (chondrocyte)
cell bulging with fat droplet
bone cell (osteocyte)
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Muscle Tissue

• Skeletal
• Attached to bones
• Striated
• Voluntary

• Smooth
• Internal organs
• Involuntary
• Cardiac
• Heart
• Involuntary
• Special end junctions

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SMOOTH MUSCLE
SKELETAL MUSCLE
width of one muscle cell
cells teased apart for clarity
cell nucleus
CARDIAC MUSCLE
junction between adjacent cells
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Nervous Tissue

• Neurons
• Excitable cells
• Neuroglia
• Protect and support neurons
• Stimulation
• Electrical charges
• Neuron stimulate or inhibit adjacent neurons or
  other cells

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Organ Systems

• Integumentary
• Muscular
• Skeletal
• Nervous
• Endocrine
• Circulatory

• Lymphatic
• Respiratory
• Digestive
• Urinary
• Reproductive

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Major Cavities in Human Body
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Three Primary Tissues

• Ectoderm
• Skins outer layer
• Nervous system
• Mesoderm
• Muscles
• Bones
• Circulatory, reproductive, urinary systems
• Endoderm
• Lining of digestive tract and organs

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Homeostasis and Systems Control

• Extracellular fluid
• Interstitial fluid
• Between cells
• Plasma
• Blood
• Compound parts of organism maintain stable fluid
  environment

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Mechanisms of Homeostasis

• Sensory receptors
• Detect stimulus
• Integration
• Selects response

• Effector
• Carry out response

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Negative Feedback

• Situation in which a change in a certain
  direction provides information that causes a
  system to change less in that direction
• Furnace with a thermostat
• Maintenance of body temperature

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Positive Feedback

• Situation in which a change in a certain
  direction provides information that causes a
  system to change more in that direction
• Childbirth
• Sexual intercourse

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Connective Tissues
A. Bone composes framework for movement,
support, and protection serves as a storehouse
for minerals manufactures blood cells
B. Cartilage- acts as cushion, lends rigidity to
structures that lack bones, provides slippery
surface to some joints
C. Dense fibrous connective Regularly arranged
tendons, ligaments joins muscles to bones or
bone to bones to aid in movement
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Connective Tissues cont
C. Dense fibrous connective Irregularly
arranged Periosteum (bone), Dura mater (Brain,
Spinal Cord), and inner layer of skin Provides
protection and carries blood supply

• Loose fibrous connective
• fibroelastic capsules of organs holds organs
  together.
• fibroareolar facial area beneath skin acts as
  filler
• reticular surrounds cells and muscle fibers
  acts a filler
• adipose around organs, beneath skin cushions,
  insulates stores fat

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Connective Tissues cont

• Liquid
• Blood - 55 liquid 45 other Plasma is 90
  water 6 liters in body 9 of body weight. 1
  salt needed for clotting. Has essential function
  in respiration, nutrition, excretion, temperature
  regulation, and protection from disease.

Lymph - found in spaces between cells and
cerebrospinal fluid bathes cells, nutrition and
disease protection.
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white blood cell
red blood cell
plasma
platelet
white blood cell
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Functions of the Integument
Barrier to disease organisms Protects against
drying out Protects against mechanical
injury Protects against chemical injury Protects
from overheating (blood flow to dermal
capillaries) Organ of the excretion system Holds
the receptors for touch, pressure, pain, and
temperature. First in excretion of waste from the
body. (Urea, carbon dioxide, water)
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In Conclusion

• A tissue is a group of cells that perform a
  common function
• An organ is a group of different tissues that
  perform a common function
• An organ system is a group of organs that perform
  a common function which contributes to the
  survival of the body

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In Conclusion

• Epithelial tissues cover external body surfaces
  and line internal cavities
• Connective tissues support, connect, strengthen,
  protect, and insulate other tissues
• Muscle tissues are contractile and move the body
  or parts of it
• Nervous tissue integrates and responds to stimuli
  about internal and external conditions

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In Conclusion

• Tissues, organs, and organ systems work together
  to maintain homeostasis
• Feedback controls help maintain internal
  operating controls
• Negative feedback mechanisms help maintain normal
  body ranges whereby positive feedback intensifies
  the changes
• Homeostasis depends on receptors, integrators,
  and effectors
• developed by M. Roig