Download UNIT 3: CELLS AND TISSUES

Unit 3: Tissues and The
Skin
Chapters 5 & 6
Types of Tissues
Tissues – groups of different cells working
together for a common purpose
Kinds:
1)
2)
3)
Epithelial  Covering
Connective Tissue  Binds and Fills
Muscle tissue  Motion
a)
4)
Skeletal, smooth and cardiac
Nervous tissue Messaging/ Communication
Epithelial Tissues
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General Characteristics
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Function – covering, barrier, protection
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Avascular
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Free surface/ Basement Membrane
Secretions and Absorptions
Diffusion from underlying tissue
Reproduce rapidly
Tightly packed cells
Important Terms for Classification
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Simple VS. Stratified
Squamous, Cuboidal or Columnar
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Pseudostratified
Ciliated
Epithelial Tissues
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Simple Squamous Ep.
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Single row of flattened cells
Thinnest of coverings
Allows substances to pass freely  important for areas that
need diffusion to happen between tissues
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Simple Cuboidal Ep.
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Alveoli (air sacs) in lungs; capillary blood vessels
Single row of square shaped cells
Central, spherical nuclei
Ovaries, kidney tubules, ducts of salivary glands, pancreas and
liver
Simple Columnar Ep.
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Single layer of tall, elongated cells
Nuclei usually at same level, near basement membrane
Digestive System
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Microvilli
Goblet Cells
Epithelial Tissues
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Pseudostratified Columnar Ep.
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Nuclei at different levels but cells reach basement
membrane
Respiratory tract/ Female reproductive tubes
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Stratified Squamous Ep.
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Cube-like at bottom, flattened as they approach free
surface
Epidermis of skin, mouth, vagina, anal canal
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Cilia and Goblet cells
Keritinization
Stratified Cuboidal Ep.
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Larger gland ducts – mammary, sweat, salivary and
pancreas
Ovarian follicles (Female Rep. Sys.) and seminiferous
tubules (Male Rep. Sys.)
Epithelial Tissues
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Stratified Columnar Ep.
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Transitional Ep.
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Cuboidal at basement membrane, elongate towards free surface
Male urethra, Vas Deferens, parts of pharynx
Specialized layers to respond to changes in tension
Bladder and passages of urinary system
Glandular Ep.
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Cells that are specialized to produce and secrete substances
into tubes (ducts) or body fluids
Exocrine – secrete into ducts that lead to internal or external
surfaces
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Simple, compound, tubular, alveolar
Also classified by how they secrete
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Merocrine – substance only
Apocrine – substance + part of cell cytoplasm
Holocrine – substance + all of cell interior
Endocrine – secrete directly into body fluids (commonly blood)
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Endocrine glands revisited in Ch. 13
Connective Tissue
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General Characteristics
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Most abundant by weight
Many functions: bind structures together; provide
support and protection; framework; fill spaces; store
fat; produce blood cells; protect against infections;
help repair tissue damage
Cells generally farther apart with lots of intercellular
material (matrix)
Cell Types
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Resident vs. Wandering cells
Fibroblast – produce fibers
Macrophages –phagocytosis
Mast Cell – produce and release chemicals
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Histamine – associated with inflammatory response
Heparin – helps prevent blood clotting
Connective Tissue
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Fiber Types
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Collagenous Fibers – tough, dense protein fibers
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Collagen - white
Great tensile strength
Dense – many; loose – few and spread out
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Elastic Fibers – stretch and recoil
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Regular vs. irregular
Elastin - yellow
Vocal cords and respiratory passages
Reticular Fibers – thin, single strands of collagen
fibers
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Highly branched for a delicate framework
Connective Tissue
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Loose Fibrous C. T.
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Adipose C. T.
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Delicate thin membranes
Scattered collagenous and elastic fibers
Binds skin to underlying tissue
Highly vascular
fat storage
Beneath skin, between muscles, around kidneys, behind eyeballs
Dense Fibrous C. T.
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Mostly fibers; few cells
Can be regular  tendons and ligaments
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Can be irreguar  dermis of skin
Elastic C. T.
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Slow to heal b/c of poor vascularization
Parallel stands or branching networks of elastic fibers
Ligamente flava, larger airways and arteries
Reticular C. T.
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Thin, collagenous fibers arranged in 3-D network
Walls of liver, spleen and lymphatic organs
Connective Tissue
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Cartilage – rigid connective tissue
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Provides support, framework, attachment, protection
of underlying tissues, structural model for developing
bones
Chondrocytes – cartilage cells
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Perichondrium – covering of cartilage
Hyaline – most common type
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Ends of bones, soft part of nose, supporting rings of
respiratory system
Bone forms from this during development
Elastic – more flexible than hyaline
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Lacunae
External ears and larynx
Fibrocartilage – shock absorber with many
collagenous fibers
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Intervertebral disks
Connective Tissue
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Bones (osseous tissue) – solid connective tissue
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Solid matrix due to calcium phosphate and calcium carbonate
(mineral salts)
Attachments for muscles, leverage, protection, inorganic salt
storage
Osteons – basic repeating unit of bone
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Blood – liquid connective tissue
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Red blood cells, white blood cells, platelets in plasma
Hematopoietic tissue
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Osteonic (Haversion) canal
Osteocytes
Lacunae
Canaliculi
Bone marrow
Reticuloendothelial tissue – largely phagocytic tissue
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Found in blood, brain, lungs, bone marrow, spleen, liver and
lymph glands
Muscular Tissue
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Elongated cells (fibers) specialized for
contraction
Skeletal:
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Smooth:
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Voluntary, striated, movement of body parts
Fibers contain many nuclei and mitochondria; very
long
Involuntary, non-striated, movement of walls of
internal organs (digestive, blood vessels, urinary etc.)
Cardiac:
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Involuntary, striated, self-exciting, rhythmic beating of
heart
Intercalated disks – hold cardiac cells together
Nervous Tissue:
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Tissue specialized to transmit electrochemical messages (nervous
impulses) throughout the body
Neurons – functional cell of nervous system
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Dendrites – receiving end
Cell body
Axon – impulses travel down axon to terminals
Synapse – space between neurons
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Neurotransmitters – chemicals released from axon into synapse
Motor neurons – send messages to effectors (muscles and
glands)
Sensory neurons – receive sensory information from external
and internal environment
Interneurons – connect and integrate information from
sensory neurons to motor neurons
Neuroglial cells – accessory cells of nervous system
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Support, bind components of nervous system together, phagocytosis,
help supply nutrients
#7
#8
#9
#10 – what type of cell is the arrow
pointing to?
Bonus:
#7
#8
#9
#10
BONUS