Download Tissues

Introduction
• Tissue:
▫ Def – cells organized into groups and layers all with
the same function
▫ Rely upon extracellular matrix (contains nutrients
needed for cells to thrive, transmits signals)
• Four types (Table 5.1):
▫
▫
▫
▫
1) Epithelial
2) Connective
3) Muscle
4) Nervous
Epithelial Tissue
• Location
▫ Lines exposed surfaces of body
▫ Forms inner lining of body cavities
▫ Covers organs
• Function
▫ Protection, absorption, secretion
• Characteristics
▫ One side is exposed, one side is anchored to basement
membrane (connective tissue)
▫ Tightly packed cells with little to no blood vessels
▫ Readily divide
Connective Tissue
• Location
▫ Throughout body (bone, blood, cartilage)
• Function
▫ Support and protection, binds structures, fills spaces,
stores fat, produce blood cells, protect against
infection, repair tissue damage
• Characteristics
▫ Cells have spaces between them filled with
extracellular matrix
▫ Can usually divide and have good blood supply
▫ Can be flexible or rigid in nature
Muscle Tissue
• Location
▫ Throughout body (skeletal muscles, heart muscle,
muscles in tracts and tubes)
• Function
▫ Provide movement
• Characteristics
▫ Cells can shorten
▫ Contract/relax in response to stimuli
Nervous Tissue
• Location
▫ Brain, spinal cord, and nerves
throughout body
• Function
▫ Transmit signals across body
▫ Coordinate, regulate, integrate body
functions
• Characteristics
▫ Respond to changes in their
surroundings
▫ Basic cell :neuron
Epithelial Tissue Classification
• Classified by shape and
# of layers
• Shape
▫ Squamous
▫ Cubiodal
▫ Columnar
• # of Layers
▫ Simple- one layer
▫ Stratified- multiple
layers
Simple Squamous
• Form
▫ Single layer, flattened, tilelike cells
▫ Tightly packed
▫ Easily damaged
• Function
▫ Diffusion (substances pass
through easily) and
filtration
• Locations
▫ Alveoli in lungs
▫ Capillaries
Simple Cuboidal
• Form
▫ Single layer cube-shaped
cells
▫ Central nucleus
• Function
▫ Secretion and absorption
• Location
▫ Lining of kidney tubules
▫ Lining of some gland
ducts (thyroid, salivary,
pancreas, liver)
▫ Covers ovaries
Simple Columnar
• Form
▫ Single layer elongated,
column-like cells
▫ Can be ciliated
▫ Goblet cell scattered
• Function
▫ Protection, secretion, and
absorption
• Location
▫ Lining of digestive tract
▫ Female reproductive tubes
(cilia aid in egg movement)
Pseudostratified Columnar
• Form
▫ Single layer elongated cells
with nuclei at different
heights, often ciliated
▫ Appear layered
▫ Goblet cells scattered
• Function
▫ Movement of particles
▫ Trap dust/microorganisms
• Location
▫ Lining of respiratory
passages
Stratified Squamous
• Form
▫ Several layers of tile-like cells
▫ Thick
▫ Divide and push old cells up
• Function
▫ Protection (microorganisms)
▫ Keritinize (harden and die)
providing layer to prevent water
loss
• Location
▫ Outer layer of skin
▫ Linings of cavities opening to
the outside
Stratified Cuboidal
• Form
▫ Several layers of cubeshaped cells
• Function
▫ Protection
• Location
▫ Linings of larger ducts of
glands
▫ Ovary follicle
Stratified Columnar
• Form
▫ Several layers
▫ Outer layer elongated cells
• Function
▫ Protection and secretion
• Location
▫ Parts of pharynx
▫ Parts of male reproductive
system
Transitional
• Form
▫ Several layers of rounded
cell that can stretch to form
layers of flattened cells
• Function
▫ Stretch
▫ Forms barrier to prevent
diffusion of materials back
• Location
▫ Bladder
▫ Ureter
▫ Parts of urethra
Glandular Epithelium
• Function: secrete and produce
• Endocrine vs Exocrine
▫ Endocrine- released into interstitial
fluid or bloodstream
▫ Exocrine- released into duct or
onto surface
• Serous vs Mucous
▫ Serous- found in cavities closed to
the inside
▫ Mucous- found in cavities with exposure to outside
Connective Tissue Cells
• Fibroblasts- fixed cells that secrete protein fibers
▫ Characteristics:
 Collagenous- thick threads with a high tensile strength but
only a little elasticity
 Elastic- thin, networked thread; not as strong but elastic
 Recticular- thin delicate threads; forms framework in some
organs
• Macrophages (histiocytes)- roaming cells that eat cellular
debris and foreign particles by phagocytosis
• Mast cells- fixed cells that release heparin and histamine
Loose Connective
• Form
▫ Scattered cells and fibers in
matrix
▫ Mainly fibroblasts
▫ Very low tensile strength
▫ Thin, delicate
• Function
▫ Binds organs together (especially
skin to underlying organs)
• Location
▫ Beneath many epithelial layers
including skin
▫ Between muscles
Adipose (fat)
• From
▫ Specialized form of loose
connective where fat cells store
enough fat to crowd other
things out of the tissue
• Function
▫ Storage of energy (in fat),
insulation, protection, cushion
• Location
▫ All throughout body
▫ Beneath skin, spaces in
between muscles, around
kidneys, behind eyes, surface of
heart, around joints
Dense Connective
• Form
▫ Few cells, highly packed with
thick collagenous fibers
▫ Very strong
▫ Few elastic fibers
• Function
▫ Binds organs together (muscle
to bone, bone to bone)
▫ Protective layer of eye
• Location
▫ Tendons and ligaments
▫ Deep layers of skin
▫ Eye
Cartilage
• Form
▫ Cartilage cell (chondrocytes)
surrounded with a gel-like matrix
▫ Rigid
• Function
▫ Supports
▫ Protects underlying tissue
(cushions bones)
▫ Forms framework with some
flexibility
▫ Provides attachment
• Location
▫ Ends of bones
▫ Ears
▫ Nose
Bone
• Form
▫ Bone cells (osteocytes)
surrounded by rigid matrix of
calcium carbonate and calcium
phosphate salts
▫ Most rigid connective tissue
• Function
▫ Supports, protects, provides
framework
▫ Muscle attachment
▫ Form blood cells
▫ Store/release inorganic
chemicals
• Location
▫ Bones
Blood
• Form
▫ Cells suspended in plasma
matrix
▫ Three types: RBCs, WBCs,
plasma
• Function
▫ Transports materials
(exchange of materials)
▫ Help maintain internal
environment
• Location
▫ Blood
Muscle Tissue
• Location
▫ Throughout body (skeletal muscles,
heart muscle, muscles in tracts
and tubes)
• Function
▫ Provide movement
• Characteristics
▫ Cells shorten
Muscle Tissue Types
• Skeletal
▫ Voluntary, striated, multiple nuclei/cell
▫ Ex: Skeletal muscles (quadriceps, triceps)
• Cardiac
▫ Involuntary, striated, one nucleus/cell
▫ Ex: Heart muscle
• Smooth
▫ Involuntary, unstriated, one nucleus/cell
▫ Ex: Esophagus, stomach wall
Skeletal Muscle Tissue
• Form
▫ Long thread-like cells with
banding, striations, along
the length
▫ Cell w/ many nuclei
• Function
▫ Voluntary movements
▫ Talk, smile, swallow,
breathe, sing, etc.
• Location
▫ Attached to bones
Cardiac Muscle Tissue
• Form
▫ Complex network of
branching, striated cells
connected by
intercalated disks
• Function
▫ Movement of heart
▫ Involuntary movement
• Location
▫ Heart (only!)
Smooth Muscle Tissue
• Form
▫ Spindle-shaped cells lacking
striations and poorly
organized
• Function
▫ Movement of internal organs
▫ Involuntary movement
• Location
▫ Walls of internal organs
(stomach, intestines, bladder,
uterus, blood vessels
Nervous Tissue
• Location
▫ Brain, spinal cord, and nerves
throughout body
• Function
▫ Transmit signals (nerve
impulses) across body
▫ Coordinate, regulate, integrate
bodily functions
• Characteristics
▫ Respond to changes in their
surroundings
▫ Basic cell: neuron
Nervous Tissue Types
• Neurons
▫ Basic cellular unit of
nervous system
▫ Transmit the messages
▫ Senses environmental
changes
• Neuroglial cells
▫ Support neurons
▫ Bind nervous tissue
▫ Supply nutrients to
neurons
Types of Membranes
• Epithelial: 3 Types
1. Serous- release serous fluid and line cavities not
exposed to the outside, lubricate membrane surface
2. Mucous- release mucous and line cavities that open
to outside (oral/nasal cavity, digestive/respiratory/
urinary/reproductive tubes)
3. Cutaneous- skin
• Connective
1. Synovial- lines joints