Tissue

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Tissue
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What is epithelial tissue? Tissue made of tightly
packed cells in which one surface borders a free
space
Epithelial tissue does not contain __blood
vessels______ Epithelial tissue has a high rate
of _regeneration_____ through rapid cell
division Epithelial cells on the underside of a
tissue are anchored to _connective tissue__ by
the _basement membrane__ What is a basement
membrane? A non-living membrane packed with
protein and carbohydrate
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Types of Epithelial Tissue Epithelial tissue is
classified by __shape______ number of __cell
layers_____
Shapes Squamous epithelial ? flattened
cells Cuboidal epithelial ? cube (square)
cells Columnar epithelial ? column (elongated
cells)
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Cell Layer Types Simple ? single
layer Stratified ? 2 or more cell
layers Pseudostratified ? single, staggered
cell layer
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Examples
Function
Tissue Type
Lining of lungs and blood vessels
Diffusion and filtration
Simple Squamous
Ducts and Glands
Tubular secretion and reabsorption
Simple Cuboidal
Stomach and intestinal lining
Absorption of nutrients
Simple Columnar
Line nasal passages, thoat
Protection with mucus
Pseudostratified Columnar
Skin
Protection
Stratified Squamous
Salivary and Sweat glands
Protection
Stratified Cuboidal
Male urinary system
Protection
Stratified Columnar
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Glands A Closer Look
What is a gland? Epithelial cells that secrete
substances
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Types of Glands Endocrine Glands Secrete
substances in to __tissue fluid____ or
_blood__ EXAMPLES Thyroid, adrenal and
pituitary glands (Hormones)
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Exocrine Glands Secrete Substances in to
_ducts_____ that open into an internal or
external __surface_________

• Unicellular Exocrine Glands
• Include __goblet cells_______ ? secrete
  __mucous __ to protect internal body surfaces

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Multicellular Exocrine Glands When classified by
shape include 2 groups ___simple________
___compound________ Simple __single ___
ducts Compound __multiple ducts EXAMPLE
EXAMPLE Sweat glands, mucous glands in small
intestine Salivary glands
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When classified by method of secretion Merocrine
glands ? Secrete fluid through
_exocytosis______ EXAMPLE Salivary and sweat
glands most exocrine glands are
merocrine Apocrine glands ? Secrete substances
when part of the gland itself _breaks
off_____ EXAMPLE Mammary glands, lining of the
ear canal Holocrine glands ? Secrete substances
by creating _new cells___ EXAMPLE Sebaceous
(oil) glands of the skin
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Intro to Connective Tissue

• What is connective tissue?
• Most abundant tissue type by weight
• Bind structures, provide support and protection,
  serve as framework, fill spaces, store fat,
  produce blood, tissue repair and immunity

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• General Connective Tissue Characteristics
• Connective tissue cells tend to be _farther
  apart___ in comparison to epithelial cells.
• The intercellular space is filled with
  _matrix______
• The matrix is made up of _fibers________
  __ground substance__
• Functions include ? binding, supporting and
  transporting substances from blood to tissue
  cells

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Types of Connective Tissue Cells What are fixed
cells? Connective tissue cells that are present
in stable amounts Type of Cell Description
Function 1. Fibroblast large, star
shaped secrete proteins that become fibers
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Type of Cell Description
Function 2. Macrophages motile cells
usually engulf and destroy attached to
fibers foreign material
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Type of Cell Description Function 3. Mast
Cells large cells usually found Secretes
near blood vessels heparin prevents
clots histamine stimulates
inflammation (allergies)
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Fibroblasts A closer looks Fibroblasts may
secrete ____3____ types of fibers __Collagenous
(white)__ fibers ? Thick strands of collagen
(protein), very strong for holding structures
together (i.e. tendons and ligaments) __Elastic_(
yellow)_ fibers ? Bundles of microfibrils
embedded in elastin (protein), provide
elasticity _Reticular_ fibers ? thin strands of
collagen, provides support within tissue
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Connective Tissue Types All connective tissue is
made of the same parts. They differ in the
relative __amounts___ of each part.
Example
Function
Description
Tissue Type
- thin delicate membranes throughout the body
- binds skin to organs - fills spaces between
muscles - provides blood to epithelial tissue

• Contains many fibroblasts
• Cells relatively far apart separated by ground
  substance

Loose Connective
- fat tissue
- cushion joints and organs - insulation
- made of adipocytes (fibroblasts with fat)
Adipose
- found in the liver and spleen
- supports the walls of organs
- made of thin collagenous fibers in a 3D
network - many macrophages
Reticular
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- ligaments and tendons
- hold body parts together
- closely packed strands of collagenous fibers -
resist breakage, low blood supply
Dense Regular Connective
- dermis inner skin layers
- strength and stability
- thick, interwoven and randomly organized
collagenous fibers
Dense Irregular Connective
- attachments between vertebrae - parts of the
heart
- provides elasticity
- many elastic fibers surrounded by collagenous
fibers and fibroblasts
Elastic Connective
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- ribs, ears, tip of nose, intervertebral discs
- support and protection
- rigid connective tissue made of chondrocytes
Cartilage
- femur, skull
- internal body support
- most rigid connective tissue - osteocytes
surrounded by hard mineral salt matrix
Bone
- red and white blood cells -platelets
- transport gasses, fight infection and blood
clotting
- cells suspended in fluid matrix (plasma)
Blood
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• Cartilage and Bone A Closer Look
• Cartilage
• Structure
• Cartilage is very __rigid______ connective
  tissue.
• Cartilage cells are called __chondrocytes__
• Chondrocytes occupy small chambers in the
  _collagen fiber/gel___ matrix called __lacunae___
• Cartilage is difficult to heal because it
  _lacks__ blood vessels and has a __slow____ rate
  of cell division.

• Function
• Provides support and protection

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Types of Cartilage Type Description
EXAMPLE Hyaline Most common cartilage
type Between ribs, Found on the ends of
bones end of the nose
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Type Description EXAMPLE
Elastic Increased flexibility External ear
from elastic fibers
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Type Description EXAMPLE
Fibrocartilage Very rigid/tough tissue In knees
and High amount of collagen intervertebral
discs
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• Bone
• Bone is the __most____ rigid connective tissue
• Structure
• Bone contains _osteocytes____ found in pockets of
  the matrix called __lacunae_____
• Bones rigidity comes from __mineral salts___ and
  __collagenous_ fibers
• Function
• Internal support
• Movement when paired with muscle
• Store calcium and produce some blood cells

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Types of Bone Type Description Example Compac
t Bone very dense, lot of blood vessels outsides
of and nerves large bones Spongy Bone more
loosely packed collagen ends of bones and
calcium compounds
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• Muscle Tissue
• General Characteristics
• Muscle cells have an __elongated_ shape and are
  often called _fibers________
• Major function ___movement ______________
• __Movement______ is caused by ___contraction___
  and ___relaxation_ of the muscle tissues
• What are the 3 types of muscle?
• 1. Skeletal
• 2. Smooth
• 3. Cardiac

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• Types of Muscle A Closer Look
• Skeletal Muscle
• Connects to __bones___________
• Control is usually __voluntary_____
• What does this mean?
• Controlled through conscious thought
• Contains alternating light and dark
  cross-markings called __striations_______
• Skeletal muscle cells are __multinucleate__(many
  nuclei)
• Movement occurs when the muscle __contracts_ and
  _protein fibers____ slide past one another.

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• Smooth Muscle
• Gets its name from the lack of
  _striations_________
• Smooth muscle cells are _shorter________ than
  skeletal muscle cells
• __spindle shaped___ cell with one centrally
  located __nucleus_________
• Movement is completely __involuntary_______
• Where is it found?
• Digestive tract

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• Cardiac Muscle
• This is only found in the _heart_______
• Cells are __striated_____ and joined end to end
  at junctions called __intercalated discs
• Contractions are _involuntary______ and do not
  even require nervous stimulation

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• Nervous Tissue
• General Characteristics
• What is the function of nervous tissue?
• Sensory reception and stimulation of a response
  through conduction of impulses
• Individual nerve cells are known as
  __neurons____________
• A cluster of _neurons_____ make up a
  __nerve______

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Neuron Structure Cell body ? main structure of
the cell Dendrites ? finger like projections
that receive sensory information Axon ? single
arm used to send out the chemical information
for response How does a neuron work? The cell
receives sensory information through the
dendrites and then sends out a response to
muscles, glands etc. through the axon.
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EXAMPLES Olfactory neuron ? smell Retinal
neuron ? sight Epithelial neuron ? touch
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Cell to Cell Contact Review What is a
tissue? A group of similar cells working together
for a specific function Within a tissue it is
critical that cells _stick__________ together and
are able to ___communicate_ with one another.
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Types of Cell to Cell Connections Tight
Junctions What is it? Rows of __proteins_______
the seal cells together What does it
do? Prevents _molecules from getting stuck in
between cells____ Where is it found? Epithelial
cells of the intestines
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Types of Cell to Cell Connections
Adhering Junctions What is it? A mass of
_proteins____ called __desmosomes_______ that
seal cells together at a _specific
point____. What does it do? Holds cells together
at areas prone to __stretching_______ Where is
it found? Skin and stomach lining
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Types of Cell to Cell Connections
Gap Junctions What is it? Protein
__channels____ in between cells What does it
do? Promotes __cell to cell communication_ by
allowing __ions______ to move between
cells. Where is it found? Muscles of the heart
and digestive tract
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Membranes What is an organ? Two or more tissues
grouped together to perform a specialized
function What are epithelial membranes? Thin,
sheet-like structures made of epithelial and
connective tissue used to cover body surfaces and
line body cavities
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Types of Epithelial Membranes
EXAMPLE
What does it do?
Whats it made of?
Type
Inner lining of thorax and abdomen
Lines body cavities w/o outside openings
Simple squamous epithelium and loose connective
tissue
Serous Membrane
Oral and nasal cavities Tubes of the digestive
and respiratory system
Lines cavities and tubes that open to the outside
Various epithelial tissue containing goblet cells
and loose connective tissue
Mucous Membrane
Skin
Protection and sensory reception
Epidermis and dermis (epithelial and connective
tissues)
Cutaneous Membrane