Transcript Human Tissue Types - Bibb County Public School District

Anatomy and
Physiology I
Tissue Types
Key Terms
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Histology:
 the study of tissues.
Tissues:
 groups of cells which are similar in
structure and which perform common or
related functions.
Four Basic Kinds of Tissues
 Epithelial
Tissue
 Connective Tissue
 Muscle Tissue
 Nervous Tissue
Epithelial Tissue
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Epithelial Tissue Locations:
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Covers the body
Lines the cavities, tubes, ducts and blood vessels
inside the body
Covers the organs inside body cavities
Epithelial Tissue Functions:
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Protection from physical & chemical injury,
Protection against microbial invasion,
Contains receptors which respond to stimuli,
Filters, secretes & reabsorbs materials and
Secretes serous fluids to lubricate structures.
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Examples of Epithelium Tissue
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Lines the respiratory tract
Lines the digestive system
Skin
Surrounding internal organs
Characteristics of Epithelium Tissue
1.
2.
3.
4.
5.
Cells are tightly packed
Regenerate easily
Avascular – lack blood vessels
apical surface – exposed surface
Basement membrane – anchors down cells
Connective Tissue
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Connective Tissue:
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Most abundant & widely distributed tissue
Connective Tissue Functions:
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Connects, binds and supports structures,
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Tendons, ligaments, etc.
Protects & cushions organs and tissues,
Insulates (fat) and
Transports substances (blood).
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Examples of Connective Tissue
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Bones
Cartilage
Tendons
Blood
Fat
Characteristics of Connective Tissue
1.
2.
3.
Most are well vascularized – have a good blood
supply
Some have very poor blood supply being
avascular.
Extracellular matrix – nonliving substance
found outside the cells
Extracellular Matrix explained
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Nonliving material between cells
Produced by the cells and then extruded
Responsible for the strength
Two components
1.
Ground substance
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2.
Of fluid, adhesion proteins, proteoglycans
Liquid, semisolid, gel-like or very hard
Fibers: collagen, elastic or reticular
Epithelial Tissue in Detail
Classification of epithelia
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According to thickness
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“simple” - one cell layer
“stratified” – more than one layer of cells
(which are named according to the shape of
the cells in the apical(base) layer)
According to shape
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“squamous” – wider than tall
“cuboidal” – as tall as wide
“columnar” - taller than wide
Classes of Epithelia
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Simple: just one
layer or cell shape
Human Anatomy, Larry M.
Frolich, Ph.D.
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Stratified:
multiple layers
and cell shapes
Simple Epithelia
Type
Cell shape
Example
Squamous
Squashed
Endothelium (lines blood
vessels), mesothelium
(serous lining of celom)
Cuboidal
Cubed
Walls of glands
Columnar
Columns
Pseudo-stratified
Flat cells give rise
to columns
Lining of gut tube;
sometimes with cilia like
lining of uterine tube
With cilia in respiratory
tubes to move
mucous/particles out of
lungs
Human Anatomy, Larry M. Frolich, Ph.D.
to protect
where diffusion is important
where tissues are involved
in secretion and absorption:
larger cells because of the
machinery of production,
packaging, and energy
requirements
Simple Squamous Epithelium
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Descriptions:
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Function:
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Single layer, flattened cells, simplest of epithelia
Allows passage of materials by diffusion and
filtration
Secretes lubricating substances
Location:
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Air sacs of lungs, lining of heart, blood vessels,
lining of ventral body cavity
Simple Cuboidal epithelium
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Descriptions:
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Function:
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Single layered, cube like, large spherical central
nuclei
Secretion and absorption
Location:
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Kidney tubules, ovary surfaces
“ciliated” literally =
eyelashes
(see next page)
Simple Columnar Epithelium
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Descriptions:
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Function:
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Single layer, tall, round or oval nuclei, some bear
cilia,
may contain mucus-secreting glands(goblet cells)
Absorption, secretion of mucus and enzymes,
cilia propels mucus
Location:
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Nonciliated lines the digestive tract
Ciliated lines small bronchi, uterine tubes, parts
of uterus.
Pseudostratified Columnar
Epithelium
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Descriptions:
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Function:
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Single layer w/ differing heights, nuclei at
different levels, may have goblet cells or cilia
Secretion(especially mucus), propulsion of mucus
by ciliary action
Location:
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Nonciliated in sperm carrying ducts
Ciliated lines the trachea and upper respiratory
tract.
Stratified: regenerate from below
Stratified Squamous Epithelium
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Descriptions: (most common stratified)
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Function:
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Several layers, surface cells are squamous, basal
cells are cuboidal or columnar
Protects underlying tissues in areas of abrasion
Location:
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Esophagus, the mouth, outer portion of skin
Rare…
Stratified Cuboidal Epithelium
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Descriptions: (rare)
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Function:
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Usually two layers of cube-like cells
Protection
Location:
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Rare
Largest ducts of sweat glands, mammary
glands, and salivary glands.
Rare…
Stratified Columnar Epithelium
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Descriptions: (rare)
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Function:
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Several layers thick, columnar with varying in
size and shape
Protection, secretion
Location:
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Rare
Large ducts of glands
Transitional Epithelium
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Descriptions:
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Function:
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Highly modified, several layers of cuboidal or
columnar cells
Stretches readily, allowing distention of
urinary organs
Location:
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Lines the ureters, bladder, parts of urethra
Human Anatomy, Larry M.
Frolich, Ph.D.
Quiz!!
E
Can You Identify the Classes of
Epithelium?
D
A
B
C
Human Anatomy, Larry M.
Frolich, Ph.D.
Specific Connective Tissue In Detail
Bone
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Descriptions: Aka: osseous tissue
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Function:
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Hard calcified matrix, surrounded by layers of
calcium salts in additions to lots of collagen
fibers
Cells sit in cavities called “lacunae”
Protection and support
Location:
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Skeletal system
Hyaline Cartilage
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Descriptions: (hyalin=glass)
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Function:
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Most common and widespread type
Collagen fibers with a rubbery matrix
Supports/reinforces, resilient cushioning
Location:
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Covers ends of bones in joints, nose, trachea,
larynx, embryonic skeleton
Elastic Cartilage
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Descriptions:
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Function:
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Collagen fibers with a rubbery matrix
Very elastic
Maintains shape of structure
gives flexibility
Location:
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External ear
epiglottis
Fibrocartilage
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Descriptions:
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Function:
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Similar to hyaline but less firm
Much like a cushion
Absorbs compressive shock
Location:
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Intervertebral discs, discs of knee joint
Dense Connective Tissue
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Descriptions:
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Function:
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Collagen fibers, fibroblasts fill gaps between
collagen
Strong ropelike structures like tendons and
ligaments
Connect muscles to bones, connect bones at
joints, lots of tensile strength
Location:
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joints
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Vocab
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Fibroblasts – cells that make collagen fibers
Tendons – attach skeletal muscles to bones
Ligaments - connect bones to bones at joints.
More stretchy and contain more elastic fibers
than tendon
Loose CT: Areolar Tissue
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Descriptions:
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Function:
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Gel-like matrix w/ all three fiber types
Very loose network w/ lots of open space
Wraps and cushions organs, a reservoir of water
and salts for surrounding tissues, important for
swelling
Location:
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Under epithelia, around organs, surrounds
capillaries
Loose CT: Adipose Tissue
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Descriptions: (fat)
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Function:
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Very similar to areolar tissue
Fat cells predominate
Insulates against heat loss, supports and
protects organs, reserve food fuel
Location:
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Under skin, around kidneys and eyeballs,
abdomen and breast
Loose CT: Reticular CT
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Descriptions:
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Function:
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Network of reticular fibers (similar to fibroblast)
Delicate network of interwoven fibers
Form soft internal skeleton that supports other
cells such as white blood cells, mast cells
Location:
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Lymphoid organs (lymph nodes, bone marrow,
spleen)
Blood
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Descriptions: (vascular tissue)
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Function:
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Red and white blood cells in a fluid matrix
(plasma)
Fibers are soluble only seen during clotting
Transportation of gases, nutrients, wastes
ect.
Location:
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Everywhere
Muscle Tissue
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Muscle Tissue:
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Associated with the bones of the skeleton, the heart and
in the walls of the hollow organs of the body.
Made to contract
Called muscle fibers because they are elongated to provide
a long axis for contraction
Muscle Tissue Functions:
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Movement
Maintains posture
Produces heat
Facial expressions
Pumps blood
Peristalsis
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Specific Muscle Tissue Types:
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skeletal muscle
Cardiac muscle
Smooth muscle
Skeletal Muscle
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Descriptions:
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Function:
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Long, cylindrical, obvious striations,
multinucleated
Voluntary movement, manipulation of the
environment, facial expression
Gross body movement
Location:
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Attached to bones
Cardiac Muscle
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Descriptions:
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Function:
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Branching, striated, uninucleated cells that fit
tightly together at junctions called
“intercalated disks”
Involuntary control, propels blood into
circulation.
Location:
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Walls of the heart
Smooth Muscle
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Descriptions: (visceral)
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Function:
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No striations, spindle-shaped w/ central nuclei
Arranged closely to form sheets
Propelles substances along internal
passageways, involuntary control
Peristalsis – wavelike motion
Location:
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Walls of the stomach, bladder, uterus and blood
vessels
Nervous Tissue
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Nervous Tissue:
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Main component of the nervous system,
ie., brain, spinal cord & nerves.
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Nervous Tissue Functions:
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Regulates & controls body functions
Generates & transmits nerve impulses
Supports, insulates and protects impulse
generating neurons.
Nervous Tissue
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Descriptions: (Neurons)
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Function:
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Branching cells, has long extended parts
Irritability and conductivity
Have “supporting cells” that insulate, support
and protect neurons.
Transmits electrical signals from sensory
receptors to effectors that control their activity
Location:
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Brain, Spinal cord and nerves
Muscle - Skeletal
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Muscle fibers (cells)
long, parallel &
cylindrical
With many nuclei
(multinucleate)
Striations (cross
stripes run
perpendicular to the
cells
Produce voluntary
movement
Locomotion
Heat
Specific Nervous Tissue Types
Nervous – Neuron
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Branching cells with
many long processes
Large central nucleus
Transmit impulses
from one area of the
body to other areas
Regulate activities
through neuron
impulses