Histology
Histology
The study of different types of tissues
Tissue: Cells working together in
functionally related groups
Histology
Separated into four major categories based on
their function and the embryonic tissue of
origin
Tissue
Function
Epithelial
Cover & Protection
Connective
Support
Muscle
Movement & contraction
Nervous
Signaling & communication
Tissue Engineering: How to Build a Heart
ANSWER THESE QUESTIONS IN
COMPELTE SENTENCES INTO YOUR
NOTEBOOK! TITLE THE SECTION: HOW
TO BUILD A HEART
1. Explain why blood supplies pose such a
challenge to tissue engineers?
2. Describe what a scaffold is. Does it have to be
human?
3. What is decellurization?
4. What is recellurization?
5. What are iPS cells?
6. What are some organs that have been
transplanted successfully?
Epithelial Tissue
Location:
◦ Lines nearly every cavity and surface of the human
body
◦ Form glands
Function:
◦ Protect the tissues they cover
◦ Regulate gas and nutrient exchange
◦ Secrete substances such as sweat, hormones,
mucus, and enzymes
◦ Provide sensation with the environment
Epithelial
Classification
◦ Last name of tissue
describes the SHAPE of
cells
◦ Squamous: cells wider
than tall
◦ Cubodial: cells are as
wide as tall, as in “cubes”
◦ Columnar: cells are
taller than they are wide,
like columns
Epithelial
Classification:
◦ First name of tissue
indicates the number of
layers
◦ Simple: One layer of
cells
◦ Stratified: More than
one layer
of cells
Epithelial
Special characteristics:
◦ Cells are packed tightly together, forming a
protective layer around organs
◦ High capacity for regeneration
◦ Produce fluids for lubricating tissues and
organs
◦ Avascular: No capillaries that directly nourish
the cells
Cells get what they need through diffusion of
nutrients through the basement membrane
Simple Squamous Epithelium
Single layer of flat cells with disc-shaped
nuclei
Function:
◦ Passage of materials by passive diffusion and
filtration
◦ Secrete lubricating substances in serosae
Simple Squamous Epithelium
Location
◦
◦
◦
◦
Renal corpuscles
Alveoli of lungs
Lining of heart, blood, and lymphatic vessels
Lining of ventral body cavity
Simple Cuboidal Epithelium
Single layer of cube-like cells with large,
spherical nuclei
Function:
◦ Secretion and absorption
Simple Cuboidal Epithelium
Location:
◦ Kidney tubules
◦ Secretory portions of small glands
◦ Ovary and Thyroid follicles
Simple Columnar Epithelium
Single layer of column-shaped cells with
oval nuclei
◦ Some may have cilia
Function:
◦ Absorption
◦ Secretion of mucus, enzymes, and other
substances
◦ Ciliated type propels mucus or reproductive
cells by ciliary action
Simple Columnar
Location:
◦ Non-ciliated: lines digestive tract, gallbladder,
ducts of some glands
◦ Ciliated form: lines small bronchi, uterine
tubes, uterus
Connective Tissues
Most abundant tissue type in the body
◦ Ex: blood, bone, cartilage, tendons, ligaments…
Made up of fibers and extracellular
components in the embedded in fluid
Types of Connective Tissues
◦
◦
◦
◦
Loose Connective Tissue
Dense Connective Tissue
Cartilage
Other Tissues
Connective Tissue
Function:
◦
◦
◦
◦
◦
Protect
Store energy
Transport
Insulate
Connect all body
tissues
Cartilage
Hyaline:
◦ Provides support while still being pliable, most abundant
form
◦ Found in the ends of long bones, nose, trachea, and
larnyx
Elastic
◦ Provides support while still able to stretch
◦ Supports external ear, epiglottis
Cartilage
Fibrocartilage:
◦ Provides strong support and handles heavy
pressure
◦ Found in intervertebral discs, pubic symphysis,
discs of knee joints
Muscle Tissue
Cells are extremely long and contain
protein fibers capable of contracting
Separated into 3 main types:
◦ Skeletal muscle tissue
◦ Smooth muscle tissue
◦ Cardiac muscle tissue
TedEd Types of Muscle Tissue
Skeletal Muscle Tissue
Voluntary muscle
◦ Can be contracted voluntarily
◦ Function in movement and maintenance of
posture
◦ Visible striations
Makes up the muscles that are attached to
our skeleton
Smooth Muscle Tissue
Involuntary muscle
◦ Muscle does not contract voluntarily
◦ Lines most of the organs of the body
◦ No visible striations
Found in:
◦
◦
◦
◦
◦
GI Tract
Respiratory Tract
Blood vessels
Bladder
Uterus
Cardiac Muscle
Heart, extremely dense, strong tissue
Involuntary
Large number of mitochondria to provide energy
for the continuous contracting of the heart
Striated like muscle tissue
Nervous Tissue
Found in the brain, spinal cord, and nerves
Consists of 2 main cells
◦ Neurons
◦ Neuroglia cells
Responsible for communication
0
