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Glandular Epithelium
• Main Function: Secretion
• Location: Lie in clusters deep to the
covering and lining epithelium
Two Types
• Endocrine
• Exocrine
Endocrine
• Secrete hormones into the bloodstream
Endocrine
• Location: pituitary, thyroid, and adrenal
glands
Exocrine
• Secrete products that are released onto
the skin surface or into the lumen of a
hollow organ.
Exocrine
• Products secreted: mucus, sweat, oil,
earwax, saliva, and digestive enzymes.
Exocrine
• Most glands are multicellular, but some are
single-celled like goblet cells.
Exocrine Glands
• Merocrine secretion - their products are
synthesized on fixed ribosomes (RER),
package in the golgi apparatus in
secretory vesicles and released via
exocytosis.
Exocrine Glands Continued
• Holocrine secretion - a secretory product
accumulates in the cytosol. Once the cell
matures it bursts and the cell itself
becomes the secretory product.
• Example: Sebaceous glands
Connective Tissue
• Vascular except cartilage and tendons
Connective Tissue
• Has a nerve supply
Connective Tissue
• Two major components:
1. Cells
2. Matrix
Types of Cells
1. Mesenchymal Cells: Mesodermal
embryonic cells that give rise to cells of
the connective tissue.
Types of Cells
2. Fibroblasts: Immature cells that secrete
the matrix in loose and dense connective
tissue.
Types of Cells
3. Chondroblasts: cells that secrete the
matrix in cartilage.
Types of Cells
• Once the matrix is produced,
chondroblasts differentiate into mature
cells called chondrocytes.
Types of Cells
4. Osteoblasts: Immature cells that secrete
the matrix in bone.
Types of cells
• Once the matrix is produced, osteoblasts
differentiate into mature cells called
osteocytes.
Types of Cells
5. Macrophages: Engulf bacteria and
cellular debris by phagocytosis.
Types of Cells
Found in lungs and spleen
Types of Cells
6. Plasma Cells: They secret antibodies.
(Antibodies are proteins that attack
foreign substances)
Types of Cells
 Found in salivary glands, lymph nodes,
red bone marrow, GI tract, and respiratory
tract.
Types of Cells
7. Mast Cells: Produce histamine.
(Histamine dilates small blood vessels
when the body undergoes injury or
infection)
Types of Cells
Found in blood vessels
Type of Cells
8. Adipocytes: Are fat cells that store
triglycerides.
Type of Cells
Found below skin, around the heart and
kidney.
Types of Cells
9. White Blood Cells: Not normally found in
connective tissue. They Migrate from the
blood into connective tissue in cases of
infection, parasitic invasion, and allergic
responses.
Connective Tissue Matrix
• Consists of:
1. Ground Substance
2. Fibers
Ground Substance
• Between cells and fibers
Ground Substance
• Supports cells and binds them together
Ground Substance
• Composed of interstitial fluid, cell
adhesion proteins, and proteoglycans.
Fibers
1. Collagen
2. Elastic
3. Reticular
Collagen
 Strong and resist pulling forces
Collagen
 Occur in bundles parallel to each other
Collagen
 Found in bone, cartilage, tendons, and
ligaments
Elastic
 Strong and can be stretched up to 150%
of their relaxed length.
Elastic
 Contain the property elasticity.
Elastic
 Found in skin, blood vessel walls, and lung
tissue
Reticular Fibers
 Provide support and strength
Reticular Fibers
• Thinner than collagen fibers and form
branching networks
Reticular Fibers
 Form a network around cells in areolar,
adipose, and smooth muscle tissue.
Reticular Fibers
 Found in spleen and lymph nodes.
Types of Connective Tissue
• Mesenchyme
• Mucous connective tissue
• Areolar connective tissue
• Adipose connective tissue
• Reticular connective tissue
• Dense regular connective tissue
• Dense irregular connective tissue
Types continued
• Elastic Connective Tissue
• Hyaline Cartilage
• Fibrocartilage
• Elastic Cartilage
• Bone tissue
• Blood tissue
• Lymph
Mesenchyme
• Irregular shaped mesenchymal cells
Mesenchyme
• Ground substance contains reticular fibers
Mesenchyme
• Mostly found under skin and along bones
of embryo
Mesenchyme
• Function: Forms all other connective
tissue
Mucous Connective Tissue
• There are widely scattered fibroblasts.
Mucous Connective Tissue
• Contains collagen fibers in ground
substance.
Mucous Connective Tissue
• Found in umbilical cord of fetus
Mucous Connective Tissue
• Support
Areolar Connective Tissue
• Loose Connective Tissue
Areolar Connective Tissue
• Contains collagen, elastic, and reticular
fibers
Areolar Connective Tissue
• Contains fibroblasts, macrophages, plasma
cells, adipocytes, and mast cells
Areolar Connective Tissue
• Found in subcutaneous layer of the skin,
papillary region of dermis of skin, and
around nerves, blood vessels, and organs
Areolar Connective Tissue
• Function: Attaches skin to underlying
tissues and organs, strength, elasticity,
and support.
Adipose Tissue
• Loose Connective Tissue
Adipose Tissue
• Contains adipocytes (store triglycerides)
Adipose Tissue
• The nucleus and cytoplasm of these cells
are in the periphery
Adipose Tissue
• Found in the subcutaneous layer deep to
the skin, around the kidney and heart,
yellow bone marrow.
Adipose Tissue
• Function: Reduces heat loss, supports,
protects, and serves as an energy reserve
Reticular Connective Tissue
• Loose Connective Tissue
Reticular Connective Tissue
• Contains reticular fibers and reticular cells
Reticular Connective Tissue
• Found in liver, spleen, lymph nodes, red
bone marrow, blood vessels, and muscles
Reticular Connective Tissue
• Function: Forms the supporting
framework of organs, binds smooth
muscle tissues together, filters and
removes worn-out blood cells in the
spleen and microbes in lymph nodes
Dense Regular Connective Tissue
• Dense Connective Tissue
Dense Regular Connective Tissue
• Contains collagen fibers arranged in
parallel bundles
Dense Regular Connective Tissue
• Shiny white matrix
Dense Regular Connective Tissue
• Contains fibroblasts in rows in between
parallel bundles
Dense Regular Connective Tissue
• Found in tendons and ligaments
Dense Regular Connective Tissue
• Function: Provides attachment between
structures
Dense Irregular Connective Tissue
• Dense Connective Tissue
Dense Irregular Connective Tissue
• Contains irregularly arranged collagen
fibers
Dense Irregular Connective Tissue
• Few Fibroblasts
Dense Irregular Connective Tissue
• Found in reticular region of the dermis of
skin, periosteum, perichondrium, joint
capsules, pericardium, heart valves, and in
membrane capsules of kidneys, livers,
testes, and lymph nodes
Dense Irregular Connective Tissue
• Function: strength
Elastic Connective Tissue
• Dense Connective Tissue
Elastic Connective Tissue
• Contains elastic fibers
Elastic Connective Tissue
• Contains fibroblasts in between fibers
Elastic Connective Tissue
• Found in lung tissue, walls of elastic
arteries, trachea, bronchial tubes, and true
vocal cords
Elastic Connective Tissue
• Function: Enables organs to stretch
Hyaline Cartilage
• Cartilage
Hyaline Cartilage
• Collagen fibers
Hyaline Cartilage
• Abundant chondrocytes
Hyaline Cartilage
• Bluish white shiny ground substance
Hyaline Cartilage
• Found in ends of long bones, ends of ribs,
nose, parts of larynx, trachea, bronchi,
and embryonic and fetal skeleton
Hyaline Cartilage
• Function: Gives a smooth surface for
movement in joints, flexibility, and support
Fibrocartilage
• Cartilage
Fibrocartilage
• Collagen Fibers
Fibrocartilage
• Chondrocytes
Fibrocartilage
• Pubic symphysis, intervertebral discs,
menisci of knee, and parts of tendons that
insert into cartilage
Fibrocartilage
• Function: Support and fusion
Elastic Cartilage
• Cartilage
Elastic Cartilage
• Elastic Fibers
Elastic Cartilage
• Chondrocytes
Elastic Cartilage
• Located in epiglottis, external ear, and
auditory tubes
Elastic Cartilage
• Function: Support and maintains shape
Compact Bone
• Bone
Compact Bone
• Contains osteons
Compact Bone
• Osteocytes
Compact Bone
• Found in bones of the body
Compact Bone
• Function: Support, protection, storage,
movement
Blood
• Blood
Blood
• Blood plasma
Blood
• Red blood cellls, white blood cells, and
platelets
Blood
• Found in Blood vessels and chambers of
heart
Blood
• Function: RBC’s transport oxygen and
carbon dioxide, WBC’s involved in immune
system response and allergic reactions,
platelets involved in clotting
Muscle Tissue
• Skeletal
• Cardiac
• Smooth
Skeletal
• Striated
Skeletal
• One nucleus
Skeletal
• Voluntary control
Skeletal
• Nucleus located in periphery
Skeletal
• Found attached to bone by tendons
Skeletal
• Function: Motion, posture, and heat
production
Cardiac
• Striated
Cardiac
• Usually contains one nucleus, but some
times contains two
Cardiac
• Involuntary Control
Cardiac
• Nucleus located in center
Cardiac
• Fibers Branched
Cardiac
• Found in Heart wall
Cardiac
• Pumps blood everywhere
Smooth
• Nonstriated
Smooth
• One nucleus
Smooth
• Involuntary
Smooth
• Nucleus located in center
Smooth
• Spindle shaped fibers
Smooth
• Found in walls of blood vessels, airways to
lungs, stomach, intestines, gallbladder,
urinary bladder, and uterus
Smooth
• Function: Motion
Nervous Tissue
• Neurons: nerve cells
• Neurons contain:
 Cell body
 Dendrites
 Axons
Nervous
• Found in nervous system
Nervous
• Function: Converts stimuli to nerve
impulses, and conducts these nerve
impulses to other neurons, muscle fibers,
and glands
Membranes
• Made up of epithelial and connective
tissue
Membranes
•
1.
2.
3.
4.
4 types:
Mucous
Serous
Cutaneous
synovial
Mucous
• Lines the passages of the digestive,
respiratory, urinary, and reproductive
tracts
Mucous
• Made up of epithelium with areolar
connective tissue beneath
Serous
• Lines cavities that are not open to the
exterior (peritoneal, pleura, and
pericardial)
Serous
• Made up of transudate(fluid that reduces
friction), mesothelium, and areolar
connective tissue
Cutaneous
• Skin
Cutaneous
• Made up of stratified squamous
epithelium, areolar connective tissue, and
dense irregular connective tissue
Synovial
• Lines joint cavities
Synovial
• It consists of epithelium with overlying
areolar connective tissue