Transcript Vertebrate Tissues

Vertebrate Tissues
Dr. Strong’s Zoology Class
OMHS
Tissues
• Groups of cells that have
specialized structural and
functional roles
• 4 basic types of tissues: epithelial,
connective, muscle, and nervous
A. Epithelial Tissue
• Protects, secretes, absorbs
• Cover body surfaces, cover and
line internal organs, compose
glands
• Always has a free surface (an
exposed surface)
Classification of Tissues
• Based upon shapes,
arrangements, and functions
- Simple – single layer
- Stratified – many layers
- Squamous - flattened
- Cuboidal –cube shaped
- Columnar – elongated shape
Simple
Squamous Epithelium
•single layer of thin, flat cells
•Allows for rapid diffusion of
substances; also filtration, osmosis
• Found in alveoli of lungs, lines
inside of blood vessels
•Thin and delicate – easily damaged
Simple
Squamous Epithelium
Simple
Cuboidal Epithelium
• single layer of cube-shaped cells
• Absorption & secretion
• lines kidney tubules, etc.
Simple
Cuboidal Epithelium
Simple
Columnar Epithelium
•Single layer of tall, narrow cells
• lines most organs of digestive tract
•Secretes digestive fluids & absorbs
nutrients from food
Simple
Columnar Epithelium
Often have microvilli and secrete mucous
Pseudostratified Ciliated
Columnar Epithelium
•Single row of cells- not all reach the
free surface, but each cell borders
the basement membrane
•Protects, secretes, & moves mucous
• lines respiratory system, mucous
traps dust, etc; cilia move mucous
out
Pseudostratified Ciliated
Columnar Epithelium
Cilia
Goblet Cellssecrete mucus
Basement
Membrane
Stratified Squamous Epithelium
•many layers of cells; cells divide in
deeper layers and push older cells
outward
•Layering = protection (prevents water
loss and entry of chemicals, microorganisms, etc.)
•forms epidermis; lines throat & mouth
Stratified Squamous Epithelium
Basement Membrane
Stratified Squamous
● Keratinized – extra, tougher
layers of dead skin cells to add
protection. Thickest on the
palms of hands and soles of
feet.
● Nonkeratinized – layers of
living cells found in areas where
friction occurs such as in the
mouth and throat where food is
chewed and swallowed.
Transitional epithelium
• Changes in response to tension
(can stretch)
• Inner lining of bladder
• Protects – prevents contents of
urinary tract from diffusing back
into internal environment
4 Basic Tissue Types
B.Connective Tissue
– Supports, binds together, protects
– Most widely distributed tissue in
body
– Usually well-vascularized
– Has a matrix - material between cells
• Consists of fibers and a ground
substance
1. Loose connective tissue
(Areolar Tissue)
• Cells are mainly fibroblasts (cells that
produce fibers in the matrix)
• Matrix = gel-like ground substance and
many collagen and elastin fibers
• Binds skin to organs & fills space
between muscles
• Has many blood vessels that nourish
nearby epithelial cells
Loose Connective Tissue
2. Adipose Tissue (fat)
• Made up of cells that store fat
• Beneath skin; between muscles;
around kidneys; surface of heart;
around joints
• Cushions joints and organs
• Insulates
• Stores energy
Adipose Tissue
Large, empty-looking cells with thin
margins; nucleus pressed against
cell membrane
•
3. Dense Connective Tissue
• Densely packed, parallel collagen
fibers (white) with only a few
fibroblasts
• Very strong; makes up tendons and
ligaments
• Low blood supply injuries slow to
heal
Dense Connective Tissue
fibroblasts
4. Cartilage
• Cartilage cells = chondrocytes
3 types of cartilage found in the body:
a. Hyaline Cartilage
• Very fine collagen fibers in matrixlooks like glass.
• Found on ends of bones, soft part of nose, rings that
support airway, fetal skeleton.
b. Elastic Cartilage
●
Very flexible. Found in ear.
c. Fibrocartilage
• Can act as a shock absorber in knee.
5. Bone
•Hardness due to mineral salts and many
collagen fibers in matrix.
Bone cells are called osteocytes.
Function - support, attachment for
muscles, mineral storage, protection
(cranial & thoracic cavities), forms blood
cells
Found in skeleton.
Bone
Haversian Canal
Osteocytes in lacunae
6. Blood
•Transports materials (nutrients and
oxygen) throughout body; helps maintain
homeostasis
•Matrix is fluid (called plasma)
Blood
Leucocytes
Thrombocytes
Erythrocytes
Six types of connective tissue
C. Muscle Tissue
• Made up of elongated cells
(muscle fibers) that can contract
• Functions in movement of body
parts
• 3 types
–Skeletal Muscle
–Smooth Muscle
–Cardiac Muscle
Skeletal Muscle
•multi-nucleated; striated – light
and dark bands
• Voluntary – can be controlled by
conscious effort
• Found: attached to bones
Skeletal Muscle
striations
Smooth Muscle
• one nucleus; unstriated
• Found: walls of hollow internal organssuch as esophagus, intestines,
stomach, blood vessels, etc.
• Involuntary
• Move food through digestive tract, blood
through blood vessels, etc.
Smooth Muscle
Nuclei
Cardiac Muscle
• Striated, one nucleus, branched
• Has intercalated disks (where cells
are connected)
• involuntary
• Found: only in heart
• Pumps blood through heart chambers
and into blood vessels
Cardiac Muscle
Intercalated disc
3 Types of Muscle Tissue
D. Nerve Tissue
• Sensory reception and
conduction of nerve impulses;
allows for communication and
coordination of body functions
• Found in brain, spinal cord,
nerves
• Cells called neurons
Nerve Tissue
Cell Body
Nucleus
Axon
Dendrites
Tissues form Organs
Most organs are made of
several types of tissues.