Download Vertebrate Tissues

Vertebrate Tissues
OMHS Human Anatomy and Physiology Class
Tissues
• Groups of cells that have
specialized structural and
functional roles.
• 4 basic types of tissues: epithelial,
connective, muscle, and nervous.
Classification of Tissues
• Based upon shapes,
arrangements, and functions:
- Simple – single layer
- Stratified – many layers
- Cuboidal –cube shaped
- Columnar – elongated shape
- Squamous - flattened
A. Epithelial Tissue
• Protects, secretes, absorbs.
• Cover body surfaces, cover and
line internal organs, compose
glands.
• Always has a free surface (an
exposed surface).
Epithelial Cont.
• Anchored to connective tissue by nonliving layer called the basement
membrane.
• Lack blood vessels.
• Readily divide (injuries heal rapidly).
• Cells are tightly packed to form a good
barrier.
Simple
Squamous Epithelium
•Single layer of thin, flat cells.
•Allows for rapid diffusion of
substances; also filtration, osmosis.
• Found in alveoli of lungs and 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 moves 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, micro-organisms,
etc.).
•Forms epidermis; lines throat & mouth.
Stratified Squamous Epithelium
Basement Membrane
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.
Glandular Epithelium
• Cells that are specialized to
produce and secrete substances.
• Usually found within cuboidal or
columnar epithelia.
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.
(continued)
• 2 types of fibers
–Collagenous fibers - thick
threads of protein (collagen);
flexible; hold things together;
white fibers.
–Elastic fibers - made of protein
called elastin; weaker than c.f.
but stretch easily; vocal cords;
yellow fibers.
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.
• Chondrocytes occupy small chambers
called lacunae.
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.
Hyaline Cartilage
lacunae
Chondrocyte
b. Elastic Cartilage
• Web-like mesh of elastic fibers.
• Provides flexible, elastic support.
• External ear and parts of larynx.
Chondrocyte
Lacunae
c. Fibrocartilage
• Very tough, contains many collagen
fibers.
• Absorbs shock.
• Found in meniscus of knee,
intervertebral discs, etc.
Fibrocartilage
lacunae
chondrocyte
5. Bone
•Hardness due to mineral salts and many
collagen fibers in matrix.
•Matrix deposited in layers called
lamellae around tubes called Haversian
canals.
•Haversian canals contain blood vessels.
Bone (cont.)
• Bone cells are called osteocytes –
located in lacunae (chambers) spread
out between lamellae.
• Support, attachment for muscles,
mineral storage, protection (cranial
&thoracic cavities), forms blood cells.
• Found in skeleton.
Bone
Haversian Canal
Osteocytes in lacunae
Bone
Haversian canal
Osteocyte
6. Blood
•Transports materials throughout body;
helps maintain homeostasis.
•Matrix is fluid (called plasma).
Blood
Leucocytes
Thrombocytes
Erythrocytes
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 the heart.
• Pumps blood through heart chambers
and into blood vessels.
Cardiac Muscle
Intercalated disc
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 are called neurons.
Nerve Tissue
Cell Body
Nucleus
Axon
Dendrites
How well do you know your body tissue types?
Essay Questions
• What essay questions can you think of
that would be a good assessment of your
learning for this unit?
– How would you………..?
– What would result if…..?
– Describe how……………
– Compare and contrast…
– Why do you think………?