Chapter 5 - Tissues

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Chapter 5 - Tissues
Membranes, Muscle Tissues, and
Nervous Tissues
Types of Membranes
• Epithelial Membranes
– Thin, sheetlike structures
– Usually composed of epithelial and underlying
connective tissues
– Cover body surfaces and line body cavities
– 3 major types
• Serous
• Mucous
• Cutaneous
Types of Membranes
• Epithelial Membranes
– Serous Membranes
• Consist of a layer of simple squamous epithelium
(mesothelium) and a thin layer of loose connective
tissue
• Cells of the membrane secrete watery serous fluid
which helps lubricate membrane surfaces
• Line body cavities that do not open to the outside
– Form the inner linings of the thorax and abdomen and cover
the organs within these cavities
• Reduce friction between organs and cavity walls
Types of Membranes
• Epithelial Membranes
– Mucous Membranes
• Consists of epithelium overlying a layer of loose
connective tissue
– The type of epithelium varies with the location of the
membrane
• Goblet cells within the membrane secrete mucus
• Line the cavities and tubes that open to the outside of
the body
– Includes oral and nasal cavities, and the tubes of the digestive,
respiratory, urinary, and reproductive systems
Types of Membranes
• Epithelial Membranes
– Cutaneous Membranes
• More commonly called skin…will be covered in next
chapter
Types of Membranes
• Synovial Membranes
– Composed completely of connective tissue
– Line joints
Muscle Tissues
• General Characteristics
– Have elongated cells commonly termed muscle
fibers
– Contractile…can shorten and thicken
• As muscle tissues contract, they pull at their attached
ends which moves body parts
– 3 types
• Skeletal muscle tissue
• Smooth muscle tissue
• Cardiac muscle tissue
Muscle Tissues
• Skeletal Muscle Tissue
– Forms muscles that usually attach to bone and that
are controlled by conscious effort (so it is often called
voluntary muscle tissue)
– Consists of cells that are long and narrow (threadlike), have alternating light and dark cross-markings
called striations, and many nuclei (multinucleate)
– When stimulated by a nerve cell, protein filaments
within the muscle cell slide past one another causing
the muscle cell to contract
• Skeletal muscles move the head, trunk, and limbs and allow
us to make facial expressions, to write, to talk, to sing, to
chew, to swallow, and to breathe.
Skeletal Muscle Tissue
Muscle Tissues
• Smooth Muscle Tissue
– Has cells that lack striations, are shorter than those of
skeletal muscle, are spindle-shaped, and have a single,
centrally located nuclei
– Comprises the walls of hollow internal organs (such as
the stomach, intestines, urinary bladder, uterus, and
blood vessels)
– Usually cannot be stimulated to contract by conscious
effort (thus, it is termed involuntary)
• Examples of locations/functions:
– moves food through the digestive tract
– constricts blood vessels
– empties the bladder
Smooth Muscle Tissue
Muscle Tissues
• Cardiac Muscle Tissue
– Only found in the heart
– Has cells that are striated and branched, have one
nucleus, and are joined end-to-end, resulting in
complex networks
• Intercalated discs (a specialized intercellular junction found
only in cardiac tissue) are located where cells touch
– Is not controlled voluntarily and can continue to
function without being stimulated by nerve impulses
– Makes up the bulk of the heart and pumps blood
through the heart chambers and into blood vessels
Cardiac Muscle Tissue
Nervous Tissues
• Found in the brain, spinal cord, and peripheral
nerve cells.
• Contain two types of cells
– Neurons
– Neurological cells
Nervous Tissues
• Neurons
– Basic nerve cells
– Highly specialized
– Coordinate, regulate, and integrate many body
functions
– Sense certain types of changes in their
surroundings and respond to these changes by
transmitting nerve impulses along cellular
processes to other neurons or to the muscles and
glands they connect with
Nervous Tissues
• Neurological Cells
– Support and bind the components of nervous
tissue
– Carry on phagocytosis
– Help supply nutrients to neurons by connecting
them to blood vessels
– Play a role in cell-to-cell communications
– May give rise to neural stem cells
Nervous Tissues
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