Tissue: The Living Fabric
Te epidermis (epithelium of the cutaneous membrane or skin)
is a keratinized stratiﬁed squamous epithelium. Explain why
that epithelium is much better suited for protecting the body’s
external surface than a mucosa consisting of a simple columnar
epithelium would be.
Your friend is trying to convince you that if the ligaments binding
the bones together at your freely movable joints (such as your
knee, shoulder, and hip joints) contained more elastic ﬁbers, you
would be much more ﬂexible. Although there is some truth to this
statement, such a condition would present serious problems. Why?
In adults, over 90% of all cancers are either adenomas
(adenocarcinomas) or carcinomas. (See Related Clinical ±erms for
this chapter.) In fact, cancers of the skin, lung, colon, breast, and
prostate are all in these categories. Which one of the four basic
tissue types gives rise to most cancers? Why do you think this is so?
Cindy, an overweight high school student, is overheard telling her
friend that she’s going to research how she can transform some of
her white fat to brown fat. What is her rationale here (assuming it
Mrs. Delancy went to the local meat market and bought a beef
tenderloin (cut from the loin, the region along the steer’s vertebral
column) and some tripe (cow’s stomach). What type of muscle
was she preparing to eat in each case?
Name the speciﬁc connective tissue type found in the following
body locations: (a) forming the soF packing around organs,
(b) supporting the ear pinna, (c) forming “stretchy” ligaments,
(d) ﬁrst connective tissue in the embryo, (e) forming the
intervertebral discs, (f) covering the ends of bones at joint
surfaces, (g) main component of subcutaneous tissue.
What is the function of macrophages?
Diﬀerentiate between the roles of neurons and the supporting
cells of nervous tissue.
Compare and contrast skeletal, cardiac, and smooth muscle tissue
relative to structure, body location, and speciﬁc function.
Describe the process of tissue repair, making sure you indicate
factors that inﬂuence this process.
Indicate which primary tissue classes derive from each embryonic
In what ways are adipose tissue and bone similar? How are they
and Clinical Application
John sustained a severe injury during football practice and is
told that he has a torn knee cartilage. Can he expect a quick,
uneventful recovery? Explain your response.
Related Clinical Terms
neoplasm of glandular epithelium, benign or malignant.
Te malignant type is more speciﬁcally called
top-se) Examination of the body, its organs, and its
tissues aFer death to determine the actual cause of death; also
called postmortem examination and necropsy.
crab, cancer) Cancer arising
in an epithelium; accounts for 90% of human cancers.
Healing by ﬁrst intention
Te simplest type of healing; occurs when
the edges of the wound are brought together by sutures, staples,
or other means used to close surgical incisions. Only small
amounts of granulation tissue need be formed.
Healing by second intention
Te wound edges remain separated,
and relatively large amounts of granulation tissue bridge the gap;
the manner in which unattended wounds heal. Healing is slower
than in wounds in which the edges are brought together, and
larger scars result.
loid) Abnormal proliferation of connective tissue during
healing of skin wounds; results in large, unsightly mass of scar
tissue at the skin surface.
zhun; “wound”) Any injury, wound, or infection that
aﬀects tissue over an area of a deﬁnite size (as opposed to being
widely spread throughout the body).
Genetic disease resulting in abnormalities of
connective tissues due to a defect in ﬁbrillin, a protein that is
associated with elastin in elastic ﬁbers. Clinical signs include
loose-jointedness, long limbs and spiderlike ﬁngers and toes,
visual problems, and weakened blood vessels (especially the
aorta) due to poor connective tissue reinforcement.
Osteogenesis imperfecta (brittle bone disease)
An inherited condition
that causes defective collagen production. Because collagen
reinforces many body structures including bones, the result is weak
bones that break easily. It is not unusual for its victims to have 30
or more fractures during their lifetime. Occurs in 1 out of 20,000
births. Misdiagnosis results in many infants coming to the ER with
multiple fractures being treated as battered babies.
o-je) Scientiﬁc study of changes in organs and
tissues produced by disease.
A collection of tissue ﬂuid, bacteria, dead and dying tissue cells,
white blood cells, and macrophages in an inﬂamed area.
tumor) Cancer arising
in the mesenchyme-derived tissues, that is, in connective tissues
A nutritional deﬁciency caused by lack of adequate vitamin
C needed to synthesize collagen; signs and symptoms include
blood vessel disruption, delay in wound healing, weakness of
scar tissue, and loosening of teeth.
VAC (vacuum-assisted closure)
Innovative healing process for
open-skin wounds and skin ulcers. OFen induces healing when
all other methods fail. Involves covering the wound with a
special sponge, and then applying suction through the sponge.
In response to the subsequent skin stretching, ﬁbroblasts in
the wound form more collagen tissue and new blood vessels
proliferate, bringing more blood into the injured area, which also
AT T H E C L I N I C