Mastering A&P: Chapter 4

What do the glands shown in A and B both have in common? Both are unicellular. Both are sebaceous glands. Both are exocrine glands. Both are endocrine glands.

Both are exocrine glands. Both glands secrete substances onto body surfaces or into body cavities.

How do endocrine and exocrine glands differ?

Endocrine glands do not use ducts. Endocrine glands secrete substances (hormones) into blood without the use of ducts, whereas exocrine glands use ducts to secrete substances into the external environment.

Which tissue type consists of a sheet of cells that covers a body surface or lines a body cavity?

Epithelial tissue Epithelial tissue is a sheet of cells that covers a body surface or lines a body cavity (epithe = laid on, covering). In addition to coverings and linings, epithelial cells can also form glands.

Nervous tissue consists mainly of neurons and collagen fibers.

False

All muscle cells contain striations.

False *Smooth muscle cells do not contain striations. Although they do contain myofilaments, their arrangement is not regular enough to generate the striations seen in skeletal or cardiac muscle cells.

Merocrine glands produce their secretions by accumulating their secretions internally until the cell ruptures.

False, this is Holocrine glands

Which of the following is true about the mode of secretion of exocrine glands? *Holocrine cells are slightly damaged by the secretory process, but repair themselves. *These glands are ductless. *Apocrine cells are destroyed, then replaced, after secretion. *Merocrine glands are not altered by the secretory process

Merocrine glands are not altered by the secretory process.

__________ are water-soluble, complex glycoproteins that are secreted by goblet cells.

Mucin Like mucous cells, goblet cells are unicellular exocrine glands that secrete mucin, a protein that combines with water to form mucus. In goblet cells, the cuplike accumulation of mucin distends the top of the cell, making these cells look like a glass with a stem, thus "goblet" cell. This distortion does not occur in mucous cells.

Which of the following characteristics is lacking in the typical areolar connective tissue pictured in the figure?

None of these characteristics is lacking: elastic properties ground substance vascularity ability to support other tissues

________ epithelium appears to have two or three layers of cells, but all the cells are in contact with the basement membrane.

Pseudostratified columnar epithelium

Smooth muscle __________.

Smooth and cardiac muscle are under involuntary control. Skeletal muscle is under voluntary control.

What function do transitional epithelia have?

Stretching *Transitional epithelium is found in the urinary system. It lines the ureters, bladder, and proximal part of the urethra--organs that are subjected to distention or stretching as urine passes through or fills them

Why are adipose tissue, blood, and bone all considered to be connective tissues?

They have a common origin: the embryonic tissue mesenchyme. Adipose tissue, bone, and blood (like all connective tissues) are derived from mesenchyme, an embryonic tissue. Also common to all connective tissues is the presence of cells surrounded by extracellular matrix that consists of fibers and ground substance.

Blood is considered a type of connective tissue.

True (1) embryologically, it has the same origin (mesodermal) as do the other connective tissue types (2) blood connects the body systems together bringing the needed oxygen, nutrients, hormones and other signaling molecules, and removing the wastes.

Glands, such as the thyroid, that secrete their products directly into the blood rather than through ducts are classified as ________.

endocrine

Arteries, veins, and lymphatics keep clots from sticking as long as their ________ is intact and healthy -simple cuboidal epithelium -endothelium -transitional epithelium -mesothelium

endothelium epithelial cells line both internal surfaces and external surfaces of the body whereas endothelial cells line the internal surfaces of the components of the circulatory system. endothelium lines blood vessels, epithelium lines stomach

Which of the following is true about epithelia? *endothelium provides a slick surface lining all hollow cardiovascular organs. *Stratified epithelia are associated with filtration. *Pseudostratified epithelia are commonly keratinized. *Simple epithelia are commonly found in areas of high abrasion

endothelium provides a slick surface lining all hollow cardiovascular organs

A substance received or given off by your body will likely pass through which tissue type?

epithelial tissue Epithelial tissue is a sheet of cells that covers a body surface or lines a body cavity (epithe = laid on, covering). In addition to coverings and linings, epithelial cells can also form glands, called glandular epithelium.

Epithelial cells contain both blood vessels and nerve fibers.

false

Intercalated discs and striations are both characteristics of skeletal muscle.

false *cardiac muscle tissue

Endocrine glands are often called ducted glands.

false *exocrine

What are the three main components of connective tissue?

ground substance, fibers, and cells

Which of the following increases the surface area of certain epithelial tissues? *cilia *desmosomes *basement membrane *microvilli *basal lamina

microvilli Microvilli are small finger-like projections that greatly increase the surface area of epithelial cells (thus epithelial tissues), an important attribute of tissues that have a role in absorption and secretion.

You observe a tissue under a microscope. There appears to be a lumen on one side of the tissue. Lining this lumen is a single layer of epithelial cells that seem to have long, fingerlike projections. Beneath the projections, the cells seem to have the shape of shoeboxes and are packed tightly together. What type of tissue are you looking at?

simple columnar epithelium The shoebox represents the columnar shape. It is a simple epithelium because the cells are arranged into a single layer. Additionally, the fingerlike projections are likely to be microvilli.

Which tissue type is formed by many cells joining together, which are multinucleated?

skeleton Yes, skeletal muscle cells are elongated and many can be quite long; therefore, they have multiple nuclei.

A many-layered epithelium with cuboidal basal cells and flat cells at its surface would be classified as _______.

stratified squamous epithelium

A many-layered epithelium with cuboidal basal cells and flat cells at its surface would be classified as ________.

stratified squamous epithelium

A smooth muscle cell has a central nucleus but lacks striations.

true

Squamous cells are flattened and scale-like when mature.

true

What distinguishes the gland in A from the gland in B?

whether or not the secretory cells are destroyed in the process of secretion