Chapter 4 Flashcards
(32 cards)
What are tissues?
specialized cells of the same type that perform a common function in the body.
Name the four major tissue types. Briefly, what are their functions?
connective tissue
muscular tissue
nervous tissue
epithelial tissue
What are the three basic components that all connective tissues contain? What is the matrix portion of
connective tissue?
specialized cells (These are living cells.),
ground substance (nonliving),
protein fibers (nonliving).
The term matrix includes ground substance and fibers.
Connective tissue consists of living cells in a nonliving matrix.
What three types of fibers are found in connective tissue?
collagen, reticular, and elastic fibers
Describe fibrous connective tissue. Distinguish among loose fibrous connective tissue, adipose tissue, and dense fibrous connective tissue.
Loose fibrous connective tissue (areolar) supports epithelium and many internal organs.
Adipose tissue is a specialized form of connective tissue in which cells enlarge and store fat.
Dense fibrous connective tissue contains collagen fibers packaged together and makes up tendons and ligaments.
Describe supportive connective tissue.
Cartilage and bone are supportive connective tissues with a solid extracellular matrix.
Cartilage is more flexible than bone.
Distinguish among the following types of cartilage: hyaline cartilage, elastic cartilage, fibrocartilage.
hyaline cartilage (at the ends of bones and comprising the fetal skeleton),
elastic cartilage (forming a flexible frame for the outer ear),
fibrocartilage (making pads in the knee and vertebral column).
What substances are responsible for the hardness of bone?
The matrix of bone is hard because it contains inorganic salts, particularly calcium salts.
Distinguish between compact bone and spongy bone.
Compact bone makes up the shaft of the long bone. It consists of cylindrical structural units called osteons. The central canal of each osteon is surrounded by rings of hard matrix. Bone cells are located in lacunae between the rings of matrix.
Spongy bone is made up of bars and bony plates and is lighter than compact bone.
Describe the following liquid connective tissues: blood, lymph. What makes up the matrix of each?
What kinds of cells are found in each?
Blood is a connective tissue in which the matrix is a liquid called plasma. Red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes) are in blood.
Lymph is also a fluid connective tissue. It is a clear, watery fluid derived from tissue fluid that contains white blood cells.
Describe the function of muscle tissue
Muscular tissue is specialized to contract. It is composed of cells called muscle fibers.
Distinguish among the following types of muscle: skeletal muscle, smooth muscle, cardiac muscle.
Where is each type found? Are they voluntary or involuntary? Do they have striations? What are intercalated disks?
Skeletal muscle is called voluntary muscle and contains stripes or striations. It is found in muscles attached to bones. Skeletal muscle cells are multinucleate.
Smooth muscle lacks striations, is composed of spindle-shaped cells, and is found in internal organs. It is also known as visceral muscle. Smooth muscle cells have one nucleus per cell. Smooth muscle is involuntary.
Cardiac muscle is also striated. It has one nucleus per cell. Cardiac muscle is involuntary and is found only in the walls of the heart. Cardiac muscle cells are branched and contain intercalated disks.
What are the two components of nervous tissue? What are the three functions of nervous tissue?
Nervous tissue consists of nerve cells, called neurons, and neuroglia, the cells that support and nourish the neurons.
The nervous system serves three purposes: sensory input, integration of data, motor output.
Describe the three parts of a neuron and their functions.
- dendrites to receive signals from sensory receptors or other neurons,
- cell body where the nucleus is located,
- axon to conduct nerve impulses.
Name three kinds of neuroglial cells. What are their functions?
There are several types of neuroglial cells, which support, nourish, and protect neurons. Examples include microglia, astrocytes, and oligodendrocytes.
Describe the function and location of epithelial tissue
Epithelial tissue covers the body and lines its cavities.
Epithelial cells are exposed to the environment on one side.
On the other side, a basement membrane joins epithelium to underlying connective tissue.
Describe simple epithelia. What shapes are found among these cells? Where would simple epithelia
be found?
Simple epithelia have only a single layer of cells, which can be:
flattened (squamous),
cube-shaped (cuboidal), or
resembling rectangular columns (columnar).
This type can be found in the air sacs of lungs, in the walls of blood vessels, covering the ovaries, lining kidney tubules, and lining the digestive tract
Describe pseudostratified columnar epithelium. Where would it be found?
Pseudostratified columnar epithelium is so named because it appears to be layered, but each cell actually touches the basement membrane.
This type can be found in the lining of the trachea.
Distinguish between the following types of glandular epithelia: exocrine glands, endocrine glands.
Give examples of each.
When an epithelium secretes a product, it is said to be glandular.
Exocrine glands secrete their product onto the outer surface or into a cavity via a duct, while endocrine glands secrete their products directly into the bloodstream.
What is stratified epithelium? Distinguish between stratified squamous epithelium and transitional epithelium. Where would each be found? What is keratin?
Stratified epithelia have layers of cells piled one on top of the other, the bottom layer touching the basement membrane.
Stratified squamous epithelium can be found in the nose, mouth, esophagus, anal canal, outer portion of the cervix, and vagina.
The outer layer of the skin contains stratified squamous epithelium reinforced by keratin.
Transitional epithelium is used to imply changeability, because it changes in response to tension. It forms the lining of the urinary bladder.
Define: integumentary system. What is its function?
The integumentary system, or skin, is an example of an organ system because it contains accessory structures such as nails, hair, and glands.
Skin covers the body and protects underlying tissues from physical trauma, pathogen invasion, and water loss.
Describe the functions of the following epidermal cells: basal cells, Langerhans cells, melanocytes.
The epidermis contains basal cells that produce new epithelial cells, which become keratinized as they move toward the surface.
Specialized cells called Langerhans cells phagocytize pathogens and protect the body from invading organisms.
Melanocytes produce melanin, the main pigment responsible for skin color, and protect the skin from the damaging effects of ultraviolet radiation.
Epidermal cells can also make vitamin D.
What might be the effect of ultraviolet radiation on the epidermis?
Too much ultraviolet radiation is dangerous and can lead to skin cancer. Basal cell carcinoma is the most common type of skin cancer and the most curable. Melanoma is extremely serious. Steps should be taken to protect the skin from ultraviolet radiation.
Describe the structure of the dermis of the skin. What types of tissues would be found here?
The dermis, a largely fibrous connective tissue, contains epidermally derived glands and hair follicles, nerve endings, and blood vessels.
Sensory receptors for touch, pressure, temperature, and pain are also present.
