Chapter 4 - Membranes

Synovial membranes line joints.

Lymph leaving lymph nodes includes many lymphocytes, while lymph from the small intestine has a high content of newly absorbed dietary lipids.

Platelets are essential for blood clotting.

Skeletal muscle tissue is usually attached to bones by tendons.

Mucous membranes line the entire digestive, respiratory, and reproductive tracts, and much of the urinary tract.

In the iris of the eyes, walls of hollow internal structures such as blood vessels, airways to lungs, stomach, intestines, gallbladder, urinary bladder, and uterus.

Blood plasma and formed elements—red blood cells, white blood cells, and platelets.

They line joint cavities and consist of areolar connective tissue; they do not have an epithelial layer.

Synovial fluid lubricates and nourishes the cartilage covering the bones at movable joints and contains macrophages that remove microbes and debris from the joint cavity.

Neurons and neuroglia.

The skin covers the surface of the body.

Skeletal muscle tissue consists of long, cylindrical, striated fibers with alternating light and dark bands. The fibers vary greatly in length and are multinucleated with nuclei at the periphery. It is considered voluntary because it can be made to contract or relax by conscious control.

It is flexible, allows movement, provides support, and is usually surrounded by a perichondrium.

Skeletal muscle tissue, cardiac muscle tissue, and smooth muscle tissue.

No, existing cardiac muscle fibers do not undergo mitosis to form new cells.

When an action potential occurs in a muscle fiber, the muscle fiber contracts, resulting in activities such as movement of the limbs, propulsion of food through the small intestine, and movement of blood out of the heart and into the blood vessels of the body.

Adhesions are abnormal joining of tissues, commonly forming in the abdomen around a site of previous inflammation or after surgery.

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease of connective tissue that can cause tissue damage in every body system. It is an autoimmune disease marked by periods of exacerbation and remission.

Atrophy is a decrease in the size of cells, leading to a subsequent decrease in the size of the affected tissue or organ.

The two layers of a serous membrane are the parietal layer, which lines the cavity wall, and the visceral layer, which covers and adheres to the organs within the cavity.

Cardiac muscle tissue consists of branched, striated fibers with usually one centrally located nucleus. The fibers attach end to end by transverse thickenings of the plasma membrane called intercalated discs, which contain desmosomes and gap junctions. It is involuntary and allows for quick conduction of electrical signals throughout the heart.

Dense regular, dense irregular, and elastic.

BAT generates heat.

Neurons exhibit sensitivity to various types of stimuli, convert stimuli into nerve impulses (action potentials), and conduct nerve impulses to other neurons, muscle fibers, or glands.

Stem cells divide to replace lost or damaged cells, residing in protected locations in the epithelia of the skin and gastrointestinal tract, and in red bone marrow to provide new red and white blood cells and platelets.

Tight junctions form fluid-tight seals between cells.

Transitional epithelium (urothelium) consists of several layers of cells whose appearance varies with the degree of stretching. It lines the urinary bladder.

A membrane is a flat sheet of pliable tissues that covers or lines a part of the body.

An epithelial membrane is a membrane that consists of an epithelial layer and an underlying connective tissue layer.

Lymph is the extracellular fluid that flows in lymphatic vessels. It is a liquid connective tissue consisting of several types of cells in a clear liquid extracellular matrix similar to blood plasma but with much less protein.

Red blood cells transport oxygen and some carbon dioxide.

Neuroglia do not generate or conduct nerve impulses but have many important supportive functions.

Hypertrophy is an increase in the size of a tissue because its cells enlarge without undergoing cell division.

The presence of specific voltage-gated ion channels allows action potentials to propagate along the plasma membrane of a neuron or muscle fiber.

Fibrosis is the process where fibroblasts synthesize collagen and other extracellular matrix materials to form scar tissue.

Epithelial cells have a continuous capacity for renewal.

A tissue is a group of cells, usually with similar embryological origin, specialized for a particular function.

Simple cuboidal epithelium, a single layer of cube-shaped cells, functions in secretion and absorption. It is found covering the ovaries, in the kidneys and eyes, and lining some glandular ducts.

The types of loose connective tissue are areolar connective tissue, adipose tissue, and reticular connective tissue.

The function of cardiac muscle tissue is to pump blood to all parts of the body.

Membranes are flat sheets of pliable tissue that cover or line a part of the body. Most membranes consist of an epithelial layer and an underlying connective tissue layer.

Dendrites are the major receiving or input portion of a neuron.

Motion, including constriction of blood vessels and airways, propulsion of foods through the gastrointestinal tract, and contraction of the urinary bladder and gallbladder.

To respond to stimuli by converting the stimuli into electrical signals called nerve action potentials and conducting nerve impulses to other cells.

Bone

Muscular tissue has a relatively poor capacity for renewal of lost cells.

Nutrition, blood circulation, and age.

Yes, mature, differentiated cells such as hepatocytes (liver cells) and endothelial cells in blood vessels can undergo cell division during tissue repair.

Epithelial tissue has many cells tightly packed together and is avascular, while connective tissue has relatively few cells with lots of extracellular material.

Cell types in connective tissue proper include fibroblasts, macrophages, plasma cells, mast cells, adipocytes, and white blood cells.

The functions of skeletal muscle tissue include motion, posture, heat production, and protection.

White blood cells carry on phagocytosis and mediate allergic reactions and immune system responses.

Smooth muscle tissue consists of nonstriated fibers, with spindle-shaped cells that are thickest in the middle, tapering at each end, and containing a single, centrally located nucleus.

Tissue rejection is an immune response of the body directed at foreign proteins in a transplanted tissue or organ. Immunosuppressive drugs, such as cyclosporine, have largely overcome tissue rejection in transplant patients.

Xenotransplantation is the replacement of a diseased or injured tissue or organ with cells or tissues from an animal. Porcine and bovine heart valves are used for some heart-valve replacement surgeries.

The ability to respond to certain stimuli by producing electrical signals such as action potentials.

Because of a smaller blood supply

Nervous tissue consists of neurons (nerve cells) and neuroglia.

There are four basic types of tissues: epithelial, connective, muscular, and nervous.

Nonciliated simple columnar epithelium lines most of the gastrointestinal tract and contains specialized cells that perform absorption and secrete mucus. Ciliated simple columnar epithelium is found in a few portions of the upper respiratory tract, where it moves foreign particles trapped in mucus out of the respiratory tract.

Mucous membranes line body cavities that open to the outside.

Cardiac muscle tissue is located in the heart wall.

A cell body, dendrites, and an axon.

In the liver, spleen, and lymph nodes.

Mucous, serous, and cutaneous membranes.

The connective tissue layer of a mucous membrane is areolar connective tissue, called the lamina propria.

Serous fluid acts as a watery lubricant that allows organs to glide easily over one another or to slide against the walls of cavities.

The replacement of worn-out, damaged, or dead cells by healthy ones.

The three types of muscular tissue are skeletal, cardiac, and smooth.

Neuroglia do not generate or conduct nerve impulses but have other important supporting functions.

Connective tissue consists of relatively few cells and an abundant extracellular matrix of ground substance and protein fibers. It usually has a nerve supply and is highly vascular.

A mucous membrane, or mucosa, lines a body cavity that opens directly to the exterior. It consists of a lining layer of epithelium and an underlying layer of connective tissue.

Neurons are sensitive to various stimuli, convert stimuli into electrical signals called nerve action potentials, and conduct these action potentials to other neurons, muscle tissue, or glands.

With aging, glucose is haphazardly added to proteins inside and outside cells, forming irreversible cross-links between adjacent protein molecules. Collagen fibers increase in number and change in quality, affecting the flexibility of arteries. Elastin thickens, fragments, and acquires a greater affinity for calcium.

Blood and lymph.

The cutaneous membrane consists of a superficial portion called the epidermis and a deeper portion called the dermis.

Granulation tissue is actively growing connective tissue that forms across a wound or surgical incision to provide a framework that supports epithelial cells.

Epithelial tissues get progressively thinner, connective tissues become more fragile, increased incidence of skin and mucous membrane disorders, wrinkles, more susceptibility to bruises, increased loss of bone density, higher rates of bone fractures, and increased episodes of joint pain and disorders.

Cell junctions are points of contact between adjacent plasma membranes.

Stratified epithelium consists of several layers of cells. The cell shapes at the apical layer can be squamous, cuboidal, or columnar, and it functions in protection and secretion.

Serous membranes line cavities that do not open directly to the outside.

The principal epithelial membranes of the body are mucous membranes, serous membranes, and the cutaneous membrane (skin).

The axon is the output portion of a neuron, conducting nerve impulses toward another neuron or to some other tissue.

Signs and symptoms of SLE include painful joints, low-grade fever, fatigue, mouth ulcers, weight loss, enlarged lymph nodes and spleen, sensitivity to sunlight, rapid loss of scalp hair, and anorexia. A distinguishing feature is a 'butterfly rash' across the nose and cheeks.

Tissues heal faster and leave less obvious scars in the young than in the aged; surgery performed on fetuses leaves no scars.

Satellite cells are stem cells in skeletal muscle tissue that do not divide rapidly enough to replace extensively damaged muscle fibers.

Vitamin C affects the normal production and maintenance of matrix materials, especially collagen, and strengthens and promotes the formation of new blood vessels.

Epithelial tissue consists mostly of cells with little extracellular material between adjacent plasma membranes. It is avascular but has a nerve supply and a high capacity for renewal.

The three types of fibers are collagen fibers, elastic fibers, and reticular fibers.

The epithelial layer of a mucous membrane acts as a barrier that microbes and other pathogens have difficulty penetrating. It also secretes mucus to prevent cavities from drying out, traps particles in the respiratory passageways, lubricates food in the gastrointestinal tract, secretes enzymes needed for digestion, and is the site of food and fluid absorption.

Synovial membranes are composed of a discontinuous layer of cells called synoviocytes and a layer of connective tissue (areolar and adipose) deep to the synoviocytes.

Nervous tissue has the poorest capacity for renewal.

Wound dehiscence is the partial or complete separation of the outer layers of a sutured incision.

The two types of glandular epithelium are endocrine and exocrine. Endocrine glands secrete hormones into interstitial fluid and then into the blood, while exocrine glands secrete into ducts or directly onto a free surface.

Muscular tissue consists of elongated cells called muscle fibers or myocytes that can use ATP to generate force. It produces body movements, maintains posture, generates heat, and provides protection.

When an action potential forms in a neuron, the neuron releases chemicals called neurotransmitters, which allow neurons to communicate with other neurons, muscle fibers, or glands.

Tissue repair is the replacement of worn-out, damaged, or dead cells.

The subtypes of epithelial tissue include covering and lining epithelium (surface epithelium) and glandular epithelium.

The ground substance supports and binds cells together, provides a medium for the exchange of materials, stores water, and actively influences cell functions.

Neurons and muscle fibers are considered excitable cells because they exhibit electrical excitability, the ability to respond to certain stimuli by producing electrical signals such as action potentials.

Tissue regeneration is the process where parenchymal cells accomplish the repair, leading to a near-perfect reconstruction of the injured tissue.

New cells originate by cell division from the stroma (supporting connective tissue) or from the parenchyma (cells that constitute the functioning part of the tissue or organ).

Covering and lining epithelium can be simple, pseudostratified, or stratified. The cell shapes may be squamous (flat), cuboidal (cubelike), columnar (rectangular), or transitional (variable).

The two major subclasses of connective tissue are embryonic (found in embryo and fetus) and mature (present in the newborn).

Simple squamous epithelium, a single layer of flat cells, is found in parts of the body where filtration or diffusion is a priority process. Endothelium lines the heart and blood vessels, and mesothelium forms the serous membranes that line the thoracic and abdominopelvic cavities.