Module 4 Tissues Flashcards
Define the term tissue.
A tissue is a group of similar cells that usually have a similar embryological origin and are specialized for a particular function.
Name the 4 primary adult tissue types.
Epithelial tissue, connective tissue, muscle tissue, and nervous tissue.
Describe epithelial tissue.
Covers the body surfaces; lines hollow organs, body cavities, and ducts; and forms glands. Epithelial tissue provides external protection for underlying tissue.
Describe connective tissue.
Protects and supports the body and it’s organs, binds organs together, stored energy reserves as fat, and provides immunity.
Describe muscle tissue.
Is responsible for most movement and generation of force.
Describe nervous tissue.
Initiates and transmits action potentials (nerve impulses) that help coordinate body activities, monitors the external environment, and contributes to homeostasis.
Describe the cell shapes and arrangement of layers for surface epithelium.
Shape: squamous, cuboidal, columnar.
Arrangement of layers: simple, pseudostratified, stratified.
Describe the general features of epithelial tissues.
Arranged in sheets (single or multiple), packed cells with many cell junctions, apical surface and basal surface attached to a base membrane, has nerve supply and high capacity for renewal, avascular.
Describe the basement membrane.
Made of a cellular layer of collagen and glycoproteins called the basal lamina; often underlain w/a layer of reticular fibers and glycoproteins called the reticular lamina.
What functions do the epithelia include?
Protection, filtration, lubrication, secretion, digestion, absorption, transportation, excretion, sensory reception, and reproduction.
Describe the cell shapes.
Squamous (flat), cuboidal (cube-like), columnar (tall rectangular), and transitional (variable).
Describe the cell layers and their arrangements.
Simple (1 layer), stratified (several layers), pseudostratified (1 layer that appears as several).
Describe the simple squamous epithelium.
Consists of a single layer of flat, scale-like cells. It is adapted for diffusion and filtration and is found in the lungs and kidneys.
It is found in parts of the body that are subject to little wear and tear. The _____ lines the heart and blood vessels.
Endothelium
The ___ lines the thoracic and abdominopelvic cavities and covers the organs with them.
Mesothelium
Describe the simple cuboidal epithelium.
Consists of a simple layer of cube-shaped cells, and performs the functions of secretion and absorption. Found in the kidneys.
The simple columnar epithelium consists of a single layer of rectangular cells, which can have 2 forms: _____ and _____.
Nonciliated simple columnar epithelium and ciliated simple columnar epithelium
Describe nonciliated simple columnar epithelium.
Contains microvilli to increase surface area. Lines most of the gastrointestinal tract.
What do goblet cells do?
Secrete mucous
Describe ciliated simple columnar epithelium.
Contains cells with cilia-motile, hair like processes that help to move fluids or particles along a surface. Lines the uterine tubes.
Describe stratified epithelium.
Has at least 2 layers of cells, more durable and protective.
Describe pseudostratified epithelium.
Has only 1 layer but gives the appearance of many. All cells are attached to the basement membrane, but some do not reach the apical surface
Describe pseudostratified ciliated columnar epithelium.
The cells that reach the surface either secrete mucus (goblet cells) or bear cilia that sweep away mucus and trapped foreign particles. Lines the airways of most upper respiratory tract.
Describe pseudostratified nonciliated columnar epithelium.
Contains no cilia or goblet cells. lines ducts if many glands; parotid glands.
Describe stratified squamous epithelium.
Consists of several layers of cells in which the top layer of cells is flat and the deeper layers vary in shape from cuboidal to columnar. Located in the skin and vagina.
The ___ ___ replicate by mitosis and ultimately work their way to the surface.
Basal cells
Describe keratinized stratified squamous epithelium.
A tough layer of keratin (a protein resistant to friction w/a capacity to repel bacteria) is deposited in the surface cells.
Describe non keratinized stratified squamous epithelium.
Does not contain keratin and remains moist.
Describe stratified cuboidal epithelium.
A rare tissue that consists of 2 or more layers of cube-shaped cells w/mainly a protective function. Found in the esophagus.
Describe stratified columnar epithelium.
Consists of several layers of cells of which only the top layer is columnar. It is somewhat rare and functions in protection and secretion.found in the pharynx, excretory ducts of some glands such as esophageal glands.
Describe transitional epithelium.
Consists of several layers of cells; their appearance is variable. Capable of stretching and thus permits the distention of an organ. It lines the urinary bladder and portions of the ureters and urethra.
What is a gland and name the 2 types.
A single cell or mass of epithelial cells adapted for secretion. Endocrine and exocrine.
____ glands are ductless; their secretory products (hormones) enter the extracellular fluid and diffuse into the blood.
Endocrine
____ glands (sweat, oil, digestive glands) secrete their products into ducts that empty at the surface of the covering and lining of the epithelium or directly onto a free surface.
Exocrine
What is the function of the endocrine glands?
Produce hormones that regulate various body activities.
What is the function of the exocrine glands?
Produce substances such as sweat, oil, earwax, saliva, or digestive enzymes.
Describe the general characteristics of connective tissues and discuss their differences from epithelial tissue.
CT is the most abundant and widely distributed tissue in the body. Unlike epithelial tissue, CT do not occur on free substances and is highly vascular (except for cartilage and tendons). CT like epithelium had a nerve supply.
What are the 3 basic elements of connective tissues?
Cells, ground substance and protein fibres (the latter 2 combine to form the matrix).
What are the representative cells and fibres present in the connective tissues?
Fibroblasts (most numerous in CTs), collagen fibres, mast cells, plasma cells, ground substance, neutrophils, eosinophils, adipocytes, elastic fibres, macrophages, and reticular fibres.
Describe the matrix.
Is abundant w/relatively few cells, tends to prevent tissue cells from touching on another; it can be fluid, semifluid, gelatinous, fibrous, or calcified; is usually secreted by the CT cells and determines the qualities of tissues.
___ cells have names that end in blast (fibroblast, chondroblast), whereas ___ cells have names that end in cute (osteocyte, adipocyte).
Immature, mature.
Most __ cells have a reduced capacity for cell division and matrix formation, and are mostly involved in maintaining the matrix.
Mature
Fibroblasts
Secrete fibres and matrix, are large flat cells with branching processes
Macrophages or histiocytes
Develop from monocytes and are phagocytic, a type of white blood cell
Mast cells
Abundant and alongside blood vessels and produce histamine, are involved in the inflammatory response and also kill bacteria.
Adipocytes or fat cells
Store energy in the form of fat, are fat cells
Plasma cells
Are an important part of the body’s immune response
The ground substance and fibres deposited in the space between the cells comprise the matrix of connective tissue. What are some of the substances found in the ground substance?
Hyaluronic acid, chondroiton sulfate, dermation sulfate, and keratan sulfate.
What are the 3 types of fibres embedded in the matrix between the cells of connective tissues?
Collagen fibres, elastic fibres, and reticular fibres.
What are collagen fibres?
Composed of the protein collagen, are very tough and resistant to stretching, yet allow some flexibility in the tissue; they are found in bone, cartilage, tends and ligaments.
What are elastic fibres?
Composed of the protein elastin, provide strength and stretching capacity and are found in the skin, blood vessels and lungs.
What are reticular fibres?
Consisting of collagen and glycoprotein, provide support in the walls of the blood vessels and form a strong, supporting network around fat cells, nerve fibres, and skeletal and smooth muscle fibres.
What are the 5 types of connective tissue (CT)?
Loose connective tissue, dense connective tissue, cartilage, bone, and liquid (blood, lymph).
Name the 3 types of loose connective tissues.
Areolar connective tissue, adipose tissue, reticular connective tissue.
Name the 3 types of dense connective tissues.
Dense regular connective tissue, dense irregular connective tissue, elastic connective tissue.
Name the 3 types of supporting connective tissue and their subclasses.
Cartilage; hyaline cartilage, fibrocartilage, elastic cartilage.
Bone tissue.
Liquid connective tissue; blood, lymph
Describe areolar connective tissue.
Loose connective tissue; fibres are loosely arranged among the many cells; located in the skin and it’s functions are strength, elasticity and support.
Describe the ground substance.
Aids in the passage of nutrients from the blood vessels of the connective tissue to adjacent cells and tissues. Found in the subcutaneous layer.
Describe adipose tissue.
A loose CT consisting of adipocytes, which are specialized for storing triglycerides. It reduces heat loss through the skin; serves as an energy reserve; supports, protects and generates considerable heat to help maintain proper body temperature in newborns (brown fat).
Describe reticular connective tissue.
Consists of a fine interlacing of reticular fibres and reticular cells. It forms the stroma of certain organs, and helps to bind together the cells of smooth muscle, filters and removes worn out blood cells in spleen and microbes in lymph nodes.
Dense connective tissue contains thicker, denser and more numerous fibres than loose CT but considerably fewer cells. Name the 3 types of dense connective tissues.
Dense regular CT, dense irregular CT, elastic CT.
Describe dense regular connective tissue.
Consists of bundles of collagen fibres in a regular, orderly and parallel arrangement that confers great strength. Forms tendons, most ligaments, and aponeuroses.
Describe dense irregular connective tissue.
Contain collagen fibres that are irregularly arranged; found in parts of the body where tensions are exerted in various directions (skin), heart valves, the pericardium, tissue surrounding cartilage, and periosteum.
Describe the elastic connective tissue.
Consists of elastic fibres and fibroblasts; quite strong and can recoil back to its original shape after being stretched. Found in lung tissue and elastic arteries.
Cartilage consists of a dense network of collagen fibres and elastic fibres embedded in chondroitin sulfate. Name the 3 types of cartilage.
Hyaline cartilage, fibrocartilage, elastic cartilage.
Describe the properties of cartilage.
It’s collagen fibres give it strength, and it’s chondroitin sulfate gives it resilience. Chondrocytes occur w/in spaces called lacunae in the matrix. Cartilage is surrounded by dense irregular CT membrane called the perichondrium. Cartilage has no blood vessels or nerves except in the perichondrium.
What is hyaline cartilage?
The most abundant but the weakest type of cartilage. It has fine collagen fibres embedded in a gel-like matrix. Provides flexibility and support and at the joints, reduces friction and absorbs shock. Found in ends of long bones, nose, skeleton of a fetus.
Describe fibrocartilage.
Contains bundles of collagen fibres in its matrix. It does not have a perichondrion. Due to its combined strength and rigidity, it is the strongest of the 3 types of cartilage.
Describe elastic cartilage.
Contains a threadlike network of elastic fibres within the matrix. A perichondrium is present. Elastic cartilage provides strength and elasticity and maintains the shape of certain organs.
Cartilage growth is accomplished by ___ (endogenous - from within) growth and ___ (from without) growth.
Interstitial, appositional
Bone (osseous tissue) consists of a matrix containing mineral salts and collagenous fibres and cells called osteocytes. It is either compact or spongy. The basic unit of compact bone is the osteon (Haversian system) which consists of 4 parts which are
The lamella, lacunae, canaliculi, a central (Haversian) canal.
What is the lamella in bone tissue?
The lamella are concentric rings of matrix that consist of mineral salts that give bone it’s hardness, and collagen fibres that give bone it’s strength
What is the lacunae in bone tissue?
Lacunae are small spaces between the lamellae that contain mature bone cells called osteocytes.
What are canaliculi in bone tissue?
Canaliculi are minute canals - containing the processes of osteocytes - which provide routes for the nutrient and waste transport.
What is a central Haversian canal within bone tissue?
A central (Haversian) canal contains the blood vessels and nerves. Spongy bone has trabeculae rather than osteons.
What functions does the bone have?
Supports, protects, help to provide movement, stores minerals, and houses blood forming tissue.
What are the 2 types of liquid connective tissue? A liquid connective tissue has a liquid as it’s extracellular matrix.
Blood and lymph
Blood (vascular tissue) consists of a liquid matrix called plasma, and formed elements. Formed elements includes erythrocytes, leukocytes, and thrombocytes which have specific functions such as:
Red blood cells (erythrocytes) function in transporting respiratory gases.
White blood cells (leukocytes) are involves in phagocytosis, immunity, and allergic reactions.
Platelets (thrombocytes) function in blood clotting.
Erythrocytes
Red blood cells
Leukocytes
White blood cells
Thrombocytes
Platelets
What is lymph?
The interstitial fluid flowing in the lymph vessels.
What are the 3 types of muscle tissue?
Muscle tissue, skeletal muscle tissue, smooth (visceral) muscle tissue.
Describe muscle tissue.
Consists of fibres (cells) that are modified for contraction, and thus provide motion, maintainence of posture and heat production.
Describe skeletal muscle tissue.
Is attached to bones, is striated, and is voluntary. Cardiac muscle tissue forms most of the heart wall, is striated, and is usually involuntary.
Describe smooth (visceral) muscle tissue.
Found in the walls of hollow internal structures (blood vessels and viscera), is nonstriated, and is usually involuntary. It provides motion (construction of blood vessels and airways, propulsion of foods through gastro tract, and contraction of urinary bladder and gallbladder).
Identify the major cells and participants of nervous tissues.
The nervous system, neurons, neuroglia.
Describe the nervous system.
Is composed of only 2 principal kinds of cells: neurons (nerve cells) and neuroglia (protective and supporting cells).
Most ___ consist of a cell body and 2 types of processes called dendrites and axons.
Neurons
Describe neurons.
Sensitive to stimuli; convert stimuli into nerve impulses; and conduct nerve impulses to other neurons, muscle fibres or glands.
___ protect and support neurons, and are often the sites of tumours of the nervous system.
Neuroglia
What are membranes and epithelial membranes and list the 4 different types?
Membranes are flat sheets of pliable tissue that cover or line a part of the body. Epithelial membranes consist of an epithelial layer and an underlying connective tissue layer.
Synovial, mucous (mucosae), epithelial layer of a mucous membrane, connective tissue layer of a mucous membrane.
Synovial membranes (mucosae)
Line cavities that open to the exterior, such as the gastrointestinal tract
Epithelial layer of a mucous membrane
Is an important aspect of the body’s defense mechanisms, acting as a barrier to pathogens and a trapping surface for particles.
Connective tissue layer of a mucous membrane is called the lamina propria. A serious membrane does what?
Lines the body cavity that does not open directly to the exterior, and covers the organs that lie without the cavity. Ex: the pleural, pericardium, peritoneum. These membranes consist of parietal and visceral portions.
The ___ layer secretes a lubricating serous fluid that reduces friction between organs and the walls of the cavities in which they are located.
Epithelial
___ membranes line joint cavities, bursae and tendon sheaths a s do no contain epithelium; they also secrete a lubricating ___ fluid.
Synovial; synovial
___ ___ is the process of replacing dead or damages cell. Repair can occur only in inflammation is complete.
Tissue repair
