Chapter 4 Flashcards
Define tissues, histology, and list the four main types of tissue
Groups of cells that are similar in structure and perform a common or related function; the study of tissues; epithelial, connective, muscle, nervous
List the structures of epithelial tissue
Number of layers: simple, stratified
Cell shape: squamous, cuboidal, columnar
List the functions of epithelial tissue
Protection, absorption, filtration, secretion, excretion, sensory reception
List the characteristics of epithelial tissue
Polarity, specialized contacts, supported by connective tissue, avascular but innervated, regeneration
Simple squamous epithelium
Description: single layer of flat cells with a central nucleus
Function: allows materials to pass by diffusion and filtration; secretes lubricating substances in serosae
Location: kidney glomeruli, air sacs of lungs, lining of heart, blood vessels
Name the two specially named simple squamous epithelia and state their location
Endothelium: lines hollow organs of the cardiovascular system
Mesothelium: found in serous membranes
Simple cuboidal epithelium
Description: single layer of cube-like cells with large, spherical central nuclei
Function: secretion and absorption
Location: kidney tubules, ducts and secretory portions of small glands, ovary surface
Simple columnar epithelium
Description: single layer of tall cells with round to oval nuclei; may have cilia or goblet cells
Function: absorption, secretion of mucus, enzymes, and other substances, ciliated type propels mucus
Location: digestive tract (stomach to rectum), small bronchi (ciliated)
Pseudostratified columnar epithelium
Description: single layer of cells of differing heights with nuclei at different levels
Function: secrete and propel substances, such as mucus
Location: trachea and upper respiratory tract
Stratified squamous epithelium
Description: thick membrane composed of several layers with flat surface cells
Function: protects underlying tissues in areas subjected to abrasion
Location: esophagus, mouth, vagina, epidermis of the skin
Transitional epithelium
Description: resembles stratified squamous and stratified cuboidal, depending on degree of organ stretch
Function: stretches readily
Location: lines the ureters, bladder, and part of the urethra
Define and state the relationship of gland and secretion
Consists of one or more cells that make and secrete a particular product; the product is called a secretion, which is an aqueous fluid that usually contains proteins
Differentiate between exocrine and endocrine glands
Exocrine: secrete their products onto body surfaces or into body cavities
Endocrine: ductless glands that produce hormones and secrete them into the extracellular space
Differentiate between multicelluar and unicelluar glands
Multicellular glands are more complex than unicellular glands (such as mucus and goblet cells) and contain a epithelium-derived duct and secretory unit
Describe how multicellular exocrine glands are classified structurally and functionally
Structure: simple glands, compound glands
Secretory units: tubular, alveolar, or tubuloalveloar
Mode of secretion: merocrine, holocrine, (apocrine)
List the common characteristics of connective tissue
Common origin (mesenchyme), degrees of vascularity (high to low), large extracellular matrix
List and describe the structural elements of connective tissue
Ground substance, fibers (collagen, elastic, and reticular), cells (fibroblasts, chondroblasts, osteoblasts, fat cells, white blood cells, mast cells, macrophages
Connective Tissue: Name the subclasses of Connective Tissue Proper
- Loose connective tissue: areloar, adipose, reticular
2. Dense connective tissue: regular, irregular, elastic
Connective Tissue: Name the subclasses of Cartilage
- Hyaline
- Elastic
- Fibrocartilage
Connective Tissue: Name the subclasses of Bone Tissue
- Compact bone
2. Spongy bone
State the four classes of Connective Tissue
Connective tissue proper, cartilage, bone, blood
Connective Tissue Proper: loose connective tissue, areolar
Description: Gel-like matrix with all three fibers and cells (fibroblasts, macrophages, mast cells, some white blood cells)
Function: Wraps and cushions organs, important role in inflammation
Location: widely distributed under epithelia: lamia propia of mucous membranes, packages organs, surrounds capillaries
Connective Tissue Proper: loose connective tissue, adipose
Description: Sparse matrix, closely packed fat cells, nucleus pushed to side
Function: Reserve food fuel, insulates against heat loss, supports and protects organs
Location: Under skin in subcutaneous tissue, around kidneys and eyeballs, within abdomen and breasts
Connective Tissue Proper: loose connective tissue, reticular
Description: network of reticular fibers in a loose ground substance, reticular cells lie on the network
Function: Forms a soft internal skeleton (stroma) that supports other cell types such as white blood cells, mast cells, and macrophages
Location: Lymphoid organs (lymph nodes, bone marrow, and spleen)
Connective Tissue Proper: dense connective tissue: dense regular
Description: parallel collagen fibers, few elastic fibers, fibroblasts
Function: attaches muscles to bones or muscles and bones to bones; withstands great tensile stress in one direction
Location: tendons, most ligaments
Connective Tissue Proper: dense connective tissue, dense irregular
Description: irregularly arranged collagen fibers, some elastic fibers, fibroblasts
Function: withstands tension in many directions, provides structural strength
Location: fibrous capsules of organs and joints, dermis of skin
Connective Tissue Proper: dense connective tissue, elastic
Description: dense regular tissue containing high proportion of elastic fibers
Function: allows tissue to recoil after stretching, maintains pulsatile flow of blood through arteries
Location: walls of large arteries (aorta), ligaments associated with the vertebral column, walls of bronchial tubes
Cartilage: hyaline
Description: amorphous but firm matrix, slight network of collagen fibers
Function: supports and reinforces, cushion, resists compressive stress
Location: forms most of the embryonic skeleton; covers the ends of long bones in joint cavities, cartilage of the nose, trachea, and larynx
Cartilage: elastic
Description: similar to hyaline, but more elastic fibers in matrix
Function: maintains the shape of a structure, allowing great flexibility
Location: External ear, epiglottis
Cartilage: fibrocartilage
Description: matrix similar to but less firm than hyaline cartilage; thick collagen fibers
Function: tensile strength allows it to absorb compressive shock
Location: intervertebral discs, discs of knee joint
Bone
Description: hard, calcified matrix with many collagen fibers, well vascularized
Function: supports and protects, levers for muscles, stores calcium, other minerals, and fat, marrow inside bones in the site for blood cell formation
Location: bones
Connective tissue: blood
Description: red and white blood cells in a fluid matrix (plasma)
Function: transport respiratory gases, nutrients, wastes, and other substances
Location: contained within blood vessels
Skeletal muscle
Description: long, cylindrical, multinucleate cells, with striations
Function: voluntary movement, locomotion
Location: skeletal muscles attaches to bones and sometimes skin
Cardiac muscle
Description: branching, striated, uninucleate cells with intercalated discs
Function: involuntarily propels blood into the circulation as it contracts
Location: the walls of the heart
Smooth muscle
Description: spindle-shaped cells with central nuclei, no striations, cells arranged closely to form sheets
Function: Propels substances or objects along internal passageways involuntarily
Location: mostly in the walls of hollow organs
Nervous tissue
Description: contains neurons and supporting cells
Function: transmit electrical signals which controls activity; supporting cells support and protect neurons
Location: brain, spinal cord, and nerves
Describe the structure and function of cutaneous, mucous, and serous membranes
Cutaneous: covers the body surface
Mucous: line the body cavities that are open to the exterior
Serous: line the body cavities that are closed to the exterior
Outline the process of tissue repair
- Inflammation: clot forms, scab forms on surface
- Organization: blood clot replaced by granulation tissue
- Regeneration and fibrosis: surface epithelium regenerates, underlying scar tissue
Indicate embryonic origin of each tissue class
Epithelium: all three (ectoderm, mesoderm, endoderm)
Muscle and connective: mesoderm
Nervous: ectoderm
Inner lining of digestive system: endoderm
