Chapter 4

Question 1

Define tissues, histology, and list the four main types of tissue

Answer 1

Groups of cells that are similar in structure and perform a common or related function; the study of tissues; epithelial, connective, muscle, nervous

Question 2

List the structures of epithelial tissue

Answer 2

Number of layers: simple, stratified

Cell shape: squamous, cuboidal, columnar

Question 3

List the functions of epithelial tissue

Answer 3

Protection, absorption, filtration, secretion, excretion, sensory reception

Question 4

List the characteristics of epithelial tissue

Answer 4

Polarity, specialized contacts, supported by connective tissue, avascular but innervated, regeneration

Question 5

Simple squamous epithelium

Answer 5

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

Question 6

Name the two specially named simple squamous epithelia and state their location

Answer 6

Endothelium: lines hollow organs of the cardiovascular system
Mesothelium: found in serous membranes

Question 7

Simple cuboidal epithelium

Answer 7

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

Question 8

Simple columnar epithelium

Answer 8

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)

Question 9

Pseudostratified columnar epithelium

Answer 9

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

Question 10

Stratified squamous epithelium

Answer 10

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

Question 11

Transitional epithelium

Answer 11

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

Question 12

Define and state the relationship of gland and secretion

Answer 12

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

Question 13

Differentiate between exocrine and endocrine glands

Answer 13

Exocrine: secrete their products onto body surfaces or into body cavities
Endocrine: ductless glands that produce hormones and secrete them into the extracellular space

Question 14

Differentiate between multicelluar and unicelluar glands

Answer 14

Multicellular glands are more complex than unicellular glands (such as mucus and goblet cells) and contain a epithelium-derived duct and secretory unit

Question 15

Describe how multicellular exocrine glands are classified structurally and functionally

Answer 15

Structure: simple glands, compound glands
Secretory units: tubular, alveolar, or tubuloalveloar
Mode of secretion: merocrine, holocrine, (apocrine)

Question 16

List the common characteristics of connective tissue

Answer 16

Common origin (mesenchyme), degrees of vascularity (high to low), large extracellular matrix

Question 17

List and describe the structural elements of connective tissue

Answer 17

Ground substance, fibers (collagen, elastic, and reticular), cells (fibroblasts, chondroblasts, osteoblasts, fat cells, white blood cells, mast cells, macrophages

Question 18

Connective Tissue: Name the subclasses of Connective Tissue Proper

Answer 18

1. Loose connective tissue: areloar, adipose, reticular

2. Dense connective tissue: regular, irregular, elastic

Question 19

Connective Tissue: Name the subclasses of Cartilage

Answer 19

1. Hyaline
2. Elastic
3. Fibrocartilage

Question 20

Connective Tissue: Name the subclasses of Bone Tissue

Answer 20

1. Compact bone

2. Spongy bone

Question 21

State the four classes of Connective Tissue

Answer 21

Connective tissue proper, cartilage, bone, blood

Question 22

Connective Tissue Proper: loose connective tissue, areolar

Answer 22

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

Question 23

Connective Tissue Proper: loose connective tissue, adipose

Answer 23

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

Question 24

Connective Tissue Proper: loose connective tissue, reticular

Answer 24

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)

Question 25

Connective Tissue Proper: dense connective tissue: dense regular

Answer 25

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

Question 26

Connective Tissue Proper: dense connective tissue, dense irregular

Answer 26

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

Question 27

Connective Tissue Proper: dense connective tissue, elastic

Answer 27

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

Question 28

Cartilage: hyaline

Answer 28

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

Question 29

Cartilage: elastic

Answer 29

Description: similar to hyaline, but more elastic fibers in matrix
Function: maintains the shape of a structure, allowing great flexibility
Location: External ear, epiglottis

Question 30

Cartilage: fibrocartilage

Answer 30

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

Question 31

Bone

Answer 31

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

Question 32

Connective tissue: blood

Answer 32

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

Question 33

Skeletal muscle

Answer 33

Description: long, cylindrical, multinucleate cells, with striations
Function: voluntary movement, locomotion
Location: skeletal muscles attaches to bones and sometimes skin

Question 34

Cardiac muscle

Answer 34

Description: branching, striated, uninucleate cells with intercalated discs
Function: involuntarily propels blood into the circulation as it contracts
Location: the walls of the heart

Question 35

Smooth muscle

Answer 35

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

Question 36

Nervous tissue

Answer 36

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

Question 37

Describe the structure and function of cutaneous, mucous, and serous membranes

Answer 37

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

Question 38

Outline the process of tissue repair

Answer 38

1. Inflammation: clot forms, scab forms on surface
2. Organization: blood clot replaced by granulation tissue
3. Regeneration and fibrosis: surface epithelium regenerates, underlying scar tissue

Question 39

Indicate embryonic origin of each tissue class

Answer 39

Epithelium: all three (ectoderm, mesoderm, endoderm)
Muscle and connective: mesoderm
Nervous: ectoderm
Inner lining of digestive system: endoderm