Chp 4: Tissues

Question 1

TIssue: definition

Answer 1

Groups of cells, similar in structure and perform a common/related function

Question 2

4 Major Types of Tissues

Answer 2

epithelial, connective, muscle, nervous

Question 3

3 Primary Germ Layers, from which germ layers are each of the major tissue types derived?

Answer 3

Superficial to deep: ectoderm, mesoderm, endoderm
Epithelium: all 3
Nervous: ectoderm
Muscle and Connective: mostly mesoderm

Question 4

How do we classify epithelial tissues?

Answer 4

By number of layers (simple vs stratified)

Those that can’t be placed in other categories: transitional epithelium and pseudostratified epithelium

Question 5

Simple Epithelia

Answer 5

Single layer: Absorption, secretion, filtration

Question 6

Simple Squamous epithelium

Answer 6

flattened laterally, spare cytoplasm
thin and permeable, important for diffusion and filtration (kidney glomeruli, air sacs of lungs, lymphatic vessels- endothelium and serous membranes- mesothelium)

Question 7

Simple cuboidal epithelium

Answer 7

single layer, as tall as wide

secretion and absorption, located in kidney tubules, ducts and secretory portions of small glands, ovary surface

Question 8

Simple columnar epithelium

Answer 8

tall, closely packed cells
Absorption and secretion
Lines digestive tract, secretes mucus; ciliated variety lines bronchi, uterine tubes, and regions of uterus

Question 9

Pseudostratified columnar epithelium

Answer 9

All cells rest on basement membrane, only tallest reach surface of epithelium
secretes mucus, absorbs
ciliated variety lines respiratory tract, nonciliated type in sperm ducts/ducts of large glands

Question 10

Stratified squamous epithelium

Answer 10

thick membrane composed of several cell layers
Protects underlying tissues from abrasion
Nonkeratinized tpye forms moist linings of esophagus, mouth, and vagina
Keratinized variety forms epidermis of skin

Question 11

Transitional Epithelium

Answer 11

Resembles both stratified squamous and stratified cuboidal; cells of basal layer are cuboidal or columnar, cells of apical (surface) layer vary in appearance depending on degree of organ distension (stretching)
Stretches readily, permits stored urine to distend urinary organ. Located in ureters, bladder, part of urethra

Question 12

Gland

Answer 12

One or more cells that make and secrete a particular product

Question 13

Exocrine Glands

Answer 13

Secrete products onto body surfaces or into body cavities

Mucus, sweat, oil, salivary glands, liver (secretes bile), pancreas (secretes digestive enzymes) etc.

Question 14

Endocrine Glands

Answer 14

Ductless glands, produce hormones

Question 15

Goblet cells

Answer 15

Unicellular exocrine glands; cuplike accumulation of mucin distends the top of the cell (making it look like a glass with a stem)

Question 16

Structural elements of connective tissue

Answer 16

3 Main elements: ground substance, fibers (collagen, reticular, elastic) , cells

Question 17

Common Characteristics of Connective Tissues

Answer 17

Common origin (mesenchyme)
Degrees of vascularity
Extracellular matrix

Question 18

Matrix

Answer 18

Ground substance (unstructured material that fills space between cells) + fibers

Question 19

Cells of connective tissue proper

Answer 19

Fibroblasts, fibrocytes, defense cells, adipocytes. Binding tissue, resists tension, provides reservoir for water and salts, fat storage

Question 20

Cells of Cartilage

Answer 20

Chondroblasts, chondrocytes

Resists compression, cushions, supports body structures

Question 21

Cells of bone

Answer 21

osteoblasts, osteocytes

hard tissue, resists compression and tension; support

Question 22

Connective tissue proper: loose CT: areolar

Answer 22

Gel-like matrix, all 3 fiber types, fibroblasts, macrophages, mast cells, some WBCs
Wraps and cushions organs, phagocytosis, inflammation
Widely distributed under epithelia of body

Question 23

Connective tissue proper: loose CT: adipose

Answer 23

Sparse matrix, closely packed adipocytes (nucleus pushed to side by large fat droplet)
Provides reserve food fuel, insulates, supports and protects organs
Under skin in subcutaneous tissue, around kidneys and eyeballs, within abdomen, in breasts

Question 24

Connective tissue proper: loose CT: reticular

Answer 24

Network of reticular fibers in loose ground substance
Fibers form soft internal skeleton (stroma) that supports other cell types
Location: lymphoid organs (lymph nodes, bone marrow, spleen)

Question 25

Connective tissue proper: dense CT: regular

Answer 25

``` Primarily parallel (slightly wavy) collagen fibers, fibroblasts Attaches muscles to bones or to muscles, attaches bones to bones, withstands tension Tendons, most ligaments, aponeuroses ```

Question 26

Connective tissue proper: dense CT: irregular

Answer 26

Primarily irregularly arranged collagen fibers, fibroblasts Withstands tension Location: fibrous capsules of organs and of joints, dermis of skin, submucosa of digestive tract

Question 27

Connective tissue proper: dense CT: elastic

Answer 27

Dense regular CT with high proportion of elastic fibers Allows tissue to recoil, maintains pulsatile flow of blood through arteries, aids recoil of lungs following inspiration Location: walls of arteries, within some ligaments of vertebral column, w/in walls of bronchial tubes

Question 28

Cartilage: Hyaline

Answer 28

Amorphous but firm matrix; collagen fibers ; chondroblasts produce matrix and when mature (chondrocytes) lie in lacunae Supports and reinforces, cushions, resists compression Forms most of embryonic skeleton, covers ends of long bones, costal cartilages of ribs, cartilages of nose, trachea, larynx

Question 29

Cartilage: elastic

Answer 29

similar to hyaline cartilage, with more elastic fibers maintains shape while allowing great flexibility location: supports external ear (pinna); epiglottis

Question 30

Cartilage: fibrocartilage

Answer 30

Matrix similar to but less firm than that in hyaline cartilage Tensile strength, absorbs compressive shock Location: intervertebral discs, pubic symphysis, discs of knee joint

Question 31

Connective Tissue: Bone

Answer 31

Hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae Function: supports and protects, lever for muscles, stores Ca and other minerals and fat, marrow is site for hematopoiesis

Question 32

Connective Tissue: blood

Answer 32

Red and white blood cells in a fluid matrix (plasma) Function: transports respiratory gases, nutrients, wastes, other substances Location: within blood vessels

Question 33

Nervous Tissue cell types

Answer 33

``` Neurons: electrically excitable cells (poor capacity to regenerate) Supporting cells (glia) ```

Question 34

General Characteristics of Nervous Tissues

Answer 34

Regulates and controls body functions | Brain, spinal cord, nerves

Question 35

Skeletal Muscle

Answer 35

Long, cylindrical, multinucleate cells; obvious striations Voluntary movement; locomotion, facial expression Location: in skeletal muscles attached to bones or occasionally to skin

Question 36

Cardiac Muscle

Answer 36

Branching, striated, generally uninucleate cells that fit together at intercalated discs Function: as it contracts, it propels blood into circulation Location: walls of heart

Question 37

Smooth Muscle

Answer 37

Spindle shaped cells with central nuclei, no striations, cells arranged closely Propels substances or objects (food, urine, a baby) along internal passageways, involuntary control Location: walls of hollow organs