Ch. 4-4 Connective Tissue

Question 1

What three components does all connective tissue share?

Answer 1

1. Specialized cells
2. extracellular protein fibers
3. Ground substance

Question 2

What is ground substance?

Answer 2

A fluid that fills the space between cells and surrounds connective tissue fibers.

In CTP, it is clear, colorless, and viscous

Question 38

Classification of Connective Tissues (3)

Answer 38

1. Connective tissue proper 2. Fluid connective tissue 3. Supporting connective tissue

Question 39

Connective tissue proper

Answer 39

Broad category: divided into ‘loose’ and ‘dense’ connective tissue based on # of cell types present, proportion of fibers and ground substance Ex: Loose connective: adipose Dense connective: tendons

Question 40

Fluid Connective Tissue

Answer 40

Distinctive populations of cells suspended in a watery matrix that contains dissolved proteins

Two types: Blood and lymph

Question 41

Supporting connective tissue

Answer 41

Less diverse cell population and a matrix of more densely packed fibers. Types: cartilage and bone

Question 42

Fibroblasts

Answer 42

1. Secrete hyaluronan & proteins 2. Secrete protein subunits that assemble to form large extracellular fibers 3. Contribute to ground substance to make it viscous 4. One of two most abundant cells in connective tissue proper; only cells always present.

Question 43

Three components of connective tissue

Answer 43

1. Specialized cells 2. Extra cellular protein fibers 3. Ground substance 2+3 = matrix surrounding cells; accounts for most of the volume of connective tissue

Question 44

Fibrocytes

Answer 44

Second most abundant fixed cell in CT Proper. Differentiate from fibroblasts. Maintain the connective tissue fibers of CTP.

Question 45

Mesenchymal cells

Answer 45

Stem cells that respond to local injury or infection by dividing into daughter cells that differentiate as needed

Question 46

Mast cells

Answer 46

Cytoplasm filled with histamine and heparin

Question 47

Microphages

Answer 47

Neutrophils and eosinophils. Phagocytic blood cells, present in CTP in small numbers

Question 48

Melanocytes

Answer 48

Synthesize and store melanin. Present in connective tissue of eye & dermis of skin

Question 49

Connective tissue fibers (3)

Answer 49

1. Collagen fibers 2. Reticular fibers 3. Elastic fibers

Question 50

Collagen fibers

Answer 50

Long, straight, and unbranched. Most common fiber in CTP. Flexible, but stronger than steel when pulled from either end. Ex: Tendons (skeletal muscle to bone) Ligaments (connect bone to bone)

Question 51

Reticular fibers

Answer 51

‘reticulum’ = network 1. Form a branching, interwoven network (STROMA) that is tough and flexible. 2. Composed of same protein subunits as collagen fibers, but arranged differently. Thinner than collagen fibers. 3. The stroma stabilizes A.) the relative positions of parenchyma cells in organs and B.) positions of organ blood vessels, nerves, etc.

Question 52

Elastic Fibers

Answer 52

Contains the protein elastin. Branched and wavy; return to original length after stretching. Elastic ligaments: rare, dominates by elastic fibers. Ex: interconnecting vertebrae.

Question 53

Ground Substance

Answer 53

Fills space between cells and surrounds connective tissue fibers. Viscous due to proteogylcans and glycoproteins

Question 54

Embryonic Connective Tissue (Mesenchyme)

Answer 54

1. Mesenchymal cells 2. Mucous connective tissue (Wharton’s Jelly)

Question 55

Loose Connective Tissues

Answer 55

1. Areolar 2. Adipose 3. Reticular 4. Mesenchyme (embryos)

Question 56

Areolar tissue

Answer 56

A loose connective tissue. Least specialized connective tissue in adults. Open framework with loose structure. Absorbs shocks, distort without damage. Elastic fibers makes it resilient. Separate skin from deeper structures; has extensive blood supply that diffuses oxygen, etc. to epithelial layer. Proportion of adipocytes distinguishes from adipose tissue.

Question 57

Reticular tissue

Answer 57

Composed of reticular fibers to form a stroma complex. Fibrous framework in organs, lymph nodes, and bone marrow.

Question 58

Dense Connective Tissue (collagenous tissues)

Answer 58

A type of connective tissue proper distinguished by cell types present and relative proportion/properties of fibers.

Most of the volume is fibrous; collagen fibers are dominant.

Question 59

What are the two types of dense connective tissue?

Answer 59

1. Dense regular connective tissue 2. Dense irregular connective tissue

Question 60

Characteristics and examples of dense irregular connective tissue

Answer 60

Fibers form an interwoven network with no consistent pattern. Strengthen and support areas that resist stress from many directions, Ex: 1. Layer in skin to provide strength (leather) 2. sheaths around bone, i.e perichondrium, periosteum. 3. 'Capsule' around internal organs 4. Encloses cavities of joints

Question 61

Characteristics and examples of dense regular connective tissue

Answer 61

Collagen fibers are parallel and packed tightly to align with forces applied to the tissue. Ex: Ligaments, Tendons

Question 62

Tendons

Answer 62

Cords of dense regular connective tissue that attach skeletal muscle to bone. Collagen fibers run along longitudinal axis to transfer pull of contracting muscle to bone

Question 63

Ligaments

Answer 63

Connect bone to bone and stabilze the positions of internal organs.

Question 64

aponeurosis

Answer 64

a tendonous sheet that attaches a broad flat muscle to another muscle or to several bones of the skeleton. Can also stabilize positions of tendons and ligaments. Associated with large msucles of the skull, lower back, and abdomen; with palmar and tendons/ligaments

Question 65

perichondrium

Answer 65

dense irregular connective tissue; forms a sheath around cartilage

Question 66

periosteum

Answer 66

dense irregular connective tissue; froms a sheath around bone

Question 67

capsule

Answer 67

dense irregular connective tissue; a thick fibrous layer that surrounds internal organs like hte liver, kidneys, spleen, and encloses the cavities of joints

Question 68

Elastic Fibers

Answer 68

When elastic FIBERS outnumber collagen FIBERS, tissue has spring, resilient nature that allows it to tolerate cycles of extension and recoil. Elastic FIBERS are present in connective tissue that supports transitional epithelia, large blood vessels (aorta), and respiratory passageways.

Question 69

Elastic TISSUE

Answer 69

dense regular connective TISSUE dominated by elastic FIBERS. Elastic ligaments help stabilize vertebrae.

Question 70

Formed elements

Answer 70

Components of plasma, the watery matrix in blood. More specifically, blood cells and fragments of cells. Three types: 1. Red Blood Cells 2. White Blood Cells 3. Platelets

Question 71

What are the major subdivisions of extracellular fluid?

Answer 71

1. Plasma 2. Interstitial fluid 3. Lymph

Question 72

Lymph

Answer 72

Forms as interstital fluid enters lymphatic vessels. Composition similar to blood, but contains more lymphocytes

Question 73

Recirculation of body fluid

Answer 73

From cardovascular system, throguh interstitial fluid, to the lymph, back to cardivascular system