Lecture Quiz 3

Question 1

What are the main characteristics of connective tissues?

Answer 1

arise from a type of embryonic tissue - mesenchyme
cells lack intercellular contact
surrounded by large amounts of extracellular matrix consisting of protein fibers and ground substance
well vascularized with the exception of cartilage

Question 2

What are the functions of connective tissues?

Answer 2

structural framework (bone, cartilage)
transport of nutrients and waste (blood)
protection (bone, cartilage, adipose)
support and interconnection (tendons, ligaments, capsules)
insulation and energy storage as well as production of important cells of blood and lymphatic tissues (adipose, bone marrow)
body defense and repair (blood, lymph, dense ct)

Question 3

Describe the extracellular matrix

Answer 3

includes all materials surrounding the cells
consists of ground substance and protein fibers
product of specialized cells

Question 4

What is the relationship between connective tissue and extracellular matrix?

Answer 4

the function of connective tissue is determined by composition of the extracellular matrix

Question 5

What is the ground substance?

Answer 5

a mix of extracellular fluid, mucopolysaccharides, glycoproteins, minerals, and other substances
can be fluid, gel-like, or solid
fibers include collagen, elastic, and reticular fibers

Question 6

Describe collagen fibers

Answer 6

the strongest of the fibers with only 3% stretch

ligaments and tendons are mostly made of collagen

Question 7

Describe elastic fibers

Answer 7

composed of protein, but exhibit significant recoil when stretched
most structures that exhibit elasticity contain elastic fibers

Question 8

Describe reticular fibers

Answer 8

protein fibers that are lacy and fragile
most lymphoid structures such as lymph nodes, spleen, tonsils, Peyer’s patch contain significant amount of reticular fibers
the residence for many of our immune cells

Question 9

Describe cell development in the connective tissue

Answer 9

all cells develop from a common presursor - mesenchymal cells - that differentiate into tissue-specific blast, which in turn mature into tissue specific cells (chondroblasts and chrondrocytes for ex)

Question 10

What additional cells do connective tissues contain?

Answer 10

adipocyte - store nutrients
mast cells - detect foreign cells and initiate inflammation response by releasing heparin, histamine, and macrophages
macrophages - phagocytic cells that engulf foreign cells
white blood cells may also migrate into connective tissues to assist with immune response

Question 11

What are the two types of fluid connective tissue?

Answer 11

blood - transports fueld, nutrients, ocygen, and the cells of the immune system throughout the body. Extracellular matrix is called plasma
lymph - formed from the plasma and interstitial fluids draining from the capillary beds

Question 12

What are the cells of the immune system carried in blood?

Answer 12

erythrocytes (red blood cells)
leukocytes (white blood cells)
Thrombocytes (platelets) - just cellular debris

Question 13

What are the different types of leukocytes?

Answer 13

granulocytes - neutrophils, eosinophils, basophils

agranulocytes - monocytes, lymphocytes

Question 14

Describe areolar connective tissue

Answer 14

loose connective tissue
acts as the “packing material” of the body
it is found in all membranes and underlining epithelial tissues
site of immune response
mostly matrix with randomly arranged protein fibers of all three types
abundant intercellular spaces

Question 15

Describe adipose connective tissue

Answer 15

loose connective tissue
consists of adipocytes, cells that store energy in fat
enlarged droplets of fat push the nuclei and cytoplasm, to the periphery
two types - brown and white

Question 16

Describe reticular connective tissue

Answer 16

makes up the framework of glands, organs, and lymph nodes

Question 17

Describe dense regular connective tissue

Answer 17

strongest tissue in the body
makes up the ligaments, tendons, and aponeurosis
collagen fibers run parallel providing additional strength
slow to heal

Question 18

Describe irregular connective tissues

Answer 18

consists mostly of collagen fibers
has few cells and practically no ground substance
found in protective fascia, fibrous joint capsules, dermis, and hypodermis, pericardium, heart valves
slow to heal

Question 19

Describe elastic connective tissue

Answer 19

consists mostly of elastic fibers and therefore is capable of stretching
found in arterial walls, lungs, vocal cords, etc

Question 20

Describe cartilage

Answer 20

supportive connective tissue
flexible but strong
maintains its shape well
collagen fibers are firmly implanted in gelatinous ground substance called chondroitin sulfate - 80% water
there are three types of cartilage

Question 21

What is hyaline cartilage

Answer 21

hyaline cartilage - matrix is rich in strong collagen fibers, which provide support and hyaluronic acid that helps to reduce friction and absorb shock
precursor in bone development
most common type of cartilage
found in the nose, rib cartilage, synovial joins, and epiphysis of the bones

Question 22

What is elastic cartilage?

Answer 22

elastic fibers found in the matrix give the cartilage exceptional rebound capabilities
found in the external ear, Eustachian tubes, and epiglottis

Question 23

What is fibrocartilage?

Answer 23

contains fine collagen fibers arranged in layered arrays
exhibits exceptional resistance to compression
found in intervertebral disks, menisci of the knee join, and symphysis pubis

Question 24

Describe osseous tissue

Answer 24

matrix is rich in calcium phosphate which provides strength

two types

Question 25

Describe compact bone

Answer 25

found in the shafts of long bones and in the outer layer of all other bones its functional unit is called osteon - consists of matrix deposited in layers (lamella) around a canal containing blood vessels matrix is produced by the osteocytes

Question 26

Describe cancellous or spongy bone

Answer 26

does not have an osteon structure site of the bone growth surrounds red bone marrow

Question 27

What does the integumentary system consist of?

Answer 27

``` skin hair nails sweat glands sebaceous glands ```

Question 28

What are the functions of the integumentary system

Answer 28

protection thermoregulation vitamin production excretion of metabolic waste

Question 29

Describe the skin

Answer 29

``` largest organ in the body weighs 9 lbs avg surface area is 20 cubic ft two layers - epidermis and dermis a layer of loose connective tissue, hypodermis, can be seen below the skin ```

Question 30

Describe the epidermis

Answer 30

consists of keratinized stratified squamous epithelium | this includes keratinocytes, melanocytes, langerhans' cells, and merkel cells

Question 31

What are the five layers of the epidermis?

Answer 31

``` stratum basale stratum spinosum stratum granulosum stratum lucidum stratum corneum ``` Bad Skin Gets Large Calluses

Question 32

Describe the stratum basale

Answer 32

deepest layer of the epidermis consists of a single layer of columnar or cuboidal cells that rest on the basement membrane cells rapidly proliferate and give rise to all other layers of the epidermis

Question 33

How long does the renewal of the epidermis take?

Answer 33

3 to 4 weeks

Question 34

Describe melanocytes

Answer 34

found in the stratum basale produce melanin this is then injected into the keratinocytes of the basal layer protects the chromosomes of mitotically active basal cells against light-induced damage sun causes production of melanin granules

Question 35

Describe the stratum spinosum

Answer 35

5-10 layers of tightly interdigitating live cells irregular in shape Contain the intermediate filament pre-keratin varies in thickness

Question 36

Describe the stratum granulosum

Answer 36

3-5 layers of cells that begin to degenerate they become flat, their nuclei disintegrate, and the cellular membrane thickens multiple granules of keratin is found in this layer

Question 37

Describe the stratum lucidum

Answer 37

consists of several layers of lear, flat, dead cells only visible in thick skin best seen in palms and soles of feet

Question 38

Describe the stratum corneum

Answer 38

makes upper 2/3 of the epidermis 20-30 layers of very flat, dead cells make up the most superficial layer of skin designed for protection dead cells shed off at roughly the rate at which new cells are produced underneath

Question 39

Describe the dermis

Answer 39

consists of connective tissues and is found below the epidermal layer of skin rich in capillaries, nerves, and lymphatic vessels has two layers

Question 40

Describe the papillary layer

Answer 40

loose areolar connective tissue makes nipple-like projections into epidermis (dermal papillae) dermal papillae with overlaying epidermis make a unique pattern (fingerprints)

Question 41

Describe the reticular layer

Answer 41

makes up to 80% of the dermis dense irregular connective tissue has collagen that provides strength and elastin that provides stretch and recoil

Question 42

What causes wrinkles?

Answer 42

decreased elasticity of the dermis resorption of the bone atrophy of subcutaneous fat

Question 43

What determines skin pigmentation?

Answer 43

three pigments: melanin carotene hemoglobin

Question 44

Describe melanin

Answer 44

a dark brown protein pigment produced by melanocytes in the stratum basale that absorbs UV radiation increased exposure to UV light results in more melanin secretion varies in color and amount produced regulated genetically by the pituitary and adrenal glands

Question 45

How is melanin produced?

Answer 45

from amino acid tyrosine utilizing enzyme tyrosinase | in albinism, this enzyme is absent due to genetic mutation

Question 46

Describe carotene

Answer 46

a yellow non-polar hydrocarbon pigment produced by vegetables, such as carrots and spinach, and gives skin a yellow shade

Question 47

How does hemoglobin affect skin pigmentation?

Answer 47

iron-based protein found in the blood | skin is transparent, hemoglobin carries blood to the capillaries of the dermis and gives the skin a pink color

Question 48

What metabolic process occurs in the skin?

Answer 48

the active form of vitamin D is produced in the skin in the presence of UV light a small amount of UV light is sufficient folic acid, which is required for DNA synthesis and is needed in pregnant women, is destroyed by UV light

Question 49

Describe nails

Answer 49

facilitate grasping by the fingers analogous to the epidermis stratume basale gives rise to the entire nail adheres tightly to the epidermis at the nail bed

Question 50

Describe the hair

Answer 50

body is covered by vellus hair skull is covered by terminal hair avg head has 100,000 hairs, each living 2-4 years over 5 million hair follicles on the body hair matrix is analogous to the stratum basale

Question 51

Describe hair follicles

Answer 51

contain the root of the hair extends to the upper layers of the hypodermis its lower portion, the bulb, consists of mitotically active cells these produce keratin that does not flake off

Question 52

What is the muscle involved in a hair?

Answer 52

arrector pili smooth muscle that connects the papillary layer of the dermis and the follicle causes hair to stand up

Question 53

Describe sebaceous glands

Answer 53

secrete a lipid-rich material into the upper parts of the hair follicles or onto the surface of the skin has no softening effect on the skin very limited antibacterial and antifungal activity makes the skin water-resistant liable for acne

Question 54

What are the two types of sweat glands

Answer 54

Eccrine (merocrine) sweat glands | Apocrine sweat glands

Question 55

Describe Eccrine (merocrine) sweat glands

Answer 55

produce a secretion containing mostly water and salt important for regulation of body temperature sweat is emptied directly onto the surpace of the skin no damage to cells in gland, therefore no cellular debris

Question 56

Describe apocrine sweat glands

Answer 56

located in teh axillary and anogenital regions produce a more lipid-rich secretion that empties into the upper part of the hair follicle stimulated by sexual hormones parts of cell are pinches off to release sweat bacteria feeds on cellular debris, this causes the smell

Question 57

What are the parts of the skeleton?

Answer 57

axial skeleton - skull, vertebral column, and rib cage | appendicular skeleton - arm, shoulder, and pectoral girdle

Question 58

What are the functions of the skeletal system?

Answer 58

``` support movement protection hematopoiesis mineral storage ```

Question 59

What are the types of bone?

Answer 59

long - tibia, femur short - carpals, tarsals flat - frontal, parietal (skull) irregular - vertebrae

Question 60

What are the features of a long bone?

Answer 60

the epiphysis is the end of the bone- outer layer is compact bone, inner layer is spongy diaphysis is the shaft - a collar of compact bone and a medullary cavity filled with yellow bone marrow periosteum is outer covering of the bone

Question 61

Describe the periosteum

Answer 61

consists of a fibrous layer (dense irregular connective tissue) and an osteogenic layer that gives rise to osteoblasts contains nerves and vessels serves as a site of bone growth and repair

Question 62

What are the features of flat bone

Answer 62

spongy bone filled with red bone marrow | surrounded by thin layer of compact bone and covered by the periosteum

Question 63

Where is bone marrow taken from?

Answer 63

the pelvis

Question 64

Describe an osteon

Answer 64

functional unit of compact bone consists of columns with central Harvesian canal that carries capillaries and nerves perforating volksman canals bring vessels from the periosteum to the central canals concentric lamella composed of bone matrix and cells surround central canal

Question 65

Describe the bone matrix in an osteon

Answer 65

organic collagen fibers are oriented in the same direction in each osteon and provide high resistance to stretch calcium phosphate and hydroxyapatite provide high resistance to stretch

Question 66

What are the cells of the bone? Describe them

Answer 66

osteoblasts - produce matrix and are not embedded in it, eventually bury themselves and become osteocytes - mature cells that occupy lacunae and connect with each other thru canaliculi osteoclasts - reabsorb the bone

Question 67

How are bones typically broken?

Answer 67

torsional forces

Question 68

Describe the lamella of osteons

Answer 68

gelatinous matrix mineral salts hydroxyapatite provide high resistance to stress collagen fibers oriented in teh same direction in each osteon and provides high resistance to stretch