Lab 4/Chapter 5: Tissues and Integumentary System

Question 1

Define “tissue”

Answer 1

a group of similar cells and cell products that arise from the same region of the embryo and work together to perform a specific structural or physiological role in an organ.

Question 2

Name the 4 primary tissues types.

Answer 2

1. epithelial
2. connective
3. nervous
4. muscular

Question 3

Define “histology”

Answer 3

the study of tissues and how they are arranged into organs

Question 4

Define “extracellular matrix”

Answer 4

extracellular material (non-cellular component of tissues and organs–especially of connective tissue)

• made of fibrous proteins and a clear gel called “ground substance”
  
  • hard matrix: cartilage and bone
  • liquid matrix: blood and lymph
  • fibrous matrix: (connective tissue proper) loose and dense
  • ground substance contains interstitial fluid, proteins, and proteoglycans–typically refers to connective tissue

Question 5

What are the functions of the integumentary system?

Answer 5

• regulation of body temperature
  
  • (sweating, vasodilaton/constriction of blood cells)
• Protection
  
  • against bacteria, chemicals, UV, light, abrasion, dehydration
• sensory receptors
  
  • (touch, itch, temperature, pressure, pain, vibration)
• excretion and absorption
  
  • pain patch, excrete waste)
• synthesis of Vitamin D

Question 6

What are the two distinct regions of the integumentary system?

Answer 6

Skin (cutaneous membrane)

• epidermis
• dermis

Subcutaneous Layer

• hypodermis / superficial facia
  
  • NOT a part of the skin!

Question 7

What are the two layers of the dermis?

Answer 7

Papillary region

• finger-like projections (dermal papillae)
• Meissner’s (tacticle) corpuscles for light touch

Reticular Region

• oil glands, sweat glands, hair follicles
• lamellar / Pacinian corpuscles used for pressure (deep touch)

Question 8

What are the five distinct layers of the epidermis?

Answer 8

• stratum corneum
  
  • flat, dead cells filled with Keratin
• stratum lucidum (thick skin ONLY)
  
  • clear layer
• stratum granulosum
  
  • transitim (grainy) layer
  • above this layer is dead, below it is alive
• stratum spinosum
  
  • looks “spiny” on a slide
• stratum basale
  
  • single layer of stem cells
  • melanocytes are here

Question 9

Identify the following: hair, arrector pili muscle, sebaceous gland, sudoriferous (sweat) glands, tactile (Meissner’s) corpuscles, and lamellar (Pacinian) corpuscle

Answer 9

…..

Question 10

Give the function of the following:

hair, arrector pili muscle, sebaceous gland, sudoriferous (sweat) glands, tactile (Meissner’s) corpuscles, and lamellar (Pacinian) corpuscle

Answer 10

• Hair: vestigial, retain heat
• arrector pili: pulls hair upright
• sebaceous gland: secrete oil for hydration, empty into hair
• sudoriferous gland: apocrine for scent-stress and stimulation, merocrine/eccrine for cooling
• tactile corpuscles: light touch/sensory
• lammelar corpuscle: pressure / deep touch

Question 11

Skin reference sheet

Answer 11

Question 12

What is the location and function of epithelial tissue?

Answer 12

Location:

• epidermis
• inner lining of digestive tract
• liver and other glands

Function:

• protection (covers surface and lines body cavities)
• sensory input, absorption, makes up glands, filtration, and secretion

Question 13

What are the characteristics of epithelial tissue?

Answer 13

• avascular (without blood supply)
• annervated
• fit closely together
  
  • held by “watertight junctions” and desmosomes
• has a top (apical surface) and a bottom (basement membrane; basal surface on top of it)
  
  • may have microvilli or cilia on apical
• good regenerative powers

Question 14

What is the naming convention for epithelial tissue and what are the two exceptions?

Answer 14

• First name: number of layers, second name: shape of cells
• Exception: pseudostratified columnar epithelium (looks like baby trees growing next to tall trees–looks like many layers but is one) and transitionial epithelial tissue (bladder / ureters only)

Question 15

What is the location and function of connective tissue?

Answer 15

Location

• most abundant and widespread tissue in the body
• various types and functions

Function

• Binding of organs
• support (bone)
• physical protection
• immue protection (battlefield under skin)
• movement (bone)
• storage (fat and bone)
• heat production (brown fat)
• transport (blood)

Question 16

What are the characteristics of connective tissue?

Answer 16

• derived from mesenchyme (embryonic connective tissue)
• usually vascular (has blood vessels)
  
  • except cartilage, ligaments, and tendons–only on membrane above
• good nerve supply
• cell separated by large amount of nonliving, extracellular matrix

Question 17

What are the types of fibrous connective tissue?

Answer 17

Loose connective tissue

• more gel-like substance between cells
• areolar, reticular, and adipose

Dense connective tissue

• fibers fill spaces between cells
• dense regular connective tissue and dense irregular connective tissue

Question 18

Describe the structure, function, and location of the following 3 loose connective tissue: areolar, reticular, and adipose

Answer 18

Areolar

• loose mesh, all 3 fibers
• wraps and cushions organs
• between muscles, passageway for blood and nerves, under epithelia

Reticular

• highly branched, retains shape
• mainly reticular fibers
• soft internal skeleton for lymph nodes, spleen, and bone marrow

Adipose

• fat
• like areolar but sparse fibers
• provides energy, insulation, and padding
• brown feat produces heat (juvenils only)

Question 19

Describe the structure and location of the 2 dense connective tissues

Answer 19

Dense regular

• very strong
• mainly collagen, fibers run in one direction (parallel)
• tendons, ligaments

Dense Irregular

• mainly collagen, fibers run in all directions
• dermis, organ capsules

Question 20

What are the 3 types of fibers?

Answer 20

1. collagenous (tough, flexible, resist stretching)
2. reticular (thin, spongelike / highly branched framework)
3. elastic (thinnest) (tendency to recoil when tension is released)

Question 21

What is the structure and function of hyaline cartilage connective tissue?

Answer 21

• most abundant cartilage
• rubbery matrix
• contains chondrocytes in lacunae
• costal (ribs) cartilage
• articular cartilage
• respiratory cartilage (nose, trachea, very breakable)

Question 22

What is the structure and function of elastic cartilage connective tissue and fibrocartilage connective tissue, respectively?

Answer 22

Elastic cartilage

• similar to hyaline but elastic fibers
• flexible support
• outer ear, epiglottis

Fibrocartilage

• similar to hyaline but more collagen fibers
• strongest cartilage
• made to compress, shock absorber
• interverterbal discs, pubic symphysis, discs in knee (menisci)

Question 23

What is the structure and function of osseous connective tissue and blood as connective tissue?

Answer 23

Osseous tissue

• bone tissue
• flexible
• hard, calcified matrix with collagen
• osteocytes in lacunae
• support, protection
  
  • (work with muscles for movement, storage of fat and calcium, make blood cells)

Blood

• RBC and WBC in fluid matrix
• cardiovascular and immue systems
• plasma–blood’s ground substance

Question 24

Photomicrograph of areolar connective tissue

Answer 24

Question 25

Photomicrograph of adipose connective tissue

Answer 25

Question 26

Photomicrograph of osseous connective tissue

Answer 26

Question 27

Photomicrograph of blood connective tissue

Answer 27

Question 28

What is meant by nervous and muscular tissues being “excitable” tissues?

Answer 28

they respond to stimuli by changing membrane potential

• membrane potential is electrical charge difference (voltage) that occurs across cell membrane
• in nerve cells ,changes in voltage result in rapid transmission to other cells
• in muscle cells, changes in voltage cause contraction

Question 29

What are the 2 types of nervous tissue cells?

Answer 29

Neurons

• transmit electrical impulses
• a neuron will either go down a dendrite into the cell body or in axon away from cell body

Neuroglia

• support, protect, provide nutrients to neurons

Question 30

What are the 3 types of muscle tissue and their characteristics?

Answer 30

Skeletal muscle

• striatied, multinucleate, voluntary

Cardiac Muscle

• striated, uninucleate, involuntary

Smooth (or visceral) muscle

• nonstriated, uninucleate, involuntary

Question 31

What are the 2 types of fibrous connective tissues?

Answer 31

Loose connective tissue

• more gel-like ground substance between cells
• areolar, reticular, adipose

Dense connective tissue

• fibers fill spaces between cells
• regular/irregular

Question 32

What are the specialized cells / membranes of connective tissue?

Answer 32

• fibroblasts (make fibers)
• chondroblasts (make cartilage)
  
  • chondrocytes (cartilage cells trapped in lacunae)
• osteoblasts (make bone)
• perichondrium: membrane of dense irregular connective tissue that surrounds elastic and most hyaline cartilage (not articular) and contains reserve population of chondroblasts (to make more cartilage if needed)

Question 33

What are the 3 types of cell junctions?

Answer 33

Tight junctions

• seal off intercellular space, “watertight”
• make it difficult for substances to pass between cells
• (e.g. hold urine in bladder)

desmosomes:

• keeps cell from pulling apart
• resist mechanical stress
• e.g. skin, cardiac muscle

Gap junctions

• communicating junction (for rapid communication)
• formed by ring-like connexon
• e.g. 4 regions of the heart know to contract at the same time

Question 34

What are exocrine glands, their types, their structures, and examples?

Answer 34

• maintain their contact with surface of epithelium by way of a duct
• can be internal or external
  
  • merocrine gland: products are secreted by exocytosis
    
    • used by eccrine sweat glands (cooling)
    • suderiferous/apocrine gland: scent sweat gland
  • apocrine: fat droplets bud off plasma membrane
    
    • (e.g. milk fat secretion from mammary)
  • holocrine: products are secreted by rupture of whole gland cell
    
    • e.g sebaceous gland (oil)

Question 35

What are endocrine glands?

Answer 35

Glands that secrete hormones into the blood.

Question 36

What are unicellular glands?

Answer 36

• glands found in an epithelium that is predominantly nonsecretory
• can be exocrine or endocrine
• e.g. mucus secreting goblet cells in trachea

Question 37

What are membranes and their two types / substrates?

Answer 37

Membranes are thin sheets of tissue.

• Epithelial membranes
  
  • 2 layers of epithelial tissue over connective tissue
  • serosa, mucosa, and cutaneous membrane
• Connective tissue membranes
  
  • made only of connective tissue
  • synovial membranes (around every joint), meninges (brain and spine), periosteum (bone), perichondrium (cartilage)

Question 38

Describe the strucure and function of the 3 epithelial membranes

Answer 38

• Mucosa
  
  • lines cavities with connection to the outside
  • produces mucus
  • e.g. digestion, respiratory, urinary, reproductive
• Serous (serosa)
  
  • lines cavities with no connection to outside
    
    • visceral
    • parietal
  • produces watery serous fluid

Question 39

What are the two forms of tissue repair?

Answer 39

• regeneration: replacement of dead or damaged cells by the same type of cell as before
• fibrosis: replacement of damaged cells with scar tissue (does not restore function)

Question 40

What tissues are good / bad at repair?

Answer 40

• Good: epithelial, bone, areolar, dense irregular
• Moderate: dense regular, smooth muscle
• Poor: cartilage, skeletal muscle
• Almost none: cardiac muscle, neurons

Question 41

What are the functions of epithelial tissue?

Answer 41

• line cavities, surfaces of organs, skin
• sensory input
• secretion and absorption
• makes up glands

Question 42

What are the functions of connective tissue?

Answer 42

• protection
• binding and support
• insulation
• transportation
• most adundant and widespread tissue in the body