Exam 2 A&p

Front 1

Connective tissues

Back 1

The most abundant and widely distributed tissues in the body

-- Also the most diverse of the tissue groups

-- They perform numerous functions:

• Binding and support
  
• Protect and insulate internal organs
  
• Compartmentalization and transport
  
• Energy reserves and immune responses
  

Front 2

3 characteristics make connective tissues different from other primary tissues

Back 2

• Have mesenchyme (an embryonic tissue) as their common tissue of origin
  
• Have varying degrees of vascularity (blood vessels)
  
• Have extracellular matrix
  
• connective tissue not composed mainly of cells
  
• Largely nonliving extracellular matrix separates cells
  

-- so can bear weight, withstand tension, endure abuse

Front 3

Four main classes of connective tissue

Back 3

1. Connective tissue proper
   
2. Cartilage
   
3. Bone
   
4. Blood
   

Front 4

Connective Tissue Diversity

Back 4

Although there is diversity in the types of CT, all share a common "theme"

Sparse cells surrounded by an extracellular matrix usually secreted by the connective tissue cells

EC matrix determines the tissues's qualities

The extracellular matrix is the non-cellular material located between and around the CT cells.

Consists of protein fibers and ground substance (the ground substance can be fluid, semifluid, gelatinous, or calcified.)

Front 5

Structural Elements of Connective Tissue

Back 5

Three elements

1. Ground substance
   
2. Fibers
   
3. Cells
   

Composition and arrangement varies in different connective tissues.

Front 6

Ground Substance

Back 6

• Unstructured material that fills space between cells
  

-- Medium through which solutes diffuse between blood capillaries and cells

• Components
  

-- Interstitial Fluid

-- Cell adhesion proteins ("glue" for attachment)

-- Proteoglycans

Protein core + large polysaccharides (chrondroitin sulfate and hyaluronic acid)

Trap water in varying amounts, affecting viscosity of ground substance.

Front 7

C.T. cells secrete 3 common fibers

Back 7

Collagen

Elastic

Reticular

Front 8

Collagen

Back 8

• strongest and most abundant type
  
• tough; provides high tensile strength
  

Front 9

Elastic

Back 9

Networks of long, thin, elastin fibers that allow for stretch and recoil

Front 10

Reticular

Back 10

• Short, fine, highly branched collagenous fibers (differently chemistry and form collagen fibers)
  
• Branch, forming networks that offer more "give"
  

Front 11

Common C.T.

Back 11

"Blast" cells

"Cyte" cells

Front 12

Blast Cells

Back 12

• Immature form; mitotically active; secrete ground substance and fibers
  
• Fibroblasts in connective tissue proper
  
• Chrondroblasts in cartilage
  
• Osteoblasts in bone
  
• Hematopoietic stem cells in bone marrow
  

Front 13

Cyte Cells

Back 13

Mature form; maintain matrix

Fibrocytes in connective tissue proper

Chondrocytes in cartilage

Osteocytes in bone

Front 14

Other Common C.T. cells

Back 14

Adipocytes

Blood cells (both red and white)

Mast cells

Front 15

Adipocytes

Back 15

Store triglycerides

Front 16

Blood cells (both red and white)

Back 16

Red- erythrocytes

-- Transport oxygen

White - Macrophages, Neutrophils, Eosinophils, Lymphocytes, etc.

-- Response to injury and infection

Front 17

Mast Cells

Back 17

Initiate local inflammatory response against foreign microorganisms they detect

Front 18

Connective tissue proper

Back 18

• All connective tissues except bone, cartilage, and blood
  
• Two subclasses
  

Loose connective tissues

1. Areolar
   
2. Adipose
   
3. Reticular
   

Dense connective tissues (also called fibrous connective tissues)

1. Dense regular
2. Dense irregular
3. Elastic

Front 19

Muscle and Nerve Tissues

Back 19

Muscle and nerve tissues are the last of the 4 basic tissue types. Neurons and muscle fibers are considered excitable cells because they exhibit electrical excitability, the ability to respond to certain stimuli by producing electrical signals such as action potentials

-- action potentials can propagate (travel) along the plasma membrane of a neuron or muscle fiber due to the presence of specific voltage-gated ion channels.

Front 20

Epithelial membranes

Back 20

• Combining two or more tissues creates an organ.
  

-- Most of the organs contain the 4 basic types of tissues.

-- Epithelial membranes are the simplest organs in the body

An epithelium bound to underlying connective tissue proper

Front 21

Three types of Epithelial Membranes

Back 21

Epithelial membranes + epithelium + connective tissue

1. Mucous Membranes
   
2. Serous Membranes
   
3. Cutaneous Membrane = skin
   

Skin is not a simple organ. We will study the integument as our first organ system in the next chapter.

Front 22

Mucous Membrane

Back 22

line the "interior" body surfaces open to the outside:

Mucosa indicated location not cell composition

• Digestive Tract
  
• Respiratory Tract
  
• Reproductive Tract
  

Front 23

Serous Membranes

Back 23

line some internal surfaces:

• Parietal layer next to body wall
  
• Serous fluid between layers
  
• Visceral layer next to organ
  

Line body cavities that are closed to the exterior

Front 24

Cutaneous Membrane

Back 24

(the skin) covers the body surface

Front 25

Mucous Membranes

Back 25

line the body cavities that are open to the exterior

Front 26

Gland

Back 26

• One or more cells that make and secretes and aqueous fluid called secretion
  
• Classified by
  

-- site of product release -- endocrine or exocrine

-- Relative number of cells forming the gland

--- unicellular (e.g., goblet cells) or multicellular

Front 27

Epithelial Glands

Back 27

another example of simple organs

-- Glands that secrete their contents directly into the blood are called endocrine glands.

-- Glands that secrete their contents into a lumen or duct are called exocrine glands.

Front 28

Exocrine Glands

Back 28

Secrete substances through ducts to the surface of the skin or into the lumen of a hollow organ.

--- Secretions of some exocrine glands include mucus, sweat, oil, earwax, saliva, and digestive enzymes.

The only important unicellular exocrine glands are mucous cells and goblet cells

Front 29

Multicellular glands

Back 29

The criteria for categorizing according to function is based on the manner in which the glands secretes its product from inside the cell to the outside of the environment.

Merocrine

Apocrine

Holocrine

Front 30

Merocrine

Back 30

Most common manner of secretion

The gland releases its product by exocytosis and no part of the gland is lost or damaged

Front 31

Apocrine Glands

Back 31

"bud" their se