Tissues & Membranes Chapter 4

Page 51 Tissues Cells are grouped into kinds of tissues according to their similarities in shape, size, structure, intercellular materials, & function. There are four main types of tissues: Epithelial tissue – protects the body by covering internal & external surfaces. Connective tissue – connects organs & tissue. Muscle tissue – contains cell material that has the ability to contract & move the body. Nervous tissue – contains cells that react to stimuli & contract an impulse. Multicellular organisms are composed of different types of cells. Epithelial tissue in the lining of the small intestine absorbs nutrients. All glands are made of epithelial tissue. The endocrine glands secrete hormones, mucous glands secrete mucous, & the intestinal glands secrete enzymes. Epithelial tissue also excretes sweat. The epithelial tissue is named according to its structure. Connective tissue allows for movement & provides support for another types of tissue. Connective tissue is classified into subgroups: adipose tissue, areolar tissue, dense fibrous tissue, & support tissue Nervous tissue controls & coordinates body activities, controls our emotions, & allows us to learn through the memory process. Nervous tissue includes the special senses of sight, taste, touch, smell, & hearing.

Epithelial Tissue Pages 51 – 52 Covering & Lining Squamous epithelial cells – Flat irregularly shaped cells Cuboidal epithelial cells – Cubed-shaped cells Columnar epithelial cells – Elongated, nucleus near the bottom of the cell Glandular or Secretory Endocrine gland cells – Form ductless glands that secrete substances (hormones) Exocrine gland cells – Secrete substances directly into ducts

Connective Tissue Page 52 Adipose Stores lipid (fat) Acts as filler tissue Cushions, supports, and insulates the body Areolar (Loose) Semifluid matrix Cells: fibroblasts, macrophages, plasma cells, mast cells & white blood cells Fibers: collagen & elastin Surrounds various organs, skin & subcutaneous layer with adipose tissue

Connective Tissue (Cont’d) Pages 52 – 53 Connective Tissue (Cont’d) Dense Fibrous Ligaments Tendons Aponeuroses Fasciae Supportive Osseous (bone) tissue – Intracellular matrix contains deposits of mineral salts Cartilage Hyaline Fibrocartilage Elastic cartilage Ligaments – are strong flexible bands (or cords) that hold bonds firmly together at the joints. Tendons – are white, glistening bands that attach skeletal muscles to the bones. Aponeuroses – are flat, wide bands of tissue that hold one muscle to another or to the periosteum (Bone covering) Fasciae – are fibrous connective tissue sheets that wrap around muscle bundles to hold them in place. ***** Hyaline – forms the skeleton of embryo Fibrocartilage – a strong, flexible, supportive substance found between bones & whenever great strength (& a degree of rigidity) is needed. Elastic cartilage – the intercellular matrix is embedded with a network of elastic fibers & is firm but flexible

Connective Tissue (Cont’d) Pages 53 – 54 Connective Tissue (Cont’d) Vascular (Liquid Blood Tissue) Blood – Plasma & cellular components Lymph – Contains water, glucose, proteins, fats, salts and other tissue components

Page 54 Muscle Tissue Cardiac – striated, involuntary, & only in the walls of the heart Skeletal – striated & voluntary Smooth – nonstriated & involuntary

Page 54 Nervous Tissue Neurons found in the brain, spinal cord & nerves Irritability – ability to respond to environmental changes Conductivity – ability to carry a nerve impulse

Effects of Aging on Tissue Page 55 SB Effects of Aging on Tissue Cells become larger &less able to divide & reproduce Increase in pigments & lipids inside cells Waste products accumulate in the tissue Cell membranes change & carbon dioxide & wastes have difficulty getting out Lipofusion collects (fatty brown pigment) Connective tissue becomes progressively stiff Increased difficulty receiving oxygen & nutrients Many tissues lose mass & atrophy

Membranes Page 55 Two thin layers of tissue together form a membrane Epithelial membranes mucous or serous depending on the type of secretion produced.

Epithelial Membranes Page 55 Mucous membranes – lubricates & protects Respiratory mucosa – respiratory passages Gastric mucosa – lines the stomach Intestinal mucosa – small and large intestine Serous membranes (parietal & visceral) – Double walled membrane that produces a watery fluid Pleural membrane – lines the thoracic cavity Pericardial membrane – lines the heart cavity Peritoneal membrane – lines the abdominal cavity Cutaneous membranes (skin) – see Chapter 5

Page 55 Figure 4-1

Connective Membranes Page 56 Synovial membrane – Two layers of connective tissue Lines joint cavities – Secretes synovial fluid, which prevents friction inside the joint cavity

Page 56 Organs An organ is tissues grouped together to form a specific function Organs coordinate their activities to form a complete functional organism Organ system = Group of organs that acts together to perform a specific, related function Example: digestive system

Organs Systems Page 58 Table Integumentary – covered in chapter 5 Skeletal – covered in chapter 6 Muscular – covered in chapter 7 Nervous – covered in chapter 8, 9 & 10 Endocrine – covered in chapter 11 Circulatory – covered in chapter 12, 13, 14, &15 Respiratory – covered in chapter 17 Digestive – covered in chapter 18 Excretory – covered in chapter 20 Reproductive – covered in chapter 21

Disease & Injury to Tissue Page 56 Disease & Injury to Tissue Infection = Invasion of a microorganism causing disease Inflammation = Results in pain, redness, swelling & loss of motion Trauma Abnormal growth of cells Birth defects

Degree of Tissue Repair Page 58 Degree of Tissue Repair Repair of damaged tissues occurs continually during the everyday activities of living. Depending on the type & location of injury, some tissue is quickly repaired. Muscle tissue heals slowly Bone tissue repairs are slow because broken bone ends must be kept aligned & immobilized until the repair is done.

Tissue Repair Pages 58 – 60 Primary repair Fluid escapes from the damaged tissue, then dries & seals the wound, forming a protective scab Secondary repair Formation of granulation tissue Bactericidal fluid is secreted that reduces the risk of infection Scar formation depends on the extent of tissue damage

Tissue & Organs Transplant Page 59 SB Tissue & Organs Transplant Blood transfusions are an example of a tissue transplant All transplants (tissue & organs) must be cross-matched so recipient’s immune system will not attack the donated organ Rejection is the main problem in organ transplants Major issue: decline in the number of living donor organs available for transplants during the last 5 years. 1 donor can save as many as 8 lives.