RAD 200 Injury, Inflammation, & Repair

refers to a functional grouping of cells & intercellular substances

Tissue

one or more tissues arranged into a mass the carries out a major body function

Organ

cells that carry out the main function of an organ, and are most abundant & often unique to the organ

Parenchymal cells

What are the 4 main tissue groups

Epithelial

Connective

Muscle

Nervous

The two most varied classes of cells

Epithelial tissue cells

Connective tissue cells

Tissues covers surfaces, lines cavities, and forms glands. Work in tight clusters.

Epithelial cells

Which cells are the main tissue of the skin’s outer layer

Epithelial cells

Which cells secret of specific products (mucus,
digestive juices, sweat)?

Epithelial

What type of functions do epithelial cells have?

Special metabolic functions (exocrine and endocrine)

Cells more loosely arranged. Cells involved w/ general
support functions & transportation

Connective Tissue

Connective Tissue gross physical support include…

bone

cartilage

tendons

fascia

& other fibrous tissue

most abundant component of connective tissue (a type of protein)

Collagen

Very mobile nonepithelial cells. Function independently. Each type has a characteristic morphologic appearance

White Blood Cells (Leukocytes)

What do White Blood Cells (Leukocytes) specialize in ?

Specialized to aid in attacking foreign substances

What are 5 types of Leukocytes

Neutrophil

Monocytes

Lymphocytes

Eosinophil

Basophils

What is the blood composed of?

Plasma

White blood cells & platelets

Red Blood Cells

How much of the blood is made up of plasma?

55%

How much of the blood is made up of white blood cells & platelets?

4%

How much of the blood is made up of Red blood cells?

41%

Are tiny, colorless cell fragments in your blood that form clots to stop bleeding.

Platelets

platelets are also known as?

thrombocytes

red blood cells are also known as?

Erythrocytes

white blood cells are also known as?

Leukocytes

When the cell is attacked by a foreign substance....

Direct the attack

Release substances (lymphotoxins)

B- cells can transform into plasma cells to produce antibodies

Events Following Injury....

Necrosis (Cell death)

Inflammation

Repair

Removes cells during development, eliminates potentially cancerous and virus-infected cells, and maintains balance in the body. Occurs formation of new cells and is a Mechanism of ridding excess cells

Apoptosis

During necrosis what also occurs

Apoptosis

Apoptosis is also known as what?

programmed cell death or cellular suicide

Does apoptosis contribute to inflammation?

No

The intensity of Necrosis, inflammation & repair depend on what?

Magnitude of injury

Duration of injury

Location w/in the body

Nature of the injury

When does inflammation begin?

Shortly after effects of cell injury are evident

When do repairs become established?

Until necrosis ends

When can inflammation be a cause of necrosis

when inflammation is intense

Causes of necrosis can be of injuries that are either exogenous or endogenous

Anoxia

Hypoxia

Thrombus

Embolus

Trauma

Infection

Hypersensitivity

Lesions that can occur

changes to nucleus

necrosis

reversible cell changes

irreversible changes

atrophy

accumulation

What are the changes that can occur to the nucleus that leads to cell death

Pyknosis

Karyorrhexis

Karyolysis

Nucleus shrinks

Pyknosis

Nucleus ruptures/fragments

Karyorrhexis

Nucleus fades away

Karyolysis

cell swelling, detachment of ribosomes from granular. Cell returns to normal state

Reversible cell injury

mitochondria swell, lysosomes swell, damage to plasma
membrane and lysosomal membranes leads to enzyme leakage. Complete cell death, cell cannot return to the normal state

Irreversible cell injury

Body’s natural and protective response to injury or infection

Inflammation

what does inflammation focuses on?

Focuses on materials brought to the injured site and how they limit injury & remove necrotic debris

what process can destroy more normal
tissue than necessary

Inflammation

starts rapidly and quickly becomes severe. It may last for few weeks

Acute inflammation

Acute inflammation has cardinal signs that are?

Redness (hyperemia)

Swelling (edema)

Heat

Pain

Loss of function

May last for few weeks

long-term inflammation that may damage tissue, which can last for several months and even years (if it last more than 3wks)

Chronic inflammation

What can result from persistent acute inflammation

Chronic Inflammation

is a soluble blood protein that may leak into the inflamed site converting to fibrin.

Fibrinogen

A scab is composed largely of…

Fibrin

Fibrin helps with what?

HELPS TO BLOCK THE BLOOD FLOW

Migrate faster to the injured site. May die soon after to save powerful digestive enzymes Or may phagocytose. Important in certain types of bacterial infections

Neutrophils

movement of white blood cells in response to a chemical(in bacteria)

chemotaxis

Living cells that ingest or engulf other cells or particles

Phagocytes

Arrive later to injured site. Hardier than neutrophils Carry major load in clean up

Macrophages (large white blood cell)

Staph infections will have lots of…

neutrophils

Injured adipose tissue from a trauma will have lots of …

macrophages

Specific type of chronic inflammation characterized by focal collections of closely packed, plump macrophages. Occurs in response to certain indigestible organisms & other foreign materials

Granulomatous Inflammation

T-lymphocytes recruit large number of macrophages that engulf the offending agent. Macrophages often form a few giant cells

Info of Granulomatous Inflammation

Classic cause of granulomatous
inflammation is … and …

TB & sarcoidosis

a small, localized cluster of immune cells that forms when the body attempts to isolate substances it perceives as foreign but cannot eliminate. They are essentially defensive, noncancerous nodules caused by chronic inflammation, frequently found in the lungs, skin, or other organs

Granuloma

2 basic methods following tissue destruction

Regeneration

Fibrous connective tissue repair (scarring or fibrosis)

Replacement of the destroyed tissue by cells similar to parenchymal cells of the organ are regenerated

Regeneration

tissue previously present is replaced by fibrous tissue (scar)

Fibrous connective tissue repair

Most desirable form of repair

Regeneration

Prerequisites for regeneration to occur?

cells next to those that have died must be able to regenerate

Tissues that are continuously replacing itself have great
capacity for…

Regeneration

What’s the purpose of Fibrous Connective Tissue Repair

to provide a strong bridge between normal tissue and the
damage area

Factors Inhibiting Wound Healing

Virulence of the infective organisms

Age

Poor nutrition

Diabetes

Steroid therapy