ANAPHY-REVIEWER.docx

**ANAPHY REVIEWER** **TISSUE AND HISTOLOGY** **Tissue** - are [groups of specialized cells] and the extracellular substances surrounding them. **Histology** -- is the [study of tissue structure] Changes in tissues can result in [development, growth, aging, trauma, or disease]. For example, [ske...

**ANAPHY REVIEWER** **TISSUE AND HISTOLOGY** **Tissue** - are [groups of specialized cells] and the extracellular substances surrounding them. **Histology** -- is the [study of tissue structure] Changes in tissues can result in [development, growth, aging, trauma, or disease]. For example, [skeletal muscles enlarge because skeletal muscle cells increase in size] in response to exercise. [Reduced elasticity of the blood vessel walls] in aging people results from gradual changes in the connective tissues. [Many tissue abnormalities, including cancer, result from changes in tissues] that can be identified by *[microscopic examination.]* **FOUR TISSUE TYPES** - Nervous Tissue - Muscle Tissue - Epithelial Tissue - Connective Tissue **EPITHELIAL TISSUE** - widespread throughout the body[, covers organs, and lines body surfaces like the skin.] - anchored to a basement membrane, are [made up of tightly packed cells] containing little intercellular material, generally [lack blood vessels, and regenerate very quickly]. **THREE DISTINCT SURFACE** **Apical Surface** -- [Also called as free surface.] Refers to [the top of the epithelial cell], which [faces the lumen or the external environment.] The surface that is exposed. - Surface can be lined with **microvilli** (absorption or secretion of substances) **Basal Surface** ­- The surface of the cells that is [faces the basement membrane]. Attached to some connective tissue within and the rest of the organism. Epithelial cells exhibit **polarity** (which means opposite sides exhibit different features) **Basal Lamina** -- is [made of glycoproteins and collagen fibers which act as a scaffolding.] Basal Lamina + Reticular Lamina = Basement Membrane **CELL JUNCTIONS** - **Desmosomes -** Cell connection structures that [mechanically bind epithelial cells together.] - Connect adjacent cells with filaments. - **Tight Junction [-- ]**[Block the flow of fluid between cells.] - **Gap Junction** --Cell connection structures that [allow for intercellular communication]. Communication occurs via the exchange of ions between epithelial cell and adjacent cells. Epithelial tissues are **avascular** (not serviced by blood vessels) Epithelial tissues are **innervated** (supplied with nerves) **TYPES OF EPITHELIAL CELLS (SHAPE + LAYER)** **Simple Epithelial --** [single layer] of cell **Stratified Epithelial** -- [several layers] of cells Shape of cell has **Hexagonal base**, but height may vary. **Squamous cells** -- flat and scalelike **Cuboidal cells** -- medium height and boxy **Columnar cells** -- tall like columns A. **Simple Squamous Epithelium** - made up of a single layer of thin, flattened cells (squashed). - Because it is [suited for diffusion], it [functions in the exchange of gases in the lungs and lines blood and lymph vessels as well as body cavities] B. **Simple Cuboidal Epithelium** - consists of a single layer of cube-shaped cells with centrally located nuclei. - [functions in secretion and absorption] in the kidneys, and in secretion in glands. C. **Simple Columnar Epithelium** - is made up of a row of elongated cells whose nuclei are all located near the basement membrane. It may be ciliated. - [lines the uterus, stomach, and intestines] where it protects underlying tissues, secretes digestive fluids, and absorbs nutrients. - [In the intestine], these cells [possess microvilli] that increase the surface area available for absorption. - [Mucus-secreting goblet cells can be found among columnar cells.] D. **Pseudostratified Columnar Epithelium** - These cells appear layered due to the varying positions of their nuclei within the row of cells, but are not truly layered. - [Cilia may be present], along with mucus-secreting globlet cells, that line and [sweep debris from respiratory tubes.] E. **Stratified Squamous Epithelium** - This type of tissue is made up of layers of flattened cells that are [designed to protect underlying layers.] - [It makes up the outer layer of skin], and [lines the mouth, throat, vagina, and anal canal.] - In the skin, [outer layers of cells undergo keratinization]; however, this process does not occur where tissues remain moist in the throat, vagina, or anal canal. F. **Stratified Cuboidal Epithelium** - This tissue consists of two to three layers of cuboidal cells [lining a lumen of the mammary glands, sweat glands, salivary glands, and pancreas.] - Several layers of cells provide greater protection than one single layer. G. **Stratified Columnar Epithelium** - This tissue consists of several layers of cells and is [found in the vas deferens, part of the male urethra, and parts of the pharynx]. H. **Transitional Epithelium** - Transitional epithelium is [designed to distend and return to its normal size], as it does in the [lining of the urinary bladder.] - This design [provides distensibility] and keeps urine from diffusing back into the internal cavity. - Is [able to stretch and change shape] when a cavity is filled with liquid. I. **Glandular Epithelium** - This tissue is made up of cells [designed to produce and secrete substances into ducts or into body fluids] - Glands that secrete [products into ducts are exocrine]; those that secrete into [body fluids and blood are called endocrine] **CONNECTIVE TISSUE** - Connective tissues [bind] (ex ligament and tendons), [support, protect, serve as frameworks, fill spaces, store fat] (bones store calcium and phosporous), [produce blood cells] (transportation), [protect against infection, and repair tissue damage.] - Unlike epithelial tissues, connective tissues [have abundant matrix, or intercellular material, throughout, and have good blood supplies (except cartilage).] **FUNCTION OF CONNECTIVE TISSUE** - Connects body parts - Binding - Support - Protection - Insulation - Storage - Transportation **COMPONENTS OF CONNECTIVE TISSUE** - Extracellular fibres (Protein **fibers**) - Amorphous matrix (**Ground substance** (non-cellular material) - Stationary and Migrating cells (living cells or **cells**) **TYPES OF CELLS** **Fibroblast** - the [most common cell type], and is a [fixed, star-shaped cell that secretes fibers and is large in size] **Macrophages** - [function as scavenger cells and defend against infection] **Mast Cells** -- are [large and are located near blood vessels] where they release heparin (anticoalugant) and histamine (promotes inflammation) **TYPES OF FIBERS** **Collagenous Fibers** - (white fibers), made of the protein collagen, [add strength for holding body parts together.] - Strongest fibers, made predominately of collagen **Elastic fibers** - (yellow fibers), [made of the protein elastin], are [stretchy] and add flexibility to certain types of connective tissues. - Long and thin, made of elastin, form networks. **Reticular fibers** - [are thin collagenous fibers] that [form supportive networks] in a variety of tissues. - Similar to collagen fibers but form networks for support **TYPES OF CONNECTIVE TISSUE** - **Loose connective tissue** - [consists of relatively few protein fibers] [that form a lacy network], with numerous spaces filled with ground substance and fluid. **Areolar -** [forms delicate, thin membranes] throughout the body that [bind body parts together] such as skin and underlying organs. - The [majority of the cells are fibroblasts] that are [separated by a gel-like ground substance] that [contains collagenous and elastic fibers]. - [Support and bind other tissues] as well as empty space for storing tissue fluid **Adipose** - [designed to store fat]. - It is [found beneath the skin], around joints, padding the kidneys and other internal organs, and in certain abdominal membranes. - [Contains many fat cells] which are [able to store nutrients and also serve to insulate the body.] **Reticular** -- [similar to areolar tissue] but [contains only reticular fibers] and supports certain structures. - **Dense Connective Tissue** - [consists of densely packed collagenous fibers] and is [very strong but lacks a good blood supply]. It is [found as part of tendons and ligaments.] **Regular** -- [Many collagen fibers packed together with fibroblasts] in between which resists tension - [Collagen fibers in bundles arranged in parallel or orthogonally.] - [Form tendons, ligaments & apponeuroses]. **Irregular** -- [Many collagen fibers but not arranged in any pattern] which offers resistance in many direction. - [Collegen fibers in bundles with random orientation] resists stretching. - [Forms capsules and submucosa and forms reticular layer of skin.] **Elastic** -- [similar to regular dense connective tissue] in most respects [but it is much more elastic] - Specialized Connective Tissue **Cartilage** - rigid connective tissue that [provides a supportive framework for various structures]. It [lacks a vascular system and so heals slowly.] - [Cartilage cells (chondrocytes)] lie within lacunae in the gel-like fluid matrix. - Cartilaginous structures are [enclosed within a connective tissue perichondrium.] - [The most common], **hyaline cartilage**, is white with abundant fine collagen fibers, is [found at the ends of bones, and supports respiratory passages.] - **Elastic cartilage**, with elastic fibers, [provides a framework for the external ears and parts of the larynx]. - **Fibrocartilage**, with many collagenous fibers, is a tough tissue that [provides a shock-absorbing function] in intervertebral disks and in the knees and pelvic girdle. **Bone** - most rigid connective tissue, with [deposits of mineral salts and collagen within the matrix]. - Bone internally supports the body, protects, forms muscle attachments, and is the [site for blood cell formation.] - [Bone cells, called osteocytes], lie within lacunae and are arranged in concentric circles (osteons) around osteonic canals interconnected by canaliculi. - [Bone has a good blood supply, enabling rapid recovery after an injury] **Blood** - [composed of cells (red and white)] suspended in a [liquid matrix called plasma]. It [functions to transport substances throughout the body.] **MUSCLE TISSUE** - [main function is to contract, or shorten, making movement possible.] **TYPES OF MUSCLE TISSUE** - **Skeletal Muscle Tissue** - [attached to bone] and can be controlled by conscious effort (*[voluntary]*). - [nervous system can cause skeletal muscles to contract without conscious involvement], as occurs during reflex movements and the maintenance of muscle tone. - [Gives our body its general shape] - [Muscle contraction] results from contractile proteins [located within the muscle cells], called **Muscle Fibers** - [are long and cylindrical, *striated*, *have many nuclei*], and contract from nervous impulse. - [about 40% of a person's body weight]. - [cells are striated, or banded], because of the arrangement of contractile proteins within the cell - **Smooth Muscle Tissue** - [*lacks striations*, is *uni-nucleate (single nucleus),* and consists of spindle-shaped cells.] - [forms the walls of hollow organs], is [controlled *involuntarily.*] - [found in the skin and the eyes] **FUNCTIONS OF SMOOTH MUSCLE** 1.Present in blood vessel walls (regulates pressure and distributes blood) 2.Present in Airways (controls passage of air) 3.Present in digestive tract walls (contracts to push food along) 4.Present in the bladder (contracts to expel urine) 5.Present in the reproductive system (walls of uterus contract to push out a baby) - **Cardiac Muscle Tissue** - [found only in the heart] and consists of [branching fibers that are connected to each other with intercalated disks]. - [This *involuntary muscle* has a *single nucleus in each cell* but appears *striated*.] - [muscle of the heart; it is responsible for pumping blood] - is under involuntary (unconscious) control, although a person can learn to [influence the heart rate] by using techniques such as [meditation and biofeedback] - [cylindrical but much shorter than skeletal muscle cells]. - [intercalated disks, which contain specialized gap junctions,] are important in coordinating the contractions of the cardiac muscle cells - Cardiac muscle contraction pumps blood out of the heart. [Cardiac muscle cells (also called cardiomyocytes)] **NERVOUS TISSUE** - found in the brain, spinal cord, and nerves. - [responsible for coordinating and controlling many body activities.] - Central nervous system and Peripheral nervous system (2 types) - **Action potentials** -- [ability] of nervous tissue cells [to communicate with one another by means of electric signals] **CELL TYPE** **Neurons or nerve cell --** [conduct nervous impulses] **Neuroglia or glia** -- [helper cells, support and nourish the neurons] **Neurons** -[responsible for conducting action potentials ] **3 PARTS OF NEURONS** **Cell Body** -- [contains the nucleus]; site of general cell functions **Dendrites** -- [receive electric impulses] **Axon** -- [conduct electric impulses] **Astrocytes** -- star shaped - [subtype of glial cells] that make up the majority of cells in the human central nervous system (CNS). - [They perform metabolic, structural, homeostatic, and neuroprotective tasks] such as clearing excess neurotransmitters, stabilizing and regulating the blood-brain barrier, and promoting synapse formation **Satellite cells** -- orbit cells - A t[ype of glia found in the peripheral nervous system], specially in sensory, sympatheti, and parasympathetic ganglia. **Schwann cells** - type of [glial cell that surrounds neurons], keeping them alive and sometimes covering them with a myelin sheath, and are the [major glial cell type in the peripheral nervous system.] [They play essential roles in the development, maintenance, function, and regeneration of peripheral nerves] **MEMBRANES** **Tissue Membrane** - [thin sheet or layer of tissue] that covers a structure or lines a cavity. **Body Membranes** - [cover surfaces, line body cavities, and form protective] (and often lubricating) sheets around organs. **TWO MAJOR GROUPS:** 1**.Epithelial Membranes**, which include the cutaneous, mucous, and serous membranes 2.**Connective Tissue Membranes**, represented by synovial membranes. **EPITHELIAL MEMBRANE** **Cutaneous Membrane** - is [composed of two layers, the superficial epidermis and the underlying dermis.] - [composed of stratified squamous epithelium and dense connective tissue] - [exposed to air and is a dry membrane.] **Mucous Membrane** - [line cavities that open to the outside of the body,] such as the digestive, respiratory, and reproductive tracts - [consist of] various kinds of [epitheium resting on a thick layer of loose connective tissue.] - mucous membranes contain [goblet cells or multicellular mucous glands that secrete mucus]. - mucous membranes [also line the nasal passages] - [simple columnar epithelium of the intestine] - [stratified squamous epithelium of the oral cavity (mouth)] FUNCTION : protection, absorption, and secretion. **Serous Membrane** - [line cavities that do not open to the exterior of the body] - [consist of simple squamous epithelium] resting on a delicate [layer of loose connective tissue] - [line the trunk cavities and cover the organs within these cavities] - Serous membranes [do not contain glands], but they secrete a small amount of fluid called **serous fluid**, which [covers the surface of the membranes] **3 SEROUS CAVITIES** a. **Pleural** -- lungs b. **Pericardial** -- heart c. **Peritoneal** -- abdominopelvic cavity When the suffix [- itis] is added to the name of a structure, [it means that the structure is inflamed] **Pericarditis** - [inflammation of the pericardial membranes] **Peritonitis** -- [inflammation of the peritoneal membranes] **Pleurisy** - [inflammation of the pleural membranes] Addition : When there are too much fluid **Pleural Effusion** -- build up of fliud in the lungs **Pericardial Effusion** - build up of fliud in the heart **Ascites** - build up of fliud in abdomen **CONNECTIVE TISSUE MEMBRANE** **Synovial Membrane** - [made up of only connective tissue.] - [line the inside of joint cavities] (the space where bones come together within a movable joint) - [produce synovial fluid], which makes the joint very slippery, [reducing friction and allowing smooth movement within the joint] GLANDS - An [organ that makes one or more substances], such as [hormones, digestive juices, sweat, tears, saliva, or milk]. **TWO TYPES OF GLANDS** - **Exocrine glands** secrete [other substances] into a [ductal system to an epithelial surface or onto organ.] - [With ducts and tubes] to carry secretion away from the gland - Can be [**simple**, with ducts that have no branches,] or [**compound**, with ducts that have many branches] - produce other substances --- not hormones --- that are released through ducts to the exterior of your body, [such as sweat, saliva, and tears.] The substances released by your exocrine glands play important roles in your body. They do things like [help regulate your body temperature, protect your skin and eyes, and even help mothers feed babies by producing breast milk]. Your exocrine glands include: salivary sweat mammary sebaceous lacrimal **Lymph nodes** are [often referred to as glands, but they're not true glands]. They're [part of your immune system and help your body fight infection.] **STRUCTURE OF EXOCRINE GLANDS** **Duct - r**efers to the tube in contact with the epithelial tissue free surface, which transports the secreted material. **Secretory portion** - is found deeper in the epithelium and is composed of the cells responsible for producing the secreted material. **THREE MAJOR CATEGORIES OF EXOCRINE GLANDS** - **Unicellular --** [Composed of only a single cell], such as goblet cells that secrete mucus - **Simple Glands -** [multicellular glands] that have a single, nonbranched duct. The secretory portions of the gland can be shaped in one of two ways: **Tubular** -- is a [straight, narrow tube] the same width as the duct **Acinar -** a [saclike structure] whose width is greater than the width of the duct. **STRUCTURAL SUBTYPE** **Simple Tubular --** [glands forming a straight tube with no branching] of the secretory portion **Simple Branced Tubular --** gland with [several tubular] secretory portions [branching from the single duct] **Simple Coiled Tubular** **Simple Acinar --** glands [with a single saclike secretory portion.] **Simple Branched Acinar ---** glands [with several acinar] secretory portions branching [from the single duct.] - **Compound Glands -** are [multicellular glands that have several branched ducts.] **STRUCTURAL SUBTYPE** **Compound Tubular** ---glands [with multiple ducts, each with a narrow tubular] secretory portion **Compound Acinar** ---glands [with multiple ducts, each with several saclik]e secretory portions **Compound Tubuloacinar** ---glands with [multiple ducts], each [with several tubular and acinar] secretory portions **HOW PRODUCTS LEAVE THE CELL** 1. **Merocrine** -- [Products are released], but no actual cellular material is lost. (products lang yung umalis) - [Sweat and digestive enzymes] produced by the pancreas 2. Apocrine -- the secretory products are [released as fragrants] of the gland cell. ( umalis yung anak naiwan si apo) - [Milk secretion] by the mammary glands utilizes some apocrine secretion. 3. **Holocrine** -- involves the [shedding of entire cells.] (lahat umaa - [Sebaceous (oil) glands] of the skin utilize holocrine secretion. - **Endocrine glands** secrete [hormones] [direct to your bloodstream.] - [Have no ducts] and empty their secretions into the blood These hormones control a number of important functions in your body, such as: - growth and development - metabolism - mood - reproduction Your endocrine glands include: - adrenal glands - pituitary gland - hypothalamus - thyroid - pineal gland There are also organs that contain endocrine tissue and act as glands. These include the: - pancreas - kidneys - ovaries - testes **GLANDS TO KNOW** **Thyroid gland** - is [located in the front of your neck], just below your larynx and has [a shape similar to a butterfly.] - [secretes hormones] that affect virtually every tissue in your body - [regulate your metabolism, heart, and digestive function] - They also play a role in your [brain and nerve development, muscle control, and mood] - Your thyroid function is [controlled by your pituitary] **Pituitary Gland** - [pea-sized gland] at the base of your brain, just behind the bridge of your nose. - It's [controlled by the hypothalamus] - [often called the **master gland**] because it controls a number of other hormone glands, including the: - thyroid - adrenal gland - testes - overies **Hypothalamus** [- functions as a communication center for your pituitary gland], sending signals and messages to the pituitary to produce and release hormones that trigger the production and release of other hormones Your hypothalamus influences a number of your body's functions, including: - temperature regulation - food intake - sleep and wakefulness - thirst - memory - emotional behavior **Pineal Gland** - [located deep in the center of your brain] - Its [function is not completely understood], but we do know that it [secretes and regulates certain hormones], including **melatonin** ([helps regulate your sleep patterns], which are also known as [circadian rhythms]) - The pineal gland also plays a role in the [regulation of female hormones], which affect the menstrual cycle and fertility **Adrenal Gland** [- located at the top of each kidney]. They produce various hormones, some of which include: - cortisol - aldosterone - adrenaline - a small amount of sex hormones called androgens The hormones produced by your adrenal glands have several important functions. They help your body: - control blood sugar - burn fat and protein - regulate blood pressure - react to stressors **Pancreas** - [a long, flat organ located in your abdomen] - made up of two types of glands: [exocrine and endocrine] - surrounded by the [small intestine, stomach, liver, gallbladder, and spleen]. - plays an important role in [converting the food you eat into fuel] for your body's cells. - [also makes hormones] that [control your blood glucose levels.] - **Pancreatitis** is [inflammation of the pancreas.] **Sweat Glands** - Your skin is covered in sweat glands of which there are two types: [eccrine and apocrine.] - **eccrine glands** [open directly onto your skin and regulate your body temperature] by releasing water to the surface of your skin when your body temperature rises. [We have this since birth.] - **Apocrine** **glands** [open into the hair follicle] and are found in hairbearing areas, such as the skin, armpits, and groin. We only have it when [puberty hits, has lipid and protein.] - These glands [secrete a milky fluid], usually as a [response to stress.] Your body also contains modified apocrine glands: - on the eyelids - on the areola and nipples - in the nose - in the ears **Sebaceous glands** - [located throughout your skin], though there are few on your hands and feet and none on your palms and soles. - They [secrete an oily substance] called **sebum** that lubricates your skin. - Most of these glands [release onto a hair follicle], though a [few open directly onto the skin's surface], such as Meibomian glands on the eyelids, Fordyce spots on the genitals an upper lip, and Tyson glands on the foreskin. These glands perform a few functions in your body, such as: - regulating your body temperature by working with your sweat glands - helping your skin retain moisture - helping fight infection caused by bacteria and fungi **Salivary Glands** - located in your mouth - [produce saliva] and empty into your mouth through ducts. - serves a few important purposes, including [moistening your food to help you chew, swallow, and digest it.] - also [contains antibodies] that kill germs to keep your mouth healthy. You have hundreds of small glands located throughout your: - tongue - palate - Lips - Cheeks You have three pairs of major salivary glands, including the: - parotid glands, located in front of and just below your ears - sublingual glands, located just under your tongue - submandibular glands, located below your jaw **Mammary Glands** - type of sweat gland, are [responsible for the production of breastmilk]. - Males also have glandular tissue in the breasts, but [estrogen] produced during puberty [triggers the growth of this tissue in females.] - Hormonal changes [during pregnancy signal the ducts to produce milk] in preparation for the baby. **INFLAMMATORY** **Inflammatory response** - is a [defense mechanism] that mobilizes the body's immune [cells to isolate and destroy microorganisms] and other injurious agents, and remove foreign materials and damaged cells[. allows tissue repair to occur] **STAGES OF THE INFLAMMATORY** C- Chemical Mediators Released S- Swelling of tissue R- Recruitment of immune cells 1. **Chemical mediators released** - [A splinter] in the skin [causes damage and introduces bacteria.] - Chemical mediators of inflammation are [released or activated in injured tissues] and adjacent blood vessels - [Some blood vessels rupture, causing bleeding.] 2. **Tissue Sweeling** - Chemical mediators [cause capillaries to dilate and the skin to become red]. - [Chemical mediators also increase capillary permeability], and fluid leaves the capillaries, producing swelling 3. **Recruitment of immune cells** - [White blood cells (e.g., neutrophils]) leave the dilated blood vessels and move to the [site of bacterial infection] (battle field), where [they begin to phagocytize bacteria and other debris] **INFLAMMATION FIVE MAJOR SYMPTOMS** 1. Redness 2. Heat 3. Swelling 4. Pain 5. Disturbed Function **CARDINAL SIGNS OF INFLAMMATION** **RuCaTuDo Flaesa** +-----------------------------------+-----------------------------------+ | **Cardinal Signs** | **Physiological Rationale** | +===================================+===================================+ | 1. Rubor (Redness) | Increased blood flow | +-----------------------------------+-----------------------------------+ | 2. Tumor ( Swelling) | Exudation of fluid | +-----------------------------------+-----------------------------------+ | 3. Calor (Heat) | Increased blood flow, exudation | | | of fluid, release of inflammatory | | | mediators | +-----------------------------------+-----------------------------------+ | 4. Dolor (Pain) | Stretching of pain receptors and | | | nerves by inflammatory exudates, | | | chemical mediators | +-----------------------------------+-----------------------------------+ | 5. Functio Laesa | Pain, disruption of tissue | | | structure | | (Loss of function) | | +-----------------------------------+-----------------------------------+ **CHEMICAL MEDIATORS IN INFLAMMATORY RESPONSE** **Chemical** **Major Action** ---------------------------------- --------------------------------------------------------------------------- Histamine Immediate vasodilation and increased capillary permeability Chemotactic Factors Attract neutrophils to site Platelet Activating Factor (PAF) Activate neutrophils and platelet aggregation Prostaglandin Vasodilation, inc. Permeability. Pain, fever, potentiate histamine effect **Vasodilation** -- the widening of blood vessel. pinapalaki **WOUND HEALING** - Healing is a quality of living tissue - regeneration (renewal) of tissues **Acute** -- It heals Faster **Chronic** -- Take months to heal **THREE TYPES OF WOUND HEALING** - **Primary intention healing** - [also called primary union or first intention healing] - occurs where the tissue surfaces [have been approximated] (closed) and there is [minimal or no tissue loss but has tissue damage] - Ex. Closed surgical incision - **Secondary Intention Healing** - wound that is extensive and [involves considerable tissue loss], and in which the edges cannot or [should not be approximated.] - [repair time is longer, scarring is greater, susceptibility to infection is greater] - **Tertiary Intention Healing** - [Leaves the wound open intentionally] for it to heal. **PHASES OF WOUND HEALING** **IPMat -- Inflammatory phase, Proliferative, Maturation** 1. **Inflammatory Phase** - [begins immediately after injury and lasts 3 to 6 days]. Two major processes occur during this phase: **Hemostasis**: (the cessation of bleeding) results from vasoconstriction of the larger blood vessels in the affected area **Phagocytosis**: cell migration, leukocytes (specifically, neutrophils) move into the interstitial space [macrophages engulf microorganisms and cellular debris]; secrete an angiogenesis factor 2. **Proliferative Phase**: second phase in healing[, extends from day 3 or 4 to about day 21 post-injury] - [Fibroblasts] (connective tissue cells), which migrate into the wound starting about 24 hours after injury, [begin to synthesize collagen. ] - [Collagen] is a [whitish protein substance] that [adds tensile strength to the wound]. - [Capillaries grow across the wound, increasing the blood supply] 3. **Maturation/Remodeling Phase**: begins on [about day 21 and can extend 1 or 2 years after the injury.] - Fibroblasts continue to synthesize collagen. - [wound is remodeled and contracted]. - [scar becomes stronger but the repaired area is never as strong as the original tissue]. - [abnormal amount of collagen], can result in a [hypertrophic scar, or keloid].