ANAPHY PRELIMS WEEK 3

TISSUES

-        are groups of similar cells that work together to perform specific functions in the body.

ENDODERM

-        inner layer

-        forms the lining of the digestive tract and its derivatives.

-        nervous system, skin

MESODERM

-        middle layer

-        forms tissue such as muscle, bone, and blood vessels.

-        muscle, skeleton, kidneys, reproductive system

ECTODERM

-        outer layer

-        forms the skin

-        endocrine glands, lungs, digestive tract, liver

EPITHELIAL TISSUES

-        It covers and protects the surface of the skin and organs.

-        It forms the inner lining of the body’s cavities.

-        It lines hollows organs.

-        AVASCULAR (absence of blood supply) layer of cells.

-        It divides quickly, aiding in wound healing and replacement of cells.

-        Functions of Epithelial Tissue:

FUNCTION	DESCRIPTION
Physical Protection	Protects your underlying tissues from mechanical injury, harmful rays of the sun, and certain chemicals.
Absorption	Nutrients are absorbed through your capillaries, especially in areas like the intestines.
Filtration	Tissues are semi-permeable; they filtrate substances passing through, not allowing harmful or large particles to pass.
Secretion	Secrete hormones, enzymes, and other essential substances (e.g., in glands).
Excretion	Excrete sweat, urine, and waste products from the body.
Sensation	Contain general receptors for touch, pressure, pain, and temperature.
Regeneration	Cells divide quickly to replace damaged or dead cells, aiding in healing.

CLASSIFICATION BASED ON SHAPE

1. Simple Squamous

2. Simple Cuboidal

3. Simple Columnar

SIMPLE SQUAMOUS EPITHELIAL TISSUE

-        Flat and thin cells, resembling fish scales; ideal for diffusion and filtration (e.g., in lungs and blood vessels).

SIMPLE CUBOIDAL EPITHELIAL TISSUE

-        Cube-shaped cells with equal height and width; commonly involved in secretion and absorption (e.g., kidney tubules).

SIMPLE COLUMNAR EPITHELIAL TISSUE

-        Tall, column-like cells; specialized for absorption and secretion (e.g., lining of the digestive tract).

CLASSIFICATION BASED ON ARRANGEMENT

• Simple

  1. Pseudostratified Columnar

• Stratified

  1. Stratified Squamos

  2. Stratified Cuboidal

  3. Stratified Columnar

  4. Transitional Epithelium

SIMPLE

-        A single layer of cells; allows easy passage of materials (e.g., absorption, filtration).

PSEUDOSTRATIFIED COLUMNAR

-        False Stratified.

-        Appears layered but is a single layer with nuclei at different levels; often ciliated, functions in secretion and movement of mucus (e.g., respiratory tract).

STRATIFIED

-        Multiple layers of cells; provides protection against abrasion and stress.

STRATIFIED SQUAMOUS EPITHELIAL TISSUE

-        Many layers with flat cells on the surface; protects against wear and tear (e.g., skin, mouth lining).

STRATIFIED CUBOIDAL EPITHELIAL TISSUE

-        Two or more layers of cube-shaped cells; involved in protection and secretion (e.g., sweat glands).

STRATIFIED COLUMNAR EPITHELIAL TISSUE

-        Several layers with columnar surface cells; functions in protection and secretion.

TRANSITIONAL EPITHELIUM

-        Specialized to stretch and return to shape; found in the urinary bladder.

CLASSIFICATION BASED ON FUNCTION

1. Mucous Membrane

2. Glandular Epithelium

3. Endothelium

4. Mesothelium

MUCOUS MEMBRANE

-        Lines body cavities that open to the outside (e.g., respiratory, digestive tracts, reproductive, and urinary); secretes mucus for protection and lubrication.

-        All systems that are open to the environment are protected by mucous membranes.

GLANDULAR EPITHELIUM

-        Forms glands and is specialized for secretion; includes endocrine (hormones) and exocrine (sweat, saliva) glands.

o   Exocrine Gland – Has ducts.

o   Endocrine Gland – Ductless.

ENDOTHELIUM

-        Lines the interior of blood vessels and lymphatic vessels; provides a smooth surface for blood flow and regulates the exchange between blood and tissues.

-        Made up of simple squamous epithelium, because nutrients and oxygen cannot pass through thick stratified layers.

MESOTHELIUM

-        Lines body cavities such as the pleura (lungs), pericardium (heart), and peritoneum (abdomen); produces a lubricating fluid to reduce friction between organs.

-        Also known as serous tissue, it lines serous membranes, which have two layers:

o   Parietal layer – Outer layer, lining the cavity

o   Visceral layer – Inner layer, covering the organs

-        A serous fluid is found between these layers to prevent friction.

PARIETAL LAYER

Outer layer of the mesothelium, lining the cavity

VISCERAL LAYER

o   Inner layer of mesothelium, covering the organs

SEROUS FLUID

-        A ____ is found between the layers of mesothelium to prevent friction.

• a clear to pale yellow, watery fluid found in body cavities and tissue spaces, acting as a lubricant and facilitating nutrient transport. It's a normal component of the body, playing a vital role in lubricating and nourishing organs and tissues.

CONNECTIVE TISSUES

-        It allows movement and provides support for other types of tissues.

-        It is good blood supply and require large amounts of nourishment.

-        The abundance of intercellular material called MATRIX.

FUNCTION	DESCRIPTION
Defense against invading PATHOGENS.	Blood, a type of fluid connective tissue, contains white blood cells (WBCs) that act as soldiers to defend the body from harmful microorganisms.
Establishment of STRUCTURAL FRAMEWORK	Provides strength and support to organs and the entire body (e.g., bones and cartilage).
Protection of DELICATE ORGANS	Cushions and insulates vital organs (e.g., adipose tissue around the kidneys).
ENERGY Storage	Stores energy primarily in the form of triglycerides in adipose tissue.
Interconnection, Support, and surrounding of OTHER TISSUES	Connects and binds tissues and organs together (e.g., tendons, ligaments).
Transport of Dissolved MATERIALS AND FLUIDS	Blood and lymph, both fluid connective tissues, are responsible for transporting oxygen, nutrients, waste, and immune cells throughout the body.

MATRIX

• abundance of intercellular material

• gives the tissue its density

COMPONENTS OF CONNECTIVE TISSUES

o   Specialized Cells

o   Intracellular Protein Fibers

o   Ground Substance

CELLS FOUND IN CONNECTIVE TISSUES

-        “-blast” – Immature cells; responsible for producing the matrix.

-        “-cyte” – Mature cells; maintain the tissue.

FIBROBLASTS

Most common type of fixed cell; star-shaped; produce connective tissue fibers and secrete hyaluronan, a lubricating substance that acts as a shock absorber in joints.

CHONDROBLASTS

Immature cells found in cartilage; produce the cartilage matrix.

OSTEOBLASTS

Immature cells found in bone tissue; responsible for bone matrix production.

HEMATOPOIETIC STEM CELLS

Found in bone marrow; give rise to all types of blood cells.

FRIBROCYTES

Mature form of fibroblasts; second most common fixed cell; spindle-shaped; help maintain connective tissue fibers.

MAST CELLS

Found near blood vessels; release heparin (prevents blood clotting) and histamine (triggers inflammation). Involved in diapedesis — the movement of WBCs out of blood vessels.

MACROPHAGES

Large, irregular-shaped cells; key immune cells responsible for phagocytosis (engulfing pathogens and debris).

LYMPHOCYTES

Small WBCs involved in immunity; can develop into plasma cells that produce antibodies.

MICROPHAGES

Include types of WBCs such as neutrophils, eosinophils, and basophils; respond to signals from mast cells and macrophages.

MELANOCYTES

Found in skin and certain connective tissues; synthesize and store melanin, the pigment responsible for skin color.

CONNECTIVE TISSUE FIBERS

1. Collagenous Fiber

2. Elastic Fiber

3. Reticular Fiber

COLLAGENOUS FIBER

Description	Examples	Main Protein
- Dense connective tissue - White fibers - Long, straight, strong - No branching - Strongest and most abundant - Holds body parts together	Ligaments, Tendons	Collagen

ELASTIC FIBER

Description	Examples	Main Protein
- Found in body parts often stretched - Yellow fibers - Long, wavy, thin - Form branching networks	Vocal cords, large blood vessels, skin, lungs	Elastin

RETICULAR FIBER

Description	Examples	Main Protein
- Short and fine - Form thin, delicately branched networks - Surround small blood vessels and support soft tissues	Liver, spleen, lymph nodes (soft organs)	Collagen (Type III)

TYPES OF CONNECTIVE TISSUES

1.     Dense Connective Tissues

2.     Loose Connective Tissues

3.     Supporting Connective Tissues

4.     Fluid Connective Tissues

DENSE CONNECTIVE TISSUES

-        contain collagenous fibers.

-        They appear white due to the abundance of collagen.

-        They have a poor blood supply, which causes slow healing.

-        Also called fibrous or collagenous connective tissue.

Type of ____ Connective Tissue	Description, Function, and Location
Dense Regular Connective Tissue	Fibers arranged in parallel bundles; provides great tensile strength in one direction; found in tendons and ligaments.
Dense Irregular Connective Tissue	Fibers arranged randomly or in various directions; provides strength in multiple directions; found in dermis and organ capsules.
Elastic Connective Tissue	Contains many elastic fibers with collagen; allows stretching and recoiling; found in walls of large arteries, lungs, and certain ligaments.

DENSE REGULAR CONNECTIVE TISSUE

Fibers arranged in parallel bundles; provides great tensile strength in one direction; found in tendons and ligaments.

DENSE IRREGULAR CONNECTIVE TISSUE

Fibers arranged randomly or in various directions; provides strength in multiple directions; found in dermis and organ capsules.

ELASTIC CONNECTIVE TISSUE

Contains many elastic fibers with collagen; allows stretching and recoiling; found in walls of large arteries, lungs, and certain ligaments.

LOOSE CONNECTIVE TISSUES

-        Fill the spaces between organs.

-        Support epithelial tissues.

-        Protect the specialized cells of many organs.

-        Surround and support blood vessels.

-        Store lipids for energy reserve.

-        Create pathways for the diffusion of nutrients, gases, and waste products.

Type of Loose Connective Tissue	Description and Function
Adipose Tissue	-         Reservoir of energy (located near heart and lungs). -         functions as a cushion. -         cells packed tightly resembling a wire fence. -         90% adipocytes (fat cells). -         Brown fat: found in infants, aids in thermoregulation. -         White/yellow fat: usually found in abdomen and biceps.
Areolar Tissue	-         Binds skin to underlying organs. -         fills spaces between muscles. -         contains fibroblasts, mast cells, and macrophages. -         has loose fibers with matrix appearing “empty.”
Reticular Connective Tissue	-         Creates framework inside internal organs (stroma) -         similar to areolar tissue.

TYPES OF LOOSE CONNECTIVE TISSUE

Type of ____	Description and Function
Adipose Tissue	-         Reservoir of energy (located near heart and lungs). -         functions as a cushion. -         cells packed tightly resembling a wire fence. -         90% adipocytes (fat cells). -         Brown fat: found in infants, aids in thermoregulation. -         White/yellow fat: usually found in abdomen and biceps.
Areolar Tissue	-         Binds skin to underlying organs. -         fills spaces between muscles. -         contains fibroblasts, mast cells, and macrophages. -         has loose fibers with matrix appearing “empty.”
Reticular Connective Tissue	-         Creates framework inside internal organs (stroma) -         similar to areolar tissue.

ADIPOSE TISSUE

-         Reservoir of energy (located near heart and lungs).

-         functions as a cushion.

-         cells packed tightly resembling a wire fence.

-         90% adipocytes (fat cells).

-         Brown fat: found in infants, aids in thermoregulation.

White/yellow fat: usually found in abdomen and biceps.

AREOLAR TISSUE

-         Binds skin to underlying organs.

-         fills spaces between muscles.

-         contains fibroblasts, mast cells, and macrophages.

has loose fibers with matrix appearing “empty.”

RETICULAR CONNECTIVE TISSUE

-         Creates framework inside internal organs (stroma)

similar to areolar tissue.

SUPPORTING CONNECTIVE TISSUE

-        It has a less diverse cell population and matrix that contains many more densely package fibers.

o   Cartilage

o   Bones

CARTILAGE

-        is a tough but flexible connective tissue with a gelatinous matrix that contains an abundance of fibers.

-        It lacks nerve fibers and has a large amount of fluid in its matrix.

Type of Cartilage	Description and Location
Hyaline Cartilage	-         Most common type - Important for bone growth -         “Glassy” bluish-white appearance -         Found at ends of bones in joints, tip of nose, respiratory passages, supporting rings
Elastic Cartilage	-         Flexible -         Found in the pinna of the ear and epiglottis
Fibrocartilage	-         Tough cartilage that absorbs shock -         Located in the vertebral column

HYALINE CARTILAGE

-         Most common type - Important for bone growth

-         “Glassy” bluish-white appearance

Found at ends of bones in joints, tip of nose, respiratory passages, supporting rings

ELASTIC CARTILAGE

-         Flexible

Found in the pinna of the ear and epiglottis

FIBROCARTILAGE

-         Tough cartilage that absorbs shock

Located in the vertebral column

BONES

-        A.k.a OSSEUS TISSUE

-        Most rigid type of connective tissue.

-        Establishes the structural framework of the body.

-        Matrix contains blood vessels and is rich in calcium and phosphorus.

-        These minerals form hydroxyapatite crystals, which give bones their strength and hardness.

HYDROXAPATITE CRYSTALS

calcium and phosphorus.

COMPACT BONE

o   Also called the Haversian System. Dense and forms the outer layer of bones.

SPONGY BONE

o   Also called trabeculae. Porous and found in the inner part of bones.

FLUID CONNECTIVE TISSUES

-        Composed of cells suspended in a watery (fluid) matrix.

-        Primary function is transport of substances and immune response.

-        Two Main Types:

o   Blood: lays a role in immune defense and clotting.

o   Lymph: Helps in immune function

MUSCULAR TISSUE

-        Contracts or shortens with force to produce movement.

-        Contains myofilaments (actin and myosin) responsible for contraction.

-        Primary function: movement.

-        Muscle contractions serve several purposes:

o   a. Move the entire body (e.g., walking, lifting).

o   b. Pump blood through the heart and blood vessels (cardiac muscle).

o   c. Decrease the size of hollow organs (e.g., intestines, bladder, uterus – smooth muscle).

Feature	Skeletal Muscle	Cardiac Muscle	Smooth Muscle
Location	Attached to bones	Heart	Walls of organs, vessels, glands
Cell Shape	Long, cylindrical	Branched, cylindrical	Spindle-shaped
Nucleus	Many, at edges	One, center	One, center
Striations	Yes	Yes	No
Control	Voluntary	Involuntary	Involuntary
Spontaneous Contraction	No	Yes	Yes
Function	Moves body	Pumps blood	Moves substances (food, blood, etc.)
Special Features	None	Intercalated discs, gap junctions	Gap junctions

SKELETAL MUSCLE

Location	Attached to bones
Cell Shape	Long, cylindrical
Nucleus	Many, at edges
Striations	Yes
Control	Voluntary
Spontaneous Contraction	No
Function	Moves body
Special Features	None

CARDIAC MUSCLE

Location	Heart
Cell Shape	Branched, cylindrical
Nucleus	One, center
Striations	Yes
Control	Involuntary
Spontaneous Contraction	Yes
Function	Pumps blood
Special Features	Intercalated discs, gap junctions

SMOOTH MUSCLE

Location	Walls of organs, vessels, glands
Cell Shape	Spindle-shaped
Nucleus	One, center
Striations	No
Control	Involuntary
Spontaneous Contraction	Yes
Function	Moves substances (food, blood, etc.)
Special Features	Gap junctions

NERVOUS TISSUE

-        Found in the brain, spinal cord, and nerves.

-        Specialized for conducting electrical signals, called action potentials.

-        Main Cell Types;

1.     Neurons: Responsible for generating and transmitting nerve impulses.

2.     Support Cells: Neuroglia (Glial Cells) - Help protect, support, and nourish neurons.

NEURONS

• Responsible for generating and transmitting nerve impulses.

NEUROGLIA

• (Glial Cells) - Help protect, support, and nourish neurons.

ASTROCYTES

Regulate the environment around neurons (e.g., nutrients, ions).

OLIGODENDROCYTES

Form the myelin sheath in the CNS, enabling faster transmission of nerve signals.

MICROGLIA

Perform phagocytosis (engulfing of pathogens) in the CNS, removing debris and pathogens.

EPENDYMAL CELLS

Involved in the production and circulation of cerebrospinal fluid (CSF) — a clear and colorless fluid that surround and cushions the brain and the spinal cord.

TISSUE MEMBRANES

-        A thin sheet or layer of tissue that covers a structure or lines a cavity.

Membrane Type	Location	Tissue Composition	Key Functions
Cutaneous (Skin)	External body surface	Stratified squamous epithelium + dense connective tissue	Protection
Mucous	Cavities open to outside (digestive, respiratory, reproductive tracts)	Epithelium + basement membrane + loose connective tissue; may have goblet cells	1. Protection 2. Absorption 3. Secretion
Serous	Cavities do not open to outside (pericardial, pleural, peritoneal)	Simple squamous epithelium + basement membrane + delicate connective tissue; no glands	1. Protection 2. Hold organs 3. Selective barrier
Synovial	Freely movable joint cavities	Modified connective tissues only; produces synovial fluid	1. Reduce friction 2. Enable smooth joint movement

CUTANEOUS

Location	Tissue Composition	Key Functions
External body surface	Stratified squamous epithelium + dense connective tissue	Protection

MUCOUS

Location	Tissue Composition	Key Functions
Cavities open to outside (digestive, respiratory, reproductive tracts)	Epithelium + basement membrane + loose connective tissue; may have goblet cells	1. Protection 2. Absorption 3. Secretion

SEROUS

Location	Tissue Composition	Key Functions
Cavities do not open to outside (pericardial, pleural, peritoneal)	Simple squamous epithelium + basement membrane + delicate connective tissue; no glands	1. Protection 2. Hold organs 3. Selective barrier

SYNOVIAL

Location	Tissue Composition	Key Functions
Freely movable joint cavities	Modified connective tissues only; produces synovial fluid	1. Reduce friction 2. Enable smooth joint movement

TISSUE DAMAGE AND INFLAMMATION

-        the body's response to tissue damage, characterized by:

Sign	Description
Redness (Rubor)	Caused by increased blood flow to the affected area
Heat (Calor)	Also, due to increased blood flow (from vasodilation—the widening of blood vessels due to the relaxation of blood vessel’s muscular walls)
Swelling (Tumor)	Due to accumulation of fluid (edema—excess fluid in body tissues)
Pain (Dolor)	Result of chemical release and pressure on nerves
Loss of Function	Affected tissue may not function normally

TISSUE REPAIR

-         Substitution of viable cells for dead cells.

REGENERATION

-        New cells are the same type as those that were destroyed.

-        Normal function is usually restored.

REPLACEMENT

-        A new type of tissue develops, which eventually produces a scar and leads to the loss of some tissue functions.