Anterior/Ventral vs. Posterior/Dorsal
- Toward or at front of the body, nearest to front.
- ex: nipples are anterior to shoulders.
- Nearest to back of body.
- ex Spine is posterior to heart.
Superior vs Inferior
- Above or at higher level in human ody.
- ex: shoulders superior to hips.
- Below or at lower level.
- ex: pelvis inferior to ribs.
Lateral vs. Medial:
- Away from midline of body, median plane.
- ex: arms lateral from chest.
- Toward/at midline.
- ex: heart medial to arms.
Distal vs. Proximal:
- Farthest from origin/attachment of lime
- ex: knee is distal to hip.
- Closer to origin/point of attachment
- ex: elbow proximal to hip
Superficial vs. Deep:
- Toward/at body
- ex: skin superficial to skin
- Away/more internal to body surface.
- ex: lungs are deep to skin.
extends vertically and divides the body or organ into right and left portions
- Also extends vertically, but is perpendicular to the sagittal plane
- Divides body into anterior (front) and posterior (back) portions
- Passes across the body or an organ perpendicular to its long axis
- Divides body into superior (upper) and inferior (lower) portions
Dorsal vs. Ventral Cavities (see other set of notecards for deeper review)
What is tissue?
- Group of cells with similar structure and function plus extacellular substance (matrix).
- Histology: study of tissues.
Types of Tissues
- 1. Epithelial
- 2. Connective
- 3. Muscular
- 4. Nervous
Epithelial Tissues (function, characteristics, Basal Surface)
- Funtion: cover body and lines organs (internal and external)
- Ex. Skin, kidney, trachea, glands, etc.
cells close together (very little extracellular matrix), cells joined by special junctions, form most glands, have free surface(polarity), Avascular but innervated-lacks blood vessels but is penetrated by nerve endings. Quick cell regeneration.
attaches epithelial cells to underlying tissues
Functions of Epithelial Tissues
- 1. Protects underlying tissues
- Ex. Skin
- 2. Act as barrier:
- Ex. Skin keeps bacteria out
- 3. Diffusion and Filtration:
- Ex. Lungs and kidneys
- 4. Secretion:
- Ex. Sweat glands
- 5. Absorption:
- Ex. Small intestine
- 6. Sensory Reception (has nerve endings)
Classification of Epithelial Tissue
- Classified according to number of cell layers and cell shape.
- Simple and stratified=number of cell layers.
- Squamous (flat cells), cuboidal(cubed), columnar (taller than wide), transitional=cell shape.
Simple Squamous Epithelium
- Stracture: 1 layer of FLAT cells.
- Function: Allows passage of materials by diffusion and filtration in sites where protection is not important
- Location: Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels/capillaries, and lymphatic vessels; lining of ventral body cavity
Simple Cuboidal Epithelium:
Structure: Single layer of cubelike cells with large, spherical central nuclei.
Fn: secretion and absorbtion
Location: Kidney tubules, ducts, and secretory portions of small glands;ovary surface
Simple Columnar Epithelum:
- Structure: Single layer of tall cells with round/oval nuclei, some cells bear cilia and may contain goblet cells (mucus secreting unicellular glands)
- Function: Absorption; secretion of mucus, enzymes, and other substances.
Lines most of digestive tract (stomach to anal canal), gallbladder. Ciliated variety lines small bronchi, uterine tubes, and some parts of uterus.
Pseudostratified Columnar Epithelium
Structure: varied in height, all of its cells resst on basement membrane but only the tall cells reach the apical (top) surface of the epithelum. False impression that this epithelium is stratified.
Location: Ciliated variety lines trachea of most of the upper respiratory tubes, noncilliated: male's sperm-carying ducts & ducts of large glands
- Contains two or more layers
- Regenerate from below (basal layer cells dived and push apically to replace older cells)
- More durable than simple epithelia
- Major role: protection
Stratified Squamous Epithelium
- Structure: surface cells are squamous, deeper layers: cuboidal/columnar.
- Function: protect and acts as a barrier.Thickest and best adapted for protections.
- Location: skin, mouth, throat, esophagus.(non-keratinized)
**two types of cells: Keratinized (epidermis) which containcs protective protein-Keratin & is waterproof. Non-Keratinized forms moist lining of body openings.
Stratified Cuboidal Epithelium
Structure: Generally two layers of cube-like cells
Location: Laregest ducts of sweat glands, mammary glands, and salivary glands
Stratified Columnar Epithelium
Description—several layers; basal cells usually cuboidal; superficial cells elongated
Function—protection and secretion
Location Rare tissue typeFound in male urethra and large ducts of some glands
Description: Has characteristics of stratified cuboidal and stratified squamous, Superficial cells dome-shaped when bladder is relaxed, squamous when full
Function—permits distension of urinary organs by contained urine, stretched readily.
Location—epithelium of urinary bladder, ureters, proximal urethra
Free Cell Surfaces
- Surface not in contact with other cells.
- Smooth to reduce friction.
- Ex. blood vessels.
- Increase cell's surface area.
- Ex. small intestine.
- Move materials across cell's surface.
- Ex. Trachea.
- Produce mucus. (mucin + water), protects and lubricates internal body surfaces, it is a unicellular exocrine gland
- Ex. Stomach.
- Bind adjacent cells together.
- Ex. Intestines
Mechanical links that bind cells.
Bind cells to basement membrane.
- Small channels that allow molecules to pass between cells.
- Allow cell to communicate.
- Most common.
Epithelial cells that make and secrete substance onto a surface, into a cavity, or into blood.
Secretion: gland cells obtain needed substances from the blood and transform them chemically into a product that is then dischaged from the cell (released by process of exocytosis)
Two types: Endocrine (internal secretion) or Exocrine (extermal secretion) which can be either unicellular or multicellular.
- Glands with ducts that carry products to epithelial surfaces.
- Ex. Sweat or oil glands, salivary glands.
No ducts (directly into bloodstream), specifically creating messenger moleculeds called hormones which enter nearby capillaries and travel to specific target organs (by blood)
Ex. Endocrine cells in intestine secrete a hormone that signals for the pancreas to release the enzymes to digest a meal.
Location: Thyroid, thymus, pituitary glands, etc.
Type of Exocrine Glands
- 1. Simple: no branches.
- 2. Compound: many branches.
- 3. Tubular End of duct.
- 4. Alveolus: sac-like structure.
Connective Tissue Characteristics
Cells are separated by large amounts of extracellular matrix. (unlike epithelial cells which are crowded)
- Classified based on type of extracellular matrix and function.
- Ex. Blas cells build, clast cells carve.
contains 2 components (in varying amounts): protein fibers, ground substance, fluid. Ground substance
: proteins and sugars.
Three types of protein fibers
in C.T: elastic, reticular and collagen.
ALL C.T originated from Mesenchyme
Functions of Connective Tissue
- 1. Enclose and seperate
- Ex. around organs and muscles.
- 2. Connect tissues:
- Ex. Tendons: connect bone to muscle.
- Ex. Ligaments: connect bone to bone.
- 3. Support and Movement:
- Ex. bones
- 4. Storage:
- Ex. bones store clacium and adipose tissue stores fat.
- 5. Cushion and insulate:
- Ex. adipose tissue protect organs and helps conserve heat.
- 6. Transport (store and carry nutrients)
- Ex. Blood, fat tissues
- 7. Protect against infection
- Ex. Immune cells.
Types of Ordinary Connective Tissue
- Connective tissue Proper:
- 1. Loose Connective Tissue : areolar, adipose (fat) and reticular
- 2. Dense Connective Tissue : Dense irregular, dense regular, and elastic
- Cartilages: (Hyaline, Elastic, Fibrocartlage), 4. Osseus Bone and Blood
- **fat is considered a C.T**
Connective Tissue cells:
cells produce extracellular matrix. Fibroblasts are the cells in C.T Proper make that makes proteins/fibers and secrets ground substance molecules.
Chondroblasts (of cartilages) are the cells that make the matrix and osteoblasts in the bone.
**These cells produce the molecules that compose the ground substance** EXCEPTION: BLOOD CELLS DON'T CREATE MATRIX--PLASMA!!
Connective Tissue Fibers:
- 1.Collagen: strongest/mostabundant. Resist tension and give strengh. Strands are cross-linked to form strongness.
- 2. Reticular: short fibers clustsesred into a meshlike network that covers, supports structures that boreder C.T. ex: capillaries coated with reticular. Free-gliding which is stronger to tension than collagen.
- 3. Elastic: rubberlike protein elastin--> rubberband fn. Defining feature: ability to recoil back to its original form.
Loose Connective Tissue
Has extracellular matrix consisting of mostly of collagen fibers and a few elastic fibers. These fibers are widely separated from one another.
Areolar Connective tissue:
Most widespread type of C.T Proper:
Structure: gell-like matrix with all three fiber types, cells: fibroblasts, macrophates and some white blood cells.
Functions: Support/bind other tissues, wraps/cushions organs, holding body fluids (interstital fluid), Defending from infections-important in inflammation, and storing nutrients as fats
Location: Underlies almost ALL the epithelia, Surrounds almost all small nerves, blood/capilaries
Contains all three fibers: collagen, elastic and reticular produced by Fibroblasts (since it's C.T proper)
Structure: Closely packed adipocytes/fat cells, have nucleus pushed to side.
Function: Provides resource fuel, insulates against heat loss and supports/protects orgains.
Location: Under skin in hypodermis, around kidneys, eyeballs, abdomen and breasts.
Reticular Connective Tissues (Proper, Loose C.T)
Structure: Loose ground substance made with reticular fibers and many reticular cells. (cherry blossom tree!)
Function: Form a soft internal skeleton that support other cell types including white blood cells, mast cells and macrophates.
Location: Lymphoid orgains (lymph nodes, bone marrow and spleen)
Dense Connective Tissue
- Has an extracellular matrix that consists of densely packed fibers produced by fibroblasts.
- Contains more collagent than areolar (loose) tissue, which resist strong pulling forces.
: Irregular, Regular and Elastic
Dense Regular Connective Tissue:
Structure: Network of reticular fibers in a typical loose ground substance; reticular cells lie on the network.
Function: Fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages.
Location: Lymphoid organs (lymph nodes, bone marrow, and spleen).
Dense Irregular Connective Tissue
Structure :Primarily irregularly arranged collagen fibers; some elastic fibers; major cell type is the fibroblast.
Function: Able to withstand tension exerted in many directions; provides structural strength.
Location: Fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract.
- Type of connective tissue.
- Composed of chondrocytes.
- Contains collagen.
- Withstands compressions (ex. between joints).
- Provides support, flexibility, strength.
Types of Cartilage
- 1. Hylaine Cartilage
- 2. Fibrocartilage
- 3. Elastic Cartilage
- Location: covers ends of bones.
- Structure: some collagen fibers.
- Function: reduces friction (cushion).
- Location: in the disks between the vertebrae.
- Structure: lots of collagen fibers.
- Function: can withstand compression.
- (ex. attaches jaw to the skull and knee).
- Location: ear and tip of nose.
- Structure: elastic fibers.
- Function: can recoil.
- Two types. Compact and spongy (botth look diferent).
- Hard connective tissue.
- Composed of osteocytes.
- Liquid connective tissue.
- Erythrocytes, leukocytes, platelets.
- Transport food, oxygen, waste, hormones.
Types of Muscular Tissue
- 1. Skeletal (most muscle).
- 2. Cardiac (heart).
- 3. Smooth (organs).
Skeletal Muscular Tissue
Many nucleus peripheral (side) located and striated.
Cadiac Muscular Tissue
One (1) nucleui centrally located and striated. Under involuntary (uncunscious) control.
Smooth Muscular Tissue
One (1) nuclei centrally located and not striated.
- Consist of neurons or nerve cells.
- Found in brain, spinal cord, and peripheral nerves.
- Controls and coordinates body movements.
- Includes axons, dendrites, cell bodies.
- What is it: substituition of dead cells for viable cells.
- Regeneration: cells of same type develop no scar.
- Replacement: cell of a different type develop scar.
- Occurs when tissues are damaged.
- Signals the body's defenses (white blood cells) to destroy foreign (micro) materials and damaged cells so repair can occur.
- Chemical Mediators: released after injury and cause dilation of blood vessels.
Symptoms of Inflammation
- 1. Redness: blood vessels dilate.
- 2. Heat: due to increased blood flow.
- 3. Swelling: from water and proteins.
- 4. Pain: nerve endings are stimulated by damage and swelling.
Is a thin sheet or layer of tissue that covers a structure or lines the cavity.
Cutaneous membrane, is the exernal membrane. It is composed of stratified squamous epithelium and dense connective tissue.
Consists of various kinds of epithelium resting on a thick layer of loose connective tissue.
Three major components of Extra Cellular Matrix
- 1. Protein Fibers
- 2. Ground Substance (consisting of nonfibrous protein and other molecules).
- 3. Fluid