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248 Cards in this Set

  • Front
  • Back

Anatomical Terms &


Homeostasis

---

Surface Anatomy

Axial: Relating to head, neck and trunk, the axis of the body


Appendicular: Relating to limbs and their attachments to their attachments to the axis

Anterior Body Landmarks

Note the following regions


Abdominal

Anterior body trunk region inferior to the ribs

Acromial


point of shoulder

Antebrachial

forearm

Antecubital

anterior surface of the elbow

Axillary

armpit

Brachial

Arm

Buccal

Cheek

Carpal

wrist

Cephalic

head

Cervical

neck region

Coxal

Hip

Crural

Leg

Digital

Fingers or toes

Femoral

Thigh

Fibular (peroneal)

Side of the leg

Frontal

Forehead

Hallux

Great toe

Inguinal

groin area

Mammary

breast region

Mangus

hand

Mental

chin

Nasal

nose

Oral

mouth

Orbital

Bony eye socket (orbit)

Palmar

palm of the hand

Patellar

anterior knee (kneecap) region

Pedal

foot

Pelvic

pelvis region

Pollex

thumb

Pubic

genital region

Sternal

region of the breastbone

Tarsal

ankle

Thoracic

chest

Umbilical

Navel

Posterior Body Landmarks

--

Acromial

point of the shoulder

Brachial

arm

Calcaneal

heel of the foot

Cephalic

head

Dorsum

back

Femoral

thigh

Gluteal

buttocks or rump

Lumbar

Area of the back between the ribs and hips; loin

Manus

hand

Occipital

posterior aspect of the head or the base of the skull

Olecranal

posterior aspect of the elbow

Otic

ear

Pedal

foot

Perineal

region between the anus and external genitalia

Plantar

sole of the foot

Popiteal

back of the knee

Sacral

region between the hips (pverlying the sacrum)

Scapular

scapula or shoulder blade area

Sural

calf or posterior surface of the leg

Vertebral

area of the spinal column

Surface Anatomy Diagram

Body Orientation and Direction

Study the terms below for visual aid

Superior/Inferior (above/below)

-Superior: structures always appear above other structures



-Inferior: structures always below other structures

Anterior/Posterior (front/back)

Anterior: structures more forward




Posterior: structures toward the backside of the back

Medial/Lateral (toward the midline/away from the midline or median plane)

Medial: The sternum (breastbone) is medial to the ribs



Lateral: The ear is lateral to the nose

Cephalad (cranial) / Caudal (toward the head/ toward the tail)

In humans, they are used interchangeably with superior and inferior

Dorsal/Ventral (backside/belly side)

In humans, the terms ventral and dorsal are used interchangeably with the terms anterior and posterior

Proximal/ Distal (nearer the trunk or attached end/ farther from the trunk or point of attachment)

These terms are used to primarily locate various regions of the body of limbs.

Superficial (external) / deep (internal) (toward or at the body surface/ away from the body surface)

These terms locate body organs according to their relative closeness to the body surface

Diagram of Body Orientation and Direction

Body Plane and Sections

-section: cut


 


-plane: imaginary surface or line

-section: cut



-plane: imaginary surface or line

Planes

Three Planes

Sagittal Plane

runs longitudinally and divides the body into right and left parts


-Median(midsagittal plane): if it divides the body into equal parts or right down the midline of the body

Frontal Plane (Coronal Plane)

longitudinal plane that divides the body(or organ) into anterior and posterior parts

Transverse Plane (Cross Sections)

runs horizontally dividing the body into superior and inferior parts


Dorsal Body Cavity

-Cranial


1.brain


-Vertebral


1.spinal cavity

Ventral Body Cavity

-Thoracic:


1. heart (pericardium)


2. Lungs (pleural)


-Abdominopelvic:


1. Abdominal


2. Pelvic

Serous Membranes

-covers the organs that stay inside the body


1. Serosa: exceedingly thin, double-layered membrane


2. Parietal serosa: part of the membrane lining the cavity walls


3. Visceral Serosa: part of the membrane covering the external surface of the organs within the cavity


-Peritoneum: serosa lining the abdominal cavity and covering its organs


-Pleura: serosa lining the lungs


-Pericardium: serosa lining the heart

Abdominopelvic Quadrants

1. Quadrant: divides the abdominal surface and the adbominopelvic cavity into four approximately equal regions


-Right Upper


-Right Lower


-Left Upper


-Left Lower

Abdominopelvic Quadrant Diagram

Abdominopelvic Regions

1. Region: divides the abdominal surface and abdominopelvic cavity into nine separate regions by four planes


-Hypochondriac Regions: Flanking the epigastric region laterally and overlying the lower ribs (RH: iver, Gallbladder; LH: diaphragm, Spleen)


- Epigastric: immediately superior to the umbilical region; overlies most of the stomach (stomach)


-Lumbar Regions: Between the ribs and the flaring portions of the hip bones; lateral to the umbilical region (RL: ascending colon of large intestine; LL: descending colon of large intestine)


-Iliac Regions: lateral to the hyogastric region and overlying the superior parts of the hip bones (RI: cecum, appendix; LI: Initial part of the sigmoid colon)


-Hypogastric Region: immediately inferior to the umbilical region; encompasses the pubic area


Abdominopelvic Regions Diagram

Other Body Cavities

1. Oral Cavity (Mouth): contains the tongue and teeth


2. Nasal Cavity: located within and posterior to the nose


3. Orbital Cavities: orbits in the skull house the eyes


4. Middle Ear Cavities: contain tiny bones that transmit sound vibrations to the hearing receptors in the inner ears


5. Synovial Cavities: joint cavities- enclosed within fibrous capsules that surround the freely movable joints of the body.

Diffusion and Osmosis

----

Selective (Differential) Permeability

plasma membrane is selective about what passes through it

Passive Processes

Passive: concentration or pressure differences drive the movement


-kinetic energy: is the driving force for diffusion.

Diffusion

Diffusion: movement of molecules from a region of their higher concentration to a region of a lower concentration


-Concentration Gradient: difference in concentration


-Simple diffusion: unassisted diffusion of solutes (dissolved substances) through a selectively permeable membrane


-Facilitated Diffusion: passive transport process.

Osmosis

flow of water across a selectively permeable membrane


-water moves down its concentration gradient

Solutions

1. Isotonic: cells retain their normal size and shape


2. Hypertonic: cells lose water by osmosis and shrink


3. Hypotonic: cells take on water by osmosis until they become bloated and burst (lyses)

Filtration

Filtration: passive process in which water and solute are forced through a membrane by hydrostatic (fluid) pressure


-not selective


-depends on pressure gradient and on the size of membrane pores

Active Processes

Active Processes: whenever a cell uses the bond energy of ATP to move substances across its boundries


-Two types:


1. Active Transport


2. Vesicular Transport

Active Transport

Active Transport: requires carrier proteins that combine specifically with the transported substance


-may be primary


-driven directly by hydrolysis of ATP

Vesicular Transport

Vesicular Transport: fluids containing large particles and macromolecules are transported across cellular membranes inside membranous sacs (vesicles)


1. Endocytosis: vesicular transport moves substances into the cell


2. Exocytosis: vesicular transport moves substances out of the cell


Three types of Endocytosis

1. Phagocytosis (cell eating): the cells engulfs some relatively large or solid material such as a clump of bacteria, cell debris or inanimate particles


-not routinely done


2. Pinocytosis/ Fluid-phase endocytosis (cell drinking): the cell "gulps" a drop of extracellular fluid containing dissolved molecules


-non specific


-routine activity of cells


-receptor-mediated endocytosis: main mechanism for specific endocytosis


3. Exocytosis: vesicular transport process that ejects substances from the cell into the extracellular fluid


-Secretory vesicle: protein-coated vesicle

Diagram of Endocytosis

The Microscope

what did Biologist gain from the microscope being invented?


-valuable tool to observe and study structures like cells that are too small to be seen by the unaided eye

Care and Structure of the Compound Microscope

Compound Microscope: precision instrument and should always be handled with care

Rules for Microscope

1. Transport


2. Cleaning


3. Use


4. Storage


Transport

Transport:


-hold it in an upright position with one hand on its arm and the other supporting its base


-avoid swinging the instrument during its transport and jarring the instrument when setting it down

Cleaning

-use only special grit-free lens paper to clean the lenses


-use circular motion to wipe the lenses


-clean all lenses before and after use

Use

-always begin the focusing process with the lowest-power objective lens in position, changing to the higher-power lenses as necessary


-use the coarse adjustment knob only with the lowest-power lens


-Always use a cover slip with wet mount preparations

Storage

-before putting the microscope in the storage cabinet, remove the slide from the stage, rotate the lowest-power objective lens into position, wrap the cord neatly around the base, and replace the dust cover or return the microscope to the appropriate storage area


-Never remove any parts from the microscope; inform you instructor of any mechanical problems that arise.

Identifying the Parts of a Microscope

---

Base

-supports the microscope

Substage light or mirror

Located on the base


-light controls are located on the microscope base

Stage

the platform the slide rests on while being viewed


-Mechanical Stage (spring clips): hold the slide in position for viewing

Condenser

small substage lens that concentrates the light on the specimen


-Rack and Pinion knob: raises and lowers the condenser to vary light delivery

Iris Diaphragm Lever

arm attached to the base of the condenser that regulates the amount of light passing through the condenser

Course Adjustment Knob

Used to focus on the specimen

Fine Adjustment Knob

used for precise focusing once course focusing has been completed

Head (Body Tube)

Supports the objective lens system, which is mounted on a movable nosepiece, and the ocular lens or lenses

Arm

vertical portion of the microscope connecting the base and head

Ocular (eyepiece)

Depending on the microscope, there are one or two lenses at the superior end of the head or body tube.


-Observations are made through the ocular(s)


-An ocular lens has a magnification of 10X


Nosepeice

rotating mechanism at the base of the head


Objective Lenses

adjusting lens system that permits the use of a scanning lens (low-power lens), a high-power lens (oil immersion lens).


-different magnifying and resolving powers

Magnification and Resolution

Magnification is achieve through the interplay of two lenses


1. Ocular Lens: the real image is magnified by the ocular lens to produce the virtual image seen by your eye


2. Objective Lens: objective lens magnifies the specimen to produce a real image that is projected to the ocular



Resolution (resolving power): the ability to discriminate two close objects as separate, is not.


-Resolving Power: determined by the amount and physical properties of the visible light that enters the microscope

Total Magnification

any specimen being viewed is equal to the power of the ocular lens multiplied by the power of the objective lens used

Diagram of Compound Microscope and its Parts

Viewing Objects through the Microscope

picture

Field

the area you see through the microscope

Working Distance

length of the bottom of the objective lens from the specime

Parfocal

the slide should be in focus (or nearly so) at the higher magnification once you have properly focused

Classification of Tissues

--

Tissues

Tissues: Groups of cells that are similar in structure and function


1. Epithelial


2. Connective


3. Nervous


4. Muscle

Organ

Organ: the tissues organize to perform a specific body functions (heart, kidneys, lungs)


Histology

Study of tissues

Epithelial Tissue (Epithelium)

sheet of cells that covers a body surface or lines a body cavity


1. Covering and lining epithelium


2. glandular epithelium

Functions

1. Protection


2. Absorption


3. Filtration


4. Excretion


5. Secretion


6. Sensory Reception

Characteristics distinguish epithelial tissues from other types:

1. Polarity


2. Specialized contacts


3. Supported by Connective Tissue


4. Avascular but innervated


5. Regeneration

Polarity

-apical surface: one free surface


-basal surface: surface is significantly different

Specialized Contacts

-cells fit closely together to form membranes, sheets of cells


-bound together by specialized junctions

Supported by Connective Tissue

-cells are attached to and supported by an adhesive basement membrane (amorphous material secreted partly by the epithelial cells (basal lamina) and connective tissue cells (reticular lamina) that lie next to each other

Avascular but innervated

-supplied by nerves but have no blood supply of their own (avascular)


-Depend on diffusion of nutrients from the underlying connective tissue


*Glandular Epithelial: very vascular

Regeneration

-If well nourished, epithelial cells can essentially divide to regenerate the tissue


*This is an important characteristic because many epithelia are subjected to a good deal of friction

The covering and lining Epithelia are classified according to what two criteria:

1. Arrangement or relative number of layers


-Simple Epithelial (single)


-Stratified Epithelial (multiple)


2. Cell Shape


-Squamous (flat)


-Cuboidal (cube


-Columnar


-Transitional (able to change shape and stratification)

Simple Epithelial

-consisting of one layer of cells attached to the basement membrane

Stratified Epithelial

consisting of two or more layers of cells

Squamous

Scalelike

Cuboidal

cubelike

Columnar

column-shaped

Diagram of Classification of Epithelia

Two Categorized Types of Epithelia

1. Pseudostratified Epithelium (single player but looks like multiple)


2. Transitional Epithelium (able to change shape and stratification)

Pseudostratified Epithelium

simple columnar epithelium (one layer cells)


-Cells vary in height and nuclei lie in different layers above the basement membrane, it gives the false appearance of being stratified

Transitional Epithelium

particular stratified squamous epithelium formed of rounded (plump)


-cells with the ability to slide over one another to allow the organ to be stretched


-Found only in urinary bladder

Two types of Epithelia Glands

1. Endocrine Gland


2. Exocrine Gland

Endocrine Gland

lose their surface connection (duct) as they develop= ductless glands


-secrete hormones into the extracellular fluid


-the hormones then enter the blood or lymphatic vessels that weave through the glands

Exocrine Glands

retain their ducts and their secretion empty through these ducts either to the body surface or into body cavities


-Sweat, oil glands, liver and pancreas

Simple Squamous Epithelium
-Description: Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm
-Function: allows materials to pass by diffusion and filtration sites where protection is not important; secretes lubricating substances in serosae
-Location: Kidney glomeruli; air sacs of lungs, lining of heart, blood vessels, and lymphatic vessels lining of serosae
Simple Cuboidal Epithelium
-Description: single layer of cubelike cells with large, spherical central nuclei
-Function: secretion and absorption
-Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface
Simple Columnar Epithelium
-Description: single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain mucus-secreting unicellular glans (goblet cells)
-Function: absorption; secretion of mucus, enzymes and other substances; ciliated type propels mucus (reproductive cells) by ciliary action
-Location: Nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated variety of lines small bronchi, uterine tubes and some regions of the uterus
Pseudostratified Columnar Epithelium
-Description: single layer of cells differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting goblet cells and bear nuclei
-Function: secretes substances. particularly mucus; propulsion of mucus by ciliary action
-Location: Nonciliated type in male's sperm-carrying ducts and ducts of large glands; ciliated variety line the trachea, most of the upper respiratory tract
Stratified Squamous Epithelium
-Description: thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous);
-Function: Protects underlying tissues in areas subjected to abrasion
-Location: nonkeratinized type forms the moist linings of the esophagus, mouth and vagina; Keratinized variety forms the epidermis of the skin, dry membrane
Stratified Cuboidal Epithelium
-Description: generally two layers of cubelike cells
-Function: Protection
-Location: largest ducts of sweat glands, mammary glands and salivary glands
Stratified Columnar Epithelium
-Description: Several cell layers; basal cells usual cuboidal; superficial cells elongated and columnar
-Function: Protection; Secretion
-Location: rare in the body; small amounts in the male urethra and in large ducts of some glands
Transitional Epithelium
-Description: Resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamoslike, depending on degree of organ stretch
-Function: stretches readily and permits distension of urinary organ by contained urine
-Location: Line the ureters, urinary bladder and part of the urethra
Areolar Connective Tissue Diagram

Connective Tissue

Perform a variety of functions, but they primarily: Protect, Support and Bind together other tissues of the body


-found in all parts of the body as discrete structures or as part of various body organs


-most abundant and widely distributed of the tissue type


Loose connective

cells are fibroblasts (expect for fat- adipocytes)

Areolar Connective Tissue

found when tissue must be held in place but needs much space for fluid and vessels


- most abundant type in body


-present nearly everywhere


-collagen dominates but has elastin fibers as well

Adipose (fat) Tissue

storage and metabolism fat

Reticular

forms a supporting network


-collagen, elastic and glycoproteins are present


-found in stroma of organs and bone marrow

Dense Tissue

found when great strength and rigidity needed


-collagen is densely packed in either a regular(parallel) or irregular arrangments


-found in tendons, ligaments, organ capsules, fascia and sclera of eye


*Elastic CT a type of dense regular connective tissue is found when great flexibility is needed, elastin fibers dominate


-found in lung arteries, dermis of skin, lungs and bladder

Cartilage

nonvascular supporting tissue


-cells are called chondrocytes sitting in a lacuna


-semi-fluid extracellular matrix


-3 types:


1. Fibrocartilage: collagen (rigid, strong); found in pubic symphysis, intervertebral discs


2. Elastic Cartilage: elastin (flexible); found in epiglottis, pinna


3. Hyaline Cartilage: more ground substance than fibers (mostly water), most abundant cartilage of the body; found in nasal septum, intercostal cartilages, larynx, trachea and articular surface

Bone

vascular supporting tissue


-cells called osteocytes


-provides support to body


-stores minerals and the marrow produces blood cells


-*Haversian canal system: cells set in concentric circles surrounding their blood supply.

Blood

supports metabolically


-no fibers present


-high water content


1. Red Blood Cells: cells without nuclei, biconcave discs


2. White Blood Cells: large defensive cells


3. Platelets (Thrombocytes): cell fragments function in repair and clotting


Connective Tissue Proper

large amount of matrix:


Connective Tissue Proper: includes areolar, adipose, reticular and dense (fibrous) connective tissue, cartilage, bone and blood.


-all of these derive from an embryonic tissue called mesenchyme


Embryonic Connective Tissue: Mesenchyme
-Description: Embryonic connective tissue; gel-like substance containing fibers; star-shaped mesenchymal cells
-Function: Given rise to all other connective tissue types
-Location: Primarily in embryo
Connective Tissue Proper: loose connective tissue, areolar
-Description: Gel-like matrix with all three fiber types; fibroblasts, macrophages, mast cells and some white blood cells
-Function: Wraps and cushions organs; its macrophages phagocytize bacteria; plays important role in inflammation; holds and conveys tissue fluid
-Location: Widely distributed under epithelia of body, e.g. forms lamina propria of mucous membranes; packages organs; surrounds capillaries
Connective Tissue Proper: loose connective tissue, adipose
-Description: Matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet
-Function: Provides reserve fuel; insulates against heat loss; supports and protects organs
-Location: under skin; around kidneys and eyeballs; within abdomen, in breasts
Connective Tissue Proper: loose connective tissue, reticular
-Description: 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
Connective Tissue Proper: dense connective tissue, dense regular
-Description: Primarily parallel collagen fibers; a few elastic fibers; major cell type is fibroblast
-Function: Allows recoil of tissue following stretching; maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following inspiration
-Location: Walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes
Connective Tissue Proper: dense connective tissue, dense irregular
-Description: 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
Cartilage: Hyaline
-Description: Amorphous but firm matrix: collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae
-Function: Supports and reinforces; serves as resilient cushion; resists compressive stress
-Location: Forms most of the embryonic skeleton; covers the ends of long bones in joint cavities; forms costal cartilages of the ribs; cartilages of the nose, trachea and larynx
Cartilage: Elastic
-Description: Similar to hyaline cartilage, but more elastic fibers in matrix
-Function: Maintains the shape of a structure while allowing great flexibility
-Location: Supports the external ear (auricle); epiglottis
Bones (osseous tissue)
-Description: Hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae. Very well vascularized
-Function: Bone supports and protects (by enclosing); provides levers for the muscles to act on; stores calcium and other minerals and fats; marrow inside bones is the site for blood cell formation (hematopoiesis)
-Location: bones
Blood
-Description: Red and white blood cells in fluid matrix (plasma)
-Function: Transport of respiratory gases, nutrients, wastes and other substances
-Location: Contained within blood vessels
Nervous Tissue
-Description: Neurons are branching cells; cell processes that may be quite long extend from the nucleus-containing cell bodies; also contributing to nervous tissue are nonexcitable supporting cells
-Function: Neurons transmit electrical signals from sensory receptors and to effectors (muscles and glands); supporting cells support and protect neurons
-Location: Brain, spinal cord and nerves

Two Major Cell Populations that make up Nervous Tissue

1. Neuroglia: special supporting cells that protect, support and insulate the more delicate neurons


2. Neurons: highly specialized to receive stimuli (excitability) and to generate electrical signals that may be sent to all parts of the body (conductivity)

Muscle Tissue

highly specialized to contract and produces most types of body movement


-Three Basic Types:


1. Skeletal: the "meat" or flesh, of the body, is attached to the skeleton


-under voluntary control and its contraction moves limbs and other external body parts


2. Cardiac: found only in the heart


-intercalated discs: uninucleate cells that interdigitate (fit together) at junctions


-involuntary control


3. Smooth (visceral muscle): found mainly in the walls of hallow organs


-Two layers that run at right angles to each other

Skeletal Muscle
-Description: Long, cylindrical, multinucleate cells; obvious striations
-Function: Voluntary movement; locomotion; manipulation of the environment; facial expression; voluntary control
-Location: In skeleton muscles attached to bones or occasionally to skin
Cardiac Muscle
-Description: Branching, striated, generally uninucleate cells that interdigitate at specialized junctions called intercalated discs
-Function: As it contracts, it propels blood into the circulation; involuntary control
-Location: The walls of the heart
Smooth Muscle
-Description: Spindle-shaped cells with central nuclei; no striations; cells arranged closely to form sheets
-Function: Propels substances or objects (foodstuff, urine, a baby) along internal passageways; involuntary control
-Location: mostly in the walls of hallow organs

The Integumentary System

Skin (Integument) insulates and cushions the underlying body tissues and protects the entire body from abrasion, exposure to harmful chemicals, temperature extremes and bacterial invasion


-The hardened uppermost layer of the skin prevents water loss from the body surface


Basic Structure of the Skin

Two distinct regions:


1. Epidermis: composed of epithelium


2. Dermis: underling connective tissue


-Hypodermis (superficial fascia): immediately deep to the dermis. It is not considered to be part of the skin. Primarily of adipose tissue

Epidermis

Structurally: avascular epidermis is keratinized stratified squamous epithelium consisting of four distant cell types and four to five distinct layers

Cells of the Epidermis

1. Keratinocytes: the most abundant epidermal cells


-main function is to produce keratin fibrils


-Keratin: fibrous protein that gives the epidermis its durability and protective capabilities.


-Tightly connected to each other by desosomes


2. Melanocytes: spidery black cells that produce brown-to-black pigment called melanin


-the skin tans because melanin production increases when the skin is exposed to sunlight


-Melanin provides a protective pigment umbrella over the nuclei of the cells in the deeper epidermal layers


-a concentration of melanin in one spot is called a freckle


3. Dendritic cells (Langerhans cells): cells play a role in immunity


4. Tactile (Merkel) cells: Occasional spiky hemispheres that, in combination with sensory nerve endings, form sensitive touch receptors called tactile (merkel) discs located at the epidermal-dermal junction

Layers of the Epidermis

Epidermis consists of four layers in thin skin, which covers most of the body


-Thick skin, found on the palms of the hands and soles of the feet, contains an additional layer, the stratum lucidum


-From deep to superficial:


1.Stratum Basale


2. Stratum spinosum


3. Stratum granulosum


4. Stratum lucidum


5. Stratum corneum

Stratum Basale (basal layer)

single row of cells immediately adjacent to the dermis


-cell are constantly undergoing mitotic cell division to produce millions of new cells daily

Stratum Spinosum (Spiny Layer)

Stratum consisting of several cell layers immediately superficial to the basal layer.


-cells contain thick web-like bundles of intermediate filament made of pre-keratin protein


-appear spiky because as the skin tissue is prepared for histological exam, they shrink but their desmosomes hold tight.


-Cells divide pretty rapidly in this layer, but less so than in stratum basale


-only one that receives adequate nourishment via diffusion of nutrients from dermis

Stratum Granulosum (granular layer)

thin layer named for the abundant granules its cells contain


-Two types:


1. Lamellar granules: contain waterproofing glycolipid that is secreted into the exracellular space


2. Keratohyaline granules: combine with intermediate filaments in the more superficial layers to form keratin fibers

Stratum Lucidum(clear layer)

very thin translucent band of flattened dead keratinocyted with indistinct boundaries.


-Not present in regions of thin skin

Stratum Conreum (horny layer)

outermost epidermal layer consists of some 20-30 cell layers and accounts for some bulk for the epidermal thickness


-they are dead and flattened scalelike remnants are fully keratinized


-constantly rubbed off and being replaces

Dermis

dense irregular connective tissue making up the dermis consist of two regions:


1. Papillary Area


2. Reticular Area

Papillary Layer

the more superficial dermal region composed of areolar connective tissue


-very uneven and has fingerlike projections from its superior surface, dermal papillae, which attach it to the epidermis above (produce fingerprints, pain and touch receptors)


Reticular Layer

the deepest skin layer


-composed of dense irregular connective tissue and contains many arteries and veins, sweat and sebaceous glands, and pressure receptors


Skin Color

result of the relative amount of melanin in skin, the relative amount of carotene in skin, and the degree of oxygenation of the blood


-Carotene: yellow-orange pigment present primarily in the stratum corneum and in the adipose tissue of the hypodermis


-Jaundice: the tissues become yellowed, is almost always diagnostic for liver disease


-Addison's disease: bronzing of the skin hints that a persons adrenal cortex is hypoactive

Accessory Organs of the Skin

Cutaneous glands, hair, and nails all derivatives of the epidermis, but reside in the dermis


-originate from the stratum basale and grow downward into the deeper skin layers

Nails

hornlike derivatives of the epidermis:


-Body: visible attached portion


-free edge: portion of the nail that grows out away from the body


-Hyponychium: region beneath the free edge of the nail


-Root: part that is embedded in the skin and adheres to an epithelial nail bed


-Nail folds: skin folds that overlap the borders of the nail


-Eponychium: thick proximal nail fold commonly called the cuticle


-Nail bed: extension of the stratum basal beneath the nail


-Nail matric: thickened proximal part of the nail bed containing germinal cells responsible for nail growth


-Lunule: proximal region of the thickened nail matrix, appears as a white crescent

Nail Diagram

Hairs and Associated Structures
-Hair: structure consisting of medulla, a central region surrounded first by the cortex and then by a protective cuticle:
1. Root: portion of the hair enclosed within the follicle
2. Shaft: portion projecting from the scalp surface
3. Hair bulb: collection of well-nourished germinal epithelial cells
4. Follicle: structure formed from both epidermal and dermal cells.
-enclosed by a thickened basement membrane, the glossy membrane and a peripheral connective tissue sheath
5. Arrector pili muscle: small bands of smooth muscle cells connect each hair follicle to the papillary layer of the dermis *goose bumps*
Structure of hair and hair follicle diagram
Cutaneous Glands
Two categories:
1. Sebaceous (Oil) Glands
2. Sweat (Sudoriferous) Glands

Sebaceous Glands

found nearly all over the skin, except for the palms of the hands and the soles of the feet


-outlets for the glands of epithelial openings called pores.


-Sweat glands are categorized by the composition of their secretions


1. Exocrine (merocrine sweat) glands: produce clear perspiration consisting primarily of water, salts and urea.


2. Apocrine glands: found predominantly in the axillary and genital areas, they secrete the basic components of eccrine sweat plus proteins and fat rich substances


Photomicrographs of skin
The main structural features in epidermis of thin skin

Homeostasis

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Differentially permeable

not all substances penetrate the plasma membrane the plasma equally

Solutions

all of the liquids found in organisms

Solute

the particles found in organism


-salt, proteins

Thermal Kinetic Energy

the energy associated with a constant random motion of cells

Kinetic

the energy seen in moving bodies

Potential

energy that is stores or inactive

Brownian Movement

movement of invisible particles

Concentration Gradient

unequal distribution of molecules

Diffusion

the movement of molecules down their concentration gradient

Passive Diffusion

movement is caused by the passive diffusion to occur

Osmosis

diffusion of water through a differentially permeable membrane from a region in which it is highly concentrated to a region in which its concentration is lower

Electrolytes

substances that break up into separate ions when dissolved in water

Net movement

which way the concentration is moving

Active Transport

solute molecules may move against a concentration gradient

Parfocal

when the object is in focus under low power it is also in focus under medium and high power

Field of View

angle of visible field

Depth of Field

amount of distance between the nearest and farthest objects that appear in acceptably sharp focus

Focal Plane

represents the area in a camera where light is focused.

Slides!

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Simple Squamous

Simple Columnar
Simple Cubodial

Stratified Squamous

Transitional Epithelium

Connective Tissue Proper; Loose Connective: Areolar

Connective Tissue proper; loose connective, adipose

Connective Tissue proper; loose connective, reticular

Dense Connective: Regular

Kelly

Dense Connective: Irregular

Kelly

Cartilage: Fibrocartilage

Cartilage: Elastic 40X

Cartilage: Elastic 10X

Cartilage; hyaline

Bone

Blood

Skeletal Muscle10X

Skeletal Muscle 40X

Smooth Muscle 40X

Cardiac Muscle
Nervous Tissue

Skin (unpigmented + pigmented)

X

Skin (Human Scalp)
Pacinian Corpsucle

Hair Follicle Model