1) Tissue Level of Organization

saggital plane

left/right

coronal plane

front/back

transverse plane

top/bottom

oblique plane

passes through the body at an angle other than 90 or 180 degrees

What are serous membranes?

What are the types of serous membranes and their functions?

Where are they found?

• serous membranes line ventral body cavities

• 2 types

  • parietal: lines cavity

  • visceral: covers organ

• locations

  • pleura (lungs)

  • pericardium (heart)

  • peritoneum (abdominopelvic cavity)

What do endocrine glands do?

secrete hormones directly into the interstitial fluid to be absorbed into the blood stream

What are synovial membranes?

lines joint cavities, produces fluid within joint

the apical surface may contain…

microvilli and sometimes cilia

What are microvilli?

• finger-like projections that increase surface area

• faces the lumen of the organ

• ex: found in the small intestine

What are cilia?

• hair-like structures that have a cytoskeleton to work together to transport fluid or sense the environment

• ex: found in the airways

Epithelia is labile, what does that mean?

has the ability to replace damaged or lost cells fast

What are gap junctions and where are they found?

• connect neighboring cells

• allows intracellular exchange/communication

• found in granulosum

What is the function of hemidesmosomes?

anchor basale to basement membrane

What are desmosomes and where are they found?

• anchors neighboring cells

• responsible for tissue peeling instead of fragmenting

• found in spinosum

What is the function of simple squamous epithelium and where is it found?

• reduces friction, controls vessel permeability, and performs absorption and secretion

• found in areas of fast exchange:

  • mesothelial lining of the pleura, pericardial & peritoneal cavities

  • endothelial lining of the heart and blood vessels

  • portions of kidney tubules (thin segments of nephron loops)

  • inner lining of cornea

  • alveoli of lungs

What is the function of stratified squamous epithelium and where is it found?

• provides physical protection against abrasion, pathogens, and chemical attacks

• found in areas where cell shedding is frequent

  • surface of skin (keratinized)

  • lining of mouth, throat, esophagus

  • rectum, anus

  • vagina

What is the function of simple cuboidal epithelium and where is it found?

• secretion and absorption

• found in kidney tubules and some ducts

What is the function of stratified cuboidal epithelium and where is it located?

• Secretion and absorption

• Found in some exocrine gland ducts (sweat glands, salivary glands, mammary glands) and some endocrine ducts of the pancreas

What is the function of transitional epithelium and where is it located?

• expands and recoils after stretching

• found in the urinary bladder, renal pelvis, ureters

What is the function of pseudostratified ciliated/non-ciliated columnar epithelium and where is it found?

• protection, secretion, move mucus with cilia

• found in the lining of nasal cavity, trachea, bronchi, and portions of male reproductive tract

What is the function of stratified columnar epithelium and where is it found?

• Protection

• Small areas of fairings, glottis, anus, memory, glands, salivary gland, ducts

What is the function of simple columnar epithelium and where is it found?

• secretion and absorption

• found in the lining of the stomach, intestine, gallbladder, uterine tubes, collecting ducts of kidneys

What are the three types of membranes?

Epithelium, mesothelium, endothelium

What epithelium is corneum and what is in it?

stratified squamous epithelium, dead keratinocytes

What is lucidum made of and where is it found?

clear cells, thick skin

What junctions are found in granulosum epithelium?

gap junctions → intracellular exchange/communication granules

What junctions are found in spinosum epithelium?

Desmosomes → skin peeling polygonal cells

What junctions are found in basale epithelium?

hemidesmosomes → anchors it to basement membrane tall cells, rapidly regenerate, melanocytes

What is the function of tight junctions?

• Connect surface layer

• Water resistant

• Prevent unwanted losses or absorption

What cell type is always present in connective tissue?

fibroblasts → secrete hyaluronan and proteins

What are fibrocytes?

spindle-shaped cells that maintain ground substance of connective tissue proper

What are mesenchymal cells?

stem cells that repair

What are macrophages?

large phagocytic cells that engulf damaged cells or pathogens that enter the tissue → fixed or freely floating around

What are lymphocytes?

traveling cells that increase in number wherever tissue damage occurs → can develop into plasma cells which produce antibodies

What are microphages (neutrophils and eosinophils)?

phagocytic blood cells

What are melanocytes?

synthesize and store the brown pigment melanin, which gives tissues a dark color → found in basale layer of epidermis

What is the endothelium and what does it do?

• Specialized squamous epithelium lining blood vessels

• Supports exchange, especially at capillaries

• Regulates vascular tone, coagulation, inflammation, and permeability

What does nitric oxide promote?

vasodilation (increased blood flow, decreased blood pressure)

What do reticular cells do and where are they found?

• stabilize position of organ’s blood vessels, nerves by synthesizing reticular fibers → these fibers resist forces applied from many directions because they form a network rather than share a common alignment

  • found in the parenchyma of organs (liver)

collagen fibers

• has fibrous protein subunits wound together like a rope → stronger than steel

• most common fibers in connective tissue proper

elastic fibers

• after stretching, they return to their original length thanks to the protein, elastin

• elastic ligaments (rare) interconnect vertebrae

What does ground substance do?

fill the space between cells and surrounds connective tissue

• composition depends on the consistency of the connective tissue

  • ex: CaPO4 crystals → solid (bone)

adipose tissue

• loose connective tissue proper

• provides padding and cushions shocks, insulates, stores energy

reticular tissue

• loose connective tissue proper

• provides supporting framework

• found in liver, kidneys, spleen, lymph nodes, and bone marrow

areolar tissue

• loose connective tissue proper

• cushions organs, provides support but permits independent movement

• has phagocytic cells that provide defense against pathogens

• found within and deep to the dermis of skin, and covered by the epithelial lining of the digestive, respiratory, and urinary tracts

how do dense connective tissues differ from loose connective tissues?

fibers create most of the volume of dense connective tissues

What tissue makes up tendons, ligaments, and aponeuroses (sheath that covers muscles)?

• dense regular tissue

• attaches to and pulls muscles, reduces friction of muscles, stabilize position of bones

• found between skeletal muscles and skeleton (tendons, aponeuroses), between bones or stabilizing positions of internal organs (ligaments)

What is the class, function, and location of elastic tissue?

• dense irregular tissue

• stabilizes positions of vertebrae and penis, cushions shock, permits expansion and contraction of organs

• found between vertebrae in spinal column, ligaments supporting penis and other transitional epithelia, and blood vessel walls

define superficial fascia, deep fascia, and subserous fascia

1. superficial fascia (aka subcutaneous layer or hypodermis): between skin and underlying organs

   • made of areolar and adipose tissue

2. deep fascia: bound to capsules, tendons, and ligaments

   • made of dense connective tissue → strong, fibrous internal framework

3. between serous membranes and deep fascia

   • made of areolar tissue

hyaline cartilage

• supportive connective tissue

• provide stiff but somewhat flexible support and reduces friction between bony surfaces

• found between tips of ribs and bones of sternum, covering bone surfaces at synovial joints, supporting larynx, trachea and bronchi; forming part of nasal septumf

fibrocartilage

• supportive connective tissue

• resists compression; prevents bone to bone contact; limits movement

• found in pads within knee joint, between pubic bones of pelvis; intervertebral discs

elastic cartilage

• provides support, tolerates distortion without damage

• found in auricle of external ear, epiglottis, auditory canal, cuneiform cartilages of larynx

describe the distribution of body fluids

• 55% (females) to 60% (males) of total body mass is fluids

• Of the fluid, 2/3 intracellular fluid and 1/3 extracellular fluid

• Of the extra cellular fluid, 80% interstitial fluid and 20% plasma

Major factors that affect ECF volume

• Water vapor lost in respiration and evaporation

• Water secreted by sweat glands

• Water lost in feces

• Water lost in urine

hypotonic solution

• less water and more solutes inside cell than outside

• water moves into cell and makes it swell

• given when cells are dehydrated from diabetic ketoacidosis/hyperosmolar hyperglycemia

• ex: 0.45% saline (1/2 NS), 0.225% saline (1/4 NS), or 0.33% saline (1/3 NS)

hypertonic solution

• more water and less solutes inside cell than outside

• water moves out of the cell and it shrinks

• given via central line in ICU for pulmonary edema/fluid overload

• ex: 3% or 5% saline, D10W, 5% dextrose in 0.9% saline, 0.45% saline, or lactated ringer’s

isotonic solution

• given to increase ICF volume due to blood loss, surgery, or dehydration

• ex: 0.9% saline, lactated ringer’s

2 types of IV fluids

• crystalloids: no cellular component (synthetic)

  • ex: saline 0.9%, 0.45% NaCl, glucose and D5W 5%, 10%, 25%, ringer lactate, dextrose

• colloids: contains cells (donated)

What factors influence diffusion rates?

• distance (inversely related)

• molecular size (inversely related)

• temperature (directly related)

• gradient size (directly related)

• electrical forces

osmosis

• net diffusion of water across a membrane

• maintains similar overall solute concentrations between the cytosol and extracellular fluid

osmolarity (osmotic concentration)

total amount of solute/L of solvent in aqueous solution

tonicity

comparing osmolarity of 2 solutions

what is the only place plasma proteins can cross capillary walls? what do plasma proteins do?

• Sinusoids (liver)

• plasma proteins control water (especially albumin)

high capillary hydrostatic pressure (CHP)

• water leaves capillary and plasma proteins stay inside

• highest near arteriole and decreases along capillary length

low capillary hydrostatic pressure (CHP)

• water coming back into capillaries (reabsorption)

net filtration pressure (NFP)

• difference between capillary hydrostatic and blood colloid asthmatic pressure → NFP = CHP-BCOP

  • + at beginning of capillary

  • - at end of capillary

how does the epidermis get nutrients if it’s avascular?

simple diffusion through the papillary plexus

what is integumentary system?

• body’s first line of defense against environment

• 2 major components: cutaneous layer (epidermis and dermis) & accessory structures (stuff located in dermis)

what’s the difference between tactile and lamellar corpuscles?

• tactile: detects light touch, gentle pressure

  • close to the skin surface in the papillary dermis

• lamellar: detects heavy or deep pressure and high-frequency vibrations

  • deep in the dermis, subcutaneous tissue, and joint capsules

what is papillary layer of dermis made of?

areolar connective tissue

what is reticular layer of dermis made of?

dense irregular tissue

where is non-kerantinized epithelium found in integumentary system

unexposed areas (oral cavity, anal canal, vagina)

• nonpigmented and hairless (like thick skin)

damage to what can increase the rate of insensible perspiration?

epidermis

where is carotene found

epidermis and fatty tissue of hypodermis

• orange/yellow pigment

• beta carotene is vitamin a

where are melanocytes found in light skinned ppl?

basale + spinosum

where are melanocytes found in dark skinned people

granulosum

how do melanocytes produce melanin?

• derived from the amino acid tyrosine

• packaged in melanosomes (vesicles)

• transferred to keratinocytes and maintained until fusion with lysosomes

merocrine/eccrine vs apocrine

• merocrine (eccrine): secretes directly to surface

  • more numerous

• apocrine: secretes to hair follicles

  • begins at puberty

  • controlled by nervous system and circulating hormones

sebaceous gland vs sebaceous follicle

• sebaceous gland: secrete sebum into hair follicle and epidermis

  • decreases growth of bacteria (acidic ph), lubricates, and protects the keratin of the hair shaft

• sebaceous follicle: secrete sebum onto epidermis

  • found on face, back, chest, nipples, external genitalia

vitamin D synthesis

skin sythesizies cholecaliferol (anti rachitic) from sunlight or we get it from diet → liver → kidney where it becomes calcitriol

inflammatory exudate vs. transudate

• inflammatory exudate: protein rich tissue filtrate that’s secreted in response to inflammation

• transudate: regular tissue filtrate to distribute O2 and nutrients

process of injury repair

1. migratory: horizontal migration granulation tissues

2. proliferative: vertical migration fibroclasts release collagen fibers

3. maturation: scab sloughs, collagen fibers more organized, fibroclast decrease
   4. fibrosis: scar tissue formation (ligher in color)

where does deep wound healing extend to

dermis and subcutaneous layer

• healed tissue looses some of its normal function due to the formation of scar tissue

5 layers of scalp

• skin: contains hair follicles and sebaceous glands

  • common site for sebaceous cysts

• dense connective tissue: richly vascularized and innervated

  • common site for profuse bleeding

• epicranial aponeurosis: tendon-like structure that connects occipitalis and frontalis muscles

• loose areolar connective tissue: contains emissary veins which connect veins of the scalp (extracranial venous system) to the diploic veins and intracranial venous sinuses → danger area of the scalp

  • infection can spread from scalp to meninges, leading to meningitis

  • communication thru emissary veins also manages pressure of blood in the sinuses

• periosteum: outer layer of skull bones

  • continuous with endosteum at the suture lines

decubitus ulcer

pressure ulcer due to lack of tissue perfusion

what causes burns?

thermal, chemical, electrical, or radioactive agents

superficial burns

only epidermis

• ex: sun burn

second degree / partial thickness burn

epidermis and dermis

• defines by presence of vesicles and bulla (large fluid filled blister >1cm)

third degree /full thickness

epidermis, dermis, and underlying tissue

• damage to PPTT receptors → little or no pain

• requires debridement and dermatoplasty (skin graft)

Evaluation of burns

Rule of Nines

• 9% head and neck

  • 18% in children

• 18% arms

• 36% trunk

• 1% perineum

• 36% legs

  • 14% in children

aged skin effects

• fibroclast number decreases causing wrinkles

• subcutaneous adipose tissue is lost

UVA

deep to collagen (dermis)

• aging and wrinkles

• DNA damage and cancer

UVB

epidermis

• redness burns

• cancer

basal cell carcinomas

• basal cell carcinomas: arise from stratum basale and rarely metastasize

  • 78% of all skin cancers

• squamous cell carcinomas: arise from stratum spinosum, variable tendency to metastasize

  • 20% of all skin cancers

• malignant melanomas: arise from melanocytes

  • 2% of all skin cancers

Define scab

• blood clot over a wound

• rich in fibrin

define granulation tissue

• new connective tissue and microscopic blood vessels that form on the surfaces of a wound during the healing process

• grows from the base of a wound and is able to fill wounds of almost any size

define scar

new tissue formed at the end of healing process

define keloid

Excessive growth of the fibrous tissue scar

define infarction

Dead tissue that occurs due to local blood supply being lost or inadequate

define necrosis

dead or dying cells/tissue