Chapter 6 notes


What is metaplasia?

The transformation of one tissue converted into another


Know two examples of metaplasia and what happens in each.

Bronchial metaplasia in smokers


Metaplasia in vagina of young girl


Know the cardinal signs of inflammatory response to the tissue injuries including what happens during each response.

Heat- due to vasodilation in response to chemicals like histamine

Redness-caused by increased blood flow due to vasodilation

Swelling- response to histamine, making endothelium of blood vessels leaky

Pain- activation of pain neurons by prostaglandin release



Classify epithelial tissue types based on cell shape and number of cell layers.

Simple- 1 layer of tissue

Stratified- 2 or more layers of tissue

Pseudostratified- 1 layer of tissue, although looks like multiple layers


Differences between endocrine and exocrine glands in terms of structure, secretion, and examples of each.

Endocrine- no ducts, secretes hormones directly into blood

Ex: thyroid gland, adrenal gland, pituitary gland, pancreas


Exocrine - has ducts, secretes products through ducts

Ex: sweat gland, tear gland, salivary gland, pancreas


Identify the four types of cell junctions from the figure (Chapter 5 document. Learn to associate the characteristic/importance of each through the diagram.


Know the following for the cell junctions. 

Tight junction: 

Characteristic

Similiar to a zipper, fuse plasma membrane of epithelial cells at apical surface

Importance

Seals off intercellular space, prevents leaks

Factors affecting the integrity of tight junction.

Lack of calcium, pathogenic organism, fibrosis, diet (sugar)

Dysbiosis: definition and causes- imbalance of microbiome in gut, leads to leaky gut. Allows harmful toxins and anti agents to enter our bloodstream

Desmosome:

Characteristic

Patch that holds cells together but does NOT fuse membrane of adjacent cell. Cannot prevent substances from passing through

Importance

Keeps cell from pulling apart, allows cell to stretch. Helps tissue resist mechanical stress

Gap junction:

Characteristic

Formed by ring-like connexons which are composed of conexon protein

Importance:

Allows nutrients, ions, and other small solutes to pass through cell. Cardiac and smooth muscle contract in unison because gap junction allows it

Hemidesmosome: (half demosome)

Characteristic

Similar in structure to desmosomes but DONT link adjacent cell. Located at basal cell which are linked to basement membrane

Importance:

Prevents epithelium from peeling away

Know two categories of body membranes. Know examples of epithelial and connective tissue membrane.

Epithelial membrane and connective tissue membrane


Mucous membrane:

Location:Respitory and Digestive

What does it secrete?Mucus

Which cells secrete mucus?Goblet cells

Importance of mucus:Prevents membrane from drying out, traps dust particles, acts as barrier


Serous membrane:

Location:Body cavities and organs with cavities

What is mesothelium?Simple Squamous epithelium that forms surface layer of membrane

What does it secrete? Serous fluid

Importance of serous fluid:allows organs to glide easily over one another or to slide against walls of the cavity


Synovial membrane:

Location:Lines cavities around freely movable joints

What does it secrete?Synovial fluid

Importance of synovial fluid: Lubricates joints for easy movement




Chapter 6: Integumentary system

Know the layers of the skin.

Two main layers making up the skin:

Epidermis and dermis


What does epidermis consist of?

Keratinized stratified squamous epithelial tissue


What does dermis contain?

Connective tissue with fibers 


Characteristics of hypodermis:

Connective tissue layer which epiderms and dermis rest on binds epidermis and dermis to underlying muscles 


Differences between the thick and thin skin.

Thick skin- Found: in palms of hands and soles of feet

Has sweat glands,  does not have hair follicles or sebaceous glands


Know ABCD of detecting early signs of malignant melanoma.

A- asymmetry

B- border irregularity
C- color

D-diameter


Know five cell layers of the epidermis in the sequential order. (From superficial to deep)

1- Stratum corneum

2. Stratum lucidum

3. Stratum granulosum                                          *remember- come lets get some beer

4. Stratum spinosum 

5. Stratum basale 


Know characteristics of each cell layer in the epidermis: (Follow chapter 6 document)

Which one rests on the basement membrane?

Stratum basale


Distinct types of cells present in the stratum basale with functions.

Keratinocytes-go through cell division to make more keratinocytes

Melanocytes-synthesize pigment melanin

Merkel cells- light touch projector


The thickest stratum:

Spinosum



Cells in this stratum contains desmosomes:

Spinosum


Distinct types of cells present in the stratum spinosum with functions.

Dendritic cells- immune cells that fight infection

Daughter Keratinocytes(living)-connect to desmosomes


Stratum containing keratohyalin granules:

Granulosum


Stratum found only in the thick skin:

Lucidum 


Stratum with dead keratinized cells having no nucleus:

Corneum 


Stratum where the mitotic divisions occur:

Granulosum


Stratum releasing lamellar bodies providing waterproof characteristic to the skin:

Granulosum


Which skin layer is responsible for the ridge pattern on our fingertips?

Papillary layer(dermis)


Where is sebaceous gland located?

Dermis


What does sebaceous gland secrete?

Sebum


Know two types of sudoriferous gland.

Eccrine and apocrine


Where is eccrine (merocrine) sudoriferous gland found?

Everywhere in the body, most concentrated on palms of hands and soles of feet


Where is apocrine sudoriferous gland found?

Groin, anal region, axilla, areola, and bearded area on males 


Functions of eccrine (merocrine) and apocrine glands

Merocrine- Secretes watery salty sweat, helps with thermoregulation

Apocrine- Secretes thicker milky fatty acids with sweat, source of sex hormones and body odor