Exam 1: Integument System and Skeletal System I

Explore the Integumentary System (Skin and Accessory Structures) and an introduction to the Skeletal System

What are the 4 major tissue types

Epithelial tissue, connective tissue, muscle tissue, & nervous tissue

What are the types of connective tissue?

Proper connective tissue, bones, cartilage, and blood

What is similar about the types of connective tissue?

Basic structure and all originate from embryonic mesoderm

What are the differences in types of connective tissue?

Vascularity, structural specific, and location

What does connective tissue do?

Supports other tissue types

What does epithelial tissue do?

Line organs, cover body, and form boundaries

What does muscle tissue do?

Movement

What does nervous tissue do?

Cell communication

What makes up a connective tissue?

An extracellular matrix and cells

What is the role of macrophage and mast cells?

Immune cells that wait for foreign substance. Always present

What is the role of lymphocyte and neutrophil cells?

Immune cells that show up when a foreign substance is detected. Increase in number

What is the role of adipocytes?

Fat cells that store energy and provide cushioning

What do capillaries do?

Small blood vessels within the CT

What is ground substance?

The base material that cells and fibers sit in

What are the types of fiber?

Collagen, Elastic, and Reticular

What are the characteristics of collagen fiber?

Thick, fibrous protein that has high tensile strength

What are the characteristics of elastic fiber?

Allow elasticity, can be stretched/deformed and return to original state

What are the characteristics of reticular fibers?

Very fine collagenous fibers tangled into a mesh

Where is areolar CT located?

Dermis of skin, basement membrane, wrapped around organs

What type of ground substance does areolar CT have?

Loose

What fiber types are in areolar CT?

Collagen, elastic, and reticular

What cells types are in areolar CT?

Fibroblasts and immune cells

What are the functions of areolar CT?

Wrap, cushion, and anchor organs in place

Where is adipose CT located?

Hypodermis and surrounding organs

What makes adipose CT different from areolar CT?

Lots of adipocytes

What is the function of adipose CT?

Cushioning, anchoring, and insulation

What type of ground substance does DICT have?

Loose

What fibers are in DICT?

Haphazardly organized collagen fibers and elastic fibers

What cells are in DICT?

Immune cells and fibroblasts

Where is DICT located?

Dermis

What are the specific functions of ET?

Protection, absorption, secretion, and propulsion

What are general characteristics of ET?

Very cellular, have tight junctions and desmosomes, and anchored by CT

What are additional characteristics of ET?

Avascular, innervated, regenerative, and polar

What are the classifications for ET?

Simple, stratified, pseudostratified, squamous, cuboidal, and columnar

What is the basement membrane?

Attaches ET to CT, and has 2 layers (basal lamina and reticular lamina)

What is transitional ET?

A stretchy form of ET than cells can slide and change from stratified to simple

Simple ET

One layer

Stratified ET

Multiple layers

Pseudostratified

Simple but appears stratified

Squamous

Flat, dome like shape

Cuboidal

Square shape

Columnar

Rectangular shape

What is your skin for?

Protection, temperature regulation, sensation, metabolism, reservoir, and excretion

What are the layers of the skin?

Epidermis, dermis, and hypodermis

What are some of the accessory structures?

Glands, hair, nails, and nervous elements

What type of tissue is the hypodermis?

Adipose tissue

What is the role of the hypodermis?

Anchor skin to underlying structures and cushioning

What tissue type is the epidermis?

Stratified squamous ET

What are the characteristics of the epidermis?

Avascular, innervated, dry, and keratinized

What are the cell types in the epidermis?

Keratinocytes, merkel cells, melanocytes, and langerhans cells

Describe keratinocytes:

Connected by desmosomes, get pushed up as more form, and accumulate keratin

What is the lifespan of a keratinocyte

24-45 days

Where are keratinocytes produced?

In the stratum basal

What are the layers of the epidermis?

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum

Describe the stratum basale:

Site of keratinocyte production

What cells are found in the stratum basale?

Stem cells, melanocytes, and merkel cells

What is the most common cancer?

Basal cell carcinoma

What are melanocytes

Produce melanin

What does melanin do?

Brown pigment that protects cells from UV radiation

What is carotene?

A yellow pigment found in thick skin

What is hemoglobin?

Protein that carries oxygen and is a red pigment

What is jaundice

Accumulation of bilirubin, an orange pigment

What is melasma?

Uneven tanning caused by excess estrogen

What are merkel cells?

Touch receptors that sense pressure on skin and communicate with associated nerve fiber

Describe the stratum spinosum:

Contains lots of desmosomes and 8-10 layers of keratinocytes

What do langerhans cells do?

Detect pathogens, engage in phagocyte activity, and alert immune system

Describe the stratum granulosum:

Cell disintegration begins due to keratin buildup

Describe the stratum corneum

Thickest layer, full of dead keratinocytes, is a waterproof barrier

What is the stratum lucidum?

A translucent layer of keratinocytes called Eleidin only visible in thick skin

What causes callouses?

High amounts of friction that increases cell division

What types of accessory structures in the dermis:

Sensory receptors, nerve fibers, blood vessels, lymph vessels, glands, and hair follicles

What are the two layers of the dermis?

Papillary and Reticular

What tissue type is the papillary layer?

Areolar CT

What is dermal papillae?

Hills of papillary dermis

What are capillary loops?

Thin walls for O2 and nutrient diffusion

What can free nerve endings sense

Pain and temperature

What are meissner’s corpuscles?

Sense light pressure

What is the epidermis/dermis juncition?

Area of attachment between epidermis and dermis

What are epidermal pegs?

Where epidermis extends down into dermis

What are dermal ridges?

More pronounced and deep, can shape epidermis, and allow for gripping

What is the reticular layer made of?

Dense Irregular Connective Tissue (DICT)

What are pacinian corpuscles?

Sense deep pressure

What do the muscles in skin do?

Allow hair follicles to move and allow skin folding

What are langer lines?

Parallel collagen bundles visible from far away

What causes stretch marks and scarring?

Damage to the dermis which cannot repair well

 What does too much melanin cause?

Decreases calcium absorption

What does too little melanin cause?

Decreases red blood cell formation

What are the 2 parts of a terminal hair?

The shaft and root/bulb

What are the parts of the hair shaft?

Medulla, cortex, & cuticle

What are the parts of the hair root/bulb

Inner root sheath, outer root sheath, hair matrix, hair papilla

What is the inner root sheath made of?

Epithelial tissue

What is the outer root sheath made of?

Connective tissue

What cells are in the hair matrix?

Stem cells and melanocytes

What is the function of the hair papilla?

Provide blood supply to the hair matrix

What are the phases of terminal hair growth?

Anagen, Catagen, and Telogen

What happens during anagen?

Active hair growth for 2-7 years

What happens during catagen?

Hair growth regresses for 2-3 weeks

What happens during telogen?

Hair is dormant and already grown hair is anchored in place for 2-4 months

What happens after telogen?

Anagen is signalled for re-entry and a new hair pushes out the old hair

What are the functions of hair?

Proximity sensation, filtration, protection, UV protection, and heat loss prevention