With Correct Detailed Answers.
Functions of the Integumentary System - ANSWER- -Resistance to trauma and infection
-Prevents loss or gain of water
-Vitamin D synthesis
-Sensory receptors for heat, cold, touch, texture, pressure, vibration, and tissue injury
-Thermoregulation
How does skin resist trauma and infection? - ANSWER- -Skin has low pH to reduce bacteria and
fungi
-Cells are packed closely together with tough protein called keratin
Name 3 ways the integumentary system thermoregulates? - ANSWER- -Glands release sweat for
evaporative cooling
- Vasoconstriction
- Vasodilation
Define: Vasoconstriction - ANSWER- narrowing of blood vessels, reduces heat loss
Define: Vasodilation - ANSWER- widening of blood vessels, increases heat loss
What are the 2 main parts of the integumentary system? - ANSWER- Epidermis- outer layer
Dermis- underlying connective tissue
*Hypodermis not really part of the skin!*
What does the epidermis primarily consist of? - ANSWER- keratinized stratified squamous epithelium
What are the epidermal derivatives? - ANSWER- glands, hair, nails
What are the 4 main cell types in the epidermis? - ANSWER- - Karatinocytes
- Melanocytes
- Tactile (Merkel) cells
- Dendritic (Langerhans) cells
Keratinocytes (functions) - ANSWER- most numerous cell type, make fibrous protein keratin
Melanocytes (functions) - ANSWER- synthesize pigment called melanin
Tactile cells (functions and 2nd name) - ANSWER- also called Merkel cells, receptors for the sense of
touch, associated with a dermal nerve fiber
Dendritic cells (functions and 2nd name) - ANSWER- macrophages (big phagocytic cells) that kill
microbes
What are the layers of the epidermis (list from bottom up)? - ANSWER- - Stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
, - Stratum corneum
What layer of the epidermis is only found in thick skin? - ANSWER- Straum lucidum
How many layers are found in the stratum basale? - ANSWER- 1 layer
What cells are found in the stratum basale? - ANSWER- stem cells, keratinocytes, melanocytes,
tactile (merkel) cells
What is the importance of the stem cells in the stratum basale? - ANSWER- makes it mitotically
active, the stem cells divide and give rise to keratinocytes
How many layers are in the stratum spinosum? - ANSWER- 8-10 layers
What is the appearance of the cells in the stratum spinosum, and why? - ANSWER- The cells are
flattened, which happens as they are pushed upward
What is contained in the stratum spinosum? - ANSWER- Keratinocytes, dendridic (langerhans) cells
In which epidermis layers do keratinocytes produce waterproofing substances? - ANSWER- Stratum
spinosum, stratum granulosum
What are the waterproofing substances produced by the keratinocytes? - ANSWER- keratin, lipids
How many layers are in the stratum granulosum? - ANSWER- 3-5 layers
In what layer do the nuclei and organelles begin to degenerate in the keratinocytes? - ANSWER-
stratum granulosum
What do the cells look like in the stratum granulosum and why? - ANSWER- They continue to flatten
because of accumulation of keratin
How many layers are in the stratum lucidum, and what do they look like? - ANSWER- 3-4 layers of
translucent cells
Why are the cells in the stratum lucidum translucent? - ANSWER- the clear protein named eleidin
How many layers are in the stratum corneum? - ANSWER- up to 30 layers
What do the layers of the stratum corneum consist of? - ANSWER- dead scaly keratinized cells
What are 2 of the main purposes of the stratum corneum? - ANSWER- resistance to abrasion and
water loss
What are the layers of the dermis (from top to bottom)? - ANSWER- Papillary layer
Reticular layer
What is the papillary layer made of? - ANSWER- areolar CT
What is the reticular layer made of? - ANSWER- irregular CT and adipose
What do you find in the papillary layer? - ANSWER- Meissner's corpuscles (touch receptors)