A&P Homework #2 chapter 4/5
hemidesmosomes
bind cells to the basement membrane
which features of the skin protect us against microbes such as bacteria
1. The many layers of keratinized cells from a barrier against microbes 2. sebum contains compounds which kill bacteria 3. sweat has an acidic pH which suppresses microbial growth 4. langerhans cells can alert the immune system should microbes invade
along with sweating, which other responses by skin assists with thermoregulation?
Blood Vessels near the skin can dilate, increasing blood flow and heat loss
Which of the connective tissue fibers imparts the greatest strength?
Collagen
When an epidermal wound begins the healing process, basal cells migrate away from the basement membrane, enlarge, and migrate to fill in the wounded area. As these cells migrate from different sides of the wound, and reach each other, they stop migrating. This process is called_____
Contact inhibition
From which of the primary germ layers of the embryo does the epidermis of the skin develop?
Ectoderm
_____ covers and protects surfaces inside and outside of the body. _____ help secure most of the epidermal cells together through intermediate filaments, while____ allow communication among the epidermal cells This tissue will have a____ surface that is at the superficial layer and a ____ surface that is attached to the basement membrane by____
Epithelial tissue desmosome junctions gap junctions apical basal hemidesmosome Junctions
In a skin infection, which cell will take up and process microbial antigens
Intraepidermal macrophages (Langerhans cells)
Epithelial and connective tissues are found adjacent to each other because
epithelium is avascular and needs to exchange oxygen, nutrients and waste with the blood of highly vascular connective tissue
Tight Junctions
Protects cells from the movement of harmful substances, like hydrochloric acid
Which epidermal layer marks the transition between metabolically active cells of lower layers and the dead layers of keratinocytes of the upper layers?
Stratum granulosum
elastic fiber
allow extensibility, usually wihthout breaking
Gap Junction
contains tiny fluid-filled tunnels called connexons which allow the movement of ions and small molecules between cells. It is found between muscle cells of the heart and in organs with smooth muscle tissue such as the gastrointestinal tract
Which exocrine gland is primarily used for thermoregulation
eccrine sweat glands
Which polysaccharide is commonly found in the ground substance of connective tissues?
hyaluronic acid
Where would you be able to find dense regular connective tissue in the body?
in tendons and ligaments
A raised scar that extends into previously normal tissue is
keloid scar
Which of the following statements is INCORRECT? 1. simple squamous epithelium is found in thin layers so substances can pass through them rapidly 2. transitional epithelium change shape to allow structures such as the urinary bladder to distend and collapse 3. keratinized stratified squamous epithelium is adapted for absorption 4. ciliated simple columnar epithelium moves mucus by ciliary action
keratinized stratified squamous epithelium is adapted for absorption
Albinism is the inherited inability to produce _____
melain
What is not correct about melanin? 1. granules of melanin are produced and exported by melanocytes 2. melanin granules are the source of skin pigmentation 3. melanin is necessary for the production of vitamin D by the skin 4. melanin pigment protects DNA from damaging UV light 5. melanin granules are taken up by keratinocytes
melanin is necessary for the production of vitamin D by the skin
Reticular Fiber
modified collagen fibers used for reinforcement
The extracellular matrix of connective tissue consists of
protein fibers and ground substance
This type of exocrine gland undergoes a higher rate of mitosis due to its holocrine secretion
sabaceous gland
Which epithelial tissue is found lining the kidney glomerulus, and performs blood filtration?
simple squamous epithelium
Which tissue, depending on its location and functions, is sometimes called endothelia or mesothelia?
simple squamous epithelium
Which tissue can withstand friction and abrasion?
stratified epithelium
This layer is attached to the basement membrane by the hemidesmosomes ad to other cells by desmosomes
stratum basale
collagen fiber
strongest and most abundant protein
Which is not true about eccrine/merocrine sweat glands? 1. they begin to function at puberty 2. they are found throughout the body 3. their excretory duct terminate at the surface of the epidermis 4. they regulate body temperature
they begin to function at puberty