Studied by 38 people
2 primary bronchi
what does the trachea branch into?
bronchi, conducting bronchioles, terminal bronchioles, terminal bronchioles, respiratory bronchioles, alveoli
how do bronchi narrow to conduct gas exchange?
carry air in and out of lungs and protection
bronchi function
respirtory epithelium, lamina propria, some MALT/ mucous glands/ hyaline cartilage, smooth muscle, adventitia
structure of bronchi
thinning of the epithelium, pseudostratified turns to simple columnar
major change between bronchi and bronchioles
thinning epithelium, lamina propria, smooth muscle
structure of bronchioles
clara cells
- Specialized cells found in terminal and respiratory bronchiole epithelia \n • Clara cells have domed, non-ciliated apical surfaces \n • Cytoplasm includes secretory granules and SER
surfunctant production (prevents airway collapse), produce antimicrobial peptides, detoxification, stem cells
Functions of clara cells
bronchus, cartilage in wall
bronchus or bronchiole? how is it identified?
bronchiole, simple cuboidal epithelium with smooth muscle
bronchus or bronchiole? how is it identified?
respiratory bronchiole, alveolar duct, alveolar sacs, alveoli
what structures in lungs are capable of gas exchange and how do they branch?
thinner epithelium and increased capillary density
what allows gas exchange to occur as airways narrow?
alveoli
where does the most gas exchange occur?
simple cuboidal epithelium but without underlying smooth muscle
Respiratory bronchiole structure
thin with simple squamous epithelium and little underlying ct, lots of capillaries
Alveolar ducts and alveoli structure
type I alveolar cells
Very thin squamous epithelial cells, majority of cells in alveoli for gas exchange
type II alveolar cells
larger epithelial cells that produce surfactants
dust cells
macrophages in alveoli that phagocytose inhaled particles and pathogens
terminal bronchiole, respiratory bronchiole, alveolar duct, alveoli
type I alveolar cells, type II alveolar cells, dust cells, capillaries
protection, sensory, temp regulation, metabolic
functions of the skin
epidermis, dermis, subcutaneous layer
layers of the skin (outside to inside)
stratified squamous keratinized
what type of epithelium in the epidermis?
face, lips, scalp
where is the kertinized epidermis thinnest?
soles of feet, elbows
where is the kertinized epidermis thickest?
wavy
what is the appearance of a stratified squamous keratinized epithelium basement membrane?
keratin
tough, strong, resilient protein fiber that forms intermediate filaments inside the epithelial cells in the epidermis
the entire cytoplasm becomes filled with keratin fibers and nuclei die
why do cells in the upper levels of skin become keratinized?
keratinocytes
name for cells of the epidermis
stratum basale
epidermis cells that are attached to the basement membrane; includes mitotically active stem cells whose division continuously replenishes the epithelium
stratums basale, spinosum, granulosum, ludicum, corneum
epidermis layers from youngest up
stratum spinosum
Metabolically active epidermis cells
stratum granulosum
-cells undergoing keratinization and producing lipid secretions to prevent water loss
-visibly darker stained epidermis layer
stratum lucidum
thin layer of epidermis cells completing keratinization
stratum corneum
dead, fully keratinized, protective apical cells
desmosomes to hold cells together
what are the “spines” in the stratum spinosum and their function?
keratohyaline granules
what are the basophilic protein masses in the stratum. granulosum called?
secretion of lipids
how does stratum granulosum prevent dehydration?
corneum, lucidum, granulosum, spinosum, basale
name the epidermis layers
basal epidermis layer
where are melanocytes found?
melanocytes
-cells that produce black or brown pigments for the skin that protects from UV light
-recognizable by pale cytoplasm
langerhans cells
-population of skin-resident macrophages
-function as immune cells in phagocytosis and antigen presentation
stratum spinosum, clear cytoplasm and irregular cell shape/size
where are langerhans cells mostly found, how are they identified?
merkel cells
Epidermis sensory cells that can respond to light touch
corneum, granulosum, lucidum, spinosum, basale, keratinocytes, melanocyte, langerhans cell
numbers then letters
highly proliferative and high carcinogen exposure (UV)
why is the epidermis prone to cancer?
dermis
underlying supportive connective tissue directly under epidermis
papillary dermis
interface with epidermis; loose CT and blood vessels (must supply blood to epidermis!)
reticular dermis
dense irregular CT that surrounds hair follicles and glands; contains nerves and vasculature
elastic fibers
found in dermis for flexibility
increases adhesion and resistance to mechanical stress
why is the interface between the dermis and epidermis wavy?
blisters
what occurs when the epidermis and papillary dermis become detatched
stratum corneum, spinosum, basale, lucidum, granulosum
name the epidermis layers
corneum and ludidum
in which layers are the cells dead (fully keratinized)?
stratum granulosum
Which layer produces lipids for water retention?
stratum basale
Which layer contains stem cells?
stratum spinosum
Which layer contains specialized desmosomes to maintain epithelial integrity and confer resistance to mechanical stress and abrasion?
epidermis, papillary dermis, reticular dermis, epidermal ridges, dermal papillae
name these skin layers then blue and red arrows
when it is hot so the body can lose heat
when does blood travel through papillary loops?
shunts to block bloodflow to papillary loops
what is used when its cold to maintain internal body temperature?
sensory receptors
• Nerve endings in skin – either encapsulated \n and/or formed into semi-organized structures, \n or existing as free nerve endings with no \n myelin or capsule
response to sensation and touch
what is the function of sensory receptors?
meissner corpuscles
-located in dermal papillae directly under epidermis
-sensitive to light touch
meissner corpuscle
what structure?
lamellated corpuscles
-Located in dermis or subcutaneous layer of skin
-less sensitive, sense vibrations or pressure
-Concentric circular layers of axons and Schwann cells, encapsulated by CT
lamellated corpuscle
what structure?
meissner corpuscles, light sensation
Which sensory structure and what is its function?
lamellated corpuscles, pressure or course touch
Which sensory structure and what is its function?
epidermal invaginations
from where do hair follicles form?
fully keratinized cells
what makes up the hair
hair bulb
-At base of hair follicle \n • Includes hair (dermal) papilla \n • Also includes bulb matrix
bulb matrix
includes melanocytes and epidermal stem cells that are \n actively dividing and undergoing keratinization to produce the hair
hair root sheath
- Encompasses the hair as it extends towards the skin surface
• Includes inner epithelial root sheath and outer connective \n tissue root sheath
medulla
innermost cells of the hair
cortex
surround the medulla in the hair, most densely packed with keratin
cuticle
thin outer layer of squamous cells on hair
glassy membrane
discreet basement membrane secreted by hair follicle root epithelial cells
arrector pili muscle
smooth muscle attached to hair
sebaceous glands
glands always associated with hair follicles that produce lipids to protect hair and epidermis
acinar glands with holocrine secretion
what type of glands are sebaceous glands
cells rupture and die to distribute their product
what is holocrine secretion?
dermal papilla, hair bulb, CT root sheath, epithelial root sheath, transition to hair
name the structure of the hair follicle
temp regulatuion, antibacterial, waste disposal, pheromone production
functions of sweat
eccrine
widely distributed sweat glands– temperature regulation and waste disposal
apocrine
armpits, genitalia, eyelid – pheromone production (vestigial in humans)
dermis and subcutaneous layers
where are sweat glands located?
meandering tubular glands in dermis
structure of eccrine sweat glands
ducts are acidophilic from mitochondria, glands have mostly clear cells and a few dark staining
hoe do eccrine ducts vs glands stain
stratified cuboidal
what epithelium is found in sweat ducts?
large lumens
major difference in apocrine sweat gland appearance
eccrine, apocrine
identify the sweat glands
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Flashcard (23)