Histology Quiz 9

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