barriers to infection

what are physical barriers to infection

skin, hair, mucosal/mucus, cilia, and mechanical flushing

examples of mechanical flushing

tears saliva and urine

chemical barriers

sebum, sweat, lysozyme, stomach acids, antimicrobial peptides, local pH

Biological

resident microbiota

how does biological barriers works

compete with pathogens for space and nutrients

how does hair work for a physical barrier

traps particles debris and microorganisms before they reach epithelial surfaces

chemical barriers

sweat glands, sebaceous glands

sebacous glands

they are a part of follicles, and they produce sebum

what does sebum do

it lubricates and waterproofs skin and hair and creates a chemical barrier to inhibit microbial growth

sweat glands

located within the dermis and produce sweat glands

what does sweat do

It is important for thermoregulation

holocrine

the entire cell breaks down e

eccrine

exocytosis “exits” the cell, remains intact

apocrine

The apical portion pinches off and exits the rest of the cell remains

excytosis methods

holocrin eccrine appocrine

excytosis

an active rransport process where a cell exples a large molcules proteins or waste material by fusing internal vessicles with the cell membrane

how does sebum help the immune system

the fatty acids in it inhibit microbial growth

examples of specialized speacous glands

sheep- lanolin

pig- carpal glands

goats- horn glands

lanolin locations

infraorbital: by the eye

interdigital: between the cloven hooves on the cranial section of cleft

inguinal pouches: in the crotch

what does the lanolin gland contain

fine hairs and sebacous oill

anolin

a fatty yellow substance that coveres and sticks when dry “wool wax”

carpal glands location

inner lower part of the front legs near the carpus

what is a carpal gland

exocrine scent organ

what are carpal glands used for

to mark scent, by rubbing galnds against ground or vegitaiton. it is more developed in boars and cycling females

horn glands

caudal to the base of the horn, and secreation increase during mating

sweat gland location

located in the dermis

what does sweat contian

water, electrolytes, and small amounts of other substances

what does the evaporation of sweat do

it removes heat and plays a large role in thermoregulation in some species

horse sweat gland location

all over the body l

latherin

a component in the protein rich sweat in horses that spreads though oily hair coat for evaporation. can creast foam

sweat glands in pigs

very limited and ineffective for cooling, use wallowing and shade for thermoregulation

sweat glands in dogs

located in paw pads. and contributes littel to cooling so they rely on panting to cool themselvs

what do body/ apocrine sweat glands prodece on dogs

they produce scent not sweat

primary defense of mucosa

mucus tight junctionas flushing and microbiota

primary defenses of skin

kertin lipids and shedding of cells

spaces that use mucosa

upper respirtory tract, mouth and esphagus, lungs, GI tract, urinary bladder, female repro tract, eyes/ conjunctiva

what do golet cells do

produce mucus

what do ciliates cells do

allow movement of mucus in the lumen

how does biofilm help

it has antimicrobial peptides

mucus process

trap moce and removes

how does mechnical flushing work

it contioulsy removes pathogens from exposed sufaces.pathogens need time to adhere to an epithlial suface before it can colonize or invade

machincal flushing examples

tears saliva and urine lyso

lysozyme

it is an enzyme that is an antimicrobial found in body fluids such as tears slaiva milk egg whites and mucus

what do lysozymes do

the break bonds with in the peptidoglycan chain (cell wall), and due to weakend cell wall the bacteria dies

biofilm

community of microorganisms attached to a surface.

what is the biofil surrounded by

a self produced extracellular matrix

how does a biofil work

it prevents bacterial attachment howver can cuase diffucultiesl beucsae it can be diffucult for drugs to penetrate

how does residnet microboita work

they use the nutrients so that possible pathogens have no nutrients to grow. it proveds colonization resistance

types of antimicrobial peptides

dedensins and cathlicidicans what

what doe defensins do

they damage the microbial membrane

what do cathelicidians do

they disrupt microbial membrans recriut immune cells and support woound healing