Respiratory defense mechanisms

Organ	Example defense	Defense interfered with
		Disease/disorder	Environmental
Eyes	Vision	Chlamydia Conjunctivitis	Dust Ammonia
Tongue	Taste		Food - palatability
Mouth/pharynx	Amylase Sneezing	Aujeszky’s Disease Actinobacillus pleuropneumoniae Haemophilus parasuis Streptococcus suis et al., Mycoplasma hyorhinis Pasteurella multocida E. coli PCV2 Other mycoplasma’s
Tonsils	Normal microbiota Lymphoid tissue Rapid healing Washing with liquids		Mycotoxins
Epiglottis/larynx	Size Separates swallowing and breathing
Nose	Small entrance
Turbinates	Size Mucocilary escalator down to throat High blood volume High humidity Centrifugal forces Smell Immune response Natural microbiota Lysosymes and other antimicrobial agents in mucus. Sneezing	Inclusion body rhinitis Bordetella bronchiseptica Pasturella multocida toxins Post-weaning sneezing Pasteurella multocidia Mycoplasma’s	Ammonia Other poison gases Dust Low water
Trachea	Length Corners/bends High air velocity Centrifugal forces Mucocilary escalator up to throat Immune response Lysosymes and other antimicrobial agents in mucus	Mycoplasma hyopneumoniae Swine Influenza	Low water Ammonia Dust
Right apical bronchus
Bronchus and bronchi
Lung general		Ascaris suum Metastrongylus apri Classical Swine Fever Actinobacillus pleuropneumoniae Pasteurella multocidia Streptococci Archanobacterium pyogenes
Alveolus	Alveolar macrophage Immune response Alveolar fluid	PRRSv	Dust: 3.6-1 µm
Pleura	Immune response - Fibrosis	Glässer’s Disease Actinobacillus pleuropneumoniae Tail biting and other vices	Flooring Vice issues
Respiratory lymphoid tissues	Immune response	PCV2 SIV	Mycotoxins Low Vit E Colostrum intake
Stomach	Acid Proteases Vomiting	Gastric ulcer Hyostrongylus dentatum	Low water Not eating Feed particle size
Intact skin epidermis	Normal microbiota Continuous surface	Vice – tail biting etc Damage to feet Fighting	Rough floors Sharp edges Pig processing Injections

Intestinal defense mechanisms

Organ	Example defense	Defense interfered with
		Disease/disorder	Environmental
Eyes	Vision Avoidance of unusual food	Chlamydia Conjunctivitis	Food colouring – note pigs are colour blind
Nose	Smell Avoidance of unusual or unpalatable food		Toxin smells
Tongue	Taste and feel food		Toxin taste Sharp objects
Mouth/pharynx	Teeth to break up food particles Salivary enzyme actions on sugars	Aujeszky’s Disease Haemophilus parasuis Streptococcus suis Mycoplasma hyorhinis PCV2 E. coli Salmonella Clostridia Teeth hygiene Tooth wear	Stones Sham chewing
Tonsils	Normal microbiota Lymphoid tissue Rapid healing		Mycotoxins
Epiglottis	Size Separates swallowing and breathing Coughing
Stomach	Acidic environment Proteases Mucus Pyloric torus protect stomach from alkaline	Gastric ulcer Hyostrongylus dentantum	Low water Not eating Feed particle size
Small intestine	Sudden change in pH Bile production Digestive enzymes Rapid cell turn over (every 3 to 6 days) Mucus One way flow - peristalsis Microbiota – Lactobacilli and Bacilli Large amounts of diluting water Microaerophilic Lymphoid tissue Epithelial attachment Diluting effect of water Genetic attachment changes – F4 F18 Defensins Tight junction epithelium Immune response Diarrhoea	Clostridium perfringens Clostridium difficile Enteric Diarrhoea virus Escherichia coli Isospora suis Lawsonia intracellularis Salmonellosis TGE PED Trichuris suis Yersinia enterocolitica Strongyle/parasites PCV2	Myotoxins Vit E Low iron Low water availability Poor colostrum intake
Large intestine	Ileocaecal valve Diluting water control One way flow - peristalsis Change in O2 concentration Indigenous microbiota Diarrhoea	Brachyspira hyodysenteriae Brachyspira pilosicoli Other Brachyspira
Rectum/anus	One way flow Defecation	Rectal prolapsed Salmonellosis	Chilling and piling Coughing
Liver		Clostridium novii
Intact skin epidermis	Normal microbiota Continuous surface	Vice – tail biting etc Damage to feet Fighting	Rough floors Sharp edges Pig processing Injections

Urogenital defense mechanisms

Organ	Example defense	Defense interfered with
		Disease/disorder	Environmental
External genitalia	Shape Flushing sterile urine Normal microbiota	Vulva biting	Poor water flow Other vices
Urethra	Male - length
Bladder	Transitional layer Glycopolypeptide layer Cell loss Epithelial attachement, E. coli F1, P Urination Flushing sterile urine	Actinobaculum suis Escherichia coli Streptococcus suis Crystaluria	Water restriction Feed minerals Feed toxins Floor hygiene Floor mobility - stance
Ureterovesical junction	Length Colosure during urination Sterile urine
Ureter	Sterile urine
Pelvis	Sterile urine
Pyamid shape – Duct of Belini	Sterile urine
Nephron	Sterile urine	Actinobaculum suis Leptospirosis
Glomerulus	Sterile urine Filter blood	PDNS
Vagina	Robust immune defence Especially under progesterone Normal microbiotia Flushing of sterile urine	AI contamination Vaginitis with streptococci and Staphylococci et al.,	Water restriction Floor hygiene
Cervix	Closure Flushing of sterile urine Normal microbiota	Cerviculitis with variety of environmental bacteria	Water restriction Floor hygiene
Uterus	Robust immune defence under progesterone	Parvovirus Aujeszky’s Disease PRRSv Enterovirus JEV Streptococci Leptospirosis Brucella suis PCV2 Congenital tremor virus Classical Swine Fever	Feed – mycotoxins Midwifery practices Mating practices
Tubal junction/oviduct	Controlled flow Restricted entry of semen
Ovary		Cystic ovaries	“Stress” issues
Prepuce	Normal microbiota High pH	Preputial diverticulitis
Vas Deferens	Length Ejaculation
Reproductive organs
Testes	Blood testes barrier	Brucella suis