PHYL 142 Final

Pathogen

something that causes and generates disease (bacteria, fungi, parasites)

Innate immune system

System we are born with, include skin, mucus, sweat, tears, gastric acid, human microbiota

Mucus

contains mucins, enzymes & defensins, trap/impede pathogen entry, neutralize pathogens

Mucins

glycoproteins, thicken extracellular fluid, retain water, slow & impede pathogen movement

Sweat

Acidic pH, high salt (hypertonic to pathogens), defensis, dermcidin

Tears

Lysozyme, mucins, surfactants

Gastric acid

In stomach, contains hydrochloric acid, denatures proteins, dissolves microbes or inhibits growth

Human microbiota

Makes it difficult for pathogens to develop, secrete chemicals that impede pathogenic bacteria, crowd out other bacteria, compete for resources

Steps of phagocytosis

Chemotaxis & adherece of microbe to phag, ingestion of microbe, formation of phagosome, fusion of phagosome with a lysosome forming a phagolysosome, digestion of ingested microbe by enzymes, formation of residual body containing indigestible material, discharge of waste materials

Chemotaxis

movement of cells towards or away from chemical,

Diapedesis

passage of blood cells through capillary walls, help RBCs as well as macrophages get to different parts of the body

Complement proteins

mostly produced by liver, always circulating;remain inactive if not needed, activated by pathogens

Complement protein functions

recruit macrophages, activate mast cell degranulation, can also attack pathogenic cells itself

Interferons

Inc. antiviral defenses, inc. DNA repair, MHC-1 & MHC-2 presentation, NK cell activity & destruction of infected cells

Interferon alpha

prod. by cells infeceted w viruses, attracts & stimulates NK cells & enhances resistance to viral infection

Interferon beta

secreted by fibroblasts and slows inflammation in damaged area

Interferon gamma

secreted by T & NK cells, stimulate macrophage activity

Inflammation

bodily response to injury or disease in which heat, redness & swelling occur to eliminate harmful substances & repair damaged tissue

4 signs of inflammation

Heat, pain, redness, swelling

Histamine

Causes vasodilation, inc. vessel permeability, inc. fluids also leak, leading to heat, redness & swelling

Fever

Pyrexia, add energy & speed up metabolism in immune cells, make body inhospitable for foregin bacteria, inhibit bacterial & viral enzymes, stresses out our body

Pyrogens

Chemicals that cause the body to produce more heat, released by bacteria & immune cells

Normal body temp range

96.8-99.5 F

hypothermia

Temp < 95 F

fever

Temp > 100.4

hyperpyrexia

Temp > 104 F

Neutrophils

Phagocytic, degranulation, promote inflammation & recruit other immune cells, form NETs, expendable

Degranulation

release of toxic chemicals from cellular vesicles (granules)

Defensins

enzymes that produce free radicals, degrade extracellular matrices,

Pus

Thick opaque fluid, result from inflammation or infection, contain remnants of infection (proteins, pathogen remnants, cell 7 tissue debris, dead WBCs)

NK cells

Innate cells, recognize abnormal cells, cause apoptosis,

NK cell self tolerance

NK cells read MHC-1 of all cells, induces apoptosis on any infected or tumorous cells

MHC- 1 & 2 location

found on surface of all cells

MHC-1

Cells display their own proteins on MHC-1 receptors, serve as ID for cells

MHC-2

Present extracellular antigens, displayed by pro APCs

Professional APCs

Dendritic cells, macrophages, B cells

Antigen-presenting cells (APCs)

Present antigens from foreign particles to T cells, so the body can learn how to respond to the invader, or alert T cells that a cell is compromised

Cytotoxic T cells

Detect pathogen antigens, kill infected cells

T helper cells

Support cells that phagocytize pathogens, tell cytotoxic T cells to activate & multiply, help macrophages become deadlier

T regulatory cells

Protect self cells from cytotoxic T cells, important in immune self-tolerance

B cells

Produce immunoglobulins, can create enormous variety of antibody binding sites, shuffle genes that make antibody lift & heavy chains

Plasma cells

produce and secrete antibodies

T&B memory cells

Record of past antigens, allow faster response to same antigen in future, prod. in primary response

Secondary lymphoid organs

Sites where lymphocytes mount adaptive immune responses; examples include lymph nodes and spleen

GI tract

runs from mouth to anus

Mesentery

a fused double layer of the parietal peritoneum that attaches parts of the intestine to the interior abdominal wall, serve as scaffold for blood vessels

GI tract organs

oral cavity, pharynx, esophagus, stomach, small intestine, large intestine

Accessory organs (digestive)

Teeth, tongue, salivary glands, liver, gallbladder, pancreas

Mastication

chewing

Saliva

1-1.5 L produced daily, 99% h20, fluids & digestive enzymes help digest food, normal pH range 6.35-6.85

Enzymes in saliva

Salivary amylase, lingual lipase, immunoglobulins, lysozyme, peroxidases, defensins

Teeth

Deciduous, incisors, canines, premolars, molars

Deciduous teeth

baby teeth

Permanent teeth

Replace baby teeth

Incisors

Shaped like dull blades, slice food, 4 on top 4 on bottom

Canines

Tears up food, 2 on top, 2 on bottom

Premolars

8 total

Molars

6 on top, 6 on bottom

Deglutition (steps)

Bolus gets swallowed -> tongue pushes up against hard palate, soft palate is closed -> Hyoid pulls up & forward, epiglottis shuts

Esophagus layers

Lumen, mucosa, submucosa, muscularis externa, adventitia

Peristalsis

series of wave-like involuntary contractions

Muscle contraction during peristalsis

contraction of circular muscle -> contraction of longitudinal muscle

regions of the stomach

Cardia, fundus, body, pylorus

layers of muscularis externa (stomach)

(deep) Oblique, circular, longitudinal

Parietal cells

prod. hydrochloric acid, secretes intrinsic factor,

Intrinsic factor

protein which is important for absorption of vitamin B12

Mucus cells

prod. mucus

Chief cells

secrete pepsinogen

Pepsinogen

needs to combine with hydrochloric acid to become pepsin (active), helps breakdown food molecules

G cells

produce gastrin

Gastrin

peptide hormone, increases stomach motility, stimulates acid & enzyme production

Peptic Ulcers

Gastric acid eats away at stomach lining

Common cause of peptic ulcers

Helicobacter pylori, invades mucosal layer, secretes proteases & toxins

Mechanical digestion (stomach)

churning and mixing until food is a soupy liquid called "chyme"

Hydrochloric acid

helps break down food in the stomach

Duodenum

Where food first enters the intestines, produces gastrin

Cephalic phase

thinking of food, inc. hunger, stimulating stomach

Gastric phase

Gastric acid released stimulating prod. & release of other substances (HCL, mucus, pepsinogen)

Intestinal phase

Bolus moves on into the intestines

Secretin

Inc. pancreatic secretion of bicarbonate, Inc. bile production by liver

Cholecystokinin (CKK)

Fatty acids & amino acids stimulate release, inhibits gastric emptying, inc. bile production, suppresses hunger, keeps food in stomach longer, more time to digest

Glucose-dependent insluniotropic polypeptide (GIP)

Abnormally high GIP levels dec. gastric acid, stimulated by high glucose duodenal content, stimulates release of insulin

Ileum

Thinner circular folds, smaller villi, absorbs vitamin B12 & bile acids, longest portion, contains peyer's patches

Peyer's patches

clusters of lymphatic tissue around small intestine to monitor digestive system

Lobes of the liver

Left lobe, caudate lobe, right lobe, quadrate lobe.

lipoproteins

LDL, HDL, transport cholesterol, triglycerides & fats

Coronary ligament

Anchors liver to diaphragm

Blood flow through the liver

portal vein->portal venules->sinusoids->central venule->sublobular veins->hepatic veins->IVC

Liver cells

Kupffer cells, hepatocytes,

Kupffer cells

~80-90% of all resident (fixed) macrophages, Dispose pathogens, foreign particles & debris, Recycle cell debris & large molecules, release inflammatory cytokines

Hepatocytes

~80% of the livers mass, prod. plasma proteins, Metabolize carbs, fats & lipids

Bile

A substance produced by the liver that breaks up fat particles, stored in gallbladder

Porta hepatis

Where the hepatic portal vein, artery and common bile duct enter the liver

Gallbladder

Stores & concentrates bile produced in the liver

Pancreas

produces insulin and glucagon

Pancreatic duct

Carries exocrine secretions of pancreas to duodenum

Pancreatic acini

exocrine cells that secrete digestive enzymes into the pancreatic duct; 99% of pancreatic cells

Pancreatic islets

Secrete insulin & glucagon into the bloodstream

Pancreatic juice

Exocrine secretion, basic pH, helps neutralize chyme, 1L prod. per day

Pancreatic juice enzymes

Amylases, lipases, proteases, nucleases