Unit 4; urninary, immune, digestive

Pathogen

Disease causing agent

Microorganisms

Bacteria, fungus, protozoa, viruses, and prions are _______

Disease

A disorder of structure or function, especially one that produces specific signs or symptoms or that affect a specific location and is not directly a result of physical injury

Bacteria

2-3 billion species, less than 0.5% cause diseases in humans. Produce toxins that poison or harm the host cells

Virus

Contain genetic information, use host cells to replicate and multiply

Prions

Infectious misfolded proteins, can cause properly folded proteins to unfold and refold into the wrong shape

Fungus

Eukaryotic, doubling time of hours

Protozoan

Malaria, amoeba

Immune system

Defensive and counter-attacking system, attempts to prevent or stop invasions of pathogen causing diseases

Nonspecific or innate immunity

Inborn, same defense regardless of pathogen type

Specific or acquired immunity

Part is inborn, part develops over time, specific attack on a specific pathogen

1st line of defense

Physical and chemical surface barriers, skin, mucous membrane, hair, tears, saliva, urine, defecation, sebum, gastric juices, vaginal secretion, lysozyme, flora, etc. INNATE IMMUNITY

2nd line of defense

Internal cellular and chemical defenses, anti microbial proteins, basophils and mast cells, neutrophils and macrophages, INNATE IMMUNITY

Basophils and mast cells

2nd line of defense that attacks fever and inflammation

Neutrophils and macrophages

2nd line of defense that attacks phagocytes

3rd line of defense

ACQUIRED IMMUNITY, T cell and B cell lymphocytes, antibodies, and macrophages, protect against cancer cells

Lymphatic system

Functions: picks up fluid lost from the capillaries and returns it to the blood, defense against pathogens, involved in production, maintenance and distribution of lymphocytes in the body, lymphatic capillaries in small intestine absorb fats

Primary lymphoid organs

Red bone marrow and thymus gland

Secondary lymphoid organs

Spleen and lymph nodes

Lymph

Fluid in the lymphatic vessels

Red Bone Marrow

Site of blood cell production, more in children and decreases with age, B cells mature into bone marrow.

Thymus gland

Bilobed gland above heart in thoracic cavity, largest in children and shrinks over time, immature T cells from bone marrow move to thymus and mature (95% stay)

Spleen

In upper left region of abdominal cavity (under stomach), filled with white pulp containing lymphocytes and red pulp filtering erythrocytes

Lymph nodes

Small oval shaped structures, along lymphatic vessels, containing B cells and T cells and macrophages, common in the neck, armpits, and groin region.

Lymph vascular system

functions: Drainage, delivery and disposal.

Lymph capillaries

At the start of the drainage network, merge into larger vessels containing smooth muscles and valves. Fluid in vessels move by skeletal muscle contractions.

Integumentary system

The body’s covering, skin. Provides protection, maintenance of homeostasis, sensory, and synthesis of chemicals

Accessory organs of integumentary system

Oil glands, sweat glands, hair, nails

Epidermis

Keratinized stratified squamous epithelium

Keratinocytes

Make keratin (water insoluble substance), outermost layer dead keratinocytes, no specific defense

Melanocytes

Make melanin, role in skin color

Langerhan cells

Defense cells

Granstein cells

Control immune response

Dermis

Dense irregular connective tissue, elastin and collagen fibers, contains blood vessels and nerve endings

Glands

Sweat glands: thermal homeostasis, sebaceous glands: oils skin and keeps hair flexible, Hair follicles and nails.

Hypodermis

Layer beneath dermis, specialized loose connective tissue, adipose, fat as an insulator and cushion

Mucous membranes

Provide nonspecific immunity, are epithelial, line any cavity open to the exterior: mouth, digestive, respiratory, urinary, and reproductive tract. Mucous secreted by some of the goblet cells, slows down pathogens by trapping them and moving them out of the body

1st line of integumentary defense

Sebum, perspiration, tears, saliva, gastric acid, and bacteria flora. Chemical surface barriers, when the physical innate barriers fail to stop a pathogen, the chemical barriers aid in the first line of defense.

Sebum-1

1st line of integumentary defense, Oil from sebaceous glands, a protective acidic film over skin that kills many bacteria

Perspiration, tears, saliva-1st line of integumentary defense

Contains enzymes called lysosomes, a natural antibacterial chemical

Gastric acid-1

1st line of integumentary defesnse, Produced by stomach lining, extremely low pH, kills many pathogens

Normal bacteria flora-1st

1st line of integumentary, Take up the space and make environment unavailable for other microbes

2nd line of integumentary defense

Cells, proteins, and other

Cells-2

2nd line of integumentary defense, Monocytes, macrophages, neutrophils, dendritic cells, natural killler cells, mast cells, eosinophils, and basophils

Proteins-2

2nd line of integumentary defense, Interferon, anti microbial peptides, complement system

Phagocytes

A WBC that engulfs and destroys foreign agents

Phagocytosis

The engulfing of foreign material or substances by specialized WBC

Macrophages

A phagocytic WBC that engulfs anything detected as foreign.

“Off the shelf” mechanisms of defense

Phagocytosis, fever, inflammation used to counter threats in general and prevent infection

Interferon

Attacks virally infected cells, secreted by virus infected cells and passes to nearby uninfected cells, neighboring cells become infected with the virus, then interferon inside of them kills the virus

Fever

Results in elevation of basal body temp about 98.6 degrees F or 37 degrees C

Pyrogens

Proteins that reset the body’s thermostat to a higher temp that is harmful to the pathogens both directly and indirectly. Directly: prevent pathogen growth at higher temp. Indirectly: aids defensive mechanisms by raising the metabolic rate. The elevated temp allows enzymes to start the repair process and work faster

Inflammatory response

1. Histamine is released by mast cells (basophils in the skin) and causes vasodilation and capillaries are more permeable.

2. Increased blood flow causes warmth and redness and may inhibit some pathogens.

3. Increased blood flow brings more leukocytes; macrophages or neutrophils first to damage

4. Neutrophils release cytokines to call for more leukocytes including macrophages

3rd line of integumentary defense

Cells involved in acquired immunity: B cells, Helper T cells, Cytotoxic T cells, dendritic cells, antigen presenting cells. Protects against specific pathogens, cancers, and is dependent on B and T cells.

Adaptive immune system

When physical barriers and inflammation don’t prevent invasion, the ___ is mobilized. 1. Specificity (only against one antigen) 2. Diversity (combined against billions) 3. Memory (storage for next invasion)

Effector cells

Cells that respond immediately

Memory cells

Cells that are set aside for a second or third encounter

Antibody-mediated acquired immunity

B lymphocytes create disease fighting compounds called antibodies

Cell mediated acquired immunity

T lymphocytes directly attack pathogen-containing cells through direct cell to cell contact

B cells

Produced in bone marrow and sent to lymphatic system, produce antibodies and are apart of an antibody-mediated immunity

Cytotoxic (killer) T Cells

Produced in bone marrow and go to thymus for development. Take part in cell mediated immunity

Helper T cells

Cells used in both types of responses, cell mediated and antibody mediated immunity

MHC Markers

Major histocompatibility complex, genes code for these proteins, some of these proteins stick out of cell membranes

Antigen Presenting Cells (APC)

Macrophages and dendritic cells (phagocytotic cells), enzymes break antigen into pieces, pieces join with MHC markers and move to plasma membrane, helper T cells bind, release cytokines, B and T cells are activated in large numbers

Immunoglobulins

Proteins produced by B cells with various shapes, antigen binding sites and other sites with special roles. There are 5 types.

IgM

Immunoglobulin first formed in newborn and first infection

IgD

Immunoglobulin on surface of immature B cells

IgG

Immunoglobulin that is the main antibody in circulation

IgA

Immunoglobulin found in milk and saliva

IgE

Immunoglobulin for parasitic infections and allergic responses.

Perforins

A vacuole in cytotoxic T cells that punch holes in target cells.

Apoptosis

Programmed cell death, if there is something wrong with the cell then it is supposed to commit cellular suicide for the sake of the whole organism. Cancer cells can avoid cell death

Immunity

Ability to combat disease

Natural immunity

Gained through infections

Artificial immunity

Gained through medical intervention

Active immunity

Makes own antibodies

Passive immunity

Given prepared antibodies

Digestive System

Gastrointestinal Tract, has both major and accessory organs, lined with epithelial tissue: mucous membrane, and the muscular wall for peristalsis.

Mucosa

The soft tissue that lines the body’s canals and organs along the digestive tract. Made of epithelial tissue.

Submucosa

A thick layer of connective tissue that surrounds the mucosa

Muscularis

The smooth muscle with two sub layers, longitudinal and circular that surrounds the mucosa membrane.

Serous-adventita

The outermost layer of connective tissue, furthest from the lumen

Ingestion

Intake of food via mouth

Digestion

Mechanical or chemical breakdown of food into their subunits

Movement

Food must be moved along the GI tract in order to fulfill all functions; mixing

Absorption

Movement of nutrients across the GI tract wall to be delivered to cells via blood

Elimination

Removal of indigestible molecules; defecation

Mouth

Food processing begins mechanically and chemically here

Incisors

Chisel shaped, bite off chunks of food

Canines

Cone shaped, tear food

Premolars and molars

Broad crowns and rounded cusps, grind food

Saliva

Mostly water, bicarbonate buffer, and mucins

Salivary amylase

Begins starch digestion

Swallowing

Transition from the mouth to the stomach via the esophagus, includes voluntary and involuntary phases

Peristalsis

Moves bolus down to stomach, smooth muscle lines the entire digestive tract to accomplish progression of the bonus through the tube.

Sphincter

Smooth muscle rings that contract to constrict, sealing off entry/exit

Stomach

Food storage, mechanical and chemical digestion, muscular, stretchable sac, mixes and stores ingested food

Chyme

Gastric juices and food bolus

Rugae

Folds in walls of empty stomach

Pepsinogen or pepsin

Begins the digestion of protein