Disease causing organisms called _______ are responsible for many diseases in humans. Each pathogen has a different lifestyle and attacks the body in a specific way.
This system includes the cells, tissues, and organs responsible for defending the body.
The ability to resist infection and disease is _____.
Several anatomical barriers and defense mechanisms that either prevent or slow the entry of infectious organisms, or attack them if they enter are called _______ defenses.
Innate or Nonspecific
If bacterial pathogen invades peripheral tissues, lymphocytes organize a defense against that particular type of bacterium in a process known as what?
Approximately ___% of circulating lymphocytes are classified as T Cells.
Lymphocyte cells that attack foreign cells or body cells infected by viruses.
Cytotoxic T Cells
Lymphocyte cell that stimulates the activation and function of both T cells and B cells.
Helper T cells
Lymphocyte cells that inhibit the activation and function of both T cells and B cells.
Suppressor T Cells
B Cells Make up ______ % of circulating Lymphocytes.
NK Cells make up the remaining _____ of the circulating lymphocytes
Small lymphoid organs ranging in diameter form 1 mm to 25 mm.
The greatest number of lymph nodes is located where?
Small lymphoid organs that defend us against bacteria and other invaders.
A lymph Node functions like a ____ ____ ____.
Kitchen water filter
Lymph nodes serve as both a ____ and ____ system.
Filtering and Warning
The adult ____ contains the largest collection of lymphoid tissue in the body.
What 3 functions does the spleen perform?
1) Removing abnormal blood cells and other blood components by phagocytosis.
2) Storing iron recycled from red blood cells
3) Initiating immune responses by B cells and T cells in response to antigens in circulating blood.
_____ Defenses do not discriminate between potential threats and respond the same regardless of the invader.
Innate or Nonspecific
Seven Major categories of innate defenses include:
1) Physical Barriers
3) Immunological Surveillance
6) Inflammatory Response
Defense that keeps hazardous organisms and materials outside the body.
Engulf pathogens and cell Debris
The destruction of abnormal cells by NK cells in peripheral tissues.
Chemical messengers that coordinate the defenses against VIRAL infections.
System that consists of circulating proteins that assist ANTIBODIES in the destruction of pathogens.
A localized, tissue-level response that tends to limit the spread of an injury or infection.
an elevation of body temperature that accelerates tissue metabolism and the activity of defenses.
What occurs during the inflammatory response?
1) Blood flow increase
2) Phagocytes activated
3) Capillary permeability increased
4) Complement activated
5) clotting reaction walls off region
6) Regional temperature increased
7) Adaptive defenses activated
How do Nk cells kill cellular targets.
1) Recognition and adhesion
2) Realignment of Golgi Apparatus
3) Secretion of perforin
4) Lysis of abnormal cell
A localized tissue response to injury.
Inflammation has several effects:
1) The injury is temporarily repaired, and additional pathogens are prevented from entering the wound.
2) The spread of pathogens away from the injury is slowed.
3) Local, regional, and systemic defenses are mobilized to overcome the pathogens and facilitate permanent repairs (regeneration).
normally begins to develop after birth. it continues to build as you encounter "new" pathogens or other antigens.
Naturally acquired active immunity
Stimulates the body to produce antibodies under controlled conditions so that you will be able to overcome natural exposure to the pathogen in the future.
Artificially induced active immunity.
____ immunity is produced by transferring antibodies from another source.
If a baby receives antibodies from the mother, either during gestation or in early infancy (Through Breast Milk)
Naturally acquired passive immunity
if a person receives antibodies to fight infection or prevent disease. For example, via injection.
Artificially induced passive immunity
4 properties of immunity are:
A specific defense is activated by a specific antigen, and the immune response targets that particular antigen and no others.
Results in part form the large diversity of lymphocytes present in the body, and in part form variability in the structure of synthesized antibodies.
Versatility of immunity
The immune system does not respond to all antigens, in a condition described as
____ Cells play a role in initiating, maintaining, and controlling the immune response.
_____ cells are responsible for cell-mediated immunity.
______ cells stimulate the responses of both T cells and B cells.
Helper T cells
Cells that respond to antigens they have already encountered by cloning more lymphocytes to ward off the invader.
Memory T Cells
Cells that inhibit T cell and B cell activities and moderate the immune response.
Suppressor T cells
Occurs when an antigen-glycoprotein combination capable of activating T cells appears in a plasma membrane.
Two major classes of MHC proteins are known:
An antigen bound to a class ____ MHC protein acts like a red flag that in effect tells the immune system "Kill Me".
An antigen bound to Class ___ MHC protein tells the immune system. "This antigen is dangerous, get rid of it".
Class I MHC proteins are in the plasma membranes of ____ nucleated cells.
Class II MHC proteins are present only in the plasma membranes of ______ cells and ____.
_____ cells respond to antigens by producing specific antibodies
_____ are responsible for launching chemical attacks on antigens by producing specific antiBodies.
B cell plasma membranes contain Class ____ MHC proteins.
Body fluids contain five classes of antibodies, or immunoglobulins (Igs):
IgG, IgE, IgD, IgM, & IgA
Antibody that accounts for 80 % of all antibodies, are responsible for resistance against many viruses, bacteria, and bacterial toxins. These antibodies can cross the placenta, and maternal forms provide passive immunity to the fetus during embryological development.
Antibodies that attach to basophils and mast cells; when bound to antigen, the cell is stimulated to release histamine and other chemicals that accelerate inflammation; Important in the allergic response.
Antibody that binds to antigens in the ECF; this binding can play a role in the sensitization of the B cell involved.
The first class of antibody secreted after an antigen is encountered.
The anti-A and anti-B antibodies responsible for agglutination of incompatible blood types are ____ antibodies, which also attack bacteria that are sensitive to them.
This antibody is found primarily in glandular secretions such as mucus, tears, saliva, and semen.
These antibodies attack pathogens before they gain access to internal tissues and circulate in the blood as individual molecules or in pairs.
The primary response, which takes about 2 weeks to develop peak antibody levels and activities. IgM and IgG antibody concentrations....
Do not remain elevated
The secondary response, rises to levels much higher than those of the primary response, and antibody activity ....
remains elevated for an extended period after the second exposure to the antigen.
The course of the body's response to a bacterial infection. (Order)
2) NK Cells
4) Cytotoxic Cells
5) Plasma Cells
6) Antibody Titer
We can regard digestive functions as a series of six integrated steps:
2) Mechanical processing
Major subdivisions of the digestive tract are:
Oral Cavity, teeth tongue
Pharynx, Esophagus, Stomach
Small intestine, Large intestine
Responsible for mechanical processing, moistening, and mixing with salivary secretions.
Oral cavity, teeth, tongue.
Responsible for muscular propulsions of materials into the esophagus.
responsible for the transport of materials into the stomach.
Responsible for the chemical breakdown of materials by the acid and enzymes; mechanical processing through muscular contractions.
Responsible for enzymatic digestion and absorption of water, organic substrates, vitamins, and ions.
Responsible for secreting lubricating fluid containing enzymes that break down carbohydrates.
Responsible for the excretion of bile, (important for lipid digestion), storage of nutrients, many other vital functions
Responsible for the storage and concentration of Bile
in this organ, the exocrine cells secrete buffers and digestive enzymes; the endocrine cells secrete hormones.
____ consists of waves of muscular contractions that move a bolus, or soft rounded ball of digestive contents, along the digestive tract.
____ does not follow a set pattern and does not push materials along the tract in any one direction.
Each gastric pit communicates with several gastric glands where?
In the fundus and body of the stomach
Gastric glands are dominated by two types of secretory cells:
Parietal cells and chief cells
Together, the Parietal and Chief cells of the gastric glands secrete about ______ mL of gastric juice each day.
1500mL or (1.6 qt.)
Parietal cells secrete what?
Intrinsic Factor &
A glycoprotein that helps the absorption of vitamin b12 across the intestinal lining.
The secretion of parietal cells can keep the stomach contents at pH ______.
The highly acidic environment of the stomach has four important functions
1) The acidity of gastric juice kills most of the microorganisms ingested with food.
2) The acidity denatures proteins and inactivates most of the enzymes in food.
3) The acidity helps break down plant cell walls and the connective tissues in meat.
4) An acidic environment is essential for the activation and function of pepsin, a protein-digesting enzyme secreted by chief cells.
Plays a key role in the digestion and absorption of nutrients where 90 % of absorption takes place.
This portion of the small intestine is a "mixing bowl". It receives chyme from the stomach and digestive secretions from the pancreas and liver.
The bulk of chemical digestion and absorption takes place in this portion of the small intestine.
This sphincter controls the flow of material from the ileum into the cecum of the large intestine.
This phase of gastric activity begins when you see, smell, taste, or think of food; generally lasts only minutes.
This phase of gastric activity begins with arrival of food in the stomach and builds on stimulation provided by the cephalic phase.
The stimulation of the _____ _____ produces powerful contractions called Mixing Waves.
Stimuli that initiate the gastric phase are:
1) Distention of the stomach
2) An increase in the pH of the gastric contents
3) the presence of undigested materials in stomach
This phase of gastric activity begins when chyme reaches the small intestine.
Takes place when materials enter the digestive tract through the mouth; an active process involving conscious choice and decision making.
The crushing and shearing that makes materials easier to propel along the digestive tract.
The chemical breakdown of food into small organic fragments suitable for absorption by digestive epithelium.
The movement of organic molecules, electrolytes (inorgainic ions), vitamins, and water across the digestive epithelium and into the interstitial fluid of the digestive tract.
The removal of waste products from body fluids.
These glands produce mucus when chyme enters the intestines; the mucus also contains bicarbonate ions to raise the pH of the chyme.
These lymphoid tissues are most abundant in the terminal portion of the ileum near the entrance to the large intestine.
This organ is primarily an exocrine organ that produces digestive enzymes and buffers.
The pancreatic duct delivers secretions from the pancreas to the _______.
Each day the pancreas secretes about ____ ml of pancreatic Juice.
What are three things that stimulate pancreatic secretions?
2) cholesystokinin (CCK)
3) Vagus nerve stimulation during Cephalic Phase
an enzyme that breaks down certain starches; almost identical to salivary amylase.
Breaks down certain complex lipids, releasing products (such as fatty acids) that can be easily absorbed.
Enzyme that breaks down RNA, or DNA.
Enzymes that break apart certain proteins.
This enzyme breaks apart large protein complexes.
This enzyme breaks small peptide chains into individual amino acids.
The liver carries out more than 200 functions which fall into 3 categories:
1) Metabolic regulation
2) Hematological regulation
3) Bile production
This is the primary organ involved in regulating the composition of circulating blood.
The livers regulatory activities affect the following:
1) Carbohydrate Metabolism
2) Lipid Metabolism
3) Amino Acid Metabolism
4) Waste Product Removal
5) Vitamin & Mineral storage
6) Drug inactivation
The liver stabilizes blood glucose levels at about ______ mg/dL.
When converting amino acids to lipids or carbohydrates, or when breaking down amino acids to get energy, the liver strips off the amino groups in a process called ...
As a result of deamination, ammonia is formed. the liver then neutralizes it by converting it to ____, a harmless compound excreted by the kidneys.
The liver is the largest blood reservoir in your body and it receives about _____ % of cardiac Output.
As blood passes through it, the liver performs the following functions:
1) phagocytosis and Antigen Presentation
2) Synthesis of Plasma Proteins
3) Removal of Circulating Hormones
4) Removal of Antibodies
5) Removal of Toxins
6) The Synthesis & Secretion of Bile
____ Cells in the liver sinusoids engulf old or damaged red blood cells, cellular debris, and pathogens, removing them from the bloodstream. They are antigen presenting cells that can stimulate an immune response.
The liver is the primary site for the absorption and recycling of what hormones?
1) Epinephrine & Norepinephrine
3) Thyroid Hormones
4) Steroid Hormones
Bile salts break the lipid droplets apart in a process called ______, which dramatically increases the surface area accessible to enzymes.
A major function of the gallbladder is what?
Whenever chyme enters the duodenum, _____ is released, relaxing the hepatopancreatic Sphincter and stimulating contractions of the gallbladder that push bile into the small intestine.
Secreted by G cells in the duodenum when exposed to large quantities of incompletely digested proteins. This hormone's functions include promoting increased stomach motility and the production of gastric acids and enzymes.
Hormone released when chyme enters the duodenum; primary effect is the secretion of bile, and buffers, which elevate the pH of chyme. Also reduces gastric secretions and motility rates.
The net effects of ____ are to increase the secretion of pancreatic enzymes and push pancreatic secretions and bile into the duodenum.
This hormone produces the inhibition of gastric activity along with the stimulation of insulin release at the pancreatic islets.
GIP (Gastric Inhibitory Peptide)
This hormone Stimulates the secretion of intestinal glands, dilates regional capillaries, and inhibits acid production in the stomach; provides an efficient mechanism for removing absorbed nutrients.
Vasoactive Intestinal Peptide (VIP)
This hormone is released when chyme enters the duodenum and stimulates mucin production by the submucosal glands.
Less than _____ % of the nutrient absorption under way in the digestive tract occurs in the large intestine.
The reabsorption of water is an important function of what organ?
The large intestine
Roughly _____ml of material enters the colon each day, but only ____ mL of feces is ejected.
1500 & 200
In addition to reabsorbing water, the large intestine absorbs a number of other substances that remain in the feces or were secreted into the digestive tract along its length. T or F?
The normal bacterial residents of the colon generate three vitamins that supplement our diets. They are:
1) Vitamin K
3) Vitamin B5
A fat-soluble vitamin the liver requires for synthesizing four clotting factors, including prothrombin.
A water-soluble vitamin important in various reactions, notably those of glucose metabolism.
water-soluble vitamin required in the manufacture of steroid hormones and some neurotransmitters.
Vitamin B5 (Pantothenic Acid)
Maltase splits bonds between the two glucose molecules of the disaccharide ____.
Sucrase breaks down the disaccharide sucrose into ____ and _____.
Glucose & Fructose
Fructose is a ______ sugar.
Lactase Hydrolyszes the disaccharide into a molecule of _____ & ____.
Glucose & Galactose
The proteolytic enzyme secreted in an inactive form by chief cells of the stomach.
Pepsin works effectively at a pH of ______.
_____ from the small intestine triggers the conversion of trypsinogen to trypsin.
At a pH of 7-8, pancreatic proteases can begin to work. _____, ______, & _______ are like pepsin in that they break specific peptide bonds within a polypeptide.