Unit 4 BMS Exam Missouri State

Learn about the Immune System and Digestive system

What are the lines of defense?

barriers to entry: physical and chemical

• skin and mucous membranes and chemical secreted

innate immunity (less specific)

• phagocytic leukocytes

• complement proteins

• inflammation

• fever

Adaptive immunity

• antibody mediated immunity

• B cells 

• Antigens 

  • anything that antibody will bind

  • cell mediated immunity

    • T cells 

what is the first line of defense?

Intact skin

linings of body cavities and tubes

chemical barriers to infection

not considered part of the immune system

• skin, mucous membrane, mucous, hairs, tears, saliva, uriine, defecation, and vomiting

• sebum, lysozyme, gastric juices, vaginal secretions

• normal bacterial “flora” intestines

What is immunity?

the body’s overall ability to resist and combat something not itself

innate immunity

What is adaptive immunity triggered by? What is it?

the innate immunity

• changes with exposure

• antibodies specific to a particular pathogen

  • WBC proliferate and respond

• 1-2 weeks to develop 

  • memory of cells left behind allow for a more rapid response to next pathogen appearance

  • IgG- immunoglobulin gamma 

What is an antigen?

Something an antibody will bind to

What is the difference between innate and adaptive?

Innate

• immediate

• 1000 presence receptros 

• nonself chemical cues on or in pathogens 

Adaptive 

• 7-10 days 

• vast number of receptors 

• antigens of pathogens. toxins, proteins

• LONG TERM

What is a pathogen?

something that causes disease

• fungus, bacteria, protozoa, viruses, prions

What is a disease?

a disorder of structure or function especially one that produces specific signs or symptoms or that affects a specific location and is not simply a direct result of physical injury

• diseases have

  • specific location

  • clinical sign: measured

  • symptom: IE stomach ache

  • not a direct result of physical injury

What are the different kinds of cells and what do they function as?

Granulocytes (neutrophils, eosinophils, basophils) are involved in the rapid, innate immune response, while agranulocytes (lymphocytes, monocytes) are crucial for the specific, long-term adaptive immune response. Granulocytes work by releasing cytotoxic agents, while agranulocytes function by producing antibodies (lymphocytes) and engulfing pathogens and presenting antigens to trigger an adaptive response (monocytes). 

A granulocytes include monocytes and lymphocytes 

• monocytes include dendritic and macrophages and bridge the gap between the innate and adaptive immune system

• lymphocytes include B and T cells 

What is a fever?

A systemic response to a local infection

What are bacteria?

2-3 billion species on earth and less than 0.5 percent cause disease in human

• are treated by antibiotics

• bacteria enter the body

• multiply

• produce toxins- virulence factors that harm the hosts cells 

  • poke holes in cells

  • degrade tissues

  • prevent protein synthesis

  • cause cell death

What are viruses?

Contain genetic information- DNA or RNA in a protein coat and may have a lipid coat

use the host cells replication machinery to multiply

NOT ALIVE

What are prions?

misfolded proteins

presence of prion causes properly folded proteins or unfold and refold in the wrong shape

NOT ALIVE

• Bovine spongiform encephalopathy: Mad cow

• Creutzfeldt-Jakob Disease, Kuru: humans 

• scrapie: sheep

• chronic wasting disease: deer

What is a fungus?

Eukaryote

doubling time of hours

How are pathogens spread?

• direct contact

• bodily fluids- blood, feces, saliva, semen, vaginal fluid, other

• contaminated water, food, drink

• from soil

• inhaling droplets from air

• contact of pathogen with mucous membrane

• contact of pathogen with open wound

What are nosocomial infections?

hospital infections

What is the immune system?

Defesive and counter attacking system

attempts to prevent/stop invasions of pathogens causing disease

What are the two systems to defend against pathogens?

Nonspecific (or innate) immunity

• inborn

• same defenses regardless of the pathogen

Specific (or adaptive) immunity

• part is inborn- part develops over course of life

• a specific attack against a specific pathogen

What is the second line of defense?

Internal chemical and cellular defenses

• innate immune system: interferons (signal protein that alerts nearby cells) and the complement system (a group of blood proteins that are activated in a cascade to fight infection and inflammation)

• fever, inflammation (basophils and mast cells) and phagocytes (neutrophils and macrophages)

What is the interraction between microbes and humans?

microbes in our environment

• body 

• used to make many foods ( food micro)

• used to make drugs (pharmaceutical micro)

• used to recycle nutrients (decomp) and clean up waste (environmental micro)

• some cause diease in humans (medical micro)

What are different kinds of antigens made of?

proteins, lipids, oligosaccharides

What is the lymphatic system?

Functions 

• picks up fluid lost from the capillaries an returns it to the blood

• defense against pathogens 

•       production, maintenance, and distribution of lymphocytes in the body

• lymphatic capillaries in small intestine absorb fats 

Lymph is the fluid in lymphatic vessels

• tonsils are lymph nodes

• when infection occurs, proliferation of WBCs and causes tenderness in lymph vessels

What are the primary and secondary lymphoid organs?

primary organs:

• Red bond marrow: produce WBCs and B cell mature in bone. more in children

• Thymus galnd: where some WBC mature and is not needed when older

  • bilobed gland above heart

  • largest in children

  • T cells mature here from bone marrow and most stay here

Secondary organs

• spleen 

  • white(produce lymphocytes and antibodies) and red pulp (blood filtering)

  • Contain B, T and Macrophages 

  • upper left region of abdominal cavity (under stomach)

• lymph nodes 

  • small oval shaped structures along lymph vessels

  • contain B T and macrophages

  • common in neck, armpits and groin

What does the lymphatic system do summed up?

• drain excess interstitial fluid

• delivery

  • to blood stream

  • lymph nodes

• disposal

  • phagocytosis of pathogens

• lymph capillaries

  • in all tissues

  • contain openings

  • merge into larger vessels that contain smooth muscles and valves

• Fluid moves due to skeletal muscle contraction like veins 

What is the integumentary system?

skin is part of the first line of defense

• integument

  • protection(water loss, infection, trauma)

  • maintenance of homeostasis (body temp)

  • sensory

  • synthesis of chemicals (melanin and vitamin D)

• Accessory organs include sebaceous glands, sweat glands, hair, and nails

• CONTAINS THREE LAYERS CALLED THE EPIDERMIS< DERMIS, and HYPODERMIS 

What is the epidermis made of and its funciton?

Made of keratinized, stratified squamous epithelium

• keratinocytes- make keratin (water insoluble substance)

  • outermost layer is dead keratinocytes- nonspecific defense

• Melanocytes: makes melanin: role in skin color

• langerhands cells: defense cells

• granstein cells- Control immune system ( dentritic cells)

Also arrector pilli make hair stand up to create a layer of still air close to skin

What is the dermis?

Dense irregular connective tissue

• Elastin and collagen fibers 

blood vessels and nerve ending 

sebaceous and sweat glands 

hair follicles and nails l

What is the hypodermis?

subcutaneous layer and is the layer beneath the dermid

• specialized loose connective tissue (adipose)

• fat: used as insulatory and cushion

What are mucous membranes?

Provide nonspecific immunity

• made of epithelium

• line any cavity open to exterior

• Mouth

  • digestive tract

  • resp tract

  • urinary tract

  • reproductive tract

Secreted by some of the epithelial cells called goblet cells 

• mucous slows down pathogens by trapping

• and this mucous with pathogens is moved out of the body

What do chemical barriers do?

When physical fails, chemical barriers aid

• include

  • sebum or oil from sebaceous glands 

    • acidic and antimicrobial

  • Perpiraition, tears, saliva

    • contain enzyme called lysozyme, a natural antibacterial chemcial 

  • Gastic acid: extremely low pH killing most pathogens

  • Urine and vaginal secretions

    • acidic

  • normal bacterial microbes 

    • outcompete other microbe and protect against harmful pathogens 

What is the second line of defense

phagocytes: WBC that engulfs and destroys foreign agens 

phagocytosis: engulfing foreing material or substances by specialized WBC

Macrophages: Phagocytic WBC that engulfs anything detected as foreign: some trigged by APC

What is the play by play of innate immunity in action?

• pathogen enters the body

  • macrophages arrive

    • release cytokines  (chemical messages) which cause inflammation 

• Complement system now activated

  • attract other phagocytes

  • bind to the pathogen

  • forms the membrane attack complex

    • makes hole in cell wall

  • trigger inflammation

EFFECTIVE AGAINST BACTERIAL INFECTIONS NOT VIRAL

What is inflammation?

Form of positive feedback

Fast and general response to tissue infection or damage

Histamine is release by Mast cells (basophils in the skin) from breaking open from trauma

• cause vasodilation and capillaries are more permeable (lead out fluids causing edema and pain due to pressure)

Increased blood flow causes warmth and redness

• may inhibit some pathogens 

increased blood flow brings more leukocytes 

• neutrophils are the first to damage- phagocytosis 

Neutrophils release cytokines to calle for more leukocytes including macrophages

• Chemotaxis: movement or organism or cell due to chemical stimuli

What are the key indicators of inflammatioin?

Heat, redness, swelling, pain, and Loss of Function

What happens in the second line of defense with a viral infection?

Interferons

• interfere with viral infection by attacking virally infected cells 

Signal released by a virus infected cell

• bind to receptors on nearby uninfected cells 

• inhibit protein synthesis and cause RNA degredation

  • neighboringWhat is  cell is now resistant to viral infection

What is a fever?

defined as a change in the body’s temperature set point

results in an elevation of basal body temperature above 37 degrees celcius or 98.6

proteins called pyrogens reset the body’s thermostat ot a higher temp

• macrophages release interleukins (pyrogens)

• stimulate the brain to release prostaglandins- lipid based

  • rise the temps set point 

• increase metabolism to support immune cells 

• fevers above 42 degrees C or 107 F are medical emergency

How does a fever harm pathogens directly and indirectly?

prevents growth at higher temps

aids defensive mechanisms by raising the metabolic rate

Elecated temperature: enzymes repair processes work faster, cells move more quickly, and specific immune cells are mobilized more rapidly

What is the third line of defense?

Adaptive or acquired immunity

specific defenses

• protects against a specific pathogens 

• protects against cancer

• dependent on B and T cells (lymphocytes)

  • Recognition or self V nonself

  • specificity: each B and T cell makes receptors for one kind of antigen

  • diversity: B and T cells collectively may have receptors more more than 2 Billion antigens 

  • Memory: some B and T cells first formed held in reserve for future needs

How to lymphocytes become specialized for different roles?

Effector cells: respond immediately

Memory cells: Set aside for a second or third encounter

Plasma cells: make antibodies 

What are the two types of effector T cells?

Helper T cells: used in both responses and use signaling to help with B, T, and Macrophages

cytotoxic T cells: Killer T cells: produced in the bone marrow and go the the thymus gland for development. Part of cell mediated immunity

What are the two methods for combating pathogens in the third line of defense?

Antibody mediated ( or humoral) acquired immunity 

• B lymphocytes create disease fighting compounds called antibodies 

Cell- mediated (cellular) acquired immunity

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

What do the different types of lymphocytes do?

B cells: produced in bone marrow, sent to lymphatic system

• produce antibodies: antibody mediated immunity

Cytotoxic  (Killer) T cells 

• produced in bone marrow and go to the thymus gland for development 

• cytotoxic T cells: cell mediated immunity 

Helper T cells

• used in both types of responses

What are MHC complexes?

Major histocompatability genes code for these proteins

• some of these proteins stick out of cell membranes 

• T cells have receptors that recognize them

Lymphocytes have receptors on their cell membranes 

• detect the exact antigen

Each lymphocyte receptors are specific to only one antigen

• will ignore all others

What are antigen presenting cells?

The include macrophages and dendritic cells (phagocytic cells)

Enzymes break antigen into pieces 

pieves join with the MHC markers (antigen-MCH complexes) and move to plasma membrane

Helper T cell binds, release cytokines 

• B and T cells activated in large numbers

Helper T cells can bind and release cytokines and stimulate proliferation

Plasma cells make more antibodies 

What are the important aspects of antibodies?

shape of antibodies

diversity and specificity or antibody mediated immunity

Binding of antigens

How are B cells activated?

When antibodies bind, B cells divide

Helper T cells produce cytokinds

B cell descendants become memory B cells or plasma cells (effector B cells) and release thousands of antibodies

What happens after antibodies bind to antigens?

neutralization- clumping of microbes- stick to antigens- activate complement system- cells lysis

clumping of microbes and sticking to antigens enhances phagocytosis 

What are immunoglobulins and the different types

proteins produced by B cells- various shaped Antigen binding sites: other sites with special roles

types 

Ig M: first formed in newborns and first infection Group of 5

IgD: found on the surface of immature B cells

IgG: Main antibody in circulation

IgA: found in milk and saliva

IgE: parasitic infection and allergic response found of basophils, mast cells, esosinophils 

Responses by antibodies can’t reach threats _________ cells 

inside cells like infected cells

What does an APC do?

presents an antigen to a t cell

• helper T cells and cytotoxic T cells 

Tragets: viruses, bacteria, some protozoa and some fungi and cancerous cells

What do cytotoxic T cells do to attack target cells?

release perforins

Cytotoxic T cells have vacuoles containing granzymes and perforins 

• these perforins punch holes in target cells 

• followed by granzymes that cause the cell to undergo apoptosis

What are natural killer cells?

Some T lymphocytes differentiate into NK cells

• attack virus- infected cells and tumor cells, killing through cell to cell contract

NK are acturally a part of the nonspecific immune response 

they remove all foreing of infected cells in the same way

they make holes in cells thus killing them

• similar mechanism is used by cytotoxic T cells 

They do not respond to immunization or produce clones of memory cells

What are the two types of immunity? What are the two types of immunity for each of these situations?

ability to combat disease

• natural immunity- through an infection

• artificial immunity: through medical intervention

two sub categories

• active immunity: makes own antibodies (natural infection arfiticial vaccine)

• passive immunity: given prepared antibodies

What is immunological memory?

• Memory cells provide many years of immunity to a pathogen

• effector cells form during primary immune response

  • memory T and plasma cells form during a second adaptive response

  • memory cells determined by the type of antigen exposure

What is the advantage of active immunity?

it creates memory cells

• produced during primary response remain in the body for years until the same antigen reappears- start secondary response

• second response is faster because immune system only needs to stimulate the specific memory cells

What is active immunization?

Vaccine first injection+ booster shot

• killed or extremely weakened pathogens

• inactive forms of natural toxins

• transgenic viruses

What is passive immunization?

injections of purified antibodies

How does the covid vaccine work?

A small portion of the spike protein gene is introduced into you cells and the cell then reads that sequence to build the spike protein

your cell breaks down the spike protein into fragments and then presents on its surface

The mRNA introduced from the vaccine is later destroyed by the cell

when vaccinated cell dies, it will leave behind debris from the spike protein

that debris can then be engulfed by an antigen presenting cell and presents on the cell membrane

the APC presents the spike protein to helper T cells which then raises the alarm for fighting infection

Activated B cells will start to divide and pour out antibodies to target the spike protein on the surface of the coronavirus

APcs can also activate killer T cells to seek out and destroy the infected cells which are displaying the spike protein on their surface

What are allergies?

Harmless substances that provoke an immune attack

Common allergens 

• pollen

• variety of foods and drugs

• dust mites

• fungal spores

• insect venom

• ingredients in cosmetics

What is anaphylactic shock

whole body allergic response in the blood stream and can be fatal with extreme vasodilation.

What is the small intestine?

An inch and a half in diameter 

• 20 feet long

• Absorbs nutrients through villi that move substances into the bloodstream

• epithelium of villi

  • each epithelial cell has about 1700 microvilli

  • also called the brush border

• Submucosa extends into the lumen creating these big folds called villi

What are the accessory organs of the digestive tract?

the pancrease, liver, and gall bladder

What does the pancreas do for the digestive tract?

• pancreas produced key digestive enzymes

• - located behind and below the stomach

• four types of pancreatic enzymes

  • target carbohydrates, proteins, lipoids, and nucleic acids

  • enzymes work best in neutral pH or slightly alkaline

  • pancreas creates bicarbonate to neutralize the acid of the stomach

    • to protect tissue and allow the enzymes to work

What does the liver do for digestion? what does the gall bladder do?

sits in the curve of the stomach

makes bile

• used in fat digestion

rids body of excess cholesterol and biliruben from dead red blood cells

synthesizes important proteins in blood plasma and converts potentially toxic ammonia to urea

stores some excess blood glucose as glycogen

removes hormones that serve their functions from blood

remove ingested toxins such as alcohol from blood 

stores some vitamins and minerals

the gall bladder stores bile and is a smooth muscle sac that injects into the small intestine when needed.

How does the liver get bile to the area it needs to?

liver has a duct specifically called the common bile duct and once the duct fills with bile excess spills into the gall bladder until it contracts and spills into the duodenum

Does the pancreas have ducts?

The pancreas has many ducts where they contain endocrine cells secreting hormones and exocrine cells secreting enzymes into the duodenum through ducts

A sphicter at the end of these ducts called the sphicter of odie.

• chime apearing in the duodenum is the stimulus for opening that sphincter

Acini  are the cells found in the pancreas that secrete into the ducts enzymes and bicarboneate

hepatopancreatic sph

What does the liver do?

The live processes incoming nutrients into substances required by the body

• hepatic portal system

  • diverts blood from small intestine into the liver

  • vein that connects the capillary bed of the small intestine and the colon to the capillary bed of the liver and the liver processes the nutrients

• removes alcohol and ammonia (converted to urea)

• inactivates many hormones

• takes up billiruben (heme group minus the iron)

  • pigments formed by aging or damages RBC and is a part of bile

• If the liver has to process a ton of alcohol the billiruben can circulate at high levels and causes a person to turn yellow

Study the GI tract. What is the hepatic portal vein? What is a gall stone

All of the veins from the stomach, the spleen, the large intestine, small intestine, and pancreas fuse into one big vein called the hepatic portal vein to the liver which converts monosaccharides into glycogen, amino acids into plasma protein or secrete. excess amino acids can be converted to ammonia and urea or long chains of fatty acids.

When too much bile is produced and stored for too long in the gall bladder. Also can be caused by too much cholesterol

What are the parts of the small intestine?

Duodenum

• regulation: begins process of digestion bc it takes time

• first section of the small intestine

• entering chime triggers hormone signals that stinumate the release of digestive enzymes

Jejunum

• next section

• most digestion and nutrient absorption occurs here

Ileum 

• last section

• catcher of what is left over and finish the rest of the digestion

What is digested in the small intestine?

• fats (lipases)

• carbohydrates

• proteins and peptides

Bile salts in bile make fat digestion easier

• emulsify large fat globules into smaller ones (emulsification)

• fat and water don’t mix and most of the body is water and they tend to clump (amphopathic bile salts)

What is segmentation in the small intestine?

smooth muscle rings repeatedly contract and relax (only circulatory muscle)

mixes digested material and allows for mechanical digestion

What are the enzymes that digest each macromolecule and where?

Carbs

• salivary amylase: salivary glands; mouth and stomach active; breaks down polysaccharides; results in disaccharides and oligosaccharides

• pancreatic amylase: pancrease: small intestine: polysaccharides: disaccharides and monosaccharides:

• disaccharidases

Trypsinogen and chymotrypsinogen are activated in the lumen of the small intestine at a neutral ph

LOOK AT TABLE TO FINISH

What provides the energy for the active transport of monosaccharides?

The movement of sodium down its concentration gradient

How are lipids transported across the lumen? protein?

protein into amino acids and active transport.

• fats go to free fatty acids and monoglycerides

  • they diffuse across the plasma membrane because they are fat soluble into the brush border cells

  • in these they are converted to triglycerides

  • these are then covered with proteins and form lipoproteins (chilomicrons)which are expelled by exocytosis into the tissue fluid

    • these are too big for capillaries and are take by the lymph vessels which carry them back to the blood stream where generally taken by the liver and converted to LDL

• Fat absorption in the small intestine involves emulsification by bile, breakdown by lipases, formation of micelles, which ferry products (fatty acids, monoglycerides) to intestinal cells, where they are repackaged into chylomicrons and enter the lymphatic system, while shorter chains go directly to the blood, bypassing the lymph

What is the large intestine and what does it do?

anything not absorbed in the small intestine moves here

• cellulose cant be digested by us but some bacteria can

• bacteria help us get vitamin K

water leaves the colon via osmosis (about 400 mL)

• material gradually concentrated into feces consisting of undigested matter and bacteria (1/3 of the dry weight)

Eating triggers colon to contract and making way for incoming food

• anticipatory reflex

color of feces is from the bile

What are the different parts of the large intestine

the illium of the small intestine connects to the cecum(ileocecal valve and sphincter) (appendix here), the ascending colon, transverse colon, descending colon, sigmoid colon, and through the internal and external anal sphincter and anus and rectum ( combined the anal canal

What is the appendix?

Surrounded by a lot of nerves and could perhapse prime you for an immune response

• immune monitors ingestion

What is the rectum?

Pretty much used for defecation storage

• as streches it triggers a reflex from the spinal cord where the internal anal sphincter which is smooth muscle would relax requiring you to keep it in with the external anal sphincter which is skeletal muscle until the time and place are appropriate  

• less connective tissue

What are the pockets in the colon?

called houstra

The houstration compact the waste material and keep it from moving too quickly to allow for absorption

What are controls over digestion?

Nerves and hormones regulate food digestion

• controls are sensitive to food presence in the GI tract and foods chemcial makeup

• Endocrine cells in the GI tract: many different types secrete hormones

  • secretin (stimutates secretion due to acid and leads to fluid and bicarbonate from the pancreas and also stimuates secretion of bile in the liver), gastrin (from the stomach and more gastric activity like contraction and secretion) , and Cholecystokinin (CCK when material macro nutrients hits the duodenum: enzyme that stimulates movement of the gall bladder to digest fat and the pancreatic enzymes)

  • GIP: gastrin insulinotropic peptide: stimulates the production of the  insulin from the endocrine pancreas when food hits mostly the small intestine

What is a summary of the receptor controls? what are hormone controls?

PLEASE STUDY

• sight smell etc stimulate secretion of saliva

Interic nervous system

What are digestive system disorders?

Heartburn: acidic chyme backs up into the esophagus

• lower espohageal sphicter could become scarred and amount of acid gets worse and worse and leads to GERD

hepatitis: inflammation of the liver, some caused by viruses

• cant process absorbed nutrients as well and leads to malnutrition

cirrhosis: long term inflammation due to heavy alcohol consumption

• liver cells destroyed by ethanol and they die, scarring and collagen is laid down and loss of liver function and lack of plasma protein (destruction of hepatocytes)

What are some colon problems?

Constipation:

• food residues remain in the color too long

• feces become dry and hardern

• typically due to lack of cellulose as they attract water in the feces and allow the waste to move easier

• Can lead to obstruction 

• often caused by lack of fiber in the diet

Diverticulitis

• inflammation of the diverticulla (part of the houstra)

• serious complecations

  • can lead to rupture of the colon into the abdominal cavity

Irritable bowel syndrome (IBS)

• most common intestinal disorder

• symptoms iinclude abdominal pain and alternating diarrhea and constipation

• can be really damaging to mucosal layer

Crohns disease

• damage to intestinal lining

• autoimmune disorder where antibodies attack cells

• can lead to colonic rupture

Colorectal cancer

• one of the most common cancers

• polyps may be an precursor of colorectal cancer: can be biopsied 

What are some malabsorption disorders?

• Lactose intolerance

  • caused by deficiency pf lactase

  • lactose traps water and bacteria can ferment this and produce gases and causes bloating and pain

• ciliac disease

  • gluten intolerance

  • triggers an autoimmune response

  • autoimmune disorder

• CF

  • deficiency of normal pancreatic enzymes for normal digestion and bile 

  • leads to malnutrition

What are some infections of the digestive system?

Diarrhea

• watery feces

• may be caused by intestinal infection or rotavirus

• sphicters open up and stuff moves through quickly with the digestion of a pathogen

Peptic ulcer

• open sore in the stomach lining (due to activity of acid or pepsin) or small intestine

  • anxiety can lead to food just sitting in the stomach and when the acid and pepsin are produced the somach can degrade father and farther and can lead to sepsis

food poisoning

• caused by bacteria such as salmonella

• can lead to amesis or vomiting

How does the digestive system contribute to homeostasis?

Not a homeostatic system but contributes to homeostasis

Breaking down food into nutrients, vitamins, and minerals

• absorbed into the bloodstream

absorbing water

eliminating solid wastes as feces

What are Good Food Choices

Biggest proportion of the plate is vegetables

• green leafy and other colors 

Smallest portion of your plate should be fruit (10-35 percent)

Whole grains should be about ¼

• not as processed due to nutrients

Healthy protein should be about ¼ 

• fish, poultry, beans, nuts and limit the amount of red meat that is eaten

DRINK A LOT OF WATER

What kind of fats?

Consume healthy oils like olive and canola oil

it says limit butter but its not as bad as people liked to believe

use polyunsaturated fats and avoid trans fats 

What are proteins?

• contain 20 amino acids. 

• can make some but requires others from diet known as essential amino acids

• amino acid deficiency can be a result of vegan diets

• most people consume too much protein

  • extra amino acid is stored as fat

• Conditionally essental- humans can make these but during certain stages of life or under certain conditions require us to consume more

Non essental: humans make them

What are the “good” and “bad” cholesterol?

Bad:

• low density lipoproteins (LDLs): more fat less protein

  • carries cholesterol from the liver to other parts of the body

  • can cause deposits in arteries - atherosclerosis

Good:

• high density lipoproteins: less fat more protein

  • carries cholesterol from other parts of the body back to the liver

  • can scavenge lipids desposited in arteries

BOTH NECESSARY BUT PROPORTION MATTERS. REALLY NEED TO GET LIPOPROTEINS TO CELLS AND BACK

What fats should you have in your diet?

Most should be unsaturated and polyunsaturated fats: vital for brain function and they can lower LDL and provide essential fats in your body needs but cant produceitself

limit saturated fats like red meat and cheese: can increase cardiovascular disease and raises bad cholesterol levels

Trans fats: increases risk of heart disease and raises bad cholesterol levels cbecause the high heat changes the chemical composition

What are supplements?

always best to get nutrients though food

we do not know all the details about how nutrients are used or the necessary combinations

most supplements arer poorly absorbed and end up in feces or urine

What is the digestive system?

A long tube where food is broken down and nutrients in it are absorbed

it means the GI tract 

has major and accessory organs lined with epithelium tissue facing the lumen

• and mucus protects food and enhances diffusion

Food moves in one direction

not homeostatically regulated and extends mouth to anus

What are the four layers of the digestive tube?

mucosa: inner layer of epithelial tissue

submucosal layer: connective tissue

muscularis: smooth muscle with two sublayers 

• longitudinal and circular

Serosa: outer layer of thin membrane secrets serous

Contains nerves and blood vessels

What is the interic nervous system?

regulates all GI functions and does not require any input but can be influenced by sympathetic and parasympathetic

How many sphincters are in the digestive system?

There are six main sphincters and are located at junctions between the GI tract sections

control the movement of material in the tube

What is the two sphincters of the esophagus?

Upper esophageal sphincter which is weak and the lower esophageal sphincter ( gastroesophageal sphincter until not

• lower can lead to acid reflux as it is between the stomach and esophagus

phincter muscles relax and open pathways and contract closing them

What are the main steps in the digestive process?

Ingestion: intake of food via the mouth

digestion: mechanicall or chemically breaking down food into their subunits 

mechanical processing and motility: 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 cell via the blood

Elimination: removal of indigestible molecules: defecation

What are enzymes?

Functional proteins that work best under set of optimal conditions

• pH, temperature, substrate, and product levels

• specific for a particular substrate and catalyze a reaction

• names are usually built from name of subsrtrate followed by ASE