biology option D Flashcards
CLASSES OF NUTRIENTS (6)
carbohydrates, proteins, lipids, vitamins, minerals and water
malnutrition
health condition caused by a deficiency, imbalance or excess of nutrients in the diet.
it is caused by improper diet
anorexia, how is it caused, symptoms, etc.
psychiatric illness caused by voluntary (sometimes not) starvation and loss of body mass. the amounts of nutrients consumed are too less of what the body’s energy requires.
results:
There is wasting of muscles, resulting in loss of strength, infertility, hair loss, slow heart rate, poor circulation.
skeletal muscle is digested and heart muscle deteriorates
(breakdown of the heart muscles)
exocrine glands function
produce and secrete substances onto an epithelial surface - on the body or the lumen of the digestive track
what controls the secretion of the digestive juices
mechanical, nervous and hormonal mechanisms.
sympathetic system controls what
FIGHT OR FLIGHT
controls processes involved in responses to danger. it slows down the digestion when there is no food available
parasympathetic system controls what
REST AND DIGEST
homeostasis and processes related to rest and digestion., it speeds up digestion when food is ingested
essential nutrients
those that cannot be synthesized by the body therefore must be ingested as part of the diet.
non-essential nutrients
those that can be made by the body or can be replaced
how to find BMI
kg\m2
iron defficiency and how to get it form
anemia, fatigue, poor concentration, not enough oxygen
get iron from meat and spinach
Vitamin C defficiency and where to get it from
it can get you scurvy - this condition involves bone and blood vessel disease, bleeding in the hands
you can get it from citrus, bell pepers and broccoli
energy homeostasis
process that regulates food intake and energy flow
which part of the brain receives signals from fat cells that they are hungry?
hypothalamus
scurvy symptoms, causes, treatment
causes - not enough Vitamin C
symptoms - joint, muscle or leg pain, teeth falling out, skin bruises easily
treatment - eat vitamin C
PKU symptoms, causes, treatment
treatment - taking a PKU formula to make sure you have enough essential protein
causes- a change in the gene PAH, it makes the acid built up in the body
symptoms - being sick, behavioural dificulties, different skin and color of eyes
rickets causes symptoms and treatment
symptoms - pain, skeletal deformities
causes - lack of vitamin D or calcium
treatment - increasing the intake of vitmain D or calcium
osteomalacia causes symptoms and treatment
causes - lack of vitamin D or calcium
symptoms - pain in the bones and joints, bones break easily, difficulty walking
treatment- vitamin D or calcium, phosphate supplements
concequences of obesity
heart problems, cancer, diabetes
which hormone affects apetite
leptin, it supresses the apetite targeting hypothalamus part of the brain
Determination of the energy content of food by combustion.
First, the mass of the food is being recorded by a scale.
The mass of the water that is going to be heated is measured by a scale.
The temperature of the water is being recorded by the thermometer.
The food is being burned or heated (combusted) below the water to release energy in a form of heat.
measuring the increase of the temperature comparing the initial temperature and the changed temperature.
The energy is calculated by the formula:
Q (J) = Mass of water (g) × 4.2 (J/gºC) (the heat capacity of water) × Temperature increase (ºC)
to find it per a gram of food, you divide by the mass of a food.
calorimeter can be used
which nerves are involved in the digestion
the medulla of the brain sends nerve impulses to the stomach
the stretch receptors of the stomach send nerve impulses to the secretory cells of the gastric glands
mucus cells in gastric pits
secrete mucus
pariental cells in the gastric pits
responisble for gastric acid secretion which aids in the digestion, and control of harmful bacteria
chief cells in gastric pits (explain how the product changes itself)
secrete pepsinogen which is a proenzyme which than changes from inactive enzyme in the acidic environment to an active acid (pepsin) to not digest the cell it is produced in.
pepsinogenbreak down proteins
G-Cells in the gastric pits
secrete the hormone gastrin into the blood it helps fro growth o the gastric mucosal.
which hormones are involved in the chemical control of digestion
gastrin, secretin and somatostatin
mechanical mechanism
chewing, mixing and squeezing food in the stomach, it controls the secretion of digestive juice - the body prepares for some food
chemical mechanism
stomach acids, bile and enzymes
gastrin hormone function and target
is produced by G-CELLS in the lining of the stomach.
function - helps mucosal growth of the gastric
target - pariental cells
Secretin hormone function and target
produced by the S cells (small intestine)
function: regulates growth of epithelial cells in the pancreas, neutralizes pH allowing enzymes in the pancreas to function.
target: pancreas
somatostatin hormone function and target
produced in pancreas, hypothalamus.
function:pancreatic and pituitary secretion (the production and release of enzymes and hormones by the pancreas; Hormones secreted from the pituitary gland), modify neurotransmitters and memory formation in the central nervous system.
role of proton pump inhibitors
they reduce stomach acid secretion (REFLIUXUI)
THE BARRIER - MUCUS, could be broken down for some people, then acid damages the stomach, causing bleeding = ulcer.
other have a problem with the muscle that prevents the acid to come from the stomach = ACID REFLUX
PPIs (proton pump inhibators) are a treatment that bind to a single proton pump (kuris ten pumpavo H+ kad atsirastu acids) and reduce the acid in the stomach - they are replaced and recycled. only acid conditions convert them to an active form
mucus function
protect from the acid damaging the stomach
protect from bacteria (when eating raw meat)
the travel of gastric acids, what is it, where does it come from, etc
hydrogen ions are actively transported, they-re pumped, chlorine follows those positive iones and they meet in the stomach to produce gastric acids:
gastric acids are secreted from gastric pits and stimulates the release of stomach acids.
if stomach pH drops too low (too acidic) gastric secretion is inhibited by secretin or sematostatin
stomach ulcers
because the patien has been eating spicy food or is stressed, there might be too much gastric acids, or helicobacter pylori, they can damage mucus layer, which might developm into a gastric ulcer.
symptoms: stomach pain, heartburn, nausea.
helicobacter pylori where is it what does it do
another cause of gastric ulcers is the presence of this bacteria. it produces toxins that cause continuous gastric production.
treatment:
antibiotics
PPI
cholera causes symptoms and treatment
cause: intestine gets the cholera bacteria from water that has been contamined by feces (poop) of a person that has the bacteria.
symptoms: diarrhea, vomitting, thirst
treatment: hydration
more present in underdeveloped countries
The bacteria produces a toxin that enters and binds to intestinal epithelial cells and causing ions to move into lumen of intestine. Water leaves the cells by osmosis and causes watery faeces.
adaptation of villi
microvilli - increases the surface area
dense capillary network - rapidly transports absorbed products
single layer epithelium - minimises diffusion to the blood
lacteals - absorbs lipids
intestinal glands - release digestive juices
membrane proteins - makes the transport faster of digested materials into epithelial cells.
function of epithelial layer and its adaptation
INTESTINES
apsauginis layer, ziuri kurias cells ileisti kuriu ne, tvirtas.
tight junctions - barrier- separate tissue spaces and regulate selective movement of solutes across the epithelium. mitochondria - for atp for active transports of molecules
pinocytotic vesicles - carries fluid to the cell
the control of gastric secretion (process of food digesting)
person eats a food product, stretch receptors send signals to the brain which triggers the secretion of digestive juices
stomach releases gastrin, which promotes production of stomach acids
intestine releases secretin to stimulate secretion of pancreatic juice and bile
fibre in the intestines
Roughage provides bulk in the intestines to help keep materials moving through the gut. prevents constipation as it draws water into the intestine
Roughage also absorbs water, which keeps bowel movements soft and easy to pass
more water - waster go
liver receives oxygenated blood via
receives via hepatic artery which is used to sustian liver cells
liver receives nutrient rich blood via
portal vein
liver’s deoxygenated blood is transported from the liver via
portal hepatic vein
liver is responsible for
storing glycogen, cholesterol, detoxification, breakdown of red blood cells and the production of bile salt.
liver lobule
- hexogen shaped area of tissue, contains a central vein that drains blood away from the lobule
sinusoids
small blood vessel found in the liver that exchange materials, they have increased permeability to allow larger molecules to enter and leave bloodstream because of gaps
how blood circulates in the liver
oxygenated blood comes from hepatic artery and nutrient rich blood from the hepatic portal vein. they go through lobules. there blood starts to mix and drain through sinusoids. kupfer cells in the wholes gather up the materials that should not be drained (PROTECTS THE LIVER FROM BACTERIAL INFECTIONS). mixed blood gets absorbed by hepatocytes, they also are responsible for detoxication.
Hepatocytes also produces bile.
everyhting drain out the central vein and finally through hepatic vein
bilirubin
a yellowish pigment that is made during the breakdown of red blood cells
it also may damage the newborn baby’s brain because of its toxins that can go through the thin layer between blood and brain
jaundice
a symptom of liver disease. when liver cannot process bilirubin it goes to the blood causing jaudice - men’s skin becomes yellow, eye whites too.
treated only when recognizing why it has happened: liver disease, damage to red blood cells, something to the gallbladder.
treatment to remove bilirubin involves exposure to ultraviolet light, either to sun or special “bili” lamp.
it is very dangerous to babies because it may cause brain damage, and in adults, they normally just experience itchiness.
bile and bile salts
made in the liver stored in gallbladder, it helps with digestion. made as a part of natural breakdown of hemoglobin, normally liver makes other chemicals rom it and secretes it in bile, but it may leak out
bile salts break fats down
product of the breakdown of red blood cells
when red blood cells age, they are engulfed by Kupffer cells. the molecule is split into globin chains and a heme group. globin chains are recycled, and heme group is further broken down into iron and bilirubin. The kupffer cells release bilirubin into the blood. the iron is transported to the liver for storage or to the bone marrow for synthesis of new blood cells.
features and functions of cardiac muscle
Cardiac muscle cells contract without stimulation by the central nervous system (contraction is myogenic)
Cardiac muscle cells are branched (Y-shaped), allowing for faster signal propagation and contraction in three dimensions. INTERCONNECTINESS
Cardiac muscles cells are not fused together, but are connected by gap junctions at intercalated discs. this porvides rapid movement of ions, low electrical resistance.
Cardiac muscle cells have more mitochondria, as they are more reliant on aerobic respiration than skeletal muscle
have one nuclei
being interconnected because of their Y-shapes and being electrically connected due to gap junctions allows wave of depolarization to pass easily from one cell to a network of cells leading to a synchronized contraction of muscle.
signal traveling to contract the heart
sinoatrial node (SA node, or pacemaker) in the right atrium is triggered, it sends signals to atrioventicular node (AV ). Atria contracts (atrial systole). signals from AV node are sent triggering purkinje fibres in the walls of the ventricles and ventricles contract. atriocentricular valves shut! after the ventricles are meptied the semilunar valves close.
hypertension causes and consequences
causes: unhealthy lifestyle choices such as not getting enough physical activity or too much stress.
consequence: damage to the heart and coronary arteries, including heart attack.
thrombosis causes and consequences
causes: when there is too much LDL, the plaques are forming, they might damage the coronary wall and then blood clots and blocks the vein or artery
consequences: pain, chest pain, stroke or heart attack
artificial pacemaker
a medical device that delivers electrical impulses to the heart in order to regulate heart rate
treating:
Abnormally slow heart rates
defibrillator
Fibrillation is the rapid, irregular and unsynchronised contraction of the heart and is treated with deibrillator applying controlled electrical current to the heart
it depolarizes the heart so it can ‘start’ beating again.
ECG - ELECTROCARDIOGRAM
shows the the heart rate, sees how often does it contract
vitamins - functions, what are they
organic molecules, acts like deoxidatns and regulates hormones
Vitamins - water soluble and fat soluble
water-soluble - have to be constantly consumed and any excess is lost in urine.
fat soluble - can be stored in the body
type 1 vs type 2 diabetes
auto-immune destruction of insulin-secreting cells in the pancreas (type 1) pancreas does not make - secreted by beta-cells
decreased responsiveness of body cells to insulin due to burn-out (type 2 diabetes) - injections of insulin
Passage through which food passes from month to anus
alimentary canal
endocrine vs exocrine glands
endocrine - secrete directly into the bloodstream,
exocrine - secrete into ducts (a tube, canal, or vessel conveying a body fluid)
insulin vs glucagon hormone
Glucagon helps prevent blood sugar from dropping, while insulin stops it from rising too high.
glucagon released by alpha cells
insulin secreted by beta-cells
cholesterol’s role in the body
synthesis of vitamin D, steroid hormones, production of bile and component of membranes.
cardiac muscles vs skeletal muscles
cardiac are shorter and wider, most commonly have just one nucleus per cell.
features of AV node that lead to the delayed initiation of contraction.
has a more negative resting potential
fewer gap junctions between the cells
why the delay in conduction is good?
it ensures that the atria contract and empty the blood they contain into the ventricles first, before the ventricles contract.
if the contraction of ventricles would happen too early, it would lead to too small a volume of blood entering the ventricles.
the sound of the heart
when atrioventricular valves close, there is a first sound, when the semilunar valves close, there is the second sound
glycogenesis
glucose converted into glycogen
glycogenolysis
glucagon is carried in the blood and glycogen is broken down
