Chapter 3: Transport Flashcards
What determines nature of cells work?
Genes
Tissues form _______
Cells form _______
Organs form _______
Tissues form organs
Cells form tissues
Organs work together as body systems
Which is the largest organ in our body?
Skin
What supplies tissues?
Body fluids
Describe the cardiovascular system
Blood carries water-soluble nutrients from small interstine to liver to heart via veins and CO2 is removed and O2 is exchanged in alveoli in lungs. De-oxygenated blood flows to kidneys where waste is removed by nephrons and excreted in urine.
What does lymph do?
Lymph carries fat-soluble nutrients from small intestine to the thoracic duct through the bloodstream near the heart
What is the role of arteries?
Carry oxygen and nutrients to tissues
How does blood circulate among cells?
Capillaries exchange oxygen and nutrients between cell fluid and extracellular fluid
What are fat-soluble nutrients converted to?
Chylomicrons in the lymph vessels
Which hormone regulates blood glucose?
Insulin (brings glucose level down) and Glucagon (brings glucose level up- RECEPTORS IN LIVER)
What is the hunger hormone?
Grehlin
What is peristalsis?
Movement in muscular walls in the digestive system
What happens during fight or flight response?
- analgesic response: pain-numbing chemical
- digestive system shuts down
- liver releases extra glucose and fat for energy
- insulin resistant so glucose level rises
- muscles tense/ heart rate rises/pupils dilate
What is CHO, protein and fat broken down into
CHO- monosaccharides
Protein- Amino Acid
Fat- Fatty acid+ glycerol
What is the oesophagus lined with?
Thin mucus membrane to protect from hot or sharp food
What is the role of the stomach?
- churns and mixes food to liquid mass (chyme)
- 3 layers of muscle
- controlled by cardiac sphincter (allows food into stomach) (not true valve)
- Pyloric valve (food into small intestine)(true valve)
- adds HCL, pepsin and gastric juice
Why does our stomach not get damaged from HCL?
Mucus protects stomach wall
What happens in the stomach?
HCL denatures protein then pepsin breaks it down
What injures mucus membrane?
H. Pylori and lifesyle choices
What is heartburn?
- Oesophagus is burning due to backflow of stomach acid
- Take antacids for treatment
Which is the major site of digestion?
- Small Intestine
- Pancreas secretes bicarbonate that nutralises stomach acid
- Pancreatic juice creates lipase (digests lipids) and protease (digests proteins)
Where is the presence of bile?
- synthesised in liver
- stored in gall bladder
- enters small intestine via bile duct
- bile emulsifies ( forces fatty parts to mix with water)
What does villi and microvilli do?
Increase surface area of small intestine
What is the role of the large intestine?
- Reabsorbs water and minerals
- passes waste and some water to rectum
How to reduce problems in the lower gut (diarrhoea, constipation and intestinal gas)?
More fibre and activity
Where is fat and CHO stored?
Fat: adipose tissue
CHO: Glycogen in liver and muscles
What is alcohol?
- Lipid solvent
- Denatures cells protein structure
- ethanol
- Toxin because calls die when denatured
Is alcohol a nutrient Does it provide energy?
No
Yes
How does alcohol enter the body?
- Diffuses through stomach wall to bloodstream
- absorbed into small intestine
Physical effects of alcohol?
- Increased urine output
- Mineral loss
- collects in liver
- flows through body and brain (fast drinker)
How is alcohol connected tot he brain?
- Depressant (sedates nerve cells)
- Judgement and reasoning, voluntary muscle control, heart action
- passing out helps against lethal dose
How is alcohol connected to the liver?
- liver detoxifies
- 80% alcohol dehydrogenase (ADH)
- 10% MEOS system (increases tolerance)
- 10% excreted through breath and urine
- Stimulates fat synthesis in liver
What are the impurities in alcohol called?
- Congeners
- cause hangover (dehydration and rehydration of the brain and accumulation of formaldehyde)
Long-term effects of alcohol?
- liver deteriorates
- synthesis of blood lipids increase
- toxic to muscles
- increased BP
- dementia
- Increased cancer risk
- increased death risk
Health effects of wine?
- Lowers high BP
- May protect against heart disease
- Purple contains phytochemicals
- In elderly people, small doses of wine may improve appetite
