F2 Organ systems Flashcards
describe how oxygen is transported in the gas exchange system
- from lungs to tissues
- carried by haemoglobin in red blood cells
describe how carbon dioxide is transported in the gas exchange system
- from tissues to lungs as bicarbonate dissolved in the blood
where do nutrients / waste products need transportation between by the circulatory system?
- between tissues and sites of absorption, synthesis or excretion
give an example of a site of absorption of nutrients in the circulatory system
GI tract
give an example of a site of synthesis of waste products in the circulatory system
liver
give an example of a site of excretion of waste products in the circulatory system
kidney
how can cells communicate at long range?
via hormones
give 3 examples of defence mechanisms
- white blood cells
- antibodies
- clotting machinery
state the body parts involved the systemic circulation in order
left ventricle
aorta
body tissues
vena cava
right atrium
describe what happens in the systemic circulation system
oxygenated blood goes to the tissues where it is deoxygenated then it is taken back to the heart
state the body parts involved the pulmonary circulation in order
right ventricle
pulmonary artery
lungs
pulmonary vein
left atrium
describe what happens in the pulmonary circulation system
deoxygenated blood is taken to the lungs where it is oxygenated then it is taken back to the heart
simply describe the structure of cardiac muscle
- type of striated muscle
- made of contractile cells (myocytes)
how are the structures of cardiac and skeletal muscle similar?
- cardiac is striated and made of contractile cells (myocytes)
- skeletal is striated and made of contractile cells (not called myocytes)
how is the heart muscle supported, give an example
- supported by network of coronary blood vessels
- eg. left coronary artery
what feature of the network of capillaries in the body allows for efficient exchange?
large surface area
what does the network of capillaries have a large surface area between?
- blood plasma
- tissue interstitial fluid
why do the capillaries need a large surface area?
- for nutrient / gas exchange
what is the function of the lymphatic duct system?
- drains excess interstitial fluid to circulation
- has role in immune defence (lymph nodes contain white blood cells)
how can the lymphatic system have a role in the immune system?
the lymph nodes contain white blood cells
what does the spleen do?
acts as red blood cell store and large lymph node
describe the cross-section of an arteriole
- particularly muscular
- endothelial cells line the inner vessel wall
describe the function of the circular smooth muscle in the arteriole walls
- contraction decreases vessel diameter which regulates blood flow to different tissues (eg. changes in posture / exercise)
- contraction changes the size of the lumen which is used to control blood flow and blood pressure
state the order of body parts in the airways
trachea
bronchi
bronchioles
alveoli
how is the airway diameter controlled?
- controlled by circular smooth muscle (especially of the bronchioles)
what drug can the smooth muscle in the airways be targeted by?
salbutamol (a common asthma drug)
where are oxygen and carbon dioxide exchanged?
- between air in the alveolar ducts / sacs and the network of surrounding capillaries
what is the function of the GI tract?
digestion and absorption of nutrients
what is the site of absorption of orally administered drugs?
GI tract
what is the function of the salivary glands?
- fluid secretion
- lubricates food as we chew
what is contained in the fluid secretion of salivary glands and what is its function?
- amylase
- starts partial digestion of carbohydrates in the mouth
describe the stomach in the GI tract and its function in the digestive system
- contains pepsin (protein enzyme)
- highly acidic
- mechanical dispersion
describe the duodenum in the GI tract and its function in the digestive system
- main site of digestion
- lipid emulsification via bile (from the liver)
- trypsin, amylase, lipase etc. (mainly from the pancreas)
describe the jejunum / ileum (small intestine) in the GI tract and their function in the digestive system
- absorption of digested nutrients
- main site of absorption
describe the function of the colon in the digestive system
- fluid / water reabsorption
what are villi and what are they lined with?
- invaginations on the surface of the GI tract
- villi are lined with epithelial cells
what are the roles of intestinal epithelial cells?
- lining / diffusion barrier
- fluid / ion transport
- transport processes for nutrients
what do intestinal epithelial cells have and what is the purpose of these?
- microvilli
- further increase surface area for diffusion and absorption
in the GI tract, what is the purpose of the circular smooth muscle layers?
- provide muscular support and control
- coordinates peristalsis
what is peristalsis?
- movement of gut contents along the GI tract
how are enzymes in the pancreas transported to the intestine?
- the pancreas has a duct leading to the duodenum
- enzymes produced in the pancreas are secreted down this duct
describe exocrine glands
- what are they formed by?
- what do they do?
- example
- formed by acini cells (enzyme secretory cells)
- release contents to a body surface eg. gut lumen
- eg. pancreatic enzymes
describe endocrine glands
- what do they do?
- example
- release contents to the blood circulation (especially hormones)
- eg. pancreatic islets produce insulin / glucagon
give some examples of essential functions the hepatic system performs
- glucose storage (as glycogen)
- processing of red blood cells
- bile production
- metabolism of drugs / toxins
give an example of a function that the renal system carries out
- fluid, salt and waste product excretion
pharmacologically, what do the hepatic and renal systems work together to control?
drug concentrations in the blood
what are glial cells? give an example of one of their functions in the CNS
- perform several supporting roles for neurons
- eg. production of an insulating myelin sheath
what does a myelin sheath allow for?
allows for saltatory conduction and faster transmission of electrical impulses
function of a synapse in the CNS
release of neurotransmitter to stimulate next neuron / target cell
function of axon in the CNS
propagates electrical action potential
function of dendrite in the CNS
receives input from other neurons
function of cell body / soma of a neuron
storage of the nucleus and mitochondria
