quiz 2 Flashcards
what layers are visible upon centrifugation of blood?
plasma, leukocytes and erythrocytes
Blood vessel A is three times the diameter of blood vessel B. Compare their resistance and flow
Resistance in vessel A is 1/81 that of vessel B as resistance = 1/(r^4). Flow in vessel A is 81 times that of vessel B as flow = r^4
What is the function of Type I cells in the lungs?
they’re the cells in alveoli across which gas exchange occurs
what are the three germ layers?
ectoderm, mesoderm, endoderm
what are the three structural types of capillaries?
continuous, fenestrated and sinusoids
what are capacitance vessels?
blood reservoirs that contain 65% of the blood supply
Describe endospore structure
Endospores are structurally complex. They’re enriched with calcium ions. They contain dipicolinic acid and their core contains SASPs (small acid soluble proteins)
What is serum therapy?
Passive antibody therapy first used in the 1890s. Antibodies are specific to the pathogen and are taken from an immunised individual. It can show lot to lot variation
what type of blood cell is the first line of defence in the body’s immune system?
granulocytes
describe some of the functions of the gut microbiota
- de-polymerisation of complex carbohydrates
- produce glycosidehydrolases and polysaccharide lysases
- ferment saccharides as the main source of energy for intestinal epithelial cells
- synthesise essential amino acids and vitamins
why is folic acid recommended to pregnant people?
advised to be taken when trying to get pregnant and up to 12 weeks pregnant to significantly reduce risk of neural tube defects eg spina bifida
what is the heart’s natural pacemaker in a healthy individual?
the sinoatrial node. Found in the wall of the right atrium and produces an electrical impulse that travel through the heart and cause contraction, setting the rhythm of the heart
what is the main factor affecting peripheral resistance in blood vessels?
the degree of constriction of the arterioles (arteriolar tone)
what is emphysema?
long term progressive disease that causes alveoli sac to break and burst. It also damages the bronchioles leading to difficulty in emptying gases from the alveoli. Therefore, gas exchange sites will be lesser than the normal healthy person. Smoking is known to increase the risk of developing this condition.
What affects blood pressure?
blood volume, peripheral resistance and cardiac output
what is the typical blood pressure in a normal healthy individual?
120/70 mmHg
outline the order of human evolution
Primates -> Hominidae -> Homininae -> Hominini -> Humans
According to molecular data, when did humans and chimps share a common ancestor?
5 to 8 million years ago
what does an embryoblast go on to form?
an embryo
What is the function of the SRY gene?
it codes for a transcription factor which regulates the gene producing anti-Mullerian hormone
what is a primary endocrine organ?
organ with main function being to secrete hormones
what is a secondary endocrine organ?
an organ which secretes hormones but that’s not its main function
outline the order of how life on Earth is thought to have begun
simple molecules (eg elements) -> complex molecules (eg lipids/proteins) -> organisation into cells -> replication -> complex biological pathways
Which scientist proposed the ‘Primordial Soup’ theory?
Alexander Oparin
What is asthma?
Chronic inflammatory disease of the airways where the smooth muscle around the bronchioles contracts more than normal. Increased mucus production limits airflow in and out of the lungs.
how many children and adults are affected by asthma in the UK?
approx 1.1 million children and 4.3 million adults
how is asthma treated?
using beta-adrenoreceptor agonists eg Salbutamol
how many people in the UK are affected by emphysema?
1.2 million
outline the visual pathway
retina -> optic nerve -> optic chiasm -> lateral geniculate body -> primary visual cortex
what will excess secretion of thyroid hormones lead to?
weight loss as thyroid hormones play a role in determining the basal metabolic rate
what type of relationship is seen between fungi and algae in lichen?
Mutualistic as the fungi provide protection and structure and the algae produce organic matter
what is a commensal relationship?
a relationship where one organism benefits and the other is neither benefited or harmed
function of ADH
causes urine to become more concentrated by increasing water reabsorption in the DCT by inserting aquaporins
why does the thyroid gland require iodine?
to synthesise thyroid hormones T4 and T3. Iodine deficiency can lead to cretinism
