Y1 AFL 2020/2021 questions

how is the proxima radioulnar joint classified by its shape?

pivot joint

which one of these enzymes unwinds supercoiled DNA?

topoisomerase

Outline the movement of chromatids during meiotic division?

in the first meiotic division, unlike mitosis, sister chromatids migrate as a pair to the same daughter cell

DNA polymerases copy information from ...

the template which is read 3' to 5'

the nucleolus is the site of what?

ribosomal RNA synthesis

which molecules act to connect the pathways of glycolysis, TCA cycle and the electron transport chain?

ATP, pyruvate, NADH and O2

in the absence of oxygen, TCA cycle will ...

slow down because of decreased NAD+ concentrations

what Superfamily of receptors found primarily in bacteria and yeasts may have a role in pathogenicity of the latter?

histidine kinase

which one of these signalling systems may have a role as a tumour suppressor by means of the 'bystander' effect?

juxtacrine

Hardening of zona pellucida known as cortical or zona reaction is a direct result of what?

contact between plasma cell membranes of the sperm and oocyte

stem cells located at the bottom of the colonic crypt are ...

multipotent

What is a key feature of necrosis compared to apoptosis?

necrosis is characterised by a loss in membrane integrity

the process of cell proliferation coordinated by the. cell cycle is regulated by ...

the expression of cyclins

during which phase of mitosis does chiasma occur?

prophase 1

how many cervical spinal nerves are there?

8

DNA replication/new strand synthesis occurs in what direction?

5' to 3'

How many thoracic vertebrae are there?

12

A primary spermatocyte contains how many chromosomes?

46

How many chromosomes does a spermatid have?

23

Where is inhibin produced in males and females?

Males - Sertoli cells (testes)

Females - Granulosa cells (ovaries)

What forms the blood testis barrier?

tight junctions between sertoli cells

A bacterial infection due to contaminated food or water is an example of what type of transmission?

Vehicle transmission

At what stage in life is spermatogenesis initiated?

at puberty

How would you best describe an aneuploid cell?

a cell with a numerical abnormality of chromosomes

Glucagon is an example of what?

A catabolic hormone

What is the function of pancreatic polypeptide?

inhibit pancreatic secretions (insulin and glucagon)

Aspirin inhibits the synthesis of prostaglandin from which acid?

arachidonic

Articular cartilage is formed by which of the following?

chondrocytes

Which of the following cells acts as mechanoreceptors in the epidermis of the skin?

Merkel cells, Ruffini, Meissners and Pacinian corpuscles

What does polygenic mean?

Many genes influence one phenotypic trait

Which steroid hormone is responsible for the control sodium homeostasis?

aldosterone

The foramen transversarium allows the passage of which artery?

vertebral artery

What is the pentose phosphate pathway?

cytosolic pathway that completely oxidizes glucose to CO2, but neither produces nor consumes ATP

Which molecule is released upon opening of voltage gated Ca++ channels at the end of an axon?

Acetylcholine

What is the function of tyrosine kinase receptors?

important mediators in key signalling pathways like differentiation, metabolism and apoptosis

What feature of phospholipids' structure determine its biological properties?

length of fatty acid tail

Which of the following describes the mechanism of action of propranolol?

antagonist of the beta adrenergic receptor

What is released due to low oxygen levels in the renal circulation?

Vasopressin (ADH)

What is released due to decreased serum calcium (hypocalcaemia)?

parathyroid hormone

What is released due to decreased delivery of sodium and chloride ions in the macula densa?

Renin (for the RAAS system)

This connective tissue has sparse, irregular network of collagen fibres and elastic fibres suspended within a large amount of ground substance

loose areolar tissue

What type of epithelium refers to a single layer of cells but the nuclei are at different places in each cell

pseudostratified columnar

What is the first layer the sperm cell has to penetrate to fertilise the egg

corona radiata

Which of these processes accurately describing hatching?

on day 5, the blastocyst is released from the zona pellucida to allow for implantation

Which of the following best describes MHC class 1 cells?

found on all nucleated cells and works with CD8+ to endogenously process pathogens

Which of these antibodies are found in mucous/secretions

IgA

This substance is a precursor of most sex hormones and is synthesised from cholesterol.

pregenelone

Pregnancy is a state of what ...

compensated respiratory alkalosis

What structures in an ovary doesn't occur if fertilisation doesn't occur?

corpus albicans (degraded corpus luteum)

the compression of this structure results in altered sensation on the palmar side of the thumb and lateral 2 and a half digits

median nerve

This is the strongest form of cartilage in the body

fibrocartilage

Which class of hormone are important in the production of prostaglandins?

Eicosanoids (derived from fatty acid)

These are released by osteoblasts to cause differentiation of osteoclasts from their precursors?

RANKL

A very important vitamin for the synthesis of collagen.

vitamin C

Which hormone is inhibited by alcohol?

vasopressin (cant retain water)

What hormone causes hepatocytes to produce IGF -1?

Growth hormone (GH) - stimulate lipolysis

Which hormone causes germ cell development?

FSH

This part of the male urethra passes through the deep perineal pouch

membranous

What nerve is most likely to be damaged with foot drop in the leg?

deep fibular nerve

Posterior compartment of the leg is innervated by which nerve?

tibial nerve

What is a derivative of penis in males and clitoris in females?

genital tubercle

The process of indroducing an antigen to induce a production of antibodies in a host

active vaccination

an agent that activates Toll like receptors on innate immune cells such as dendritic cells to modulate an immune response

adjuvent

Which best desribes the canalicular stage of lung development?

the lumen of the bronchi and terminal bronchioles become larger and highly vascular

This artery supplies the adductor magnus, brevis and longus

profunda femoris (medial compartment)

These cells of the kidney contain a brush border and are important for the reabsorption of glucose

epithelium of PCT

this nerve provides parasympathetic innervation to the bladder?

pelvic nerve (autonomic innervation)

Which ion channel in the heart are blocked by local anaesthetics?

voltage gated fast Na+ channels

Which protein influences a developing protein to become a biological male?

SRY protein

which of the following best describes eGFR?

how much fluid passes from capillaries across basement membrane into the bowman's space in both kidneys per minute

At which stage of meiosis do egg cells arrest at before birth?

prophase 1

the anamtomoses of the sphenopalatine, anterior and posterior ethmoidal and superior labial arteries form which structure?

Little's area

at which spinal level does the upper pole of the right kidney lie?

T12

What connects the liver to the diaphragm?

Triangular ligaments

what connects the liver to the abdominal wall?

falciform ligament

What is the first layer the surgeon will have to cut through in the gut wall?

serosa (from the outermost from the lumen)

What is the innermost layer of the scrotum?

tunica vaginalis

Where are the D cells in the GI tract and what do they release?

Antrum and somatostatin

What is the outer most layer of the scrotum?

dartos fascia (after skin obvs)

What is bradykinin and what does it do?

hormone released by the kidneys in response to the presence of PGs, ADH, angiotensin II. A vasodilator

Which of the following nerve fibres is responsible for vibration, light touch and proprioception

A beta fibres

Ductal cells in the pancreas are responsible for secreting what?

bicarbonate

Injury of this ligament stops the anterior movement of the tibia?

ACL

What gives stools its brown colour?

stercobilin (converted from bilirubin)

What best describes preload?

volume of blood that the ventricle has available to pump

Which tracts decussate in the midbrain?

dorsal columns/medial lemniscus

which part on an ECG corresponds to the time taken for the action potential to travel through the SAN, AVN and the bundle of His?

PQ interval

Which vitamin is essential in the clotting casacade?

vitamin K

Which of the following factors is made when VwF interacts with Glycoprotein 1a/11a?

fibrinogen

Which of the following cells are responsible for making up the blood brain barrier?

Astrocytes

A lesion in the optic chiasm would lead to what sight abnormality?

bitemporal heminopia

Which of the following nerves controls movement of the neck?

cranial 11 (accessory)

A lesion to which tract would result in a loss of contralateral loss and crude touch and pressure?

anterior spinothalamic tract

Parkinson's disease is due to a reduction of dopamine in which structure of the brain?

substantia nigra pars compacta

One single mossy fibre is able to excite a single granule cell. true or false?

false - multiple have to excite with summation, climbing fibres are the ones where one is required.