BRS MOCK 7 - Brainstem, Pancreas, HNS 1,2

Question 1

What cranial nerves emerge from the midbrain?

Answer 1

Cranial nerves III and IV emerge at this level.

Question 2

What cranial nerves emerge from the pons?

Answer 2

Cranial nerves V, VI, VII & VIII.

Question 3

What cranial nerves emerge from the medulla?

Answer 3

Cranial nerves IX, X & XII emerge from medulla.

Question 4

What tract are cranial nerves part of?

Answer 4

Corticobulbar.

Question 5

Where does corticobulbar tract teminate?

Answer 5

Medulla.

Question 6

What makes up the cerebral peduncles?

Answer 6

Corticospinal and corticobulbar tract.

Question 7

Where are the cerebral peduncles?

Answer 7

Anterior portion of midbrain.

Question 8

What do cranial nerves do once they emerge from corticobulbar tract?

Answer 8

Synapse with nuclei. Neurones from nuclei then go on and innervate structure in head, face, tongue and neck.

Question 9

Which motor pathway has fibres which cross in the medulla? Where in the medulla does it cross?

Answer 9

Corticospinal. Cross over at pyramidal decussation.

Question 10

Where are the descendings tracts in the medulla?

Answer 10

Medullary pyramids (anterior surface of medulla).

Question 11

Anterior CNS blood supply?

Answer 11

Internal carotid system

Question 12

Posterior CNS blood supply?

Answer 12

Vertebrobasilar

Question 13

General somatic afferent nerve fibres function?

Answer 13

Fibres carry general sensation from skin, muscles, joints of head and neck.

Question 14

General somatic efferent nerve fibres function?

Answer 14

Fibres innervate skeletal muscles.

Question 15

General visceral afferent nerves fibres function?

Answer 15

Fibres carry sensation from viscera of head, neck, thorax and abdomen.

Question 16

General visceral efferent nerves fibres function?

Answer 16

Fibres are the preganglionic parasympathetic neurons to cranial, thoracic and abdominal viscera.

Question 17

Special somatic afferent nerve fibres function?

Answer 17

Fibres carry special senses of hearing and balance

Question 18

Special visceral afferent nerve fibres function?

Answer 18

Fibres carry taste sensation.

Question 19

Special visceral efferent nerve fibres function?

Answer 19

Innervate skeletal muscles of the jaw, face, larynx and pharynx.

Question 20

Abdominal accessory organs start out as?

Answer 20

Foregut outgrowths.

Question 21

What do acini in the pancreas do?

Answer 21

Secrete pro enzymes into ducts.

Question 22

What do duct and centroacinar cells secrete into the pancreatic juice?

Answer 22

Bicarbonate ions.

Question 23

What does bicarbonate in the pancreatic juice do?

Answer 23

Neutralises acid chyme from stomach which prevents damage to duodenal mucosa. Raises pH to optimum range for pancreatic enzymes to work.

Question 24

What structures also produce bicarbonate instead of bicarbonate present in pancreatic juice?

Answer 24

Bile from liver and alkaline fluid from brunners glands.

Question 25

How is bicarbonate secrete from pancreatic duct cells?

Answer 25

Carbonic anhydrase catalyses reaction of carbon dioxide with water to produce bicarbonate and H+ ions. Bicarbonate exchanged for chloride ion; bicarbonate enters lumen of duct while chloride enters duct cell. Sodium from blood enters duct cell while H+ enters blood.

Question 26

How is high sodium in the blood maintained?

Answer 26

Na+/K+ exchange pump driven by ATP. Potassium into duct cell while sodium pumped into blood.

Question 27

What drives water into lumen of pancreatic duct?

Answer 27

Sodium moves into lumen of duct down gradient from blood via paracellular junctions and water follows.

Question 28

What channel drives chloride ions return to the lumen of the pancretic duct?

Answer 28

CFTR channel (cystic fibrosis transmembrane conductance regulator).

Question 29

Why is pancreatic venous blood acidic but gastric venous blood is alkaline?

Answer 29

In pancreas H+ ions are released into blood. In stomach bicarbonate ions are released into blood.

Question 30

Digestive enzymes in acinar cells are stored in what?

Answer 30

Zymogen granules.

Question 31

What ensures that enzymes produced in pancreas are only activated once they enter the duodenum?

Answer 31

Trypsin inhibitor and enzymes are secreted as inactive pro enzymes.

Question 32

What is the main enzyme that activates other proteolytic and lipolytic enzymes in the duodenum?

Answer 32

Trypsin.

Question 33

What protein results in conversion of trypsinogen to trypsin? Where is this protein found?

Answer 33

Enterokinase secreted by duodenal mucosa. Found on the duodenal brush border.

Question 34

What does lipase require for action?

Answer 34

Colipase and bile salts.

Question 35

During cephalic and gastric phase what is mainly secreted in the pancreatic juices?

Answer 35

Enzyme rich juice. Lacks carbonate.

Question 36

What is the gastric phase of pancreatic juice secretion?

Answer 36

Pancreatic juice secretion due to food arriving in the stomach.

Question 37

What is the intestinal phase of pancreatic juice secretion? How is it different from the gastric and cephalic phase?

Answer 37

Hormone mediated when gastric chyme enters the duodenum. Both enzymes and carbonate released.

Question 38

What stimulates enzyme secretion in pancreatic juice?

Answer 38

Acetylcholine from vagus nerve and cholecystokinin from duodenal I cells.

Question 39

What stimulates release of cholecystokinin?

Answer 39

CCK releasing peptide due to increase in amino acid and fatty acids in lumen of duodenum. Gastrin releasing peptide.

Question 40

What inhibits release of CCK?

Answer 40

Trypsin.

Question 41

What triggers release of secretin from S cells?

Answer 41

Drop in pH in duodenum.

Question 42

When does CCK affect bicarbonate secretion?

Answer 42

When paired with secretin it can cause a large increase in bicarbonate secretion. On its own has no effect on bicarbonate secretion.

Question 43

What is held within the anterior cranial fossa?

Answer 43

Frontal lobe.

Question 44

What is held within the middle cranial fossa?

Answer 44

Temporal lobes.

Question 45

What is held within the posterior cranial fossa?

Answer 45

Cerebellum and brainstem.

Question 46

What connects the orbit to the middle cranial fossa? What is present in this canal?

Answer 46

Optic canal. Optic nerve, ophthalmic artery.

Question 47

What does the superior orbital fissure contain?

Answer 47

Ophthalmic divison of trigeminal nerve (V1), oculomotor nerve (III), Trochlear nerve (IV), Abducent nerve (VI), Superior ophthalmic vein.

Question 48

What does foramen rotundum contain?

Answer 48

Maxilary division of trigeminal nerve (V2).

Question 49

What does the foramen ovale contain?

Answer 49

Mandibular division of trigeminal nerve (V3).

Question 50

What does the foramen spinosum contain?

Answer 50

Middle meningeal artery.

Question 51

What does the middle meningeal artery supply with oxygen?

Answer 51

Dura mater.

Question 52

What does the internal acoustic meatus contain?

Answer 52

Facial nerve (VII) and Vestibulocochlear nerve (VIII).

Question 53

What does the jugular foramen contain?

Answer 53

Glossopharayngeal nerve (IX), Vagus nerve (X), Accessory nerve (XI).

Question 54

What does the hypoglossal canal contain?

Answer 54

Hypoglossal nerve (XII).

Question 55

What does the hypoglossal nerve innervate?

Answer 55

Tongue muscles.

Question 56

What vein runs over the sternocleidomastoid muscle?

Answer 56

External jugular vein.

Question 57

What are the 2 layers of the dura?

Answer 57

Periosteal and meningeal.

Question 58

What is the largest dural venous sinus?

Answer 58

Superior sagittal sinus.

Question 59

What is contained within the carotid sheath?

Answer 59

Internal jugular vein, common carotid artery and vagus nerve.

Question 60

What divides the anterior and posterior triangles of the neck?

Answer 60

Sternocleidomastoid muscle.

Question 61

What nerve innervates the sternocleidomastoid muscle?

Answer 61

Accessory nerve.

Question 62

What does contraction of posterior crico-arytenoid muscles do?

Answer 62

Open/abduct vocal folds.

Question 63

What does contraction of lateral crico-arytenoid muscles do?

Answer 63

Close/adduct vocal folds

Question 64

What does contraction of cricothyroid muscle do?

Answer 64

Tense vocal folds and change pitch.

Question 65

What are the divisions of the vagus nerve that innervate the larynx?

Answer 65

Superior laryngeal nerve and recurrent laryngeal nerve.

Question 66

What does the superior laryngeal nerve divide into?

Answer 66

Internal and external laryngeal nerve.

Question 67

A lesion to the internal laryngeal nerve causes what?

Answer 67

Loss of sensation above vocal folds.

Question 68

A lesion to the external laryngeal nerve causes what?

Answer 68

Paralysis of cricothyroid muscle.

Question 69

A lesion to recurrent laryngeal nerve causes what?

Answer 69

Paralysis in all muscle of larynx except cricothyroid and loss of sensation below vocal folds.