IC6

Question 1

The lymphoid (lymphatic or immune) system consists of cells, tissues and organs that are involved in the ______

Answer 1

defense of the body against invasion by bacteria, viruses and other foreign bodies.

Question 2

Examples of primary lymphoid tissue

Answer 2

Thymus, bone marrow

Question 3

Diff btw Primary and secondary Lymphoid tissue

Answer 3

Primary: origin of lymphocytes
Secondary: where lymphocytes reside and function

Question 4

Shape of lymph nodes

Answer 4

Bean-shaped

Question 5

B lymphocytes differentiate and mature in the ______

Answer 5

bone marrow

Question 6

T lymphocytes differentiate and mature in the ____

Answer 6

thymus

Question 7

Location of thymus

Answer 7

Between lungs, above heart

Question 8

Change in thymus over time

Answer 8

Becomes more fibrous and fat as it has encountered more antigens hence become less active

Question 9

Does thymus contain afferent and efferent vessels?

Answer 9

no afferent lymphatic vessels but efferent vessels are present

Question 10

Epithelial reticular cells (EC) are thought to produce thymosin and thymopoetin, which promote _____

Answer 10

T cell differentiation and proliferation

Question 11

Negative selection in medulla allows survival only of ______

Answer 11

T cells that do not tightly bind self antigens presented by dendritic cells there

Question 12

Positive selection in cortex allows survival only of _____

Answer 12

T cells with functional TCRs recognizing both MHC I and II molecules

Question 13

Location of lymph nodes

Answer 13

Thorax (near armpit) & abdomen

Question 14

Do lymph nodes contain afferent and efferent vessels?

Answer 14

Yes for both

Question 15

Lymphocytes in the blood enter through the walls of postcapillary venules (also known as _____) in the lymph node

Answer 15

high endothelial venules

Question 16

Which organ is the largest single lymphoid organ?

Answer 16

Spleen

Question 17

What is the red and white pulp found in the spleen?

Answer 17

Red pulp: splenic cord
White pulp: lymphatic nodule

Question 18

Red pulp cords is also known as ____

Answer 18

Billroth’s cords

Question 19

Splenic sinusoids are characterised by

Answer 19

▪ Wide and irregular lumen
▪ Discontinuous lining of endothelial cells (stave cells)

Question 20

Type of cells in the anterior pituitary

Answer 20

*Chromophils (secretory cells in which hormone is stored in cytoplasmic granules)
– Acidophils
– Basophils

*Chromophobes (degranulated chromophil cells)

*Melanotrophs

Question 21

Various hormones secreted by acidophils

Answer 21

– Acidophils
* Somatotrophs (growth hormone)
* Mammotrophs (prolactin)

Question 22

Various hormones secreted by basophils

Answer 22

– Basophils
* Gonadotrophs (FSH, LH )
* Corticotrophs (ACTH or corticotropin)
* Thyrotrophs ( TSH )

Question 23

Various hormones secreted by melanotrophs

Answer 23

Melanotrophs
-Melanocyte stimulating hormone

Question 24

Parts of the pituitary gland

Answer 24

Anterior - Pars distalis, Pars intermedia, Pars tuberalis

Posterior - neural stalk, pars nervosa

Question 25

control of anterior pituitary function

Answer 25

Anterior pituitary control by the hypothalamic hypohyseal portal system (primary and secondary capillary plexus) Additional control is by negative feedback which depends on plasma levels of hormones secreted by the anterior pituitary

Question 26

2 functional groups of hormones

Answer 26

Hormones directly acting on non-endocrine tissues e.g. growth hormone, prolactin, ADH Hormones modulating the activity of other endocrine glands e.g. TSH, FSH, LH, adrenocorticotrophic hormone (ACTH)

Question 27

control of posterior pituitary function

Answer 27

Posterior pituitary secretion -Hypothalamic hypophyseal tract (Axons)

Question 28

structure of the adrenal medulla

Answer 28

Large polyhedral and pale staining chromaffin cells

Question 29

Identify the three layers of the adrenal cortex and its respective hormones

Answer 29

Zona Glomerulosa (aldosterone) Zona fasciculata (glucocorticoids, adrenal androgens) Zona reticularis (glucocorticoids, Androgens)

Question 30

Pancreas – differentiate the islets of Langerhans from the exocrine cells

Answer 30

Endocrine cells appear rounded or polygonal,smaller and lightly stained than exocrine cells

Question 31

different types of islet cells

Answer 31

Alpha, beta, Delta, PP/F cells

Question 32

Role of oxytocin

Answer 32

Oxytocin causes uterine contraction during labour and milk expulsion from mammary gland

Question 33

Role of ADH

Answer 33

ADH mainly acts on renal tubules, reducing urinary flow by increasing water absorption

Question 34

Organs not under pituitary control

Answer 34

Pancreas , Adrenal medulla , Parathyroid

Question 35

adenohypophysis refer to ___

Answer 35

anterior pituitary

Question 36

Neurohypophysis refer to ___

Answer 36

Posterior pituitary

Question 37

Action of somatostatin (secreted by Delta cells of islets of Langerhans)

Answer 37

suppresses release of insulin, glucagon

Question 38

Action of pancreatic polypeptide (secreted by PP/F cells of islets of Langerhans)

Answer 38

inhibits secretion of pancreatic enzymes

Question 39

Is epithelial reticular cells (EC) more in thymus cortex or thymus medulla?

Answer 39

Thymus medulla

Question 40

Thymus cortex Vs Medulla: which one has more lymphocytes?

Answer 40

Cortex

Question 41

Thymus cortex Vs Medulla: Colour

Answer 41

Cortex: Peripheral dark staining region; Medulla: Lighter central region

Question 42

The innate immune system acts immediately when pathogens invade. (T/F)

Answer 42

T

Question 43

Chemical barrier for entry of pathogens

Answer 43

Sweat and tears

Question 44

Which cell is responsible for switching off the immune response, CD8+?

Answer 44

Suppressor T cells

Question 45

How is natural killer cell different from cytotoxic T cells?

Answer 45

Same function, but natural killer cell lack some typical lymphocyte feature

Question 46

Action of cytotoxic T cells

Answer 46

It secretes perforin which forms a pore in the target cell membrane

Question 47

Epithelial reticular cells (EC) are thought to produce_____ and______, which promote T cell differentiation and proliferation

Answer 47

thymosin, thymopoetin

Question 48

Hassall’s corpuscles is found in thymus _______

Answer 48

medulla

Question 49

postcapillary venules is also known as ______

Answer 49

high endothelial venules

Question 50

Name one mammotroph

Answer 50

Prolactin

Question 51

Hormones stored in neurohypophysis (posterior pituitary)

Answer 51

Antidiuretic hormone & Oxytocin

Question 52

Organs not under pituitary control

Answer 52

Pancreas , Adrenal medulla , Parathyroid

Question 53

Role of Parafollicular cells

Answer 53

Secrete Calcitonin

Question 54

Colloid contains ______ which is under TSH control

Answer 54

thyroglobulin

Question 55

Role of parathyroid glands (4 tiny glands located behind thyroid gland)

Answer 55

Secretes parathyroid hormone which raises blood calcium levels

Question 56

Are steroids stored in granules?

Answer 56

No. Steroids are not stored in granules and they diffuse through the plasma membrane

Question 57

What does adrenal cortex synthesise?

Answer 57

Cholesterol/ steroid

Question 58

Cells found and hormones secreted in Adrenal medulla

Answer 58

- (Pale staining) Chromaffin cells – Ganglion cells – Epinephrine and norepinephrine produced

Question 59

Role of Somatostatin

Answer 59

suppresses release of insulin, glucagon

Question 60

Role of Pancreatic polypeptide

Answer 60

inhibits secretion of pancreatic enzymes