exam deck 9

Question 1

Where are olfactory receptors located?

Answer 1

Within ~5 cm² of olfactory mucosa deep in the nasal cavity.

Question 2

How do olfactory receptor neurons detect odorants?

Answer 2

Cilia on the neurons bind odorants, triggering a G-protein second messenger system

Question 3

How does olfactory sensitivity compare to taste?

Answer 3

Olfaction has a broader range of sensitivity and is categorized into seven primary smell qualities.

Question 4

What are the seven primary smell qualities?

Answer 4

Peppermint, musk, floral, ethereal, pungent, putrid, and camphoraceous.

Question 5

How do bipolar olfactory cells connect to the brain?

Answer 5

They link to the olfactory bulb via short axons.

Question 6

Where do olfactory bulbs project their signals?

Answer 6

To ipsilateral and contralateral regions of the olfactory cortex via olfactory tracts.

Question 7

How do bi-directional projections in olfactory pathways contribute to function?

Answer 7

They allow for smell localization.

Question 8

What happens to the lens during near vision?

Answer 8

Ciliary muscles contract, causing the lens to round up.

Question 9

What happens to the lens during distant vision?

Answer 9

Ciliary muscles relax, and suspensory ligaments pull the lens into a flatter shape.

Question 10

What are cone cells specialized for?

Answer 10

Color vision and high acuity in bright light.

Question 11

What are rod cells specialized for?

Answer 11

Low-light vision and sensitivity to light intensity.

Question 12

What is lateral inhibition, and what does it enhance?

Answer 12

A neural mechanism that enhances contrast and sharpens visual signals.

Question 13

Where do retinal ganglion cells (RGCs) project in mammals?

Answer 13

To the lateral geniculate nucleus.

Question 14

How is the 3D topographical map in visual pathways formed?

Answer 14

By complementary expression of ligands and receptors in nasal and temporal axons.

Question 15

What is the most common form of color blindness?

Answer 15

Red-green blindness.

Question 16

What are scotomas, and what causes them?

Answer 16

Blind spots caused by damage to the fovea or retinal lesions.

Question 17

What is the role of the optic chiasm in visual processing?

Answer 17

It is a decision point where some axons cross to the opposite hemisphere.

Question 18

What is the average blood volume in a typical adult male?

Answer 18

~5 liters (7-8% of body weight).

Question 19

Name the main functions of blood.

Answer 19

Transport (gases, nutrients, waste), thermoregulation, pH maintenance, clotting, and defense.

Question 20

What are the components of plasma?

Answer 20

Plasma is 95% water and contains proteins like albumin, globulin (α, β, γ), and fibrinogen.

Question 21

What is colloid oncotic pressure?

Answer 21

The pressure exerted by plasma proteins that draws water into capillaries, opposing hydrostatic pressure.

Question 22

What is hypoproteinemia, and what does it cause?

Answer 22

Abnormally low plasma protein levels, causing edema due to reduced oncotic pressure.

Question 23

Describe red blood cells (RBCs).

Answer 23

Biconcave, non-nucleated, flexible cells with a 120-day lifespan, transporting gases via hemoglobin.

Question 24

What stimulates erythropoietin secretion, and where is it produced?

Answer 24

Hypoxia stimulates erythropoietin secretion, primarily from the kidneys (85%) and liver (15%).

Question 25

What are the five types of white blood cells (WBCs)?

Answer 25

Neutrophils, Basophils, Eosinophils, Monocytes, and Lymphocytes.

Question 26

Which WBCs respond to bacterial and viral infections?

Answer 26

Neutrophils respond to bacterial infections; lymphocytes respond to viral infections.

Question 27

How are white blood cells formed (leukopoiesis)?

Answer 27

Leukopoiesis is controlled by cytokines like Colony Stimulating Factors and interleukins, which adapt to infection types.

Question 28

What are platelets, and what is their function?

Answer 28

Platelets are cell fragments that mediate clotting by adhering to damaged vessel walls.

Question 29

What governs platelet formation?

Answer 29

Thrombopoietin regulates platelet formation.

Question 30

Define haematocrit.

Answer 30

Haematocrit is the percentage of red blood cells in blood, normally 40–50%.

Question 31

What factors influence blood viscosity?

Answer 31

Haematocrit, temperature (higher temp decreases viscosity), and flow rate (lower flow increases viscosity).