Expert ord

Question 1

What processes signify the absorptive phase?

Answer 1

Increased insulin levels.
Increased glycogenesis, converting glucose to glycogen.
Increased lipogenesis which is converting glucose to adipose tissue.
Increased glycolysis, converting the glucose to ATP

Question 2

Biochemical changes during the postabsorptive phase:

Answer 2

Increased glycogenolysis: The liver breaks down stored glycogen into glucose and releases it into the bloodstream.

Increased lipolysis: When glucose levels are low, the body switches to using stored fats as an energy source. Hormones such as glucagon promote the breakdown of stored fats into fatty acids, which can be used by cells for energy.

Increased gluconeogenesis: Gluconeogenesis is the process by which the liver synthesizes glucose from non-carbohydrate sources, such as amino acids and fatty acids.

Increased ketone body production: When fatty acids are metabolized in the liver, they produce ketone bodies, which can be used by the brain as an energy source during prolonged fasting or starvation.

Question 3

What is the difference in glycogenolysis in muscles vs liver?

Answer 3

Glycogenolysis in muscles provide energy only to the muscles. Liver an release it into the blood stream to raise blood sugar.

Question 4

What can fatty acids and ketones be used for in the bodies?

Answer 4

Fatty acids almost all of the tissues except nervous system can use for energy, ketones all tissues can use for energy including nervous system but is usually used after prolonged starvation

Question 5

What can fatty acids and ketones be used for in the bodies?

Answer 5

Fatty acids almost all of the tissues except nervous system can use for energy, ketones all tissues can use for energy including nervous system but is usually used after prolonged starvation

Question 6

Describe how fat is metabolized

Answer 6

Fat metabolism involves the breakdown of dietary fats into chylomicrons, which are transported in the bloodstream. Lipases, such as LPL, act on the chylomicrons, breaking down triglycerides into free fatty acids and glycerol, which are then utilized by cells for energy or storage.

Question 7

What hormones regulate the transition from feasting to fasting?

Answer 7

insulin, glucagon, adrenaline and cortisol but it’s mainly decreasing levels of insulin that triggers the shift from feasting to fasting

Question 8

What is basal metabolic rate?

Answer 8

basal metabolic rate, heart, muscle, liver, kidneys and brain at rest in a room with comfortable temperature but without food for at least 12h.

Question 9

What are the hunger and satiety hormones’ called?

Answer 9

leptin is satiety hormone regulated by adipose tissue storages and ghrelin is hunger hormones also regulated by amount of adipose tissue and if the stomach is empty or stretched

Question 10

How is the temperature of the body sensed and regulated?

Answer 10

Central thermoreceptors are mainly located in the hypothalamus and drive negative feedback to control core body temperature. Peripheral thermoreceptors in skin regulate feedforward (before change occurs) by controlling vasodilation.

Question 11

How can we control body temperature?

Answer 11

To control body temperature we have shivering thermogenesis which is shivering to produce heat and nonshivering thermogenesis with is based on brown adipose tissue procent in infants but limited in adults.

Question 12

What does TV, EV, IRV, ERV and dead space stand for?

Answer 12

Tidal volume (TV) is the volume of air entering the lungs in a single inspiration. TV during normal breathing is 500 ml. Inspiratory reserve volume is maximum inspiration, resting tidal volume is what is left in the lung after a normal expiration. Expiratory reserve volume is forced expiration and residual volume is what is still left. Then there is dead space that is part of the TV not available for gas exchange.

Question 13

What determines the gas pressure?

Answer 13

The concentration of the gas and volume

Question 14

What is ventilation perfusion matching achieved by?

Answer 14

– Oxygen driven vasoactivity
– CO2 driven bronchoconstriction

Question 15

How does 2,3-Dyphosphoglycerate affect oxygen saturation?

Answer 15

It decreases the affinity so it moves the oxygen dissociation curve to the right

Question 16

What effect does pH have on the oxygen dissociation curve?

Answer 16

The effect of pH on the Oxygen Dissociation Curve is called the Bohr effect and facilitates the downloading of oxygen to working muscles and the hemoglobin will be less saturated moving the curve to the right

Question 17

What effect does CO have on hemoglobin?

Answer 17

CO has a 210 times higher binding affinity for Hb so it competes with O2 for transport and reduced O2 transport.

Question 18

In what ways are CO2 transported in the blood?

Answer 18

CO2 is highly soluble in plasma (so much more than oxygen). 10% of CO2 is transported dissolved in plasma
* 25-30% of CO2 is transported in hemoglobin as carbaminohemoglobin
* The remaining CO2 (60-65%) is transported as bicarbonate in a reaction catalyzed by carbonic anhydrase (only present in RBCs, not in plasma)
* Bicarbonate is exchanged for chloride to maintain electroneutrality (chloride shift)

Question 19

In the kidney where does active transport occur and what is taken up again by active transport?

Answer 19

CO2 is highly soluble in plasma (so much more than oxygen). 10% of CO2 is transported dissolved in plasma
* 25-30% of CO2 is transported in hemoglobin as carbaminohemoglobin
* The remaining CO2 (60-65%) is transported as bicarbonate in a reaction catalyzed by carbonic anhydrase (only present in RBCs, not in plasma)
* Bicarbonate is exchanged for chloride to maintain electroneutrality (chloride shift)

Question 20

What stimuli does juxtaglomerular cells react to and what happens when they get this stimuli?

Answer 20

(1) reduced blood perfusion (via baroreceptors),
(2) during reduced [Na+] in macula densa and
(3) during sympathetic neural innervation → water reabsorption

Question 21

What is the RAAS system composed of?

Answer 21

renin, angiotensin II, and aldosterone. Renin initiates the activation of the RAAS system, angiotensin II causes vasoconstriction and stimulates the release of aldosterone, and aldosterone promotes sodium and water reabsorption while increasing blood volume and blood pressure.

Question 22

What does the antidiuretic hormone system in the kidneys do?

Answer 22

➢ Released from posterior pituitary as a response to low blood pressure or increased plasma osmolality (increased salt concentration) that is sensed by osmoreceptors
➢ Stimulate reabsorption of water through upregulation of Aquaporins in late distal tubule and collecting duct

Question 23

How can the kidneys regulate the pH in the body?

Answer 23

To regulate pH, the kidneys have the ability to reabsorb or excrete hydrogen ions and bicarbonate ions. When the blood becomes too acidic (low pH), the kidneys can increase the reabsorption of bicarbonate ions and simultaneously secrete more hydrogen ions into the urine. This helps to raise the blood pH.

Conversely, when the blood becomes too alkaline (high pH), the kidneys can decrease the reabsorption of bicarbonate ions and increase the secretion of bicarbonate ions into the urine. This results in a decrease in blood pH.

Question 24

How can the body regulate the pH in the body through breathing?

Answer 24

Deeper more rapid breathing increases breathing slower more shallow breathing reduces pH

Question 25

How does the sympathetic and parasympathetic nervous system look and work differently?

Answer 25

The sympathetic division has short, preganglionic fibers and long postganglionic fibers. The preganglionic fibers are close to the CNS. Parasympathetic nervous system have long preganglionic fibers and short postganglionic
fibers close to the target.

The sympathetic ANS works with acetylcholine and norepinephrine while the parasympathetic only works with acetylcholine.

Question 26

Which receptors belongs to the somatic motor, sympathetic ANS and parasympathetic ANS system?

Answer 26

Somatic motor, nicotinic and ACH
Sympathetic ANS, nicotinic and alpha and beta adrenergic and acetylcholine and norepinephrine and epinephrine
Parasympathetic, only acetylcholine and nicotinic and muscarinic

Question 27

The sympathetic nervous system acts on the heart through:

Answer 27

• Phosphorylation of Ca2+ channels →increased Ca2+ influx → increased contraction
• Activation of pacemaker channels → faster heart rate

Question 28

The parasympathetic nervous system acts on the heart through:

Answer 28

• Decreased force of contraction
• Reduced heart rate
• Inhibition of AV node
• Activation of M2 -receptors

Question 29

Vascular tone, the contractile activity of vascular smooth muscle cells in the walls of small arteries and arterioles.

How is it regulated in regards to receptors and neurotransmitters?

Answer 29

• Regulated by sympathetic division
• Activation of α1 receptors → constriction
• Activation of β2 and α2 receptors
• Vascular endothelium
• Circulating hormones

Question 30

ANS regulation of circulation – feedback systems:

Answer 30

• The baroreflex = a homeostatic mechanism
• It’s found in the arch of the aorta, carotid sinus etc

Question 31

ANS regulation of circulation– the respiratory system:
* Parasympathetic regulation:

Answer 31

• Ach → activation of M3 -receptors in smooth muscle cells → Ca2+↑ → bronchial constriction
• Non-Ach (e.g. NO) → bronchial dilation

Question 32

ANS regulation of circulation– the respiratory system:
Sympathetic regulation:

Answer 32

• Circulating epinephrine → activation of β2 -receptors → cAMP↑ → altered phosphorylation of myosin in smooth muscle → bronchial dilation
• (Locally released norepinephrine)

Question 33

Overlapping feedback systems:

Answer 33

Baroreceptors (stretch of vessels)
Chemoreceptors (sense blood gasses and pH)
→ Cardiovascular center and respiratory center in brainstem
* Regulation of respiratory muscles → ventilation rate

Question 34

Describe types of hmophilia their cause and treatmeant

Answer 34

• Hemophilia A: Deficiency of factor VIII
• Hemophilia B: Deficiency of factor IX
  Clinical features of hemophilia A and B are almost identical
  For treatment-recombinant factors VIII and IX
• von Willebrand disease: deficiency or defect in von Willebrand factor