Unit 3: Chapter 8 - Homeostasis of Blood Sugar and Gas Concentrations

Question 1

Blood sugar level

Answer 1

The amount of glucose in the blood
Constant supply is needed for cellular respiration
Narrow limits between 4 and 6 millimoles per litre
Glucose is sourced from carbohydrates in our food
Broken down into glucose molecules during digestion

Question 2

Glycogen

Answer 2

Long chain of glucose molecules

Question 3

Pancreas

Answer 3

X

Question 4

Beta cells

Answer 4

Cells within the islets of Langerhans in the pancreas

Secret insulin

Question 5

Insulin

Answer 5

X

Question 6

Glycogenesis

Answer 6

X

Question 7

Glycogenolysis

Answer 7

X

Question 8

Alpha cells

Answer 8

Located within the Islets of Langerhans in the pancreas

Secrete glucagon

Question 9

Glucagon

Answer 9

X

Question 10

Gluconeogenesis

Answer 10

A process whereby glucagon stimulates the liver to produce new sugar molecules from fats and amino acids.

Question 11

Adrenocorticotropic hormone

Answer 11

X

Question 12

Glucocorticoids

Answer 12

X

Question 13

Cortisol

Answer 13

Xxx

Question 14

Adrenaline

Answer 14

X

Question 15

Noradrenaline

Answer 15

X

Question 16

Storage of glucose

Answer 16

Glycogen (Long chains of glucose) in the liver (100g) and muscles cells (400g)
Pancreas (bets cells) produce the hormone insulin that mops up blood sugar (decrease)
Stimulates process of glycogenesis
Insulin also:
Accelerates transport of glucose into cells for use
Stimulates conversion of glucose

Liver
Receiv w blood supply from the hepatic portal vein; bringing blood from stomach, spleen pancreas small and large intestines
Either uses glucose for energy, stores as glycogen (6hr supply) continues circulation of body or stores as fat for long term storage

Question 17

Release of glucose

Answer 17

If blood sugar levels drop below normal, glucose will be released back into the blood stream

Pancreas (alpha cells) produce glucagon increases blood sugar levels
Stimulates process of glycogenolysis chemically breaks down glycogen into glucose
Glucagon stimulates the liver to produce sugar molecules from fats and amino acids called gluconeogenesis

Adrenal cortex is stimulates by ACTH - the adrenocorticotropic hormone from the anterior lobe of the pituitary. It secures glucorticoids (cortisol) which increase blood sugar levels
Glucocorticoids stimulates process of glycogenolysis chemically breaks down glycogen down into glucose

Adrenal medulla synthesises adreline and noradremine which inceeases blood sugar levels
Stimulates production of lactic acid from glycogen in muscles

Question 18

Phrenic nerve

Answer 18

Diaphragm controlled by the phrenic nerve

Question 19

Intercostal nerves

Answer 19

Control the intercostal muscles

Question 20

Respiratory centre

Answer 20

X

Question 21

pH range of the blood?

Answer 21

7.2-7.4

This allows haemoglobin to work effectively

Question 22

The two groups of neurons that control breathing?

Answer 22

The Dorsal (inspiration centre) (back)
And ventral (expiration centre)

Question 23

Voluntary control of breathing?

Answer 23

Controlled by the cerebral cortex to decending tracts in the spinal cord

Question 24

Hyperventilation

Answer 24

May occur voluntarily or may be stimulated by stress/pain
Results in more oxygen and less carbon dioxide than required
Corrects itself by inhibiting the breathing reflex

Question 25

Autonomic nervous system

Answer 25

When receptors detect changes to blood concentrations, never impulses are stimulated and received by the spinal nerves

Question 26

Central chemoreceptors

Answer 26

X

Question 27

Peripheral chemoreceptors

Answer 27

In the heart and the neck, the aortic and carotid bodies also detect changes in gas concentrations