Homeostasis

Question 1

Homeostasis

Answer 1

Maintains constant internal environment

Necessary because enzymes need specific pH levels, temperatures and ion concentrations to work

Question 2

Homeostatic Processes

Answer 2

Involve nerves and hormones
Keeps internal environment within tolerance limits
Control metabolism, and physiological and behavioural activities.

Question 3

Hormones

Answer 3

Chemical messengers
Released from endocrine glands into blood plasma
Affect target organs

Question 4

Positive Feedback

Answer 4

amplifies/reinforces original stimulus to maintain homeostasis

Question 5

Negative Feedback

Answer 5

reduces effect or eliminates original stimulus in order to maintain homeostasis

Question 6

Negative Feedback Cycle

Answer 6

1. Stimulus
2. Receptor
3. Modulator
4. Effector
5. Response
6. Feedback

Question 7

Stimulus

Answer 7

Change to stable state

Question 8

Receptor

Answer 8

Detects change

Question 9

Modulator

Answer 9

Processes information and stimulates response

Question 10

Effector

Answer 10

Effect of stimulus is counteracted

Question 11

Response

Answer 11

Action of the Effector

Question 12

Feedback

Answer 12

Steady state has been restored

Question 13

Glycogenesis

Answer 13

The production of glycogen, mostly from glucose

Question 14

Glycogen

Answer 14

Long strings of glucose molecules

Stored in the liver and skeletal muscles

Question 15

Insulin

Answer 15

Pancreatic hormone
Stimulates glycogenesis
Decreases blood sugar levels
Secreted by beta cells

Question 16

Glycogenolysis

Answer 16

Break down of stored glycogen into glucose

Question 17

Glucagon

Answer 17

Pancreatic hormone
Stimulates glycogenolysis
Increases blood sugar levels
Secreted by alpha cells

Question 18

Islets of Langerhans

Answer 18

Clusters of hormone-secreting cells within the pancreas

Two types of cells: alpha and beta

Question 19

Alpha Cells

Answer 19

Type of cell in the Islets of Langerhans

Secrete glucagon

Question 20

Beta Cells

Answer 20

Type of cell in the Islets of Langerhans

Secrete insulin

Question 21

Adipose Tissue

Answer 21

Fat storing tissue

Question 22

Gluconeogenesis

Answer 22

Process of creating glucose from substances other than stored glycogen, e.g., proteins

Question 23

Adrenal Cortex

Answer 23

Outer part of the adrenal glands

Question 24

Adrenal Medulla

Answer 24

Inner part of the adrenal glands

Question 25

Glucocorticoids

Answer 25

Hormones secreted by adrenal cortex Includes cortisol Stimulate glycogenolysis Increase the rate at which amino acids are brought to the liver for gluconeogenesis

Question 26

Adrenaline

Answer 26

Hormone secreted by adrenal medulla Increases blood sugar levels Counteracts effects of insulin Stimulates lactic acid production, which can then be converted into glucose

Question 27

Blood Sugar Homeostasis

Answer 27

Contribution of the liver, adrenal glands and pancreas to keep blood glucose levels between 4 & 6 mmol/L

Question 28

Chemoreceptors

Answer 28

Located in medulla oblongata (in brain) Monitor blood sugar levels Send messages to hypothalamus

Question 29

Hypothalamus

Answer 29

Located at the base of the brain Connected to pituitary glands by infundibulum Contains two kinds of nerve cells, one set for the APG and the other for the PPG Sends hormones to PPG to be secreted Sends releasing/inhibiting factors to APG

Question 30

Anterior Pituitary Gland

Answer 30

Pituitary gland in front Secretes hormones, regulated by factors sent by hypothalamus Connected to hypothalamus by blood vessels

Question 31

Posterior Pituitary Gland

Answer 31

Gland behind Secretes hormones sent to it Does not create it's own hormones Connected to hypothalamus by nerves

Question 32

Pineal Gland

Answer 32

Deep in brain Secretes melatonin Decreases in size after puberty Stimulated by darkness

Question 33

Adrenocorticotropic Hormone

Answer 33

Released by APG | Stimulates release of cortisol from adrenal cortex

Question 34

Lipid-soluble Hormones

Answer 34

Steroid hormones Slow acting, long lasting Diffuse directly into cell Bind to receptor protein, forming hormone-receptor protein complex Complex binds to genes that code for specific proteins Either inhibits or increases protein synthesis

Question 35

Water-soluble Hormones

Answer 35

Peptide/amine hormones Fast acting, don't last long Cannot cross cell membrane Bind to receptor protein in cell membrane Activates secondary messenger, which diffuses throughout the cell Secondary messengers activate specific enzymes

Question 36

Lipid Soluble Hormones to Know

Answer 36

Aldosterone Cortisol Known as corticosteroids

Question 37

Infundibulum

Answer 37

Stalk connecting the hypothalamus to the pituitary gland

Question 38

Phrenic Nerve

Answer 38

Stimulates diaphragm

Question 39

Intercostal Nerve

Answer 39

Stimulates intercostal muscles

Question 40

Restriction Enzymes

Answer 40

Enzymes used to cut sections of DNA | Specific to recognition sites

Question 41

Sticky ends vs blunt ends

Answer 41

Sticky ends: