Signalling Between Cells 1 Flashcards
Why do cells need to communicate?
Process information Self preservation Voluntary movement Homeostasis Professional Soccer Holigans Vote
What is the physiological response for Hypoglycemia?
Glycogen breakdown (glycogenolysis) Gluconeogenesis Glucagon-Secreted by alpha cells of the Islets of Langerhans Glucagon- stimulates glycogenolysis and gluconeogenesis within the liver- increasing blood glucose level
What is endocrine signalling?
Hormone travels within blood vessels to acts on a distant target cell
Name examples of endocrine signalling?
Insulin produced in the pancreas acts on the liver, muscle cells & adipose tissue Adrenaline produced in the adrenal glands acting on the trachea
Why is the physiological response for glucose homeostasis?
Physiological response -Glucose uptake -reduced Glycogenolysis -Reduced gluconeogenesis
Describe the process for glucose homoeostasis- hyperglycemia?
Increased blood glucose - insulin secretion by beta- cells in the Islets of Langerhans Insulin has paracrine effects: Inhibiting glucagon secretion Insulin also has endocrine effects on the liver
What is paracrine signalling?
Hormone acts on an adjacent cell
Name an example of paracrine signalling?
Nitric oxide produced by endothelial cells in blood vessels Osteoclasts activating factprs produced by adjacent osteoblasts
What does nitric oxide do?
When you run or lift weights, your muscles need more oxygen which is supplied by the blood. As the heart pumps with more pressure to supply the muscles with blood, the lining in your arteries releases nitric oxide into the blood, which relaxes and widens the vessel wall, allowing for more blood to pass though.
Describe an example of cell signalling in the immune system involving MHC class 2 molecules?
Blood borne virus (e.g. Hepatitis C) detected within blood stream by antigen presenting cell (APC) APC digests pathogen expresses major histo-compatibility (MHC) class II molecules on surface Circulating T-lymphocyte engages with MHC molecule through T-cell receptor (TCR) interaction
What is autocrine signalling?
signalling molecule acts on the same cell
Give an example of autocrine signalling?
Why do cells need to communicate in the context of self preservation?
Identify danger & take appropriate actions Spinal reflexes Sympathetic nervous system
Why do cells need to communicate in the context of Homeostasis?
Thermoregulation Glucose homeostasis
Why do we need to process information?
Sensory stimuli (e.g. sight, sound)
