Endocrine system Flashcards
The endocrine system consists of
many organs and endocrine glands that secrete hormones
Hormones control/ coordinates body processes that
require multiple organs to interact for a combined effect
Hormones have a longer…… and a slower…..
longer effect period and slower response
Hormones are
chemical messengers that are secreted in small quantities and transported in the blood
Homeostasis
Internal conditions are kept near constant by control systems
Sensory cells are responsible for
detecting information about the conditions in the body and in the surroundings
Physiological factors that are controlled
The conditions inside the body that should be maintained so that cells are able to function
Core body temperature- metabolic wastes- Blood pH- blood glucose concentration- water potential of the blood - concentration of respiratory gases in the blood core body
…… influence how the cells work
features of the surrounding tissue fluid
The features of the surrounding tissue fluid that influence how a cell works……,……. and……
Temperature/ water potential / glucose concentration
How come the glucose concentration of the surrounding tissue fluid effect how a cell works
- low glucose levels would mean the cell will lack energy since respiration will not happen
-High glucose levels will have an osmotic effect in which metabolic rate is affected
How come the temperature of the surrounding tissue fluid affect how a cell works
- high temperature will increase the metabolic rate, but going over this might cause the proteins to denature
- low temperate means a low metabolic rate
How come water potential of surrounding tissue fluid affect how a cell works
- too much water leaving the cell by osmosis bc of a low water potential in the tissue will lead the cell to shrink which will slow or stop metabolic reactions
- too much water entering the cell by osmosis bc of high water potential in the tissue fluid will cause the cell to burst or undergoing lysis which might stop metabolic reactions
(positive feedback) Changes in the environment causes the change to….. ex.
amplify. depolarisation of neurones This is an example of positive feedback. The more sodium ions there are, the more voltage changes, sp the more ion channels open, so the more sodium ions diffuse in.
Positive feedback mechanisms are NOT….. They are useful for …..
Homeostatic control. activating processes
While positive feedback ……. negative feedback …..
activates processes. ensure normalcy can be restored quickly
Negative feedback mechanisms are part of
the homeostatic control system
Normal glucose level in the blood
90mg per 100cm3 of blood
Blood glucose concentration is controlled by….. in the…..
islets Langerhans in the pancreas
The two cell types that take part in the regulation of glucose in the islets Langerhans
Beta cells and alpha cells
compare the beta and alpha cells of the islets of Langerhans
Alpha cells are larger and secretes glucagon increase the glucose concentration . Beta cells smaller secret insulin decreases the glucose concentration
glucagon….. glucose concentration
increases
Alpha and beta cells act as an…. and ….. for the effectors
receptors and the hormonal control of the effectors
Alpha and beta are the receptors and the hormonal control of the effectors…….
liver, muscle and adipose fat
Alpha and beta cells play both the…. and ….. roles
receptors and main control or coordinator
Glucagon and insulin work…..
antagonistically
When glucose is absorbed into the blood from the small intestine
The blood passes by the pancreas where the increased glucose concentration is detected. Alpha cells stop secreting glucagon while beta cells increase the secretion of insulin into the blood. insulin is transported to the effectors liver, muscle and adipose fat. Insulin binds to the receptors on the effectors and triggers the absorption of glucose into the effectors. Beta cells stop secreting insulin when the set point is reached
Other than the absorption of glucose into the effectors what does the insulin trigger?
- an enzyme is stimulated causing the glucose to phosphorylate
-two enzymes are stimulated allowing glucose to be added to glycogen
Glycogenesis is
The process of converting glucose to glycogen
Insulin is made up from
51 amino acids
( low glucose level) the blood passes through the….
the blood passes through the pancreas where the low blood glucose level is detected. Alpha cells secretes glucagon while beta cells stops the secretion of insulin. While the secretion of insulin decreases the absorption of glucose into the live, muscle and adipose fat become less. The glucagon binds to its receptors on the liver and initiate a reaction cascade, ending with the break down of glycogen into glucose (glycogenolysis). The enzyme breaking down the glycogen acts on multiple endings allowing the glucose levels to increase quickly. Glucagon also stimulates enzymes responsible for making glucose from amino acids and glycerol by a process known as gluconeogenesis
Glucagon uses a process called
second messenger model
Complementary glucagon receptors are only found in the
liver
glucagon uses a process called
second messenger model
The conversion of glycogen to glucose
glycogenolysis
The conversion of non-carbohydrates to glucose
gluconeogenesis
The enzyme glycogen phosphorylase (glycogenolysis) increases the glucose levels quickly by
Acting of multiple endings of the glycogen
The enzyme in glycogenoylsis
glycogen phosphorylase
Adrenaline acts in the same way as….but
glucagon. but only allows glycogenolysis
Adrenaline is secreted from….. during……
Adrenaline glands above the kidney. stress and excitement
Adrenaline receptors are found in the
liver and muscle