Chapter 6 Flashcards
Homeostasis
Homeostasis is a complex process that maintains the internal environment of an organism within set limits so that cells and systems can function properly
Stimulus response model
a model that describes how a system responds to a stimulus
negative feedback system
a stimulus–response process in which the response attempts to revert the system back to the state it was in before the stimulus
occurred
Conduction
The transfer of heat
through physical contact
with another object
Convection
The transfer of heat via the
movement of a liquid or a
gas between areas of a
different temperature
Evaporation
The loss of heat via the
conversion of water from
liquid to gas form
Radiation
The transfer of heat via
electromagnetic waves
such as light (i.e. doesn’t
require physical contact)
Stimulus-response model structure
Stimulus-receptor-modulator-effector-response
alpha cells
cells that occupy
the islets of Langerhans and
secrete glucagon
beta cells
cells that occupy
the islets of Langerhans and
secrete insulin
islets of Langerhan
regions of
the pancreas that contain cells
that secrete hormones
Glucose
carbohydrate
that comes from the food we eat. Glucose is the main source of energy for all the cells in our body
glycogen
a polysaccharide of
glucose that stores energy. Serves as the main storage of glucose in
the body
glycogenesis
the process of
creating glycogen from glucose
glycogenolysis
the process
of breaking down glycogen
into glucose
insulin
a hormone secreted by
beta cells of the pancreas when
blood glucose levels are elevated
glucagon
a hormone secreted by
alpha cells of the pancreas when
blood glucose levels are low
Homeostatic mechanisms for increased blood glucose
beta cells release insulin. Insulin increases the uptake of glucose, effectively lowering blood glucose levels to normal level. Stop secreting insulin when level reaches homeostasis.
Homeostatic mechanisms for lowered blood glucose
alpha cells secrete glucagon. Glucagon stimulates liver cells to break down glycogen into
glucose and release it into the bloodstream via glycogenolysis.
antidiuretic hormone
A hormone that helps blood vessels constrict and helps the kidneys control the amount of water and salt in the body. This helps control blood pressure and the amount of urine that is made.
Nephron
The nephrons are the functional and structural units of the kidney. Nephrons are important because they function as factories for urine production and play a role in blood filtration
Renin
an enzyme secreted by
the kidneys in response to low
blood pressure and volume.
Renin initiates a process which
increases the reabsorption of
water and sodium, and increases
the excretion of potassium in
the distal convolut
aldosterone
a steroid hormone
secreted by the adrenal gland
following the release of renin.
Aldosterone increases the
reabsorption of water from
kidney filtrate by increasing the
reabsorption of sodium
aquaporin
a family of
transmembrane proteins
facilitating the transport of water
into and out of a cell
Filtrate
Liquid or solution that has passed through a filter
Osmosis
the passive transport of
a solvent (typically water) through
a semipermeable membrane
from a hypotonic solution to a
hypertonic solution
Baroreceptor
a type of receptor
found throughout the body that
detects changes in blood pressure
Osmoreceptor
a type of
receptor found primarily in the
hypothalamus that detects
changes in osmolality
How the body responds to low water balance
(must learn from textbook fully or notes) pg 271 and 272
When the amount of water in the body decreases, it causes both an increase in the osmolality of blood, and a decrease in blood pressure and volume. The increase in osmolality is detected by osmoreceptors in the hypothalamus, initiating a pathway involving the release of antidiuretic hormone (ADH). The decrease in blood pressure and volume are detected by baroreceptors in the kidneys, which stimulate the release of renin.
type 1 diabetes
an autoimmune
disease in which beta cells of the
pancreas are destroyed, resulting
in an inability to regulate blood
glucose levels
autoimmune disease
a disease
in which an individual’s immune system initiates an immune response against their own cells
type 2 diabetes
a disease
in which the body becomes
resistant to the effects of insulin
and/or doesn’t produce enough
insulin to maintain normal blood
glucose levels
Beta cells secrete ???
Insulin
Alpha cells secrete ???
Glucagon
Hypoglycaemia
the state of
having blood glucose levels below
the normal range
Hyperthyroidism
overactivity
of the thyroid gland, resulting in
increased production and secretion
of thyroid hormones
Impacts of Hypoglycaemia
short and long term
Short: Shakiness, sweating, light-headedness, blurred vision, fatigue
Long: Seizure, coma, death, brain damage
Impacts of hyperthyroidism
short and long term
Short: weight loss, irregular heartbeat, sleep issues, muscle weakness
Long: Heart issues, weakened bones, vision loss, reproductive issues
