ch 5 +6 Flashcards
Homeostasis and the aspects the internal body needs to regulate
Process of keeping the environment inside our body fairly constant despite external environment temperature
core body temperature glucose in blood blood pressure pH and substances in body fluid CO2 and O2 in body fluids and blood
feedback loop order and negative feedback definition
stim receptor modulator effector receptor feedback
Negative feedback: feedback that reduces affect or eliminate the original stimulus.
Tolerance limit
The limit of factors such as temp and fluid balance beyond which the body malfunctions
Positive feedback and example
Feedback that reinforces the stimulus
In labour the head pushes on the cervix,
nerve impulses sent to the brain,
brain stimulates PG to release oxytocin,
stimulates more uterus contactors and pushes more
glucose and glycogen
Glucose is stored as glycogen
- Glucose, high blood glucose/meal, 2. glycogen, blood glucose low/exercise, 3. to glucose
Role of liver when eating a meal with lots of carbs
- Glucose removed from blood by liver for live well functioning
- Glucose remove by liver and all by muscles to convert into glycogen
- Continue to circulate in the blood
- Converted into fat if an excess of that required to maintain both normal blood sugar and tissue glycogen
glycogenisis
Glucose are joined to form long chain of glycogen. This process is stimulated by pancreatic hormone insulin (decreases blood sugar level)
Glycogenolysis and Glucagon
If blood glucose level drops below normal glucagon is released. Glucagon is a hormone to trigger liver glycogen to break down into glucose.
The pancreas role
secrete islets of langerhans
- alpha cells = glucagon (increase bgl)
- beta cells= insulin (decrease bgl)
Alpha cells increase bgl by……
(3 ways)
glucagon
Stimulating glycogenolysis (conversion of glycogen to glucose)
Stimulating glycogengenesis (production of new sugar molecules from fats and amino acids, in the liver, involves breakdowns of lipid)
Having a mild stimulating affect on protein breakdown
Beta cells decrease bgl by……
4 ways
Accelerating transport of glucose from the body into body cells
Accelerating the conversion of glucose into glycogen in the liver and skeletal muscle
Stimulating the conversion of glucose into protein
Stimulating the conversion of glucose into fat in adipose tissue (lipogenesis)
adrenal cortex role
releases glucocorticoids which is cortisol
- The stimulates conversion of glycogen into glucose in the liver
- And stimulates protein breakdown in muscles
- and conversion of amino acids into glucose in the liver
adrenal medulla role
Releases adrenaline and noradrenaline
- this stimulates breakdown of glycogen in the liver and release of glucose into the blood
Heat gain and heat loss
Heat gain: heat from body processes bracket metabolism bracket, respiration of liver muscle cells. Game from surrounding’s conduction radiation
Heat loss: radiation, conduction, convection. Evaporation of water from shin and lungs and warm urine and feaces
Metabolic rate and what it is affected by
Read it which energy is released by a breakdown of food and affected by exercise, stress and body temperature
Stress effect on metabolic rate
Because of autonomic division stimulation of sympathetic nerve releases adrenaline from nerve endings
noradrenaline increases the metabolic rate for a few minutes
Temp affect a metabolic rate
For everyone degrees there is an increase of 10% of metabolic rate
Peripheral vs central
Thermo receptors
Peripheral:
In the skin and mucus
Detects changes external environment and send messages to the hypothalamus
Central:
Hypothalamus, spinal-cord, organs
detects temp in internal environment
Conduction, convection, radiation, evaporation
Conduction: transfer of heat by direct contact of particles
Convection; transfer of heat by movement of a liquid or gas
Radiation: of heat by infrared radiation being omitted by an object
Evaporation: process of a liquid forming a gas, which absorbs heat energy
Vasodilation in relation to heat
More blood transports the capillaries in the skin which increases the rate of heat loss
Sweating
Active secretion of body food by sweat glands and periodic contraction of cells surrounding the ducts to pump sweat
- it’s stimulated by sympathetic nerves and has a cooling affect
- he is a move from the skin when sweat turns to vapour resulting in cooler blood flow
Shivering
An increase in skeletal muscle tone producing rhythmic muscular tremors heat produced by muscles release in heat
Preventing temperature from falling
5 ways!!!!!
- Impulses from the hypothalamus stimulate sympathetic nerves that cause arterial to constrict. This decreases blood flow of warm blood to skin decreasing heat transfer from internal organs to the skin
- Hypothalamus stimulate adrenal medulla by sympathetic nerves. Stairs cigarettes adrenaline and noradrenaline which increases metabolism and intern increasing heat production
- Hypothalamus then stimulate of course shivering which increases body heat production from muscles
- Hypothalamus – A pituitary- thyroid stimulating hormone – thyroxine. Increase in metabolism = increasing body temp
- behaviour e.g. putting on a jumper
Preventing temperature from rising
4 ways!!
- Vasodilation increase blood flow= go to heat loss through radiation and come back
- Temperature is above 28°C make you sweat equals heat loss
- Decrease in secretion of thyroxine in the long-term
- Behaviour e.g. putting on the Aircon
Heat exhaustion versus heat stroke
Heat exhaustion occurs when the body loses excess amounts of water and salt, typically from sweating. On the other hand, heat stroke is a serious medical emergency that occurs when your body is unable to control its internal temperature.
Osmotic pressure
Tendency of a solution to take on water: the greater the difference in content the greater the pressure.
Metabolic water
Small amount of water of 10 as a byproduct of chemical processes occurring within the cells
Excretion sites
Lungs: excrete CO2 and water
Sweat glands: water containing salt, urea and lactic acid
alimentary canal: passes out bile pigments that entered the small intestine’s with bile
kidney: principal excretory organs for maintaining a constant concentration of materials
Four steps in the nephron
- Filtration – high blood pressure forces small dissolve molecules out of the blood and into filtrate
- Reabsorption –Field passes through the pots more convoluted tubules, loop of Henley, distal convoluted tubules and the collecting ducts where substances are reabsorbed.
- Secretion that materials need to be removed from the body are secreted into filtrate by peritubalar capillaries\
- Urine – water and dissolve substances make up urine
Controlling water levels
As water is lost the plasma become more concentrated and hence has a high osmotic pressure= water moving from interstitial fluid into the plasma by osmosis
This causes the interstitial water to become more concentrated and shrinks from dehydration.
This triggers Osmoreceptors in the hypothalamus to respond to the increased pressure.
How is the level of active reabsorption controlled
It is controlled by the antidiuretic hormone: ADH controls the walls of the distal convoluted tubules and collecting ducts permeability to water.
When ADH is high and when ADH is low…..
When high: tubules become very permeable, water flows out, increases concentration, reduces volume
When low: not permeable to water, fluid in tubules remain die loot
Negative feedback loop for excess sweating/ waterless
stim: osmotic pressure increases due to decrease in water and blood plasma
receptors: osmoreceptres and hypothalamus detect increased osmotic pressure
Modulator: hypothalamus stimulate posterior lobe to release ADH
Effector: ADH target nephrons, which Pam ability to water is increased
Response: water than reabsorbed into blood plasma from DCT and CD
Feedback: osmotic pressure decreases and negative feedback
Aldosterone and why/ when secreted it is secreted
what it does
a salt retaining hormone secreted by Adrenal cortex
Responds to: – decreasing concentration of sodium irons in the blood
– Decrease in blood volume
– Decrease in blood pressure
acts on the DCT and CD to increase sodium irons reabsorbed into bloodstream and amount of potassium secreted in urine
Feedback loop when thirsty
Stim: increase osmotic concentration
Receptor: Osmo receptors in the hypothalamus
Modulator: stimulation of the centre in hypothalamus makes person feel thirsty
Effector: conscious feeling of thirst
Response: fluid consumed is absorbed into Alimentary canal into plasma in blood
Feedback: returns to normal osmotic concentration
Dehydration vs water intoxication
Dehydration: personalises 2% of the normal body water and symptoms include low BP, dizziness, headache, severe thirst
Water intoxication: when body fluids become dilated and cells taking extra water by osmosis. Happens when losing a lot of water and so it’s so sweating is replaced with just water and not associated salts
Respiratory centre
in the medulla oblongata and have two other regions within:
- expiratory
and inspirator
Peripheral vs central
chemo receptors
Peripheral: all groups of cells within the walls of the aorta and carotid arteries. Sensitive to changes in oxygen, CO2 and hydrogen ions there’s a cold aortic and carotid bodies
Central: locate in the medulla oblongata . Sensitive to changes in concentration of CO2 in the blood and hydrogen irons in cerebrospinal fluid spinal fluid
Oxygen concentration when it falls below normal
The concentration has to be very low levels to have a stimulated effect.
- stimulates the peripheral chemo receptors and nerve impulses are transmitted to the respiratory Centre
- distant stimulate transmission of messages to the dark and intercoastal muscle
- breathing rate and depth increases
CO2 concentration when it rises above normal
Aceto-to increases so does the concentration of hydrogen ions
- this increase in both stimulate Central and peripheral chemo receptors
- they transmit nerve impulses to respiratory Centre resulting in increased breathing rate and depth
Central chemo receptors CO2
These are the most sensitive ones and I located in the medulla oblongata and responsible for 70 to 80% of increased breathing rate
Peripheral chemo receptors CO2
An immediate increase in breathing rate is produced by the stimulation of aortic and carotid bodies. These are stimulated by an associated increase in hydrogen ions
Hydrogen ion concentration when above normal
As hydrogen ions increase the pH of blood decreases which directly stimulates aortic and carotid body
- the bodies and transmit impulses to the respiratory Centre this equals breathing rate and depth to increase
Voluntary controlled breathing
Come from connection from cerebral cortex to descending tracks in spinal-cord. It bypasses the respiratory centre in the medulla oblongata
Acts as a protective device in which prevents gases and water into lungs
Holding breath vs hyperventilation
Holding breath:
A buildup of CO2 in plasma stimulates inspiratory Centre descent impulses to inspiratory muscles
hyperVentilation: rapid deep breathing which increases oxygen and decrease co2
Usually corrects itself as a reduction in CO2 means chemo receptors are not stimulated reducing right and up the breathing until back to normal
Factors affecting metabolic rate
exercise, hormones, body temp, age, ingestion of food, sex, stress, climate ,sleep,malnutrition, illness
Why is sweating are inafected on humid days but quite effective on dry days?
On humid days amount of water vapour already in the air is high. Therefore, water it will not evaporate readily. On the condition dual not cool down efficiently and can feel quite uncomfortable. When conditions are dry however evaporation occurs rapidly that’s cooling down the body quickly.
What are the tolerance limit for human core body temperature?
Core body temperature?
Between 36.5 and 38.5. Below 33.5 degrees Celsius is hypothermia or about 41.5 is hypothermia.
is the temperature of the bodies internal organs
Core temperature is usually one to 2° higher than the temperature at the extremities
What Piloerection
Caused by contraction of mussels that attach to each hair which serves as insolation keeping the layer of air close to the skin.
Three factors that impact blood sugar level
Diet, exercise, level of insulin, side-effects of medication, stress, illness
Three types of extracellular fluids
Plasma, lymph and intercellular/tidsue fluid
How much urine and filtrate is produced each day
180 L filtrate
800 to 2000 mL per day urine
What is your urea, where is the produce and why do we have to eliminate it
Urea is a nitrogenous waste formed in the liver. They’re the denomination of amino acid produces the highly toxic substance ammonia. Carbon dioxide combines with it for much less poisonous substance, which is a soluble organic salt of small molecules size easily transported into the blood and Eliminated be at the kidneys.
If water levels have dropped in the blood what sensation do you feel?
Then what homeostatic mechanisms are used in an effort to restore the correct amount of water and blood
thirst
Thirst reflex, increase secretion of antidiuretic hormone and increase urge to do
Kidneys role and function
Regulate the composition and volume of blood. We are removed in the form of your own. Waste includes substances from water, nitrogen and substances from protein cannibalism, hydrogen ions and inorganic ions such as sodium, chloride and potassium and hormone
co2 and hydrogen equation
CO2 + H2O = H2CO3 = H+ + HCO3-
= means break down
carbon dioxide + water = carbonic acid = hydrogen irons and bicarbonate irons
Negative feedback loop on the control breathing right through changes in concentration of carbon dioxide and pH
decreased breathing rate
Stimulus: increase in concentration of CO2 or decrease in pH
Receptor: chemo receptors in the medulla oblongata OR IN aortic and carotid bodies
Modulator: respiratory Centre in the medulla oblongata
Effector: nerve impulses
Response: increase rate of contraction of respiratory muscles
Feedback: decrease in concentration of co2 which increase breathing rate
Negative feedback loop when water is lost through excess sweating
Stimulus: osmotic pressure of the blood is raised due to decrease in water in the blood
Receptors: Osmo receptors in the hypothalamus detect the increase osmotic pressure of the blood
Modulator Colin the hypothalamus stimulate the
