Y12 Endocrine System Flashcards
(146 cards)
1
Q
What are the two kinds of glands in the body?
A
Exocrine and endocrine
2
Q
What are endocrine glands?
A
Glands that secrete hormones isn’t extracellular fluid that surrounds the cells that make up the gland. The secretion usually passes into the capillaries to be transported by the blood. Endocrine glands are ductless.
3
Q
What are exocrine glands?
A
Glands that secrete hormones into a duct that carries the secretion to the body surface of to one of the body cavities.
4
Q
3 examples of exocrine glands?
A
Sweat glands
Salivary glands
Glands of the alimentary canal
5
Q
What are the 9 major endocrine glands?
A
Pineal Hypothalamus Pituitary Thyroid Parathyroid Thymus Adrenal Pancreas Gonads
6
Q
What are the endocrine hormones of the pituitary gland?
A
Follicle stimulating hormone Luteinising hormone Growth hormone Thyroid stimulating hormone Adrenocorticotropic hormones? Prolactin Antidiuretic hormone Oxytocin
7
Q
Which hormones are released by the posterior lobe of the pituitary gland?
A
Oxytocin and antidiuretic hormone
8
Q
What hormone does the thyroid release?
A
Thyroxine which targets most body cells to increase metabolic rate and thence oxygen consumption and heat production
9
Q
What hormone do the parathyroid release?
A
Parathyroid hormone which targets the bones and kidneys to increase rate of osteoclast activity, increasing levels of calcium in blood and control phosphate levels
10
Q
What does FSH target?
A
The gonads where it stimulates growth of follicles and the production of spermatogonia
11
Q
What does Lutenising hormone target?
A
- Ovaries in females where it is involved in ovulation and maintainance of corpus luteum.
- leydig cells in the testes of males where it stimulates secretion of testosterone
12
Q
What does growth hormone target?
A
All cells, stimulating growth and protein synthesis
13
Q
What does thyroid stimulating hormone target?
A
Thyroid stimulating production of hormones of thyroid gland
14
Q
What does the adrenocorticotropic hormone target?
A
The adrenal cortex where it stimulates secretion of hormones from the adrenal cortex
15
Q
What does prolactin hormone target?
A
The mammary glands where it stimulates production of milk
16
Q
What does antidiuretic hormone target?
A
The kidneys ( specifically the distal proximal tubule and collecting duct of nephrons) where it causes reabsorption of water
17
Q
What does oxytocin target?
A
The uterus where it allows contractions during childbirth and
The mammary glands which allow the release of milk
18
Q
Where is thymosins released and what is its effect?
A
It is released by the thymus and targets t lymphocytes to stimulate development and maturation of T lymphocytes
19
Q
Where is aldosterone released and what is its effect?
A
Released by the adrenal cortex to target the kidney where it increases reabsorbtion of sodium ions and excretion of potassium ions
20
Q
What hormones are released by the adrenal cortex?
A
Aldosterone and cortisol
21
Q
Where is cortisol released and what is its effect?
A
The adrenal cortex to target most cells where it promotes normal metabolism; helps the body deal with stress and promotes repair of damaged tissues
22
Q
What hormones are produced by the adrenal medulla?
A
Adrenaline and noradrenaline
23
Q
Where is adrenaline and noradrenaline preleased and what are their effects?
A
Produced by the adrenal medulla and targets most tissues where it prepares the body for fight or flight response ; reinforcing the effects of the sympathetic nervous system
24
Q
Where is insulin released and what is its effect?
A
The pancreas to target most cells where it stimulates uptake of glucose; lowers blood glucose level
25
Where is glucagon released and what does it target?
Released by the pancreas and targets the liver and fat storage tissues to stimulate breakdown of Glycogen and fat; increase blood glucose levels
26
Where is Androgens (testosterone) released and what does it target?
In the testes where it targets many tissues to stimulate sperm production, growth of skeleton and muscles; male sexual characteristics
27
Where is ostrogen released and what does it target?
Released by the ovaries, targeting many tissues to stimulate development of female characteristics and regulate menstrual cycle
28
Where is progesterone released and what does it target?
Released via the ovaries to target
..the uterus where it regulates menstrual cycle and pregnancy
..the mammary glands where it prepares the mammary glands for milk secretion
29
Where is the hormone calcitonin produced and target once released?
Produced by the thyroid to target bones kidneys and intestines where it is involved in calcium regulation
30
How do proteins and amine hormones send chemical messages?
Proteins and amines are water soluble so they can’t enter, instead Hormone attaches to protein specific receptor in the membrane of the target cell. The combo of hormone with the receptor causes a secondary messenger substance to diffuse through the cell and activate Particular enzyme.
31
How do steroid hormones send chemical messages?
Steroid hormones are lipid soluable so they enter the target cell and combine to a receptor protein inside the cell. The receptor may be mitochondria, on other organelles of in the nucleus. The hormone receptor complex activates the genes controlling formation of particular proteins
32
What type/s of hormones can enter the cell?
Lipid hormones
33
What type/s of hormones can enter the cell?
Amines and proteins
34
Why can steroid hormones enter the cell?
Cell membrane is made of a phospholipid bylayer. Steroid hormones are lipid soluable so they enter the target cell and combine to a receptor protein inside the cell.
35
Why cant amines and protein hormones enter the cell?
Proteins and amines are water soluble so they can’t enter, instead Hormone attaches to protein specific receptor in the membrane of the target cell.
36
What are the 2 lobes of the pituitary gland, how are they different?
Anterior lobe - releases and produces hormones. hormone secretions are controlled by regulating factors. Hormones are secreted into EF surrounding the cells of hypothalamus and carried by blood to Anterior lobe.
Posterior lobe- doesn’t produce hormones but releases them. Joined to hypothalamus by the nerve fibres that come from nerve cell bodies in hypothalamus and pass through the infundibulum to the posterior lobe.
37
Relationship between hypothalamus and pituitary gland? (Posterior lobe)
Posterior lobe-
+ not a true gland as doesn’t produce hormones. hormones are produced by neurosecretory neurons
+produced in the soma, travel down axon and are stored in the axon terminals in the posterior lobe.
+ nerve impulse triggers the release of hormones from axon terminals in posterior lobe and hormones are releases into bloodstream
(Antidiuretic hormone and oxytocin)
38
Relationship between hypothalamus and pituitary gland? (Anterior lobe)
+Hypothalamus produces releasing and inhibiting factors in neurosecretory neurons.
+factor is secreted into hypophyseal portal system and bloodstream carries factors directly into the anterior lobe
+ factors reach target endocrine cells (with corresponding receptors) and initiate a response:
Releasing factor would increase production/ release of hormone. Inhibiting factor would decrease production/ release of hormone.
(Eg, growth hormone inhibiting and releasing factor)
+ hormones released travel through extracellular fluid and into the bloodstream, travelling around it until it reaches its target cells.
39
What is the infundibulum?
Infundibulum is the sack like structure that joins the pituitary gland to the hypothalamus
40
Why is regulation of calcium essential?
Essential for nerve impulse contraction and bone strength. It is controlled by calcitonin, vitamin D and parathormone
41
What happens if blood calcium levels are low?
Stimulus: low blood calcium levels
Receptor: chemoreceptors in parathyroid gland
Modulator: parathyroid gland which releases parathormone
Effector:bones, kidneys, intestines
Response:
bones- osteoclast break down bone for calcium
kidneys- reabsorption of calcium
Intestines- absorption of calcium increase
Feedback: increased calcium in bloodstream (negative)
42
What happens if blood calcium levels are too high?
Stimulus: high blood calcium levels
Receptor: chemoreceptors in parathyroid gland
Modulator: thyroid which releases calcitonin
Effector:bones, kidneys, intestines
Response:
bones- osteoblasts build up bone for calcium
kidneys- decreased reabsorption of calcium
Intestines- decreased absorption of calcium increase
Feedback: decreased calcium in bloodstream ( negative)
43
What happens if thyroxine levels in blood are too high?
Stimulus: high levels of thyroxine in blood
Receptor: chemoreceptors in hypothalamus
Modulator: hypothalamus produces thyroid stimulating hormone inhibiting factor which stimulates the anterior lobe of PG to decrease TSH production and release.
Effector: thyroid gland
Response:thyroid produceses less thyroxine
Feedback, decreased levelsof thyroxine in bloodstream ( negative)
44
What happens if thyroxine levels in blood are too low
Stimulus: low levels of thyroxine in blood
Receptor: chemoreceptors in hypothalamus
Modulator: hypothalamus produces thyroid stimulating hormone inhibiting factor which stimulates the anterior lobe of PG to decrease TSH production and release.
Effector: thyroid gland
Response:thyroid produceses less thyroxine
Feedback, decreased levelsof thyroxine in bloodstream
45
What happens if there is high metabolism/ increased body temperature
Stimulus: increased metabolism/ body temperature
Receptor: thermoreceptors in the skin and hypothalamus as well as chemoreceptors in hypothalamus detect thyroxine levels
Modulator: hypothalamus releases thyroid stimulating hormone inhibiting factor which decreases TSH production in Anterior lobe of pituitary gland affecting the thyroid gland to produce less thyroxine
Effector: somatic cells
Response: decreased metabolism causes decreased protein synthesis and cell respiration
Feedback: reduced metabolism and reduced body temperature (negative)
46
What happens if there is low metabolism/ decreased body temperature
Stimulus: decreased metabolism/ body temperature
Receptor: thermoreceptors in the skin and hypothalamus as well as chemoreceptors in hypothalamus detect thyroxine levels
Modulator: hypothalamus releases thyroid stimulating hormone releasing factor which increases TSH production in Anterior lobe of pituitary gland affecting the thyroid gland to produce more thyroxine
Effector: somatic cells
Response: increased metabolism causes increased protein synthesis and cell respiration
Feedback: increased metabolism and increased body temperature (negative)
47
What is hyperthyroidism?
Overproduction of thyroxine
48
What is hypothyroidism?
Under production of thyroxine
49
Example of hyperthyroidism and hypothyroidism?
Hyper- Graves’ disease: most common type
Hypo- hashimotos: deficiency caused by attack on the thyroid gland by patients immune system
50
Causes and effects of hyperthyroidism?
Cause: caused by an immune system reaction and there seems to be genetic predisposition for the condition
Effect: enlargement of the thyroid, because cells are overstimulated: rapid heartbeat, weight loss, increased appetite, fatigue, sweating and anxiety. In Graves’ disease protruding eyeball
51
Treatment of hyperthyroidism?
- drugs that blocks thyroid glands use of iodine
- surgery to remove some of or all of gland
- drink containing radioactive iodine molecules which are taken up by thyroid cells which kills them
52
Cause and effect of hypothyroidism?
Cause: problems which thyroid gland or pituitary gland or hypothalamus, lack or iodine in diet, surgery removing gland
Effect: slow heart rate, unexplained weight gain, fatigue or feeling lack of energy, intolerance for cold, swelling of face and goitre
53
Treatment of hypothyroidism?
- inclusion of extra iodine in diet
- thyroxine tablets
- no cure and hormone tablets must be taken for rest of life
54
What happens if there is an autoimmune attack on the thyroid causing over production of thyroxine.
Stimulus: high levels of thyroxine in blood
Receptor: chemoreceptors in hypothalamus
Modulator: hypothalamus produces TSHIF cause my decreased production and release of TSH in pituitary gland
Effector: autoimmune response leads to increase in size of thyroid
Response: thyroid continues to produce thyroxine despite no TSH available
Feedback: thyroxine remains high in blood ( positive)
55
What happens if there is a lack of iodine in diet due to an autoimmune response destroys that thyroid cells or surgery?
Stimulus: low levels of thyroxine
Receptor: chemoreceptors in hypothalamus detect
Modulator: hypothalamus releases TSHRF to pituitary gland causing increase TSH
Effector: thyroid gland is for whatever reason not able to respond
Response: no thyroxine produced
Feedback: low levels of thyroxine (positive)
56
Define thermoregulation?
The regulation of body temperature, the balance of heat gain and heat loss in order to maintain a constant internal body temperature independent of environmental temperature
57
What may the body do if temperature is too high?
- Vasodilation: radiation and convection
- Sweating: evaporation allows increased heat loss
- long term they can be an decrease in metabolic rate= heat loss
- behavioural response
58
What may the body do if temperature is too low?
- vasoconstriction decreases blood flow to skin
- adrenal medulla stimulated to secret adrenaline and noradrenaline
- shivering increases friction and cell respiration
- increased thyroxine production/ metabolism
- behavioural response
59
How is low body temperature regulated through behavioural response?
S: Low temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory center of hypothalamus
E: cerebral cortex
R: conscious changes
F: increased body temp
60
How is low body temperature regulated through shivering?
S: Low temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory center of hypothalamus sends nerve impulse to cerebral cortex
E: primary motor area in frontal lobe
R: rhythmic contracting and relaxing causing increased cell respiration and friction
F: increased body temp
61
How is low body temperature regulated through vasoconstriction?
S: Low temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory center of hypothalamus sends nerve impulse to medulla which sends message to...
E: skin blood vessels
R: prevents blood going to skin= less heat lost
F: increased body temp
62
How is low body temperature regulated through increasing metabolism?
S: Low temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory center of hypothalamus
E: somatic cells
R: more thyroxine production increased respiration
F: increased body temp
63
How is low body temperature regulated through secreting adrenaline and noradrenaline ?
S: Low temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory center of hypothalamus sends nerve impulse to medulla olongata via Autonomic nervous system sympathetic route.
E: adrenal medulla
R: release noradrenaline to increase cell respiration and heat production
F: increased body temp
64
How is high body temperature regulated through behaviouralresponses?
S: high temperature
R: heat thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory center of hypothalamus
E: cerebral cortex
R: conscious changes
F: decreased body temp
65
How is high body temperature regulated through sweating ?
S: high temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory centre of hypothalamus sends nerve impulse via Autonomic nervous system
E: sweat glands
R: produce and release sweat which then evaporates
F: decreased body temp
66
How is high body temperature regulated through vasodilation ?
S: high temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory centre of hypothalamus sends nerve impulse to medulla which sends Autonomic impulse to vessels
E: smooth muscles in arterialise going to skin
R: blood vessels vasodilation increasing blood flow to skin allowing radiation and convection
F: decreased body temp
67
How is high body temperature regulated through decreasing metabolism ?
S: high temperature
R: thermoreceptor in skin and hypothalamus
M: heat production centre of thermoregulatory center of hypothalamus
E: somatic cells
R: decreased metabolism= less heat production
F: decreased body temp
68
What is heat transfer?
Balancing the loss and gain of heat through transferring it
69
What are the 4 types of heat transfer?
Conduction
Convection
Radiation
Evaporation
70
What is conduction?
- When heat energy moves FROM A WARMER OBJECT TO A COOLER OBJECT when they are in DIRECT PHYSICAL CONTACT
- if you touch a cold object passes from your body to the object and reverse happens when you touch something hotter than ur body
71
What is convection?
- An object will HEAT OR COOL AIR as it passes over the object
- the CURRENTS OV MOVING AIR REMOVE HEAT ENERGY from the object
72
What is radiation?
- heat energy moves FROM A WARMER OBJECT ACROSS A SPACE
- no contact necessary
- if your body has higher temp than the environment you will radiate heat into environment which cools the body and visevera
73
What is evaporation?
- LIQUID water is CONVERTED to WATER VAPOR
- REQUIRES ENERGY (in the form of heat) which is taken from body-> body cools
- as we sweat the evaporation of sweat from the skin cools the body
74
How is heat produced?
Carbohydrates, proteins and lipids we eat contain energy and in the process of cellular respiration food is oxidized in cells and energy released. Whilst some energy is used for cellular and body activity, most is released in form of heat
75
What is metabolic rate?
Rate at which energy is released by the breakdown of food.
| Exercise, stress and body temperature all affect this
76
What are the types of thermoreceptor?
Peripheral and centeral
77
Where are peripheral and central thermoreceptors found?
Central- hypothalamus
| Peripheral- skin and some mucous membrane
78
What are the types of peripheral thermoreceptors?
Cold and heat receptors
79
What body temperature is leather?
Above 45°
80
What is heat stroke?
When body temperature continues to rise and regulatory Mechanisms cease and body cannot lose heat by radiation or evaporation( often due to humidity and high body temp)
Cured by quickly cooling body in cold water
81
What is heat exhaustion?
Loss of water reduces volume of blood plasma lowering blood pressure and output causing person to maybe collapse.
Often occurs as a result of extreme sweating and vasodilation
82
What temp is optimum of cellular respiration?
37°
83
True or false
| Heat gain must be equal to heat loss
True
84
Difference between validity and reliability?
Validity: how well experiment relates to the aim of the experiment.
Eg. Appropriate equipment for measurements, eliminates uncontrollable factors
Reliability: how close repeated measurements are to each other.
Eg. Fixed control variables so all test carried out same, choice of equipment
85
What disease does high blood glucose suggest?
High blood sugar= can lead to diabetes
86
What is diabetes caused by?
Caused by not enough insulin to manage glucose levels or; when insulin is not effective enough because your body is ‘insensitive’ to insulin
87
What does glucagon do?
Increase glucose levels
88
Where does insulin come from?
Secreted by beta cells in islets of langerhan in pancreas gland
89
Where does glucagon come from?
Alpha cells In islets of langerhan in the pancreas
90
Blood glucose regulation feedback loop for high blood glucose
S= Increased blood glucose levels
R= pancreas has islets of langerhan beta cells have chemoreceptors on them
M= beta cells in pancreas secrete insulin
E= all cells (protein S) , liver (glucogenesis) adipose tissue ( lypogenesis)
R= protein synthesis , glycogenesis, translocation, lypogenesis
F= decreased blood glucose
91
Blood glucose regulation feedback loop for low blood glucose
S= low blood glucose levels
R= pancreas has islets of langerhan alpha cells have chemoreceptors on them
M= alpha cells in pancreas secrete glucagon
E= liver, adipose tissue, cells
R= gluconeogenesis, lypolysis, glycogenlysis
F= increased blood glucose
(Negative feedback loop)
92
Define lypogenesis?
Metabolic formation of fat
-Happens to adipose tissue
(Decreases BG levels)
93
Define gluconeogenesis?
Making glucose from protein
-Happens to all cells
(Decreases BG levels)
94
Define lipolysis ?
Breakdown of fats and other lipids by hydrolysis to release fatty acids which converts into glucose
- adipose tissue
(Increases BG levels)
95
Define translocation?
Movement of glucose from blood stream into cells
Happens at all cells
(Decreases BG levels)
96
Protein synthesis role in glucose regulation?
Stimulated by the release of insulin and acts to reduce blood glucose levels
-Happens at all cells
(Decreases BG levels)
97
Define Glycogenolysis?
Process of converting glycogen back to glucose
| Increases BG levels
98
Define glycogenesis?
Glycogenesis is the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage.
(Decreases BG levels)
99
What responses occur to reduce blood glucose?
- translocation
- lipogenesis
- protein synthesis
- glycogenesis
100
What responses occur to increase blood glucose levels?
- lypolysis
- glycogenolysis
- gluconeogenesis
101
Benefits of stress?
- Warning system
- improve productivity and concentration
- fights tiredness and fatigue
102
Long term effects of stress?
- anxiety
- depression
- sleep problems
- digestive problems
- heart problems ( like hypotension)
103
Stress feedback loop?
Stimulus- Stressful situation (fight or flight response) so low glucose levels
Receptors- sensory receptors in AMYGDALA
Modulator- hypothalamus initiates release of adrenaline and cortisol
Effector- liver, skeletal muscle, cardiac muscle and all cells
Response- flight or flight responses Eg. Increased heart rate and cellular respiration. Metabolic Processes of glyogenolysis, lipolysis and gluconeogenesis also increase
Feedback- overcome stressor, high glucose levels in blood so increased energy production
104
What does the AMYGDALA do and where is it located?
It is a section of nervous tissue in the brain responsible for emotions, survival instincts and memory
105
What does modulator do during stress (flight or flight response) in terms of ADRENALINE
Nerve impulses via Autonomic division
- > adrenal medulla
- > adrenaline
106
What does modulator do during stress (flight or flight response) in terms of CORTISOL?
hypothalamus
- > Adrenocorticotropic hormone releasing factor
- > Anterior pituitary gland
- > ACTH released
- > reaches Adrenal cortex
- > which then releases cortisol
107
Define diabetes mellitus?
Abnormally high blood glucose levels (hypoglycaemia). There are two types, a diabetic doesn’t produce enough insulin or their cells have an abnormal resistance to the effects of insulin
108
Cause of type 1 diabetes?
Type one is insulin dependent diabetes
- occurs because of a fault in the patients immune system causes the destruction of beta cells in the islets of langerhans of the pancreas. Beta cells are therefore not producing insulin, usually begins at childbirth
109
Effects of type 1 diabetes?
- Beta cells cease producing insulin, glucose therefore cannot enter.
- can lead to kidney failure and heart attacks
- can cause blurred vision, increased thirst, increased blood pressure, frequent urination
110
Treatment of type 1 diabetes?
- Disease can be managed by giving a person insulin
- Can’t be digested into alimentary canal so treatment is regular injections of insulin or; use of programmable pump that provides continuous supply of insulin under skin
- no actual cure
111
Cause of type 2 diabetes?
Iifestyle disease caused by obesity or being overweight, risk increases when person has a diet high in fat, sugar, salt and low fibre, high blood pressure and smoking.
112
Effects of type 2 diabetes
- body is able to produce insulin but cells do not respond.
- undiagnosed can lead to heart disease, stroke, kidney disease etc.
- excessive hunger, thirst, fatigue
113
Treatment of type 2 diabetes!
No cure but is managed by:
- careful diet, regular physical activity, maintaining healthy weight and only sometimes medications that stimulate secretion of more insulin from pancreas or stimulate receptors to be more sensitive
114
Type 1 diabetes feedback loop?
Stimulus: high glucose in blood
Receptor: chemoreceptors in beta cells are damages
Modulator: beta cells do not produce insulin
Effector: liver, all cells, muscles and adipose tissue
Response: little activity (glycogenesis, lipolysis, p.synthesis, translocation)
Feedback: glucose remains high
(Positive fb loop)
115
Type 2 diabetes feedback loop?
Stimulus: high blood glucose
Receptor: chemoreceptors on beta cells
Modulator: beta cells produces insulin
Effector:insulin receptors on liver, muscle, adipose tissue (effectors) damaged
Response: slow response (glycogenesis, lipolysis, p.synthesis, translocation)
Feedback: glucose level in blood still high
116
Where on the fb loop does type 1 diabetes treatment occur?
Receptor: becomes monitoring machine
Modulator: injection or pump
117
Where on the fb loop does type2 diabetes treatment occur?
Stimulus: keeping a healthy diet, lifestyle
Effector: medication-> increases insulin sensitivity ( thence increase rate of response)
118
Gas concentration feedback loop stimulus for HIGH CARBON DIOXIDE
stimulus- high co2 level (byproduct of aerobic respiration) in bloodstream
So increased hydrogen ion levels
So decreased PH levels ( more acidic)
119
Gas concentration feedback loop receptor for HIGH CARBON DIOXIDE
Chemoreceptors in medulla oblongata and aortic and carotid bodies in arteries
120
Gas concentration feedback loop modulator for HIGH CARBON DIOXIDE
Medulla oblongata respiratory centre sends nerve impulses
| via intercostal nerve and phrenic nerve
121
Gas concentration feedback loop effector for HIGH CARBON DIOXIDE
```
Intercostal muscles ( from intercostal nerve)
Diaphragm (from phrenic nerve)
```
122
Gas concentration feedback loop response for HIGH CARBON DIOXIDE
Increased breathing rate and depth
123
Gas concentration feedback loop feedback for HIGH CARBON DIOXIDE
Decreased co2 levels in blood
So decreased H+ ion levels
So increased ph ( neutral)
124
Order of menstural hormone release?
FOLP
| FSH-> Oestrogen-> lutenising hormone-> progesterone
125
Gas concentration feedback loop stimulus for very low oxygen levels?
Decreased o2 ( must be VERY low to stimulate a response)
126
Gas concentration feedback loop receptor for very low oxygen levels?
Chemoreceptors in MO and aortic and carotid bodies
127
Gas concentration feedback loop modulator for very low oxygen levels?
Medulla oblongata ‘respiratory center’
Via intercostal nerve and phrenic nerve
128
Gas concentration feedback loop effector for very low oxygen levels?
Intercostal muscles
| Diaphragm
129
Gas concentration feedback loop response for very low oxygen levels?
Increased breathing rate and depth
130
Gas concentration feedback loop feedback for very low oxygen levels?
Increases o2 levels
131
Hyperventilation feedback loop?
Stimulus- no stimulus. Low co2 ( too low to stimulate breathing) Normal o2 levels (not low enough to stimulate breathing)
Receptor- chemoreceptors and aortic and carotid bodies don’t detect changes
Modulator- mo not instructed to initiate a response
Effector- diaphragm and intercostal muscles are relaxed
Response- no breathing
Feedback- increased co2, H+, and decreased PH. O2 is used up. Lower gas concentration after enough time to stimulate a response
132
Cause of asthma?
Caused when an airway swells and becomes inflamed and narrow
133
Symptoms of asthma?
Shortness of breath
Wheezing
coughing
134
Cause of emphysema?
Walls of airsacks in lungs (alveoli) weaken and rupture overtime reducing SA of lungs and amount of oxygen you get
135
Symptoms of emphysema
Shortness of breath
Wheezing
Chronic cough
136
Asthma feedback loop?
Stim: high co2, H+, low ph
Receptor: chemoreceptors in AC bodies and mo
Modulator:mo
Effector: diaphragm and intercostal muscles
Response: bronchioles are narrowed ( inflammation and constriction due to a trigger so breathing rate and depth don’t increase much
Feedback- co2 levels remain high, o2 decreases
137
Emphysema feedback loop?
Stim: high co2, H+, low ph
Receptor: chemoreceptors in AC bodies and mo
Modulator:mo
Effector: diaphragm and intercostal muscles
Response: alveoli number has decreased so decreased SA and insufficient gas exchange
Feedback- co2 levels remain high, o2 decreases
Treatment would be at stimulus
138
What happens when dehydrated?
Low water in bloodstream
- > low blood volume
- > low blood pressure
- > higher salt conc
- > higher osmotic pressure
139
Thirst reflex feedbackloop?
Stimulus- low h20 concentration and high osmotic pressure
Receptor- osmoreceptors in hypothalamus thirst center
Modulator- hypothalamus thirst center
Effector- cerebral cortex- frontal lobe =feel thirsty
Response- behavioural (drink water) and water is absorbed in digestive system
Feedback- increased h20 concentration and decreased osmosis pressure
140
Antidiuretic hormone feedback loop?
Stimulus- low h20 concentration and high osmotic pressure
Receptor- osmoreceptors in hypothalamus
Modulator- hypothalamus-> nerve impulse-> post.pit.gland-> ADH released
Effector- kidney ( distal convoluted tubule, collecting duct)
Response- DCT+CD become more permeable -> ADH opens water channels and water is reabsorbed
Feedback- increased h20 concentration and decreased osmosis pressure
141
High water concentration feedback loop?
Stimulus- high h20 concentration and low osmotic pressure
Receptor- osmoreceptors in hypothalamus don’t detect
Modulator- hypothalamus-> nerve impulse-> post.pit.gland-> no ADH released
Effector- kidney ( distal convoluted tubule, collecting duct)
Response- DCT+CD become less permeable -> ADH closes water channels and less water is reabsorbed
Feedback- decreased h20 concentration and increased osmosis pressure
142
What do alcohol and caffeine do to ADH?
Alcohol- prevents ADH release from pit
Caffeine- blocks ADH receptors
143
Aldosterone feedback loop for high salt concentration?
Stimulus-low h20 conc=increased osmotic pressure,high salt conc and low blood pressure
Receptors- chemoreceptors+ osmoreceptors in hypothalamus and baroreceptors in AC bodies; kidneys
Modulator- hypothalamus, ACTHRF, ant.pit.gland, ACTH, adrenal cortex, aldosterone
Effectors- kidneys- loop of henele DCT
Response- NA K pumps become active. NA is reabsorbed, K is secreted. This increases osmotic pressure as water moves from filtrate to blood stream to balance salt concentration
Feedback- high H20= decreased Osmotic pressure, decreased salt concentration, increased blood pressure
144
Aldosterone feedback loop for low salt concentration?
Stimulus-high h20 conc=decreased osmotic pressure,low salt conc and high blood pressure
Receptors- chemoreceptors+ osmoreceptors in hypothalamus and baroreceptors in AC bodies; kidneys
Modulator- hypothalamus, ACTHIF, ant.pit.gland, ACTH not produced, adrenal cortex not targeted, reduced aldosterone
Effectors- kidneys- loop of henele DCT
Response- NA K pumps become deactivated. NA stays in filtrate, K stays in blood. = maintained osmotic pressure, water doesn’t move from filtrate.
Feedback- low H20= increased Osmotic pressure, increased salt concentration, decreased blood pressure
145
High calcium feedback loop?
```
S- high blood calcium
R- chemoreceptors on thyroid
M- thyroid releases calcitonin
E- kidneys, intestines, bones
R-osteoblasts build up bone, less reabsorption of calcium in kidney,decreased absorption of calcium in intestines
F- decreased blood calcium
```
146
What is calcium needed for?
Nerve impulses, muscle contraction and bone strength
