all negative feedback loops & ch6.2

6.2 regulation of gas concentrations all negative feedback loops we need to know/in ch5-6 & recap of receptors

how are gas concs controlled?

explain how chemoreceptors control breathing

idk

define & explain hyperventilation

Thermoreceptors

A) finish the following sentence: Thermoreceptors can be Peripheral (external ___) or central (internal ___)

B) state role

C) what stimulus/s does it detect?

D) what is the location/s?

E) what is its modulator?

A) temp, temp

B) maintain body temp

C) Hot = detected by heat receptors, cold = detected by cold receptors

D) external temp = skin, internal temp (temp of blood flowing through brain) = hypothalamus

E) hypothalamus

Osmoreceptors

A) state role

B) what stimulus/s does it detect?

C) what is the location/s?

D) what is its modulator?

A) maintain body’s water content

B) changes in osmotic pressure (water concs)

C) hypothalamus

D) hypothalamus

chemoreceptors

A) finish the following sentence: chemoreceptors can be Peripheral (blood ___) or central (___)

B) state role

C) what stimulus/s does it detect?

D) what is the location/s?

E) what is its modulator?

A) plasma, CSF

B) regulation of heartbeat & breathing

C) particular chemicals (odors, tastes), composition of body fluids, pH

D) nose, mouth, blood vessels - aortic & carotid bodies, medulla oblongata

E) Medulla oblongata

Touch receptors

A) what are the other names of this receptor?

B) state role

C) what stimulus/s does it detect?

D) what is the location/s?

E) what is its modulator?

A) mechanoreceptors / pressure receptors

B) perceiving diff sensations

C) light touch, bending hair, pressure & vibrations

D) skin - some close to surface, some further down

E) not involved in homeostasis so receptors are not utilized in feedback loops - only used in reflex arcs

Pain receptors

A) what is the other name of this receptor?

B) state role

C) what stimulus/s does it detect?

D) what is the location/s?

E) what is its modulator?

A) nociceptors

B) alert to damage tissue so we take action to minimise it

C) damage to tissues

D) skin, mucous membranes, and most organs except the brain

E) not involved in homeostasis so receptors are not utilized in feedback loops - only used in reflex arcs

identify 5 negative feedback loops & identify which feedback loop has a modulator that is not in the CNS

water lvls, pH: CO2 lvls / hydrogen ion lvls, temp regulation & glucose

• glucose is the only case where the modulcator is not in the CNS

explain the negative feedback loop for low water levels

1. stimulus: Low water conc in blood

2. receptor: Osmoreceptors in hypothalamus

3. modulator: hypothalamus

4. communication corner (side mission): Releasing factors → Nerve → posterior pituitary → ADH

5. effector: DCT in the kidney

6. response: Reduces urine, increased drinking & reuptake of water

7. (negative) feedback: Water conc will increase

explain the negative feedback loop for high CO2 levels & hydrogen ions (low pH)

1. stimulus: High CO2 & hydrogen ion levels = low pH

2. receptor: Chemoreceptors & medulla - respiratory system

3. modulator: Medalla - respiratory system

4. communication corner (side mission): Nervous system / autonomic / parasympathetic - Phrenic & intercostal nerves

5. effector: Intercoastal & diaphragm

6. response: Increased breathing rate

7. (negative) feedback: CO2 & hydrogen ions decreases & pH increase

explain the negative feedback loop for temp regulation - low temp

1. stimulus: Low core temp

2. receptor: Thermoreceptors in the hypothalamus 

3. modulator: Hypothalamus

4. communication corner (side mission): Releasing factor → anterior pituitary → TSH → thyroid → T4 / thyroxine

5. effector: Muscles, smooth muscles in arterioles & body cells

6. response: Shiver, increase rate of metabolism / respiration & vasoconstriction

7. (negative) feedback: Increase in temp

explain the negative feedback loop for high glucose

1. stimulus: high blood glucose

2. receptor: Beta cells in islets of Langerhans

3. modulator: NOT in the CNS - Beta cells in islets of langerhans

4. communication corner (side mission): insulin

5. effector: Liver / muscle cells / body cells

6. response: Glycogenesis - increase uptake of glucose by muscle/cells

7. (negative) feedback: decrease blood glucose

explain the negative feedback loop for low glucose

1. stimulus: high blood glucose

2. receptor: alpha cells in islets of Langerhans

3. modulator: NOT in the CNS - alpha cells in islets of langerhans

4. communication corner (side mission): Glucagon / cortisol / adrenaline

5. effector: Liver / muscle cells / body cells

6. response: Gluconeogenesis / glycogenolysis

7. (negative) feedback: increased blood glucose