Hormones and Adrenaline Exam Notes
HORMONES
ADRENALINE
HORMONES
- Hormones are chemical messengers.
- Secreted by endocrine glands directly into the bloodstream.
- They travel to specific target organs or tissues.
- Regulate various physiological and metabolic processes.
ENDOCRINE GLANDS
- Glands are specialized organs or tissues.
- They produce and release substances such as hormones, enzymes, or other secretions.
- These substances perform specific functions: regulating processes, aiding digestion, or protecting tissues.
ADRENALINE
- Adrenaline is made in the adrenal glands above the kidney.
- Adrenaline is secreted during a condition called "FIGHT OR FLIGHT."
- Effects of adrenaline include:
- Breathing rate and depth increases: to supply the blood and muscles with more oxygen for increased aerobic respiration.
- Heart rate increases: to supply oxygenated blood rich in glucose to the muscles in a shorter amount of time.
- Liver breakdown glycogen: releasing it into the blood to provide more glucose for aerobic respiration
- Pupils dilate: to see objects more clearly.
- Redirection of Blood Flow:
- Vasoconstriction: Blood vessels in the digestive system constrict, reducing blood flow to non-essential areas.
- Vasodilation: Blood vessels in the muscles widen, increasing blood flow to areas needed for physical activity.
BENEFITS OF ADRENALINE
- Role in the "Fight or Flight" Response
- Adrenaline helps the body to:
- Respond quickly to danger or stress.
- Increase physical strength and speed.
- Improve mental alertness.
ENDOCRINE SYSTEM VS THE NERVOUS SYSTEM
| Aspect | Endocrine System | Nervous System | Similarities |
|---|
| Mode of Communication | Chemical (hormones) | Electrical impulses and chemical (neurotransmitters) | Both involve chemical messengers for communication. |
| Speed of Response | Slower (hormones take time to travel) | Faster (electrical signals travel quickly) | Both respond to stimuli. |
| Duration of Effect | Long-lasting (e.g., hours or days) | Short-lived (fractions of a second to minutes) | Both regulate and coordinate body functions. |
| Method of Transport | Hormones travel in the bloodstream | Impulses travel through neurons | Both involve a signal being sent to target areas. |
| Target Areas | Widespread (acts on multiple organs) | Localized (acts on specific muscles, glands) | Both ensure the body adapts to changes in the environment. |
| Control Center | Glands (e.g., pituitary, pancreas) | Brain and spinal cord | Both involve specialized structures (glands/neurons). |
| Energy Usage | Lower energy requirement | Higher energy usage for transmitting impulses | Both are vital for survival and homeostasis. |