Answer:
True
Explanation:
Pacemaker cells, unlike other neurons in the body, can depolarized themselves (and therefore can fire action potentials) without the need of an external innervation of the autonomic nervous system.
Each class of pacemaker cells has its own intrinsic rate.
For example, sinoatrial node rate is 60-100 bpm (the normal heart frequency).
The atrioventricular node is also part of the electrical conduction system of the heart. When the sinoatrial node fails, atrioventricular node takes the lead (40-60 bpm).
Answer:
The absence of estrogen may lead to many symptoms:
- Irregular periods
- Anovulation, and therefore, infertility
- Hot flashes
- Decreased vaginal lubrication, which can lead to painful intercourse
- Depression, because estrogen stimulates serotonin release
- Osteoporosis and bone fractures
- Weight gain
Usually the treatment for low estrogen levels is hormone replacement therapy (orally, vaginally or topically)
Answer:
D. to assist the person trapped in the house
Explanation:
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