In the example of childbirth the uterus contracts.  This pus…

In the example of childbirth the uterus contracts.  This pushes the baby’s head against the cervix.  Nerve endings in the cervix send a message to the brain that this is happening.  The brain secretes oxytocin.  Oxytocin stimulates the uterus to contract again and the baby’s head pushes even harder against the cervix.  Oxytocin is an example of:

Depolarization means that the inside of the membrane is beco…

Depolarization means that the inside of the membrane is becoming more [positive] compared to resting membrane potential. When the membrane is stimulated, Na+ channels [open] and Na+ rushes [into] the cell.  This causes [depolarization].  When the charge inside the cell reaches +30 mvs, the Na+ channels [close] and the K+ channels [open].  K+ rushes [out] the cell.  Finally the Na+/K+ pump uses [ATP] to move Na+ back [outof] the cell and K+ back [intoa] the cell.

The skin plays a large roll in maintaining homeostasis of bo…

The skin plays a large roll in maintaining homeostasis of body temperature.  The temperature range for homeostasis is housed in the [brain]. When body temperature is too [high], blood is shunted towards the [skin] and heat dissipates across the surface of the body into the atmosphere. When body temperature is too [low], blood is pulled back internally to protect the more important organs.  This leaves the extremities, like the [fingers], with less blood.