coition

Question 1

four stages of haemodynamic sequences leading to erection

Answer 1

1. flaccidity
2. tumescence
3. erection
4. detumescence

Question 2

describe flaccidity

Answer 2

• sym hypogastric nerve maintains myogenic tone of smooth muscle of cavernous trabeculae and arteries
• arterial input hindered by contraction of mounds of smooth muscle near tunica albuginea
• so low vol low pressure

Question 3

describe tumescence

Answer 3

• PS stim of pelvic nerve
• less myogenic tone in arterial smooth muscle and cavernous trabecular muscle
• AV shunts direct blood into sinuses of corpora cavernosa
• venous outflow reduced from compression of subtunical venous plexus
• large vol high pressure

Question 4

describe erection

Answer 4

penis in fully rigid state such that in and outflow of blood are nearly absent

Question 5

describe detumescence

Answer 5

pressure reduction caused by contraction of arterial smooth muscle causes arterial flow to decrease and increase venous outflow