sympathetic activity increases, causing vasodilatation

the hypothalamus signals the nucleus ambiguus allowing heart rate to increase

para-sympathetic activity increases heart rate

the pituitary signals the nucleus ambiguus allowing heart rate to decrease

acetylcholine

angiotensin

gamma aminobutyric acid

an excitatory amino acid

blood flow is increased by a reduction in hematocrit

The vasoconstrictor angiotensin II contributes to the phenomenon of reactive hyperemia

In the absence of a change in vascular resistance, an increase in arterial blood pressure from 70 to 175 mmHg will halve blood flow

According to Poiseuille's Law, the rate of blood flow is inversely proportional to the fourth power of the radius

Increased heart rate, increased ventricular end-diastolic volume or a reduction in sympathetic nerve activity

Increased stroke volume, increased cardiac contractility or increased plasma adrenaline

Increased sympathetic activity, increased ventricular end-diastolic volume or increased parasympathetic nerve activity

Increased heart rate, increased ventricular end-diastolic volume or a reduction in cardiac contractility

have a fall in arterial pressure

have an enhanced increase in parasympathetic nerve activity

have an increased heart rate response

have a normal increase in heart rate

9.0 l/min

2.5 l/min

5.2 l/min

0.5 l/min

Within 6 hours

Within 12 hours

Within 4.5 hours

Within 24 hours

Middle cerebral artery

Anterior cerebral artery

Posterior cerebral artery

Basilar artery

Subdural hematoma

Subarachnoid hemorrhage

Epidural hematoma

Intracerebral hemorrhage