week 7+8 - cardiovascular substance exchange

Question 1

SUBSTANCE EXCHANGE

Answer 1

Blood flow through capillaries
- Capillaries branch to form an extensive capillary network throughout the tissues and are found near almost every cell in the body

Question 2

VASOMOTION

Answer 2

• Smooth muscles contract and relax in metarterioles and precapillary sphincters

Question 3

SUBSTANCE EXCHANGE IN CAPILLARIES
diffusion

Answer 3

o Through fenestration
o O2, CO2, glucose, amino acids, hormones

Question 4

SUBSTANCE EXCHANGE IN CAPILLARIES
transcytosis

Answer 4

o In blood
o Pinocytic vesicles
o Lipid molecules
o Endocytosis and exocytosis

Question 5

SUBSTANCE EXCHANGE IN CAPILLARIES
bulk flow

Answer 5

o Pressure differences
o Large no. ions

Question 6

what order are vessels connected in?

Answer 6

artery –> arteriole –> capillaries –> venule –> vein

Question 7

what is your blood pressure

Answer 7

• Highest pressure at systole in arteries
  o Ventricular contraction
• Lowest pressure at diastole in arteries
  o Ventricular contraction
• PULSE: expansion & relax elastic arteries after each systole
  o “same as heart beat”

Question 8

PHYSIOLOGICAL FACTORS AFFECTING BLOOD PRESSURE:

Answer 8

• Cardiac output
  o Heart rate
  o End systolic volume
  o Myocardial contractivity
• Blood volume
  o Venous pressure
• Vascular resistance
  o Size of lumen
  o Blood viscosity
  o Vessel length
  o Venous return

Question 9

what causes changes in your blood pressure

Answer 9

• Behaviour (diet, exercise)
  o Gas and nutrient exchange to metabolic tissues
• Environment (thermoregulation
• Emotions (fright)
• Lesions in brain

Question 10

blood pressure controlled by…

Answer 10

negative feedback systems

Question 11

negative feedback systems

Answer 11

• Cardiovascular centre (CV) in medulla oblongata (brain):
  o Heart rate and stroke volume
  (feedback on blood pressure)
• Neural regulation
• Hormone regulation
• Autoregulation:
  o Local metabolic demands