Week 6 "Overview of the cardiology system"

Question 1

What are the 4 types of vessels in the cardiovascular system?

Answer 1

Buffer vessels - aorta, large and middle sized arteries
Resistance vessels - small size arteries and arterioles
Metabolic vessels- capillaries
Capacitance vessels - veins

Question 2

What mechanical factors are behind blood pressure?

Answer 2

Cardiac output (CO)
Total peripheral resistance (TPR)
BP= CO X TPR

Question 3

What are the pressures within the vascular system for RV LV Aorta and Vena cava

Answer 3

RV - 15-30
LV 100-140
Aorta- 100-140
Vena Cava- 5

Question 4

What are the features of the Buffer vessels that allow them to achieve their purpose?

Answer 4

aorta, large and middle sized arteries - tries to maintain blood pressure during systole and diastole. It achieves this through internal elastic membrane and large muscular base.

Question 5

What are the features of the resistance vessels that allow them to achieve their purpose?

Answer 5

small size arteries and arterioles - provides structure to carry blood at high pressure- muscular walls

Question 6

What are the features of the metabolic vessels that allow them to achieve their purpose?

Answer 6

capillaries - thin walls to allow for efficient diffusion. Large surface area as millions of capillaries.

Question 7

What are the features of the capacitance vessels that allow them to achieve their purpose?

Answer 7

veins - stores lots of blood ready to be used by the heart if needed. (flexible)

Question 8

What is systole

Answer 8

myocardial contraction - ejection of blood from the cardiac chamber

Question 9

What is diastole

Answer 9

myocardial relaxation - filling the chambers

Question 10

What is cardiac output?

Answer 10

CO= SV X HR
SV = blood volume ejected from each ventricle during contraction.

Question 11

What is Starlings law?

Answer 11

Starlings Law- describes the relationship between ventricular filling in terms of LVEDV (left ventricular end diastolic volume and stroke volume.
“when more blood stretches the ventricles, the ventricles contract more powerfully to pump out more blood”

The heart pups the same volume of blood out - that comes in. this occurs independent of neural or hormonal control.

Question 12

What is the baroreflex?

Answer 12

The baroreflex or baroreceptor reflex is one of the body’s homeostatic mechanisms that helps to maintain blood pressure at nearly constant levels.

Question 13

What are baroreceptors?

Answer 13

Stretch sensitive mechanoreceptors

Question 14

Where are baroreceptors located?

Answer 14

Aortic arch and the carotid sinuses

Question 15

What are examples of Sympathetic stimulation in the heart.

Answer 15

Increase in HR
Increase in SV
Increase in Resistance
Vasoconstriction

Question 16

What are examples of Parasympathetic stimulation in the heart.

Answer 16

decrease in HR
decrease in SV
decrease in Resistance
Vasodilation

Question 17

How do the lengths of Parasympathetic and Sympathetic fibres compare?

Answer 17

Parasympathetic- 
preganglionic = longer
postganglionic = shorter
Sympathetic -
preganglionic = shorter 
postganglionic = longer

Question 18

What neurotransmitters are used for PNS and SNS preganglionic neurons?

Answer 18

All preganglionic neurons release ACh (Acyetlcholine) onto nicotinic asetylcoline receptors (nACHRs)
Post ganglionic however
Sympathetic - noadrenaline
Parasympathetic - ACh

Question 19

What are some features of a nicotinic receptor?

Answer 19

1. Ionotropic (result in direct ion flow)

2. They are all excitatory

Question 20

What are some features of a Muscarinic receptor?

Answer 20

1. Can be excitatory or inhibitory in action
2. Parasympathetic
3. Use a G-Protein effect (secondary messengers)
4. Effects on heart glands eyes GI lungs

Question 21

What is Adrenergic nerve cell?

Answer 21

A nerve cell that uses adrenaline/ noadrenaline acts as a neurotransmitter.
(Sympathetic)
Symptoms - increase HR, BP, resp, shunting of blood away from GI functions, dilated pupils

Question 22

What is a Cholinergic nerve cell.

Answer 22

A nerve cell that uses Acetylcholine (ACh) as a neurotransmitter.
(parasympathetic)
Decrease HR, BP, resp, constricted pupils

Question 23

What are the three types of shock?

Answer 23

1. Hypovolemic- loss of blood volume
2. Distributive- Excessive blood vessel dilation in the wrong places (not distributing well)
3. Cardiogenic- Heart output issues
4. Obstructive- Clots as well as cardiac tamponade.