Anatomy of the heart and cardiovascular system

What is an infarct?

Dead or dying tissue resulting from lack of oxyen and nutients (ischaema)

What is usually the cause?

Acute obstruction of coronary artery - often blood clot

Over what kind of distances is diffusion fast over?

Short distances

What kind of distances is diffusion very slow over?

>1mm

Table showing time taken for glucose to diffuse to 99% equilibrium over distance x

Therefore in terms of diffsuion what does the CVC do?

Speeds up gas and solute transport over long distances (convection)

What are the 4 functions of the cardiovascular system?

• Delivery of O2 and nutrients to each cell

• Removal of CO2 and waste products from each cell

• Communication between organs through transport of hormones and other extracellular mediators

• Temperature regulation

What 2 parts can the cardiovascular circulation be divided into?

Systemic and pulmonary (lung) circuits

What within these circuits acts as thecentral pump?

The heart

What is the composition of the blood?

Blood vessel structure

What do blood vessels contain and what is their function?

Contains multiple cell layers that regulate their function

What do all blood cells contain?

Endothelial cellsW

What varies in blood cells?

The thickness of the smooth muscle and connective tissue

Blood vessels involved in the circulation

What do arteries contain?

A large lumen and a thick layer of smooth muscle (tunica media) and connective tissue (tunica adventitia)

In arteries what does the thick layer of elastic smooth muscle act as?

A pressure reservoir

Picture showing this

Artery absorbs the pressure to prevent it from passing on and bursting arterioles

What do arterioles contain?

A thin muscular wall and a small lumen

What does contraction of the smooth muscle regulate?

The diameter of the lumen

What are the 2 reasons as to why contraction of the smooth muscle is key?

It determines blood flow to organs and is a major determinant of mean arterial pressure

What do capillaries have a single layer of?

Endothelial cells

What 2 things occur in the capillaries?

• Exchange of nutrients, oxygen and waste across the capillary wall but not proteins

• Intercellular clefts and fused vesicles channels assist the exchange

What 2 things is exchange facilitated by within the capillaries?

Slow movement of blood and large surface area within the capillaries

What 3 things do venules and veins contain?

Thin walls, large diameter lumen and valves

What does a small muscle layer and large diameter lumen allow?

Storage of large blood volume (~60% of total blood volume)

Summary of structure and function of blood vessels

Overall structure of the heart

Left hand side muscle layer is thicker because it pumps blood around the whole body

Internal structure of the heart

Structure of the valves

Blood flow in the heart

Blood supply to the heart

What can coronary arterial disease lead to?

Ischemia and heart attacks

Coronary arterial disease

What causes coronary arterial disease

Treating coronary heart disease

Cerebral spinal fluid what 2 meninges in the brain is it in between?

Arachnoid and pia matter

Cerebral spinal fluid (CSF)

Blood vessels and blood brain barrior