11.1/11.2 - Circulation & Blood

Question 1

Functions of circulatory system

Answer 1

Transports substances to & from cells

What substances? Nutrients, oxygen, carbon dioxide, wastes, hormones, & immune system components

Question 2

Open vs. closed circulatory system

Answer 2

Open circulatory system: It is primarily found in invertebrates. Here, the blood flows freely through cavities since there are no vessels to conduct the blood. – Circulating fluid is pumped into an interconnected system of body cavities or sinuses where it bathes the cells directly.

Closed circulatory system: It is found in vertebrates and a few invertebrates, like earthworms. This system has vessels that conduct blood throughout the body. – Fluid is contained within network of tubes or blood vessels.

Question 3

Flow of blood in pulmonary circuit & systemic circuit

Answer 3

Blood circulation to the lungs (short loop called pulmonary circuit) can be separated from blood circulation to the rest of the body (systemic circuit) with more heart chambers

Question 4

Components of blood

Answer 4

Plasma (55%) - Has protein-rich liquid which is 90+% water. Also has serum, the fluid part of plasma.

Red blood cells (45%) - Called erythrocytes. They carry oxygen & carbon dioxide, are biconcave, have no nucleus so that there is more space for hemoglobin, and the lifespan is 120 days.

White blood cells & platelets (<1%) - Called leukocytes. Part of the immune system. It defends body against harmful substances/organisms.

Question 5

Factors that affect blood donation

Answer 5

Incompatibility occurs because the markers act as antigens, which are considered
foreign material. When the immune system detects antigens, it produces antibodies
that attach to the antigens. This causes the blood cells to clump together, blocking
blood vessels and preventing the circulation of blood and delivery of oxygen. For
example, if type A blood is transfused into a person with type B blood, the recipient
will develop antibodies in response to the type A marker.

The rhesus, or Rh, factor is an antigen that also affects compatibility.
Rh-positive individuals carry the antigen; Rh-negative individuals do not.