Page 107 - Biology Form Two

Biology for Secondary Schools

Activity 5.1: Examine the external and from transporting gases, the blood also
internal features of the mammalian transports nutrients and water needed
heart in the metabolic processes of the body.

Materials
FOR ONLINE READING ONLY
Dissected mouse or rat, forceps, and Deoxygenated blood has a high
petri dish concentration of carbon dioxide. The
vena cava has two branches that are
Procedure superior vena cava and inferior vena
1. Observe the displayed dissected cava. The superior vena cava transports
mouse or rat.
deoxygenated blood from the upper
2. Identify the external and internal parts of the body such as the head,
parts of the heart. neck, and upper limbs to the heart.

3. Describe what you have observed. The inferior vena cava transports
deoxygenated blood from the lower
parts of the body such as the lower
The flow of blood through the heart
limbs, kidney, liver, stomach, and
Task 5.2
intestines to the heart. The inferior vena
Search the library and internet sources cava and the superior vena cava, unite
for simulations/videos/images showing to form the vena cava that connects to
the flow of blood through the heart.
the right auricle.
The heart is an organ that pumps blood The right auricle receives deoxygenated

throughout the body. It is divided into blood from the body and pumps it to
two separate pumping systems, the right the right ventricle through the tricuspid
side and the left side. The right side of valve. When the right auricle relaxes,

the heart receives deoxygenated blood it is filled up with deoxygenated blood
from the vena cava and pumps it to the from the vena cava. The increased
lungs, where it picks up oxygen gas and pressure in the right auricle causes
releases carbon dioxide gas. The left muscles to contract and pump the blood
side of the heart receives oxygenated through the tricuspid valve. In the right

blood from the lungs and pumps it auricle, there is a small patch of muscle
through the arteries to the rest of the called the sinoatrial node (SAN). This
body, where oxygen gas is released and node acts as a pacemaker, setting

carbon dioxide gas is picked up. Apart the time and rate of cardiac muscle

Student’s Book - Form Two 101

05/10/2024 15:36:37
BIOLOGY FORM 2 NEW.indd 101 05/10/2024 15:36:37
BIOLOGY FORM 2 NEW.indd 101