Human Circulatory System Review

Fill-in-the-blank practice flashcards covering human circulation, cardiac cycle, blood vessels, blood pressure, and blood composition from Class 9 Biology study notes.

Transpiration creates a __________ force necessary for pulling water upward through the xylem in plants.

suction

In human beings, substances are transported throughout the body via extracellular fluids, primarily blood and __________.

lymph

The heart is made up of specialized __________ muscles that exhibit continuous, involuntary, rhythmic contraction and relaxation without fatigue.

cardiac

The opening between the Right Auricle and Right Ventricle is guarded by the __________ Valve.

Tricuspid

The opening between the Left Auricle and Left Ventricle is guarded by the __________ Valve.

Bicuspid (Mitral)

Oxygenated blood travels from the lungs to the Left Auricle via the __________ Vein.

Pulmonary

Deoxygenated blood returns from body organs to the Right Auricle through the __________.

Vena Cava

The vessel that carries oxygenated blood from the Left Ventricle to different body organs is the __________.

Aorta

The vessel that carries deoxygenated blood from the Right Ventricle to the lungs is the __________ Artery.

Pulmonary

All sequential mechanical events occurring during a single heartbeat are collectively termed the __________ cycle.

cardiac

A single cardiac cycle lasts approximately __________.

$$0.4\,seconds$$

During auricular systole, both auricles contract simultaneously while ventricles undergo __________.

relaxation

Microscopic blood vessels that are only a single cell thick are called __________.

Capillaries

The vascular hierarchy follows the pathway: Artery ➔ Arteriole ➔ Capillary Network ➔ __________ ➔ Vein.

Venule

The pressure exerted on structural walls of arteries during ventricular contraction is systolic pressure, which equals __________.

$$120\,mm\,Hg$$

The pressure exerted on structural walls of arteries during ventricular relaxation is diastolic pressure, which equals __________.

$$80\,mm\,Hg$$

Hypertension is defined as a persistent blood pressure reading of __________ or higher.

$$140/90\,mm\,Hg$$

The instrument used to measure blood pressure is a __________.

Sphygmomanometer

An average adult human possesses approximately __________ of blood.

$$5.5\,Liters$$

Plasma makes up __________ of the total volume of human blood.

$$55\% \text{ – } 60\%$$

The plasma protein essential for blood clotting is __________.

Fibrinogen

Red Blood Cells (Erythrocytes) have an average lifespan of __________.

$$120\,days$$

One hemoglobin molecule can bind up to __________ molecules of oxygen ($O_2$).

$$4$$

When carbon monoxide binds with hemoglobin, it forms a highly stable compound called __________.

Carboxyhaemoglobin

White blood cells that produce protective antibodies to neutralize and kill pathogens are called __________.

Lymphocytes

White blood cells that perform phagocytosis by engulfing and digesting pathogens are called __________.

Monocytes

Cell fragments responsible for initiating blood coagulation at injury sites are called __________ (Thrombocytes).

Platelets