The specialised patch of modified heart muscles from where contraction initiates is/are :
Which of the following blood components play a major role in blood coagulation?
In the systemic circulation, the blood vessel that carries blood from the intestine to the liver is named:
The hepatic portal vein carries blood from the intestine to the liver before it is delivered to the systemic circulation.
The pre-hypertension blood pressure value is a measurement between:
The statement incorrect about the human heart is:
Through this streak, cells migrate from the upper layer by the process called gastrulation to form the three germ layers of the embryo proper: the ectoderm, the endoderm, and the mesoderm.The cells that are destined to form the heart are also derived from this mesodermal layer.
The cardiovascular centre is located in:
The cardiovascular centre is a part of the human brain responsible for the regulation of the rate at which the heart beats through the nervous and endocrine systems. It is found in the medulla oblongata.
Where (a) is a neutrophil, identify the other four WBCs?
(a) When circulating in the bloodstream and inactivated, neutrophils are spherical.
Once activated, they change shape and become more amorphous or amoeba-like and can extend pseudopods as they hunt for antigens.
(b) Eosinophil cells are 12 - 17 µm in diameter - larger than neutrophils, and about 3 times the size of a red blood cell. You can see that eosinophils only have two lobes to their nucleus.
(c) In blood, basophils are round, but the shape changes as they migrate into tissues. They generally have a multilobed nucleus and no evidence of nucleoli.
Basophils also have an abundance of condensed chromatin around the periphery of the nucleus.
(d) Monocytes are the largest type of white blood cells and can be up to 20µm in diameter.
They have a large eccentrically placed nucleus, which is kidney bean-shaped. They have abundant cytoplasm and some fine pink/purple granules in the cytoplasm.
(e) Lymphocytes can look like monocytes, except that lymphocytes do not have a kidney-bean shaped nucleus, and lymphocytes are usually smaller.
They have a small spherical nucleus and have abundant dark staining condensed chromatin. Not much cytoplasm can be seen, and it is basophilic (pale blue/purple staining).
The layer of heart pericardium which checks its overstretching and overfilling as well as also protects the heart from mechanical injury is:
The pericardium is the protective covering of the heart. The pericardium is made of different layers to perform different functions.
The layer of heart pericardium which checks its overstretching and overfilling as well as protects the heart from mechanical injury is fibrous pericardium.
Prothrombin plays a crucial role in blood coagulation and vitamin K is considered essential for blood clotting, now read the following:
(i) Vitamin K is necessary for the synthesis of prothrombin in the liver.
(ii) Vitamin K is necessary for the synthesis of prothrombin in the bone marrow.
(iii) Vitamin K is necessary for the conversion of prothrombin into active thrombin.
Prothrombin plays a crucial role in blood coagulation and vitamin K is essential for blood clotting.
Vitamin K is necessary for the synthesis of prothrombin in the liver.
Rh incompatibility develops when:
A special case of Rh incompatibility (mismatching) has been observed between the Rh-ve blood of a pregnant mother with Rh+ve blood of the foetus.
Match Column 1 with Column 2.
Mayank stood still for a long time and he felt swelling of feet. What would you suggest to him:
During long hours of standing still swelling of feet is observe due to accumulation of blood in the lower limb, due to gravitation effect. This can be corrected by a jerk or wriggle of legs to restart circulation properly.
The middle man of our body is:
Lymph is the extracellular fluid that contains WBC’s and plasma. Lymph flows in the lymphatic system and finally drains into veins. Lymph is known as the middle man of our body.
Read the following and choose the correct option:
(i) Blood vessels include arteries and veins. Arteries carry blood from the heart to body parts and veins bring back blood from the body parts to the heart.
(ii) The blood vessel which carries blood from the heart to the lungs is a pulmonary artery and it carries oxygenated blood.
Angina pectoris is very often mistaken for:
Angina pectoris is the sensation of chest pain, pressure or squeezing or pain in the centre of the chest. These symptoms are often mistaken by indigestion.
Correct order for the increasing number of corpuscles in our blood is:
When body tissues are injured resulting in the loss of blood, the process of blood clot begins and the blood platelets release:
During an injury, the blood platelets release thromboplastin which converts plasma protein prothrombin into thrombin in the presence of calcium ions. Thrombin then converts soluble plasma protein fibrinogen into fibrin which forms a meshwork by trapping red blood cells, thus forming a clot.
The list of risk factors associated with hypertension doesn’t include:
Hypertension can cause a number of effects on the functioning of different vital functions but hypertension does not associate with hypoglycemia and diabetes insipidus.
Among mammals, the nucleus is absent in:
The nucleus is absent in mature sieve tube cells and mammalian erythrocytes. Sieve tube is described as the cells of the phloem tissue present in vascular plants. Their function is to translocate and distribute the food material to different parts of the plants. The nucleus of the sieve tube fragmented and disappeared.
On the other side, the mammalian erythrocytes are also known as red blood cells and a major component of the blood. They are formed in the bone marrow. During the process of formation of erythrocytes, the nucleus and mitochondria disappear and are converted to the mature erythrocyte. They possess a red coloured pigment which is known as haemoglobin. Erythrocytes are unable to multiply because they lack a nucleus, and they can survive for 100-120 days.
Read the following and choose the correct option:
(i) The instrument used for recording the heart’s electrical events is named electrocardiograph.
(ii) In any ECG the part of the baseline between any two deflections is called interval.
(iii) Abnormality in the working of heart changes wave pattern of ECG.
All statements are correct as the ECG pattern describes all the abnormalities in the heart.