(2) When insulin secretion in human body is insufficient, the functions of synthesizing glycogen and decomposing blood sugar will be weakened, which will lead to the increase of blood sugar concentration and exceed the normal value, and some blood sugar will be excreted with urine, which is one of the characteristics of diabetes. Therefore, urine may contain glucose. For diabetic patients, insulin preparations can be treated by injection. Protein can only be injected, not taken orally. Therefore, if the urine contains a lot of glucose, it is not a kidney disease.
(3) During strenuous exercise, metabolic wastes are mainly produced by skeletal muscle, which is an organ composed of various tissues. Please give an example of which tissues are distributed in skeletal muscle, such as epithelial tissue (inner wall of blood vessels in muscle), muscle tissue (skeletal muscle), connective tissue (tendons at both ends of skeletal muscle and membrane on the surface) and nerve tissue (nerve tissue).
(4) Metabolic waste produced by the fetus is discharged with the help of the mother, which is related to the uterus, umbilical cord, placenta and other structures. Please complete the connection sequence of mother, fetus, uterus, umbilical cord and placenta: mother → placenta → umbilical cord → fetus.
(5) Reflex refers to the regular response of the human body to internal and external environmental stimuli with the participation of the nervous system. The basic way of nerve regulation is reflex, and the structural basis of reflex activity is called reflex arc, which includes receptor, afferent nerve, nerve center, efferent nerve and effector. When the urine in the bladder accumulates to a certain amount, the pressure generated by the urine will stimulate the receptors of the bladder, and then the urine will be discharged from the bladder through the urethra through neuroregulation, which is called micturition reflex.
(6) The route of oxygen from lung to small intestine is: oxygen in lung → pulmonary vein → left atrium → left ventricle → aorta → small intestinal artery → small intestine. According to this method, the pathway of carbon dioxide produced by kidney to lung is → renal vein → systemic vein → inferior vena cava → right atrium → right ventricle → pulmonary artery → lung.
So the answer is:
(1) glomerular filtration;
(2) insulin;
(3) Epithelial tissue; Muscle tissue, connective tissue, nerve tissue.
(4) Placenta → umbilical cord → fetus;
(5) receptor;
(6)→ renal vein → systemic vein → inferior vena cava → right atrium → right ventricle → pulmonary artery → lung.