Question

QUESTION 23

1. ___ is produced from hypothalamus and released from posterior pituitary gland.

   		ACTH
   		ADH
   		Growth hormone
   		Prolactin

QUESTION 24

1. The blind spot of the eye is where ___.

   		the optic nerve leaves the eye
   		more rod cells are found than cone cells
   		the macula lutea is located
   		only cone cells exist

1 points   

QUESTION 25

1. Which of the following is responsible for the coordination of muscle movement?

   		pons
   		hypothalamus
   		cerebellum
   		medulla oblongata

1 points   

QUESTION 26

1. The aqueous humor ___.

   		is located in the posterior segment of eye
   		returns to blood through scleral venous sinus
   		is produced only in embryos
   		is a viscous gel-like material

1 points   

QUESTION 27

1. Which of the following statements about hormones is FALSE?

   		Hormones are released by endocrine cells.
   		Hormones directly control nervous system.
   		Hormones are carried to their targets through blood circulation.
   		Hormones only work on cells with the appropriate receptors.

Answer 1

Question 23.

ADH is produced from hypothalamus and released from posterior pituitary gland.

Explanation: ADH (antidiuretic hormone) is produced from the hypothalamus and carried to the posterior pituitary gland where it is stored and released when required. ADH acts on the distal tubule of the nephron and increases the reabsorption of water. Oxytocin is another such hormone produced by hypothalamus and released by posterior pituitary gland.

ACTH, growth hormone, prolactin are synthesized and released by anterior pituitary gland. ACTH (adrenocorticotropic hormone) acts on the adrenal gland and produces adrenocorticosteroids like glucocorticoids, mineralocorticoids and androgens. Growth hormone causes growth, development and repair of body tissues. Prolactin acts on the mammary gland and causes the production of milk.

Question 24.

The blind spot of the eye is where:

Answer: the optic nerve leaves the eye

Explanation: The point where the optic nerve leaves the eye lacks photoreceptor cells of retina (rods and cones). As there are no photoreceptors at this point, there is no perception of light or no image detection. This is known as physiological blind spot. Optic disc is the area from which optic nerve leaves the eye and this corresponds to the blind spot.

Question 25.

Which of the following is responsible for co ordination of muscle movement?

Answer: Cerebellum.

Explanation: Cerebellum is concerned with planning, programming and find tuning of voluntary movements. It also maintains the tone and posture of the body. It also has role in balance and equilibrium of the body.

Pons has nuclei of VIth, VIIth, VIIIth cranial nerves. The sensory nuclei of Vth cranial nerve is also in pons. Pons regulates breathing along with medulla oblongata.

Hypothalamus is the master endocrine controller as it controls the pituitary gland which is the most important endocrine gland controlling most of the other endocrine glands in the body.

Medulla oblongata along with pons controls breathing. It also has the vasomotor and cardiac center regulating the blood pressure and heart rate respectively.

Question 26.

The aqueous humor:

Answer: returns to the blood through scleral venous sinus.

Explanation: Aqueous humor is a watery fluid produced by the ciliary epithelium of the eyes. It is present in the anterior chamber and posterior chamber of the anterior segment of the eye. It is not present in the posterior segment of the eye as the posterior segment of the eye contains vitreous humor. It is not gel like but watery like thin fluid. It is also produced in adult life.

Question 27.

Which of the following statements about hormones is false?

Answer: Hormones directly control nervous system.

Explanation: Hormones do not directly control nervous system. Rather the endocrine system is under the control of hypothalamus of nervous system. Thus, nervous system and endocrine system work together to main the various physiological processes of the body and maintain a state of homeostasis.

Hormones are chemical messengers most commonly proteins which are produced by endocrine glands (ductless glands) and released directly into the blood stream. Hormones reach their target tissue via blood stream and acts on specific receptors to bring about various functions.