(SEM II) THEORY EXAMINATION 2018-19 HUMAN ANATOMY AND PHYSIOLOGY II

B.Pharm (Sem II) – Human Anatomy and Physiology-II

Detailed Explanation of Questions and Answers

Human Anatomy and Physiology focuses on the structure and functions of different organs and systems in the human body. Anatomy describes the physical structure of organs, while physiology explains how these organs perform biological processes necessary for life. This subject is essential for pharmacy students because medicines interact with various physiological systems in the body. 

Section A – Detailed Answers

Residual Volume and Inspiratory Reserve Volume

Residual volume refers to the amount of air that remains in the lungs after maximum exhalation. This air prevents lung collapse and allows continuous gas exchange even after forceful breathing.

Inspiratory reserve volume refers to the additional amount of air that can be inhaled after a normal inhalation. It represents the extra breathing capacity of the lungs.

These lung volumes are important for assessing respiratory efficiency.

Autocrine and Paracrine Glands

Autocrine signaling occurs when a cell releases chemical messengers that act on the same cell that produced them.

Paracrine signaling occurs when cells release signaling molecules that act on nearby cells in the surrounding tissue.

Both mechanisms are important for local cellular communication.

Role of CCK and Secretin in Digestion

Cholecystokinin (CCK) and secretin are hormones involved in the intestinal phase of digestion.

CCK stimulates the pancreas to release digestive enzymes and causes the gallbladder to release bile into the small intestine.

Secretin stimulates the pancreas to release bicarbonate-rich fluid that neutralizes acidic chyme entering the intestine from the stomach.

Functions of Cerebellum

The cerebellum is a part of the brain responsible for coordination and balance.

It helps regulate voluntary movements and ensures smooth execution of motor activities. The cerebellum also maintains posture and muscle tone.

Damage to the cerebellum can cause loss of coordination and balance.

Net Filtration Pressure

Net filtration pressure is the force that drives filtration of blood plasma through the glomerular capillaries in the kidneys.

It is determined by the balance between hydrostatic pressure pushing fluid out of the capillaries and osmotic pressure pulling fluid back into the capillaries.

This pressure determines the rate of filtration in the kidneys.

Brush Border Enzymes

Brush border enzymes are digestive enzymes located on the surface of epithelial cells in the small intestine.

These enzymes complete the final stages of digestion by breaking down carbohydrates and peptides into absorbable molecules.

Examples include maltase, sucrase, and lactase.

Thyroxine Hormone

Thyroxine hormone is released by follicular cells of the thyroid gland.

This hormone regulates metabolism, growth, and energy production in the body.

Functions of Hypothalamus

The hypothalamus is a small region of the brain that regulates many important physiological processes.

It controls body temperature, hunger, thirst, and hormone secretion from the pituitary gland. It also plays a role in emotional responses and circadian rhythms.

Gametogenesis

Gametogenesis is the process through which reproductive cells called gametes are produced.

In males, the process is called spermatogenesis and occurs in the testes.

In females, it is called oogenesis and occurs in the ovaries.

Connection Between Cerebral Hemispheres

The two hemispheres of the cerebrum are connected by a large bundle of nerve fibers called the corpus callosum.

This structure allows communication between the left and right hemispheres of the brain.

Section B – Detailed Explanation

Mechanism of Respiration

Respiration is the process by which oxygen is taken into the body and carbon dioxide is removed.

During inhalation, the diaphragm contracts and moves downward while the rib cage expands. This increases the volume of the thoracic cavity and allows air to enter the lungs.

Oxygen diffuses from the alveoli into the bloodstream and binds with hemoglobin in red blood cells. The oxygen-rich blood is then transported to tissues throughout the body.

Structure and Function of Cerebrum

The cerebrum is the largest part of the brain and is responsible for higher mental functions.

It is divided into two hemispheres and several lobes including frontal, parietal, temporal, and occipital lobes.

The cerebrum controls voluntary movements, sensory perception, memory, learning, and decision-making.

Digestive System and Small Intestine

The digestive system consists of organs that break down food into nutrients that can be absorbed by the body.

The small intestine is the primary site of digestion and absorption. It is divided into three parts: duodenum, jejunum, and ileum.

Digestive enzymes and bile act in the small intestine to break down carbohydrates, proteins, and fats.

Section C – Detailed Explanation

Neurohumoral Transmission in CNS

Neurohumoral transmission refers to communication between neurons through chemical messengers called neurotransmitters.

When an electrical impulse reaches the end of a neuron, neurotransmitters are released into the synaptic cleft. These molecules bind to receptors on the next neuron and generate a new electrical signal.

This process allows neurons to communicate and coordinate body functions.

Gastric Acid Secretion

Gastric acid is produced by parietal cells in the stomach.

The secretion of acid occurs in three phases: cephalic phase, gastric phase, and intestinal phase.

Hormones such as gastrin and neural signals stimulate acid secretion, which helps digest proteins and destroy microorganisms in food.

Female Reproductive Cycle

The female reproductive cycle, also known as the menstrual cycle, typically lasts about 28 days.

It involves several phases including the menstrual phase, follicular phase, ovulation phase, and luteal phase.

Hormones such as estrogen and progesterone regulate these phases and prepare the uterus for possible pregnancy.

Thyroid Hormone Regulation

Thyroid hormones are synthesized in the thyroid gland from iodine and the amino acid tyrosine.

The secretion of thyroid hormones is regulated by thyroid-stimulating hormone released from the pituitary gland.

These hormones regulate metabolism and energy production.

Structure of Liver and Role of Bile

The liver is the largest internal organ and performs numerous metabolic functions.

It produces bile, which helps digest fats by breaking large fat droplets into smaller particles. This process is known as emulsification.

Bile also helps eliminate waste products from the body.

Renin–Angiotensin–Aldosterone System (RAAS)

The RAAS system regulates blood pressure and fluid balance in the body.

When blood pressure decreases, the kidneys release renin. This enzyme converts angiotensinogen into angiotensin I.

Angiotensin I is converted into angiotensin II, which causes blood vessels to constrict and stimulates the release of aldosterone.

Aldosterone increases sodium and water retention, raising blood pressure.

Reflex Action and Reflex Arc

A reflex action is a rapid and automatic response to a stimulus.

The pathway through which a reflex occurs is called the reflex arc. It includes a receptor, sensory neuron, integration center in the spinal cord, motor neuron, and effector organ.

Reflex actions help protect the body from injury and allow quick responses to environmental changes.

Conclusion

Human Anatomy and Physiology explains how different organs and systems work together to maintain life. Understanding these processes is important for pharmacy students because many drugs interact with physiological pathways in the body.

Knowledge of organ functions, hormonal regulation, and neural communication helps healthcare professionals understand disease mechanisms and develop effective treatments.