Homeostasis and Chemical composition in the body

Question 1

What is tissue, and how is it defined?

Answer 1

Tissue is an aggregate of differentiated cells with similar properties.

Question 2

Name the major categories of distinct cells involved in cell differentiation.

Answer 2

The major categories are muscle, nervous, epithelial, and connective tissue cells.

Question 3

Define skeletal muscle cells.

Answer 3

Skeletal muscle cells are responsible for voluntary body movements and are attached to bones.

Question 4

Briefly explain the role of cardiac muscle cells.

Answer 4

Cardiac muscle cells contract to pump blood throughout the body and are primarily found in the heart.

Question 5

What are smooth muscle cells specialized for?

Answer 5

Smooth muscle cells are specialized for involuntary movements, such as those in the digestive tract and blood vessels.

Question 6

Define neurons and their primary function.

Answer 6

Neurons are specialized cells that initiate, integrate, and conduct electrical signals to other cells.

Question 7

Name the types of epithelial cells and briefly describe their functions.

Answer 7

Epithelial cell types include cuboidal, columnar, squamous, and ciliated, and they are specialized for selective secretion, absorption of ions and organic molecules, and protection.

Question 8

Define organs and how they are composed.

Answer 8

Organs are composed of two or more types of tissue working together to perform specific functions.

Question 9

Explain what an organ system is.

Answer 9

An organ system is a group of organs that collaborate to perform an overall function within the body.

Question 10

Name the main types of body fluids and their percentages in the body.

Answer 10

Body fluids include intracellular (67%), plasma (7%), and interstitial fluid (26%).

Question 11

What is the concept of dynamic constancy in the body?

Answer 11

Dynamic constancy means that a variable may fluctuate in the body in the short term but remains stable and predictable in the long term.

Question 12

What is homeostasis, and why is it important?

Answer 12

Homeostasis is a state of steady equilibrium in which a variable remains stable. It is crucial for maintaining the body’s internal environment within certain limits to ensure optimal functioning.

Question 13

What are negative and positive feedback mechanisms, and how do they work?

Answer 13

Negative feedback minimizes deviations from a set point by initiating responses that counteract the original change. Positive feedback accelerates a process, pushing the variable further from the set point.

Question 14

What can happen if a negative feedback mechanism is removed from a biological system?

Answer 14

If a negative feedback mechanism is removed, it can lead to an uncontrolled increase in the production of a product, potentially depleting the available substrate and disrupting the system’s balance.

Question 15

Describe the concept of a reflex arc.

Answer 15

A reflex arc involves a sequence of events from stimulus detection by a receptor, sending a signal to an integrating center through an afferent pathway, followed by a signal along the efferent pathway to the effector. Hormones can also act as effectors in some cases.

Question 16

What could occur in the efferent pathway of the control system if the body’s temperature increased above normal?

Answer 16

If the body’s temperature increased above normal, the efferent pathway could respond by either turning off or becoming reserved. For example, shivering (muscle contraction) would not occur, and blood vessels in the skin would dilate to facilitate heat dissipation, resulting in increased heat loss from the body.

Question 17

What types of chemical messengers play a role in homeostasis?

Answer 17

Chemical messengers in homeostasis include hormones (from endocrine glands), neurotransmitters (released by neurons), paracrine substances (for local communication), and autocrine substances (self-signaling by a cell).

Question 18

Explain the concept of acclimatization in homeostasis.

Answer 18

Acclimatization refers to the improved functioning of an existing homeostatic system, often induced by prolonged stress, resulting in reversible changes and genetic adaptations to enhance performance under new conditions

Question 19

What are the four primary types of organic molecules found in the body?

Answer 19

The four primary types of organic molecules in the body are carbohydrates, lipids, proteins, and nucleic acids.

Question 20

Why are carbohydrates important for the body, and what elements do they consist of?

Answer 20

Carbohydrates are essential for providing energy to the body. They consist of carbon, hydrogen, and oxygen atoms.

Question 21

Describe the different types of carbohydrates and provide an example of each.

Answer 21

Carbohydrates come in various types, including monosaccharides (e.g., glucose), disaccharides (e.g., sucrose), and polysaccharides (e.g., glycogen).

Question 22

Why is glycogen significant for our body?

Answer 22

Glycogen serves as an important energy storage molecule in the body, acting as a reservoir for quick energy release.

Question 23

How does the ability to convert glucose into glycogen relate to the fundamental principles of physiology?

Answer 23

The process involves transferring glucose from the bloodstream to liver cells, where it can be polymerized into glycogen. Subsequently, hepatic glycogen can be broken down into numerous glucose molecules, which are then released into the bloodstream and transported to all cells. The breakdown of glucose within cells provides the necessary energy for most cellular activities. Consequently, storing glucose as glycogen represents an efficient method of energy storage, which can be utilized when the body’s energy demands rise. This mechanism aligns with the core principles of physiology concerning energy balance and utilization.

Question 24

Explain the various types of lipids, including their structures.

Answer 24

Lipids include fatty acids (saturated, monounsaturated, polyunsaturated), triglycerides (glycerol linked to three fatty acids), phospholipids, and steroids (such as cholesterol).

Question 25

What is a protein, and how are they structured?

Answer 25

Proteins are composed of 20 different amino acids linked together by peptide bonds formed between the amino group of one amino acid and the carboxyl group of another.

Question 26

How can you describe a protein’s structure?

Answer 26

Protein structure includes primary (amino acid sequence), secondary (e.g., beta-pleated sheets and alpha helices), tertiary (3-D conformation), and quaternary (multiple polypeptide chains) structures.

Question 27

How do the terms polypeptide and protein differ from each other?

Answer 27

The distinction lies in their characteristics. A polypeptide refers to a structural unit comprising two or more amino acids bonded together by peptide bonds, without implying any specific function. In contrast, a protein is a functional molecule resulting from the intricate folding of a polypeptide into a characteristic shape or conformation.

Question 28

What are nucleic acids, and what are their functions in the body?

Answer 28

Nucleic acids, like DNA and RNA, store and decode genetic information, providing instructions for various cellular processes.

Question 29

What are the types of nucleotides found in DNA, their bases, and base pairing?

Answer 29

DNA consists of purine bases (adenine and guanine) and pyrimidine bases (cytosine and thymine). Base pairing involves G-C pairing and A-T pairing, with 3 and 2 hydrogen bonds, respectively.

Question 30

What are the key differences between DNA and RNA?

Answer 30

RNA consists of a single chain, contains ribose sugar (instead of deoxyribose), and replaces thymine with uracil (U), while DNA is double-stranded with deoxyribose sugar and includes thymine (T) instead of uracil (U).