Homeostasis and Chemical composition in the body Flashcards
(30 cards)
What is tissue, and how is it defined?
Tissue is an aggregate of differentiated cells with similar properties.
Name the major categories of distinct cells involved in cell differentiation.
The major categories are muscle, nervous, epithelial, and connective tissue cells.
Define skeletal muscle cells.
Skeletal muscle cells are responsible for voluntary body movements and are attached to bones.
Briefly explain the role of cardiac muscle cells.
Cardiac muscle cells contract to pump blood throughout the body and are primarily found in the heart.
What are smooth muscle cells specialized for?
Smooth muscle cells are specialized for involuntary movements, such as those in the digestive tract and blood vessels.
Define neurons and their primary function.
Neurons are specialized cells that initiate, integrate, and conduct electrical signals to other cells.
Name the types of epithelial cells and briefly describe their functions.
Epithelial cell types include cuboidal, columnar, squamous, and ciliated, and they are specialized for selective secretion, absorption of ions and organic molecules, and protection.
Define organs and how they are composed.
Organs are composed of two or more types of tissue working together to perform specific functions.
Explain what an organ system is.
An organ system is a group of organs that collaborate to perform an overall function within the body.
Name the main types of body fluids and their percentages in the body.
Body fluids include intracellular (67%), plasma (7%), and interstitial fluid (26%).
What is the concept of dynamic constancy in the body?
Dynamic constancy means that a variable may fluctuate in the body in the short term but remains stable and predictable in the long term.
What is homeostasis, and why is it important?
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.
What are negative and positive feedback mechanisms, and how do they work?
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.
What can happen if a negative feedback mechanism is removed from a biological system?
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.
Describe the concept of a reflex arc.
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.
What could occur in the efferent pathway of the control system if the body’s temperature increased above normal?
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.
What types of chemical messengers play a role in homeostasis?
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).
Explain the concept of acclimatization in homeostasis.
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
What are the four primary types of organic molecules found in the body?
The four primary types of organic molecules in the body are carbohydrates, lipids, proteins, and nucleic acids.
Why are carbohydrates important for the body, and what elements do they consist of?
Carbohydrates are essential for providing energy to the body. They consist of carbon, hydrogen, and oxygen atoms.
Describe the different types of carbohydrates and provide an example of each.
Carbohydrates come in various types, including monosaccharides (e.g., glucose), disaccharides (e.g., sucrose), and polysaccharides (e.g., glycogen).
Why is glycogen significant for our body?
Glycogen serves as an important energy storage molecule in the body, acting as a reservoir for quick energy release.
How does the ability to convert glucose into glycogen relate to the fundamental principles of physiology?
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.
Explain the various types of lipids, including their structures.
Lipids include fatty acids (saturated, monounsaturated, polyunsaturated), triglycerides (glycerol linked to three fatty acids), phospholipids, and steroids (such as cholesterol).
