Short Answer Study Guide Questions

Question 1

What is homeostasis? Why is it important?

Answer 1

The existence of a stable internal environment within the body. Every living organism with maintain homeostasis to survive.

Question 2

Explain the concept of feedback mechanisms in homeostatic regulation.

Answer 2

Feedback mechanisms are used to deal with stress or anything that disrupts homeostasis.

Question 3

Explain:

• Negative feedback & give examples
• Positive feedback & give examples

Answer 3

• Negative feedback: counteracts the initial stimulus to return the body to homeostasis.

EX (Negative Feedback): body temp rises, this info affects control center, sends signal to blood vessels and sweat glands in skin, responds with increased blood flow to skin (increased sweating) which decreased body temp to restore homeostasis.

• Positive feedback: an initial stimulus produces a response that reinforces that stimulus.

EX (Positive Feedback): Damage to cells in the blood vessel wall releases chemicals that begin the process of blood clotting. The chemicals start chain reactions in which cells start to form a clot. *As clotting continues, each step releases chemicals that further accelerate the process. This patches the vessel wall and stops the bleeding.

Question 4

Describe the overall functions associated with the plasma membrane and which components of the membrane are responsible for those functions.

Answer 4

• Physical isolation: the plasma membrane is a physical barrier that separates the inside of the cell from the very different surrounding extracellular fluid to maintain homeostasis.
• Regulation of exchange with the environment: the PM controls the entry of ions and nutrients, the elimination of wastes, and the release of secretions.
• Sensitivity to the environment: The PM is the first part of the cell affected by changes in the extracellular fluid. Contains molecules that act as receptors, enabling the cell the recognize and respond to specific molecules in its environment.
• Structural support: Specialized connections between plasma membranes, or between membranes and materials outside the cell, give tissues a stable structure.

Question 5

Define intracellular fluid vs. extracellular fluid.

Name the specific examples of each.

Answer 5

Intracellular fluid: Cytosol (the fluid portion of the cytoplasm inside the plasma membrane)- contains dissolved nutrients, ions, soluble and insoluble proteins, and waste products

Extracellular fluid: Interstitial fluid, (watery, surrounding environment outside of the plasma membrane)

Question 6

What are the 4 common passive processes of movement that commonly occur in the body?

Describe each and provide specific examples of each.

Answer 6

1. Diffusion - Movement a of substance from an area where its concentration is relatively high to an area where its concentration is lower. Diffusion occurs until the concentration gradient is eliminated.

EX: Respiration - Oxygen, whose concentration is higher in lungs than that in the blood get diffused into blood and carbon dioxide, whose concentration is higher in blood gets diffused back to lungs.

2. Facilitated diffusion - A passive transport process for compounds that are insoluble in lipids and too large to fit through membrane channels.

EX: Glucose transport - The glucose transporter works with the concentration gradient to move the glucose across the cell membrane.

3. Osmosis - The diffusion of water across a selectively permeable membrane in response to differences in concentration.

EX: Water moves in and out of the kidney structures called nephrons, in order to help balance out your salt and pH levels.

4. Filtration - Movement of fluid across a membrane whose pores restrict the passage of solutes on the basis of size.

EX: The urinary system - works as a filtration system by removing toxins and wastes from your body as urine.

Question 7

What is an endocrine gland? Give examples of specific endocrine glands.

Answer 7

A gland that secretes hormones into the blood and interstitial fluid

EX: Thyroid, pituitary

Question 8

What is an exocrine gland? Give examples of specific exocrine glands.

Answer 8

A gland that secretes onto the body or into a passageway connected to the exterior

EX: Oil, sweat

Question 9

What is the “matrix” of a connective tissue comprised of and why is it important to the tissue?

Answer 9

• Ground substance: varies in consistency from liquid, to gel-like, to solid, depending on specific CT.
• Protein fibers:
  • Collagen: provides strength to tissue
  • Elastic: provides elasticity
  • Reticular: provides support to tissue

The Matrix of the tissue most directly determines the functional qualities of the tissue.