Thermoregulation, Tissue Physiology, and Protein Function Flashcards

Flashcards created from the lecture material covering systems, thermoregulation reflex arcs, hypothalamic neurons, protein stability, epithelial tissue structures, and cellular junctions.

Which of the following would best be classified as a system?

A bicycle with pedals, gears, and wheels working together.

Why are proteins sensitive to environmental factors like extreme pH or temperature?

Harsh environmental conditions can cause a protein to lose its shape, resulting in a loss of function.

What is the functional role of an integration center in a thermoregulatory reflex arc?

It compares sensory input to the set point and initiates appropriate responses.

What is the correct sequence in which the human body regulates internal body temperature?

External temperature (stimulus) $\rightarrow$ heat receptor $\rightarrow$ afferent neurons $\rightarrow$ hypothalamus $\rightarrow$ efferent neurons $\rightarrow$ effectors $\rightarrow$ dilation of blood vessels and increased sweat production (effector response).

Which damage to the hypothalamus would most likely result in increased sweating at lower temperatures?

A direct injury to I neurons resulting in decreased firing.

What is the correct order of the layers of the epidermis, from deepest to most superficial, in thick skin?

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum.

What issue would a person experience if they have a condition affecting gap junctions?

Lack of communication between adjacent cells.

Why does the epithelial layer of the skin (epidermis) rely on the underlying connective tissue layer (dermis) for nutrient supply?

Epithelial tissue is avascular; the dermis provides the closest blood supply to deliver nutrients.

Which neurotransmitter is released by sympathetic neurons to activate eccrine sweat glands?

Acetylcholine.

Which structural feature of sweat gland epithelial cells ensures directional secretion of sweat to the skin surface?

Polarized distribution of ion channels and transporters.

Why might disrupting the connection between the I interneuron and the C efferent neuron lead to a significant breakdown in thermoregulation?

Because specific connections between elements are typically essential for the overall function of a biological system.

How does a fever help the body fight off a bacterial infection?

Higher temperatures disrupt weak bonds in bacterial proteins, reducing their function and slowing bacterial growth.

What occurs when cold-sensitive receptors fail to alter their ion channel structure in response to temperature drops?

When the temperature drops, no afferent signal would be generated to inform the integration center.

What is the physiological explanation for a patient being unable to sense heat at and above $52^\circ\text{C}$?

In the heat receptors, the temperature-gated ion channels responsible for detecting heat at $52^\circ\text{C}$ are nonfunctional.

Which statements accurately describe the hypothalamic thermoregulatory center regarding W neurons, I neurons, and efferent neurons?

W neurons are stimulated by warm receptors and inhibit C effector neurons; I neurons fire at a stable rate regardless of temperature changes; and C efferent neurons fire when the input from I neurons exceeds that from W neurons.

If a person is unable to sweat in response to heat, which neural stimulation pathway is disrupted?

Acetylcholine stimulation to eccrine glands.

Which practices can potentially damage the function of a purified protein stored in solution?

Microwaving the solution, adding HCl into the solution, and high-speed and prolonged sonication.

What is the role of acetylcholine in regulating cutaneous blood flow during periods of overheating?

It causes vasodilation in cutaneous vessels to increase heat loss.

What is the primary function of tight junctions between cells?

Tight junctions seal the space between cells to prevent paracellular leakage.

Which bodily structure is considered part of the external environment despite being enclosed within the body?

Lumen of the small intestine.