Physiology and Homeostasis Fundamentals

Comprehensive flashcards covering the definitions of physiology and homeostasis, body systems, and the mechanisms of positive and negative feedback as discussed in the lecture by Dr. NMKL.

How is physiology defined in the lecture?

The study of the process and functions of the body.

What is the basic structure of the human body?

The Cell.

What is the primary difference between unicellular and multicellular organisms regarding vital processes?

In unicellular organisms, all vital processes occur in a single cell, whereas in multicellular organisms, specialized cells group together to take on special functions.

What is the primary function of the Cardiovascular System?

Moves the blood around the body and perfuses tissues.

What is the primary function of the Respiratory System?

Supplies oxygen and removes carbon dioxide.

What is the primary function of the Nervous System?

Control of the whole body.

What is the function of the Gastrointestinal System?

To digest and absorb food.

What are the dual functions of the Urinary System?

Removes waste product and balances fluid.

What is the function of the Reproductive System?

Perpetuates the species.

How is Homeostasis defined?

A state of relative constancy of the internal environment of the body as a result of dynamic equilibrium.

How does the body respond to increased blood glucose levels after food absorption?

Increased blood glucose causes the release of insulin from the pancreas, which binds to cells to cause the uptake of glucose, returning blood glucose to a normal state.

What organ serves as the Thermoregulatory center for monitoring and adjusting body temperature?

The Hypothalamus.

During hot weather, how does the brain trigger heat loss through skin vessels?

The brain sends impulses to skin vessels causing Vasodilation.

How do sweat glands contribute to heat loss during hot weather?

The brain sends impulses to sweat glands resulting in sweating followed by evaporation.

During cold weather, how does the body prevent heat loss via skin vessels?

The brain sends impulses to skin vessels resulting in vasoconstriction.

What are the three components of a system that achieves homeostasis?

A Detector, a Regulator, and an Effector.

In a homeostatic system, what is the role of the Detector?

It detects deviation from normal (the stimulus).

In a homeostatic system, what is the role of the Regulator?

It receives information from the detector and sends impulses to effector organs.

What are the two possible types of responses from an Effector?

A counteraction (negative feedback mechanism) or a greater deviation of the stimulus from the normal value.

In the maintenance of blood pressure via negative feedback, what acts as the Detector for increased BP?

The baroreceptor.

Where is the integrating center (regulator) located for blood pressure regulation?

The brain stem.

What are six examples of negative feedback mechanisms mentioned in the text?

(1) Thermoregulation, (2) Blood pressure regulation, (3) Blood glucose regulation, (4) Hormone regulation, (5) Red Blood cell production, and (6) Osmoregulation.

How is a Positive Feedback mechanism described?

The initial stimulus is reinforced and amplified, leading to an increase in the effect rather than returning to the baseline state.

What are the steps of the Parturition reflex, a positive feedback mechanism?

Contraction of the uterus $\rightarrow$ descent of fetus in birth canal $\rightarrow$ discharge of stretch receptors in birth canal $\rightarrow$ release of oxytocin from the posterior pituitary $\rightarrow$ further contraction of the uterus.

What are four examples of positive feedback mechanisms?

(1) Uterine contraction during childbirth, (2) Blood clotting, (3) Lactation, and (4) Action potential.