Module 1 Flashcards

Introduction to Physiology: Regulation & Mechanisms (45 cards)

1
Q

What is physiology?

A

The study of how cells, tissues, organs, and systems function in living organisms.

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2
Q

Define Homeostasis.

A

The dynamic constancy of physiological variables despite external changes.

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3
Q

Name the three type of muscle cells

A

Cardiac, skeletal, and smooth muscle cells.

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4
Q

What is the main function of epithelial cells?

A

Selective secretion, absorption, and protection.

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5
Q

Describe a negative feedback mechanism.

A

A process where a change in a variable is countered to return to a set point.

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6
Q

Give an example of positive feedback.

A

Blood clot formation.

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7
Q

What are the components of a reflex arc?

A

Stimulus, receptor, afferent pathway, integrating centre, efferent pathway, and effector.

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8
Q

What is feedforward regulation?

A

Anticipatory changes in physiological processes to maintain stability.

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9
Q

What is the role of hormones in intercellular communication?

A

Hormones are chemical messengers that travel through the bloodstream to affect distant cells.

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10
Q

Define gap junction communication.

A

Direct transfer of molecules between adjacent cells via cytosol linkages.

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11
Q

What is a circadian rhythm?

A

A biological cycle that repeats approximately every 24 hours.

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12
Q

How does heatstroke relate to homeostasis?

A

Disruption of homeostasis due to excessive heat leads to failure in temperature regulation and hydration balance.

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13
Q

What are the three main types of connective tissue?

A

Loose connective tissue, dense connective tissue, and specialized connective tissues like blood, bone, and cartilage.

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14
Q

Differentiate between simple and stratified epithelium.

A

Simple epithelium is one cell layer thick; stratified epithelium has multiple layers.

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15
Q

What are the two primary functions of the extracellular matrix (ECM)?

A

It provides structural scaffolding for cells and transmits information via chemical messengers to regulate cellular activities.

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16
Q

Name two types of fibers found in the ECM.

A

Collagen fibers and elastin fibers.

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17
Q

What distinguishes pathophysiology from physiology?

A

Physiology refers to maintaining homeostasis, while pathophysiology occurs when homeostasis fails.

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18
Q

What is dynamic constancy in homeostasis?

A

Physiological variables fluctuate within a range but remain relatively constant over time.

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19
Q

Why does positive feedback not regulate physiological variables?

A

It amplifies changes, moving a system further from equilibrium.

20
Q

What is the role of an effector in a reflex arc?

A

It carries out the response to restore homeostasis.

21
Q

How is feedforward regulation different from feedback mechanisms?

A

Feedforward regulation anticipates changes and adjusts before they occur.

22
Q

Provide an example of an organ system and its components.

A

The urinary system includes the kidneys, ureters, bladder, and urethra.

23
Q

What tissues can compose an organ?

A

An organ can include epithelial, connective, muscle, and nervous tissues.

24
Q

What is the difference between plasma and interstitial fluid?

A

Plasma is the fluid portion of blood, while interstitial fluid surrounds cells in tissues.

25
What is the total extracellular fluid composed of?
Plasma and interstitial fluid.
26
How do biological rhythms support homeostasis?
They prepare the body for predictable changes, enabling faster homeostatic responses.
27
What is the difference between adaptation and acclimatization?
Adaptation is a genetic trait for survival, while acclimatization is a physiological adjustment to environmental changes.
28
What distinguishes paracrine signaling from endocrine signaling?
Paracrine signaling acts on nearby cells, while endocrine signaling acts on distant cells through the bloodstream.
29
How does juxtacrine signaling differ from other types of communication?
It requires direct contact between adjacent cells.
30
What are the three states of total-body balance for chemical substances?
Negative balance (loss > gain), positive balance (gain > loss), and stable balance (gain = loss).
31
Why is the “pool” concept important in physiology?
It represents the dynamically regulated concentration of substances like glucose in the body.
32
What is the dual role of glands in homeostatic reflexes?
Glands can act as receptors and integrating centers while secreting hormones as effectors.
33
Why can norepinephrine function as both a hormone and a neurotransmitter?
Its effects depend on its mode of release and the target it acts on.
34
In the case of heatstroke, why did the man stop sweating?
The body’s thermoregulatory mechanism failed, disrupting homeostasis.
35
How does fainting relate to disrupted homeostasis?
Low blood pressure and dehydration impaired the body’s ability to deliver oxygen and nutrients to tissues
36
The surprise of a phone call at 3:00 am results in an increase in heart rate. This is an example of a
acute change.
37
If an animal permits internal and external conditions to be equal, it is said to show -------------.
conformity
38
Rainbow trout captured and brought into a lab aquarium undergo a chronic adjustment to the conditions in the lab. This process is called --------------.
acclimation
39
During childbirth, muscular contractions acting to expel the fetus from the uterus induces hormonal signals that induce even more intense contractions. This is an example of ----------.
positive feedback.
40
Most of the fluid in the body is located in the
Intracellular compartment
41
How do nonpolar molecules diffuse through the hydrophobic portions of the cell membrane?
Nonpolar molecules diffuse through the membrane because they can dissolve in the fatty acid tails of the lipid bilayer.
42
A paracrine is a chemical factor released by cells that acts on neighboring cells by -----
Diffusing through the extracellular fluid, without entering the bloodstream.
43
What are the functions of cholesterol molecules within a cell membrane?
1. To limit the ordered packing of fatty acids, maintaining membrane fluidity. 2. To form lipid rafts, which are specialized membrane regions. 3.To participate in intracellular signaling.
44
What are parts of the desmosomes ?
1. Dense plaques proteins. 2. Cadherins. 3. Keratin.
45
What is the difference between saturated and unsaturated fatty acids in phospholipid tails?
1. Saturated fatty acids: Contain no double bonds between carbon atoms and are fully saturated with hydrogen atoms, resulting in straight tails. 2. Unsaturated fatty acids: Contain one or more double bonds between carbon atoms, leading to bends of approximately 30 degrees in the tail.