Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Stage 2 Biology > Topic 3: Homeostasis > Flashcards

Topic 3: Homeostasis Flashcards

1
Q

What is Homeostasis?

A

Maintenance of relatively constant internal environment, ensuring optimum conditions for body to function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the tolerance range?

A

Difference between maximum and minimum tolerance limits.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are abiotic factors that affect tolerance limits in Plants?

A
  • Light (Photosynthesis)
  • Water Availability
  • CO2 concentration
  • pH of soil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are abiotic factors that affect tolerance limits in Animals?

A
  • Body Temperature
  • Water Availability
  • Blood Glucose Levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What makes up the Stimulus Response Model?

A
  1. Stimulus
  2. Receptor
  3. Effectors
  4. Response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a Stimulus? (Stimulus Response)

A

Detectable change in the internal or external environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are Receptors? (Stimulus Response)

A

Detect Stimuli in the body.
Examples:
- Chemoreceptors (blood’s chemical composition)
- Thermoreceptors (temperature)
- Mechanoreceptors (pressure, sound, touch)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are Effectors? (Stimulus Response)

A

Glands or muscles that bring about a response.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the Response? (Stimulus Response)

A

Inhibits/reverses original stimulus

NEGATIVE FEEDBACK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What makes up the Central Nervous System (CNS)? What is its function?

A

Brain and Spinal Cord

Function: Receive messages, process & manage response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What makes up the Peripheral Nervous System (PNS)? What is its Function?

A

All other Nerves

Function: Transmission of info to & from the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the three types of Neurons?

A
  • Sensory neurons
  • Interneurons
  • Motor neurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where are Sensory Neurons located? What is its function?

A

PNS

Function: Send nerve impulses from detected stimulus towards the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where are Interneurons located? What is its function?

A

CNS

Function: Relay signals from sensory neurons to motor neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where are Motor Neurons located? What is its function?

A

PNS

Function: Sends nerve impulses from CNS to effectors (muscles & glands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the nerve cell pathway?

A

Sensory Neuron —-> Interneuron —-> Motor Neuron

17
Q

What is the structure of Nerve Cells?

A

Dendrites - receive impulses from other neurons & transmits info towards cell body.
Cell Body - Contains organelles
Axons - transmits nerve impulses towards another cell
Myelin Sheath - Insulating layer around Axons
Axon Terminals - transmits signals to other cells.

18
Q

What are the structural differences between nerve cells?

A

Size: Sensory & Motor Neurons are Longer
Location of Cell Body:
- Sensory: Axon branches from cell body (to the side)
- Interneuron: Directly between dendrites and axons
- Motor: Dendrites extend directly from cell body

19
Q

What are Reflex Responses?

A

Automatic response to a Stimulus without conscious thought

*Brain is NOT directly involved, ONLY Spinal Cord

20
Q

What is the function of the endocrine system?

A

Produce and secrete hormones that travel around the body via the blood and bind to specific receptors in or on target cells.

21
Q

What are the types of hormones?

A

Peptide - short amino acid chains (∼ 20 amino acids)
Protein hormones - long polypeptide chains
Steroids - Lipids (Hydrophobic - pass through cell membrane)
Amino-Acid derivatives - chemically altered amino acids

22
Q

How do Hydrophilic hormones cause intracellular change?

A

Hydrophilic = Water soluble (cannot pass through cell membrane)
Bind to specific receptor molecules on Target Cells.
Examples: Peptides & Protein hormones

23
Q

How do Hydrophobic hormones cause intracellular change?

A

Hydrophobic = Lipid Soluble (Can pass through cell membrane)
Bind to specific receptors inside the cell.
Examples: All Steroid Hormones

24
Q

What are the differences between the Nervous (NS) and Endocrine systems (ES)?

A

Pathway: Direct Pathway via neurons (NS), Indirect pathway via Blood (ES)
Message type: Electro-chemical (NS), Chemical (ES)
Specificity: Highly Specific target cells (NS), Multiple Target Cells (ES)
Speed: Fast Transmission (NS), Slow Transmission (ES)
Duration: Short-term (NS), Long-term (ES)

25
Q

What is the response to High Blood Glucose Levels?

A
  1. Pancreatic Cells release insulin
  2. Insulin binds to receptor/muscle cells
  3. Muscle & Liver Cells stimulate uptake of Glucose
  4. Blood Glucose Decreases
26
Q

What is the response to Low Blood Glucose Levels?

A
  1. Glucagon is secreted by Pancreas
  2. Stimulates breakdown of Glycogen in Liver
  3. Glucose is released into the blood
  4. High Blood Glucose Levels
27
Q

What is Diabetes Mellitus? (Diabetes)

A

Condition that impairs the body’s ability to process blood glucose

28
Q

What is Type 1 Diabetes?

A

Reduced production of Insulin in pancreas

29
Q

What is Type 2 Diabetes?

A

Body becomes resistant to normal effects of Insulin

30
Q

What is the role of adrenaline in Fight of Flight Responses?

A
  • Increases availability of energy ( ↑ aerobic respiration)
  • Triggers breakdown of glycogen
  • ↑ Heart and breathing rate
  • Blood Glucose is directed away from skin, Kidney’s and Digestive Organs
31
Q

What are the responses to High Body Temperature?

A
  1. Hypothalamus — Nerve Impulses — Sweat Glands — Secrete Sweat (Sweat evaporates, removing heat)
  2. Hypothalamus — ↓ secretion of TSH — ↓ secretion of thyroxine
  3. Vasodilation — Increased blood flow near surface of skin — greater heat loss
32
Q

What are the responses to Low Body Temperature?

A
  1. Hypothalamus — Nerve impulses to skeletal muscles — Shivering ( ↑ Respiration)
  2. Hypothalamus — Vasoconstriction — ↓ blood flow near surface of cells — ↓ Heat released
  3. Hypothalamus — Release of TSH — Thyroxine — ↑ heat released by cells
33
Q

What is the response to High Osmolarity (↓ Water Conc.)?

A
  1. Hypothalamus — Stimulates release of ADH
  2. ADH is transported to kidney’s via the blood
  3. ADH binds to target receptors in cells of distal convoluted tubule and collecting ducts
  4. Binding of ADH - ↑ permeability of water (water diffuses into the blood from filtrate)
  5. Osmolarity ↓
    * ↓ Volume of water excreted in Urine*
34
Q

What is the response to Low Osmolarity (↑ Water Conc.)?

A
  1. Hypothalamus inhibits release of ADH
  2. ↓ ADH is transported to kidneys — ↓ permeability to water
  3. ↓ Water is reabsorbed into the blood from filtrate
  4. ↑ Osmolarity
    * ↑ Volume of water excreted in Urine*
35
Q

What is the model answer for responding to change in homeostasis?

A

When the [receptor] detects a change in [factor] that is too [high/low], it will stimulate the synthesis and the secretion of the hormone […]. [Hormone name] will then travel around the body via the blood and bind to specific receptors on […] and thus cause …

Stage 2 Biology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions