3B4 Structure and Function of Animal Systems Flashcards
Describe how animal systems maintain homeostasis, support growth, and defend against disease through various physiological processes and immune functions.
Define:
Homeostasis
The process of maintaining stable internal conditions.
It regulates factors like temperature, pH, and glucose to ensure proper functioning.
Why is homeostasis important?
It ensures optimal conditions for cellular functions.
Maintaining stability allows processes like enzyme activity to occur efficiently.
What is the body’s reaction to a stimulus called?
Response
Being able to respond to a stimulus helps organisms react to environmental changes, maintaining homeostasis or adapting to new conditions.
True or False:
Negative feedback helps to restore balance in the body.
True
Negative feedback mechanisms are essential for maintaining homeostasis by reducing deviations from the set point.
Fill in the blank:
The body maintains blood glucose levels through _________ feedback.
negative
The pancreas releases insulin to lower blood glucose and glucagon to raise it, maintaining a stable level in the blood.
What is positive feedback?
A mechanism that amplifies a change.
It accelerates processes in the body. For example, childbirth involves a positive feedback loop of oxytocin and pressure that leads to more and more uterine contractions. This process continues until the baby is born.
What is the primary difference between positive and negative feedback?
Negative feedback counteracts changes; positive feedback amplifies them.
Negative feedback maintains stability, while positive feedback accelerates processes.
What is thermoregulation?
The regulation of body temperature.
It involves sweating, shivering, and adjusting blood flow to maintain stability.
True or False:
Positive feedback maintains homeostasis.
False
Positive feedback amplifies changes, which doesn’t stabilize conditions.
What do organs or cells that carry out responses called?
Effectors
Effectors perform actions like sweating or muscle contraction to restore homeostasis.
What is the regulation of water and salt balance called?
Osmoregulation
It helps maintain fluid balance, which is essential for proper cell function.
Fill in the blank:
Blood glucose levels are regulated by _________ feedback.
negative
Insulin and glucagon balance blood glucose levels through negative feedback.
What happens when blood pressure drops?
Blood vessels constrict, and heart rate increases.
These responses help restore normal blood pressure.
True or False:
Feedback mechanisms regulate blood pressure.
True
Negative feedback helps maintain stable blood pressure by adjusting heart rate and blood vessel diameter.
What is the hypothalamus’ role in homeostasis?
It regulates temperature, hunger, and thirst.
The hypothalamus detects changes and activates appropriate responses to maintain stability.
What happens if the body detects low blood oxygen?
Breathing rate increases.
This response helps bring in more oxygen to restore normal levels.
True or False:
Negative feedback prevents drastic changes.
True
It reduces the impact of stimuli, helping maintain homeostasis.
What is the function of the respiratory system?
To exchange oxygen and carbon dioxide between the body and environment.
The respiratory system includes organs like the lungs and the diaphragm, which facilitate gas exchange through breathing.
What is the function of the alveoli in the lungs?
To exchange gases between the air and the blood.
The alveoli’s thin walls allow oxygen to diffuse into the blood and carbon dioxide to diffuse out.
True or False:
The heart is part of the circulatory system.
True
The heart pumps blood through the circulatory system to distribute oxygen, nutrients, and waste.
What is the role of red blood cells in the circulatory system?
To carry oxygen and carbon dioxide.
Red blood cells contain hemoglobin, which binds to oxygen and carbon dioxide, enabling efficient gas exchange.
Fill in the blank:
The ________ system transports nutrients, gases, and waste products throughout the body.
circulatory
The circulatory system includes the heart, blood vessels, and blood, enabling transport within the body.
What do neurotransmitters do?
They transmit signals between neurons.
Neurotransmitters are chemicals released from neurons to cross synapses and pass information.
True or False:
The nervous system uses electrical signals to communicate between cells.
True
Neurons transmit electrical impulses that carry information quickly throughout the body.
Fill in the blank:
The endocrine system regulates body processes through the release of __________.
hormones
Hormones are chemical messengers produced by glands, affecting various body functions.
What does insulin do in the body?
It helps lower blood glucose levels.
It is produced by the pancreas and helps cells absorb glucose for energy.
What is the primary function of the excretory system?
To remove waste products and maintain water balance.
This system includes the kidneys, bladder, and urethra, which filter blood and eliminate waste.
What organs are involved in the excretory system?
- Kidneys
- Ureters
- Bladder
- Urethra
These organs work together to filter waste from blood and excrete it as urine.
True or False:
The endocrine system uses the bloodstream to deliver signals to target organs.
True
Hormones are secreted by glands and carried by the blood to organs and tissues to regulate processes.
Fill in the blank:
_________ is the process of breaking down food into smaller molecules.
Digestion
This process occurs in the mouth, stomach, and small intestine, using both mechanical and chemical processes.
What is the role of enzymes in digestion?
They break down complex molecules into simpler ones.
They speed up the chemical breakdown of food, facilitating nutrient absorption.
What substance emulsifies fats for digestion?
Bile
It is produced by the liver and stored in the gallbladder, aiding fat digestion in the small intestine.
What is the role of the diaphragm?
It helps control the expansion and contraction of the lungs.
It moves down to allow air in and up to force air out during respiration.
True or False:
The stomach is responsible for nutrient absorption.
False
The stomach primarily breaks down food, while nutrient absorption occurs in the small intestine.
Fill in the blank:
The exchange of oxygen and carbon dioxide occurs in the _________.
alveoli
Oxygen is absorbed into the blood, and carbon dioxide is expelled in the alveoli of the lungs.
What is reproduction?
The process by which organisms produce offspring.
It is essential for the continuation of species. Reproduction can be sexual or asexual, involving different methods of offspring production.
True or False:
Sexual reproduction involves only one parent organism.
False
Sexual reproduction requires two parents (male and female) to combine genetic material and produce offspring.
Fill in the blanks:
In sexual reproduction, the male sex cell is called _______, and the female sex cell is called ______.
sperm; egg
These gametes combine during fertilization to form a zygote.
What is a zygote?
The fertilized egg formed after the sperm and egg unite.
The zygote undergoes multiple divisions and differentiates to form tissues and organs.
True or False:
Development involves changes from fertilization through to maturity.
True
Development encompasses all stages of growth, including embryonic development, childhood, adolescence, and adulthood.
Fill in the blank:
Growth is primarily achieved through _____ __________ and cell differentiation.
cell division
Cell division increases the number of cells, while differentiation ensures those cells perform specialized functions.
Define:
The Immune system
The body’s defense system against harmful pathogens.
It includes various cells, proteins, and organs that work together to detect and destroy pathogens like bacteria, viruses, and fungi.
What proteins help neutralize foreign invaders?
Antibodies
Each antibody is specific to a particular pathogen, and they play a key role in the immune response.
What is the role of white blood cells?
To detect and fight infections.
White blood cells, including lymphocytes, are key players in recognizing and attacking pathogens.
True or False:
Antibodies are produced by T cells.
False
Antibodies are produced by B cells, not T cells. T cells help recognize and destroy infected cells.
What is an antigen?
A substance that triggers an immune response.
Antigens are usually found on the surface of pathogens, and the immune system reacts to them as foreign invaders.
What is an allergy?
An overreaction of the immune system to harmless substances.
Allergies occur when the immune system mistakenly treats harmless substances, like pollen, as threats.
Fill in the blanks:
________ immunity occurs when the body produces its own antibodies, while ________ immunity occurs when antibodies are received from an external source.
Active, passive
Active immunity develops after infection or vaccination, whereas passive immunity can be transferred through breast milk or antibodies from another person.
True or False:
Vaccines provide passive immunity.
False
Vaccines stimulate the body to produce its own antibodies, providing active immunity.
What is herd immunity?
Protection from disease in a population when a large portion is immune.
Herd immunity helps protect those who cannot be vaccinated, such as infants or immunocompromised individuals.
Fill in the blank:
An autoimmune disorder occurs when the immune system ________ the body’s own cells .
attacks
In autoimmune disorders, the immune system mistakenly targets normal, healthy cells.
What is rheumatoid arthritis?
An autoimmune disease where the immune system attacks joints.
This leads to inflammation, pain, and potential joint damage.
What is lupus?
An autoimmune disease that affects multiple organs.
Lupus causes the immune system to attack organs like the skin, kidneys, and heart.
What does HIV stand for?
Human Immunodeficiency Virus
HIV attacks the immune system, specifically targeting T-cells, which are crucial for immune function.
True or False:
Antibiotics treat viral infections.
False
Antibiotics only work against bacterial infections, not viral infections.
What is the difference between a bacterial infection and a viral infection?
- Bacterial infections are caused by bacteria.
- Viral infections by viruses.
Antibiotics can treat bacterial infections, but viruses require different treatments, such as antiviral medications or vaccines.
Fill in the blank:
The immune system’s response to an infection is known as the _________ response.
immune
The immune response involves detecting pathogens, activating immune cells, and producing antibodies to fight the infection.
True or False:
The bone marrow produces blood cells, including white blood cells, which play a key role in the immune system.
True
Bone marrow is a primary site for the production of immune cells, crucial for fighting infections.
