Homeostasis Flashcards
(22 cards)
What is homeostasis?
Homeostasis is the maintenance of a relatively stable internal environment within an organism. Stability is maintained by negative feedback processes.
What is an example of homeostasis?
Using the stimulus-response model, an example of homeostasis is when the body responds to a decrease in temperature (stimulus) by shivering to generate heat and constricting blood vessels (response) to conserve warmth, maintaining a stable internal temperature.
What is a negative feedback loop?
Maintain stability by adjusting responses based on changing conditions. Negative feedback mechanisms detect a change and begin a response to reverse the direction of the change in that variable.
What is the difference between the endocrine and the nervous system?
The endocrine system uses hormones released into the bloodstream to communicate and regulate body functions over a longer period, while the nervous system transmits electrical signals through neurons for rapid, short-term responses. The endocrine system is generally slower but more widespread in its effects, whereas the nervous system is faster and more targeted in its actions.
What is the CNS made up of?
Brain and spinal cord
What is the master gland, and what does it do?
The master gland, often referred to as the pituitary gland, is a small endocrine gland located at the base of the brain that regulates various bodily functions, controlling the secretion and production of hormones in other glands.
Where is the hypothalamus located, and what does it do?
It is located in the forebrain and directly above the Pituitary gland. It controls important functions like body temperature, hunger, thirst, sleep, emotions, and hormones (all associated with homeostasis) by working with the nervous and endocrine systems.
How does negative feedback assist in maintaining homeostasis?
Negative feedback helps by reversing changes in the body. For example, if body temperature rises, negative feedback mechanisms (like sweating) reduce the temperature, bringing it back to normal.
What are the main components of the brain, and what are the roles of them?
Brainstem: Controls vital functions like breathing and heart rate.
Cerebellum: Coordinates balance and movement.
Cerebrum: Handles higher functions like thought, memory, and voluntary actions.
What is the structure of a neuron?
A neuron includes a cell body, dendrites (receive signals), axon (transmits signals), and axon terminals (pass signals to other cells). Myelin sheath surrounds the axon for faster transmission.
What happens during a reflex action?
Stimulus → Receptor → Sensory neuron → Spinal cord (reflex center) → Motor neuron → Effector → Response
Why are some reactions reflex actions?
Reflex actions are automatic and protect the body from harm by providing a quick response without waiting for brain processing.
How do reflex actions differ from conscious actions?
Reflex actions are involuntary and fast, bypassing the brain, while conscious actions are voluntary and involve deliberate decision-making by the brain.
What is the overall function and key components of the endocrine system?
The endocrine system regulates body functions through hormones. Key components include glands like the pituitary, thyroid, adrenal glands, and pancreas.
How can nervous system damage result in paralysis?
Damage to the spinal cord or nerves disrupts the signal pathways, preventing the brain from controlling muscles below the injury site.
What are the effects of motor neuron disease?
Motor neuron disease damages the neurons controlling muscles, leading to weakness, difficulty moving, speaking, and eventually loss of voluntary movement.
How is technology helping people overcome paralysis?
Technologies like brain-computer interfaces, exoskeletons, and spinal cord stimulators help restore some mobility and communication in paralyzed individuals.
How have advancements in ear technology improved hearing?
Devices like hearing aids and cochlear implants amplify sound or directly stimulate the auditory nerve, helping people with hearing impairments.
How can medication control hormones?
Medications like insulin for diabetes or thyroxine for hypothyroidism regulate hormone levels, restoring balance in the body.
How do malfunctions in the endocrine system affect the body?
Malfunctions like diabetes (insulin deficiency) or hyperthyroidism (excess thyroxine) disrupt metabolism, growth, and energy balance, causing significant health issues.
What is type 1 diabetes?
It is an autoimmune disease, meaning the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas.
What is type2 diabetes?
Type 2 diabetes occurs when the body’s cells become resistant to insulin or the pancreas doesn’t produce enough insulin to maintain normal blood sugar levels and is cause by Lifestyle Factors: Poor diet, lack of exercise, and obesity.
Genetics: A family history of diabetes.
