B5- Homeostasis and Response Flashcards
1
Q
- What is homeostasis
A
- Regulation of internal conditions of a cell or organism to maintain optimum conditions of function in response to internal changes
2
Q
- What does homeostasis control
A
- Optimal conditions for enzyme action and all cell functions
3
Q
What does homeostasis control inside the human body
A
- Blood glucose concentration
- Body temperature
- Water levels
- Automatic negative response
4
Q
What is a Receptor
A
- Detect a stimulus- change in environment
5
Q
- What are
CNS
A
- Receive and process information from receptor
- Include brain and spinal cord
6
Q
what are effectors
A
- Bring about responses which restore optimum levels
- E.g muscles and glands
7
Q
- What are the steps in the nervous system
A
- Stimulus- receptor- coordinator - effector- responce
8
Q
What does the nervous stye, enable
A
- Humans to react to surroundings an coordinate behaviour
9
Q
- How is information passed in the nervous system
A
- Along neurone
- Passed as electrical impulses to CNS - brain and spinal cord
- ## CNS coordinates repose which effectors cary out
10
Q
What are motor neurones
A
- Carriers of information from CNS to rest of body
11
Q
What are sensory neurones
A
- Cells that carry impulses from organs to CNS
12
Q
What is a synapse
A
- A connection between two neurones
- Nerve signal is transferred by chemicals that diffuse across the gap
- Set off a new electrical signal
13
Q
- What are reflexes
A
- Rapid, automatic responds to certain stimuli that don’t involve conscious part of brain
14
Q
What is a reflex arc
A
- Passage of information in a reflex
15
Q
What are the steps in a reflex arc
A
- Neurons in Reflex arc go through spinal cord or brain
- When stimulus is detected by receptors impulses are sent along sensory neutron to relay neutron in CNS
- When impulses reach synapse they trigger chemicals to be related and this cares the message along to relay neurones
- When impulses reach synapse the same chemical process carry it to the motor neurone
- The impulses travel along to effector e.g muscle
- Muscle contracts and moves whatever is needed
- Quicker than normal response as no thinking time is involved
16
Q
What order does an impulse go in a reaction
A
- Stimulus
- Sensory neuron
- Relay neuron
- Motor neuron
- Effector
- Stimulus
- Re emptor
- Coordinator
- Effector
- Responce
17
Q
What are the steps in investigating reaction time - Caffeine
A
- Person being tested should sit with arm resting on edge of table
- Hold a ruler vertically between thumb and finger- zero end level with this
- Let go without warning
- Number on ruler is reaction time
- Repeated several times and find mean
- Then break and then test with non-dominant hand
- Compare results
18
Q
What is reaction time
A
- The time it takes to respond to a stimulus - can be effected by age, gender or drugs
19
Q
- How can reaction time be measured using a computer
A
- Simple computer tests can be used to measure reaction time
- E.g click a mouse in response to stimulus
- Computers give a more precise reading and more accurate
20
Q
- What are hormones
A
Chemical messengers in the flood
- control organs in the body
21
Q
What is the endocrine system
A
- Composed of glands which secrete hormones directly into the blood
- Carries to target organ
22
Q
How does the enforcing system compare to the nervous system
A
- The endocrine system is slower than the nervous system however the effects act for longer
- Hormons act generally, nerves act specifically
23
Q
What is the Pituitary gland
A
- The ,aster gland- several hormones - stimulate others glands
- Brain
24
Q
What is the thyroid gland
A
- Produces thyroxine
- Involved in regulating metabolism, heart rate and temperature
- Upper part of body near throat