revison two Flashcards
sensory organs
touch,sight,hearing,taste and smell
what are sensory receptors
sensory receptors detect stimuli from the environment and convert them into electrical signals for the central nervous system
five different sensory receptors and function
chemoreceptors- detect chemical stimuli
thermoreceptors- detect temperature
mechanoreceptors- detect touch,pressure vibrations and movement
photoreceptors- detect light
pain receptors- help respond to chemicals that have been released from damaged cells
order of parts of a neuron
. dendrites
. cell body
nucleus
. axon
myelin sheath
axon rerminal
functions of the parts of the neuron
axon- transmits electrical impulses away from the cell body
dendrite receives signals from other neuron’s
nucleus contains genetic material
mylein sheath insulates the axon to increase signal speed
axon terminal releases neurotransmitters to communicate with other neurons
what direction do messages traval in the nervous system
sensory neurons- interconnecting neurons-motor neurons
what is the impact of deterioration of mylein sheath in multille sclerosis
it disrupts the transmission of electrical impulses, leading to symptoms like weakness, numbness and coordination issues
how are signals transferred using a synapse
signals are transferred across a synapse using neurotransmitters released from the pre synaptic axon terminal to bind with receptors on the post synaptic axon terminal
what do sensory,motor and interconnecting neurons do?
sensory neurons carry messages from the receptors to the cns
motor neurons carry mesahes from the cns to effectors
interconnecting neurons connect sensory and motor neurons in the cns
define stimulus, receptor, effector and response
stimulus is a change in the environment
receptors detect the stimulus
effectors respond to the stimulus
response is the action taken as a result
negative feedback loop for glucose (write down)
negative feedback loop for water level
negative feedback loop for temperature
reflex arc of someone touching a hot iron
- receptors detect the heat from the iron (the stimulus)
- receptors send signals along sensory neuron’s to your spinal cord
- this message is then sent onto a motor neuron
- as a result, your arm moves off the hot iron
what are the parts of the brain and their functions
the cerebrum- controls conscious thought and voluntary movement
the cerebellum- controls balance and coordination
the brain stem controls body vital functions eg heart beat, breathing
what are the four parts the cerebrum is divided into
frontal lobe- located at the front of the brain, functions: emotions, memory, movement, reasoning, problem solving
parietal lobe- located between the frontal and occipital lobe, functions: control sensations, touch, temp, pressure, pain and taste
occipital lobe- located at the very back of the brain controls vision
temporal lobe- located at the very back of the brain, controls vision
what are hormones
chemical messages which are secreted by glands
endocrine glands
hypothalamus, pituitary gland, thyroid gland, parathyroids, ovaries,testies, pancreas and adrenal glands
how do hormones send messages
hormones travel in the blood stream until they reach their specific target cell
What is the primary mode of communication for hormones in the body?
Hormones communicate through the bloodstream.
True or False: Nervous system messages are slower than hormonal messages.
False.
Fill in the blank: Hormones typically have _______ effects that can last for a longer duration than nervous system signals.
prolonged
Which system is responsible for rapid responses to stimuli?
The nervous system.
Multiple Choice: Which of the following is a key difference between hormones and nervous system messages? A) Hormones are faster, B) Hormones act over longer distances, C) Hormones use electrical signals.
B) Hormones act over longer distances.
What is the term for the information that the body receives to cause a response?
stimuli
What do photoreceptors in the retina of the eye detect?
light
What type of nerve carries impulses from the retina to the brain?
optic nerve
How do gas molecules in the nose cause nerve impulses to be generated?
They dissolve in mucus, causing cilia of chemoreceptors to generate impulses along the olfactory nerve
What is the function of mechanoreceptors in the cochlea of the ear?
They detect vibrations
What type of nerve carries impulses from the cochlea to the brain?
auditory nerve
What do chemoreceptors on the tongue detect?
chemicals that are interpreted as different tastes
What do thermoreceptors in the skin detect?
heat
What do mechanoreceptors in the skin detect?
vibration, pressure, touch and pain
What are the specialized cells that collect information about the external environment called?
receptors
What do receptors do with the energy they receive from the environment?
convert it into a form that the brain can understand
Fill in the blank: Receptors are named according to the type of _______ they respond to.
stimuli
True or False: The central nervous system includes the brain.
True
What is the pituitary gland known as?
The master gland
It controls the activities of other glands by releasing hormones.
How does the pituitary gland respond to the hypothalamus?
By releasing hormones that control the activities of other glands.
What type of control does the nervous system provide?
Nervous Control
Involves neurons and electrical transmission.
What type of control does the endocrine system provide?
Chemical Control
Involves gland cells and chemical (hormonal) transmission.
What is the mode of transmission for the nervous system?
Electrical
Information is transmitted via neurons.
What is the mode of transmission for the endocrine system?
Chemical (Hormones)
Information is transmitted via gland cells.
What is the transmission pathway for the nervous system?
Neural
Information is carried via nerve pathways.
What is the speed of transmission in the nervous system?
Fast
Quick response time.
What is the duration of effect for the nervous system?
Quick
Effects are short-lived.
What is the site of response for the nervous system?
Local (Specific)
Responses are targeted to specific areas.
What is the speed of transmission in the endocrine system?
Slow
Hormonal responses take longer to manifest.
What is the duration of effect for the endocrine system?
Long lasting
Hormonal effects can persist for extended periods.
What is the site of response for the endocrine system?
Widespread
Hormones can affect target cells all over the body.
Fill in the blank: The nervous system uses _______ for transmission.
Neurons
Fill in the blank: The endocrine system uses _______ for transmission.
Hormones
What is homeostasis?
The ability to maintain a constant internal environment in response to changes in the external environment.
Which systems control homeostasis in the body?
The nervous and endocrine systems.
What is an example of a process controlled by homeostasis?
Temperature control, water balance, blood glucose.
Homeostasis can be compared to which household device?
A thermostat controlling a split-system air conditioner.
What is negative feedback?
The body senses an internal change and activates mechanisms that reverse that change.
What is positive feedback?
A process in which the body senses a change and activates mechanisms that accelerate or increase that change.
True or False: Positive feedback is commonly used in the body to maintain homeostasis.
False.
Fill in the blank: Homeostasis is regulated by feedback mechanisms in one of ___ ways.
2
What can positive feedback produce in many cases?
The opposite effect and can be life-threatening.
How many instances of positive feedback exist in the human body?
Only a few.
