Biopsychology Flashcards
What is the human nervous system?
Body wide system of nerve cells that collects information from the world, processes this info and then takes action by directing body organs and muscles via the transmission of electro chemical messages.
What is the central nervous system?
Involves complex processing. Includes the Brain for all conscious and most unconscious processing. And the spinal cord which receives and transmits information and some reflex processing.
What is the peripheral nervous system?
Body wide network of messenger neurones. Sensory neurones take info to the CNS, and motor neurone take information away from the CNS
What is the automatic nervous system?
The part of the PNS that controls actions of internal glands is a involuntary system (not under conscious control)
What is the somatic nervous system?
The part of the PNS that controls skeletal muscles. It is a voluntary system (under conscious control)
What is the Sympathetic system?
Part of the ANS. Increases bodily activities. Releases noradrenaline, activated in fight/flight response. Increased heart/sweat/breathing rate, dilates pupils.
What is the parasympathetic nervous system
Part of the ANS. Decreases bodily activities. Releases acetylcholine. Activated in rest. (Rest and digest) decreased heart/sweat/breathing rates, constricts pupils
What is homeostasis?
Our internal environment is regulated by a balance between the sympathetic and parasympathetic systems
What is the endocrine system?
Collection of glands around the body that regulate bodily functions, growth, and psychological factors. It acts by releasing chemical messengers called hormones into the blood
What does the pituitary gland do?
Master gland: hormone (ACTH), controls the release of hormones from other glands.
What does the hypothalamus do?
Hormone (CRH) links the nervous system to the endocrine system
What does the pineal gland do?
Hormone (Melatonin) modulates sleep pattern, keeping the body to a day/night rhythm
What does the thyroid gland do?
Hormone: (thyroxine) modulates metabolism (rate of energy use in the body)
What does the thymus gland do?
Hormone (thymosine) stimulates the development of T cells in the immune system
What does the pancreas do?
Hormone (insulin) regulates blood sugar levels
What do the adrenal glands do?
Hormone (adrenaline) Regulate the effects of the fight or flight response
What do the ovaries do?
(Female): hormone (oestrogen) develops secondary sexual characteristics in females
What do the testicles do?
(Male): hormone (testosterone) leads to the development of secondary sexual characteristics in males
Function of the sensory neurone?
Detect sensations at the sensory receptors. Action potential travels across the nerve passing along the myelinated axon then the electrical signal is converted into a chemical signal to cross the synapse
Function of the relay neurone?
After synaptic transmission, a new action potential forms in the dendrites, this neurone is in the spine, and sends a signal along its axon to the motor neurone
Function of the motor neurone?
Detects signal from the relay neurone via synaptic transmission and passes this signal along its own myelinated axon to stimulate an effector.
What is the synapse?
Also called axon terminal. This structure is found at the end of a nerve cell and allows neurones to communicate by passing on chemical signals this process is called synaptic transmission
What are neurotransmitters?
Chemical messengers released by neurones. These are either excitatory (stimulate/ make more likely) or inhibitory (male less likely) the development of an action potential (electric message) in other (post synaptic neurones)
What is the process of synaptic transmission?
The action potential travels down the axon of the presynaptic neurone. This forces vesicles containing neurotransmitters to merge with the cell membrane and release neurotransmitters into the synaptic cleft. Receptors on the postsynaptic neurones dendrite membrane detects the presence of neurotransmitters, changing the chemistry within the postsynaptic neurone. If the charge inside the post synaptic neurone passes a threshold a new action potential forms and the message is passed on. The neurotransmitters detach from the receptors and return to the presynaptic cell via transport proteins, this process is called reuptake.
What is excitation?
Excitatory neurotransmitters increase the likelihood of a new action potential forming in the post synaptic cell. When detected by receptors the electrical charge inside becomes more positive and likely to fire - depolarisation.
What is inhibition?
Inhibitory neurotransmitters decrease the likelihood of a new action potential forming in the post synaptic cell. When detected by receptors the electric charge inside becomes more negative and less likely to fire - hyperpolarisation
What is summation?
Combine effect of all inhibitory and excitatory influences, resulting in a new action potential forming or not forming.
What is uni direction?
Information can only be passed between pre and postsynaptic neurones in one direction. This is all due to the structure of the synapse such as the location of neurotransmitters and receptors.
What is fight or flight response?
An evolutionarily survival mechanism in response to a threat. It primes the body and mind for extreme action, such as fighting for out life of escaping a threat. The body returns to homeostasis after the threat has passed.
What is the process and mechanisms of fight or flight response?
A stressor is detected by the hypothalamus. The HPA axis in the endocrine system is activated, and the pituitary gland released ACTH; this is detected by the adrenal cortex, releasing cortisol. The hypothalamus also activated the sympathetic branch of the ANS, and the adrenal medulla is triggered via the sympathetic adrenomedullary pathway, releasing adrenaline.
What is the role of adrenaline?
Psychological effects of adrenaline include increased anxiety, attention and alertness. The physical effects of adrenaline include increased blood flow to the brain and skeletal muscles (quick thinking/reactions) and decreased blood flow to the skin and the digestive immune systems. Dilated pupils (improved vision) and faster breathing rate (increased oxygen)
Why is the fight or flight response maladaptive in the modern world?
It is frequently triggered by stimuli that cannot be run away from or fought (e.g. exams). In the short term, this results in acute stress, a response to immediate pressures, exciting in small amounts and giving you focus and energy but exhaustive if maintained. Long term frequent triggering of the fight or flight response results in chronic stress, which can result in stress related illness affecting the immune and circulatory systems.
What is localisation of function?
Functions such as movement, speech/language and memory are performed in distinct regions of the brain. The opposite view is the brain acts holistically to perform functions
What is contralateral?
Each hemisphere controls the opposite side of the body. Including both motor and sensory pathways and vision of the contralateral visual field.
What is hemispheric lateralisation?
Each hemisphere is specialised to perform different functions. (Language centres are in the left hemisphere, visuospatial tasks are best performed by the right)
What is the function of the motor cortex?
Voluntary muscle movement across the body. Contralateral. At the back of the frontal lobe and separated from the somatosensory cortex by a fold called the central sulcus. Damage: injuring results in the loss of muscle function or after severe trauma, paralysis on the opposite side of the body.
What is the function of the somatosensory cortex?
Receiving sense impressions from around the body. Contralateral. Front of the parietal lobe and separated from the motor cortex by a fold called the central sulcus. Damage: loss of sensation in opposite side in damage, ignoring areas of the body.
What is the function of Broca’s area?
Located in the left frontal lobe only, Broca’s area is responsible for speech production. Damage: motor aphasia/ difficulty producing fluent speech
What is the function of Wernickes area?
Located in the left temporal lobe only, responsible for speech comprehension. Damage: sensory aphasia/ difficulty understanding speech
Function of the auditory cortex?
Receives and processes sound information from ears. Located in both hemispheres
Function of the visual cortex?
(Occipital lobe) visual processing each hemisphere receives info from opposite visual field.