Biopsychology Flashcards
The Endocrine System
- separate from NS (Nervous System)
- acts slower but has a widespread effect
Nervous System = Nerves
Endocrine System = Blood Vessels
Hormones
- chemicals that circulate bloodstream +carried to target organs
- given hormones usually affects limited amount of cells (target cells)
- enough receptors are stimulated resulting in physiological reaction in target cell
- timing of hormone release is critical for normal functioning
Process of Hormones
- Hormones regulate by feedback
- Signal sent from hypothalamus to pituitary gland (master/releasing gland)
- Secretes ‘stimulating hormone’ into bloodstream
- Which signals target gland to secrete hormone
- either directly causes change or simulates other glands - Hypothalamus stops secreting releasing hormone + pitutiary gland shuts down secretion of stimulating hormone
Glands
(Hormones, purpose)
Pituitary - ‘master gland’
Adrenal - ‘flight-or-fight’, release of ADRENALINE
Testes - release of TESTOSTERONE (male hormone)
Ovaries - release of OESTROGEN + PROGESTRONE (female hormone)
Thyroid - regulates body metabolic rate
Pancreas - releases INSULIN, regulates blood sugar levels
Pineal - releases melatonin, regulates wake-sleep cycle
The Nervous System
- complex network of nerve cells, carry messages to/from brain + spinal cord to all around body
- helps coordinate body’s response to everything
- takes over automatic (involuntary) actions e.g heart beating + conscious (voluntary) actions e.g talking aloud
Central Nervous System (CNS)
Brain + Spinal Cord
- brain + spinal cord (no other divisions)
- where complex processing of information is done + decisions are made
Brain
- centre of awareness
- cortex is more developed in humans than other animals
- allows us to speak and have conscious thoughts
Spinal Cord
- extension of the brain
- responsible for reflexes
- transport messages to/from brain to PNS (Peripheral Nervous System)
Peripheral Nervous System (PNS)
- everything else that’s not part of CNS
- relay information from rest of body to CNS
- divides further into 2 parts; somatic + autonomic nervous system
Somatic + Autonomic Nervous System
Somatic
- no further subdivisions
- picks up information from outside world; sensory + motor pathways
- under consious control + thoughts (voluntary)
-controls skeletal muscles = surrounding skeleton e.g walking
Autonomic
- two subdivisions; PARASYMPATHETIC + SYMPATHETIC
- only motor pathways (internal information)
- maintain homeostasis(balance body conditions)
- don’t have conscious thoughts + control (involuntary)
- control smooth muscles = don’t have to think about it (heart, lungs)
Sympathetic Nervous System
‘fight-or-flight’ response
(how brain deals with physical or non-physical threats)
Parasympathetic Nervous System
‘rest-or-digest’ response
(back to resting/normal/everyday behaviour)
- when there’s threat, sympathetic nervous system kicks in
Role of Adrenaline (fight-or-flight response)
- evolutionary adaptive behaviour
- needed for survival (our ancestors)
- have smaller-scaled threats but need extra energy from adrenaline
- Amygdala (distress signal) tells when somethings doesn’t feel right
- sends signal to hypothalamus which sends two simultaneous signals two different pathways
1st Signal - Sympathomedullary (SAM)
(Process, Symptoms)
- electrical signals (quick+fast) from hypothalamus = so quick unaware decision is being made
- via sympathetic gangrelia (nerves) to stimulationg adrenal medulla
- produces + releases adrenaline
- fight-or-flight occurs only when adrenaline is released - allowing one to run or fight
- sympathetic gangrelia connected to internal organs
SYMPTOMS
- hearts pumps faster
- increased blood to brain
- digestion in halted
- saliva is inhibited
- feel sick
-butterflies
2nd Signal - Pituitary Adrenal (PAS)
(Process)
- pituitary gland controls all glands of endocrine system
- slower and same signals but brings homeostasis to body
- brings body back to calm/normal levels
- first SAM needs to play through (for 30 secs to 1 min) for PAS to kick in
- hypothalamus releases CRF; stimulates pituitary gland
- then releases ACTH, which travels to receptors around adrenal cortex (which releases corticosteroids)
- tries to reverse effects of adrenaline e.g reducing heart rate + blood levels
if threat is continuous, amygdala keeps sending signals until state of exhaustion
- PAS stops release of adrenaline
Structure of neuron
(what the parts do ?)
Dendrites = receive messages from external to cell body
Cell body - Nucleus
Myelin sheath = speeds up neuron electrical impulses
Axon = passes messages from cell body to other neurons
Terminal branches of axon = junctions with other cells
- neuron sends electrical signal that becomes chemical signal to another neuron (in brain)
- axon (away from cell body) covered in myelin sheath (speeds up transmission of signals)
- cell body in CNS, but axons + dendrites in PNS
- neurons are brain’s way of communicating which results in behaviour
Three Types of Neurones
(Sensory, Relay, Motor)
SENSORY
- carries nerve impulses from sensory receptors from external world (senses) to CNS
long dendrites - dendrites towards cell body (in brain) which is CNS; axon to another neurone
short axons - quick + fluent behaviour due to quick transmission of electric signals
RELAY
- neither sensory or motor but allows both to communicate
- exclusively in brain (CNS)
- transmits information across CNS from sensory to motor neuron
-short dendrites + axons
MOTOR
- directly or indirectly controlling muscles
- carries impulses from CNS to effectors (muscles or glands)
short dendrites - picking up info from CNS
long axons - signal sent to muscles or glands
