Biopsychology

Question 1

The nervous system

Answer 1

• the nervous system is divided into 2 main components; the central nervous system and the peripheral nervous system
• the nervous system is a network of nerve cells that transmit messages between different parts of the body, allowing communication to take place

Question 2

Central nervous system

Answer 2

• made up of brain and spinal cord
• the brain provides conscious awareness and is involved in all psychological processes
• the brain consists of many regions, which are responsible for different functions
• the spinal cord is an extension of the brain and is responsible for reflex actions

Question 3

Peripheral nervous system

Answer 3

• the role of the PNS is to relay messages from the CNS to the rest of the body
• the PNS consists of two components; the somatic nervous system and the autonomic nervous system

Question 4

Somatic nervous system

Answer 4

• the role of the SNS is to carry out sensory information from the outside world to the brain and provide muscle responses via motor pathways

Question 5

Autonomic nervous system

Answer 5

• plays an important role in homeostasis, which maintains internal processes like body temp, heart rate and blood pressure
• has two components; sympathetic nervous system and the parasympathetic nervous system

Question 6

Sympathetic nervous system

Answer 6

• typically involved in responses that prepare the body for fight or flight; impulses travel from the SNS to organs in the body to help us prepare for action when we are faced with a dangerous situation
• e.g. blood pressure, breathing and heart rate increase while less important functions like digestion, salivation and desire to urinate are suppressed

Question 7

Parasympathetic nervous system

Answer 7

• the role of the PNS is to relax the body and return us to normal resting state
• it slows down our heart rate, breathing rate and lowers blood pressure
• any reaction slowed down during a fight or flight reaction are started again e.g. digestion

Question 8

The endocrine system

Answer 8

• works alongside the nervous system to control vital functions in the body
• a variety of glands in the body produce hormones
• hormones are secreted into the blood stream and affect any cell in the body that has a receptor for that particular hormone
• most hormones affect cells in several organs or throughout the entire body, leading to many diverse and powerful responses
• thyroid gland releases thyroxine, this hormone affects cells in the heart (heart rate), it also affects cells throughout the body increasing metabolic rates, this in turn affects growth rates

Question 9

Pituitary gland (master gland)

Answer 9

• located in brain
• it controls the release of hormones from all the other endocrine glands in the body

Question 10

The hypothalamus and fight or flight

Answer 10

• the endocrine system and the ANS often work in parallel with each other
• e.g. when a stressor is perceived, the first thing to happen is that the hypothalamus triggers activity in the sympathetic branch of the ANS, the ANS changes from its normal resting state (parasympathetic state) to the physiologically aroused sympathetic state
• the stress hormone adrenaline is released from the adrenal gland into the blood stream
• adrenaline triggers physiological changes within the body (increase heart rate) which creates the physiological arousal necessary for the fight or flight response
• all of this happens in an instant as soon as the threat is detected
• once a threat has passed the parasympathetic nervous system returns the body to its resting state

Question 11

Hypothalamus effect

Answer 11

-stimulates and controls the release of hormones from the pituitary gland

Question 12

Pituitary gland
Main hormone released and effect

Answer 12

• anterior- adrenal trophic hormone = responds to stress, reduces inflammation, regulates blood, glucose and metabolism, stimulates adrenal cortex
• posterior- oxytocin = responsible for uterus contractions during childbirth

Question 13

Pineal gland
Main hormone and effect

Answer 13

• melatonin = responsible for important biological rhythms, including the sleep wake cycle

Question 14

Thyroid gland
Main hormone and effect

Answer 14

• thyroxin = responsible for regulating metabolism

Question 15

Adrenal gland
Main hormone and effect

Answer 15

• adrenal medulla = adrenaline and non adrenaline = key hormone in fight to flight response
• adrenal cortex = cortisol = stimulates release of glucose to provide the body with energy, while suppressing immune system

Question 16

Ovaries
Main hormone and effect

Answer 16

• oestrogen = controls the regulation of the female reproductive system, menstrual and reproductive

Question 17

Testes
Main hormone and effect

Answer 17

• testosterone = responsible for the development of male sex characteristics during puberty, while also promoting muscle growth

Question 18

Neurons

Answer 18

Basic building blocks of the nervous system, they are nerve cells that process and transmit messages through electrical and chemical signals

Question 19

Motor nerurons

Answer 19

Connect the CNS to effectors e.g. muscles and glands (short dendrites and long axons)

Question 20

Sensory neurons

Answer 20

Carry messages from the PNS to the CNS (long dendrites and short axons)

Question 21

Relay neurons

Answer 21

Connect the sensory to the motor neurons (short dendrites and short axons)

Question 22

Nucleus

Answer 22

Contains genetic material of cell

Question 23

Dendrites

Answer 23

Branch like structures carry nerve impulses from neighbouring neurons towards the cell body

Question 24

Axon

Answer 24

Carries impulses away form cell body down the length of the neuron

Question 25

Myelin sheath

Answer 25

Protects axon and speeds up electrical transmission of the impulse

Question 26

Mode of ranvier

Answer 26

Gaps between section of myelin

Question 27

Terminal buttons

Answer 27

Communicate with the next across in the chain across the microscopic gap called a synapse

Question 28

Electric transmission

Answer 28

- when a neuron is in a resting state the inside of the cell is negatively charged compared to the outside - when a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second causing an action potential to occur - this creates an electrical impulse that travels down the axon towards the end of the neuron

Question 29

Synaptic transmission

Answer 29

- neurons communicate with each other within groups known as neural networks - each neuron is separated from the next by a tiny gap called the synapse - within the neuron, signals are transmitted electrically, however, between neurons they are transmitted chemically across the synapse

Question 30

Synaptic transmission process

Answer 30

- when the electrical impulse reaches the end of the neuron (PRE-SYNAPTIC TERMINAL) it triggers a release of neurotransmitters from tiny sacs called terminal vesicles - once the neurotransmitter crosses the gap it is taken up by post synaptic receptor sites (dendrites on next neuron) -here, the chemical message is converted back into an electrical impulse and the process of transmission begins in the next neuron

Question 31

neurotransmitters

Answer 31

- chemicals that diffuse across the synapse to the next neuron in the brain - each neurotransmitter has its own specific molecular structure that fits perfectly into a post-synaptic receptor site (lock and key) - they have specialist functions e.g. acetylcholine (Ach) is found at each point where a motor neuron meets a muscle to contract