Factors that affect behaviour, emotion and thought.

Biological influences can be: Internal Factors Hereditary Hormonal External Factors i.e. drugs i.e. exercise These are factors that can affect our behavior, emotions and even thought.

Heredity. Key areas…….. The role of genetics. The relationship between chromosomes, DNA and genes. Fertilization Mitosis and meiosis. The relationship between heredity and the environment (Epigenetics). Things we should knowwww

Chromosomes DNA and Genes. Students annotate diagram…. Standard human cell has a nucleus and in this nucleus there is 46 chromosomes (23 pairs). These chromosomes consist of long strands of DNA, all coiled up. DNA carry the genetic code that determines the characteristics of a living thing A gene is a short section of DNA. Each gene codes for a specific protein. They are the basic unit of genetics. Human beings have 20,000 to 25,000 genes. So, for example, one gene will code for the protein insulin, which is important role in helping your body to control the amount of sugar in your blood.

Fertilization Now we know a normal human cell has 46 chromosomes, but sex cells – those cells called sperm and ovum, which are produced in the gametes, (ovaries and testes) have only half this. They only have 23 chromosomes! Each sex cell has half of each pair of chromosomes. When a sperm, which has 23 chromosomes from the father, fertilizes an ovum containing 23 chromosomes from the mother, these two cells fuse to create a new cell called a zygote, which will now have 46 chromosomes (23 pairs) just like a normal human cell again – half from mum half from dad.

Mitosis This is how we go from a single cell, a zygote, to a full sized human being. Mitosis is when a cell divides itself in half to make two identical copies. Before mitosis, the cell creates an identical set of genetic information – this is called DNA replication.

Meiosis This is the process of creating the sex cells (sex cells = half number of chromosomes). Firstly there is a parent cell, which makes identical copies of all its chromosomes “DNA replication” this is then followed by cell division, to create two daughter cells, which are copies of the original parent cell. This is called “meiosis 1” These two daughter cells both then divide again to create 4 daughter cells, which is called “meiosis 2”. These 4 new daughter cells have half the amount of chromosomes as their parent cell.

What is Epigenetics? The term epigenetics refers to heritable changes in gene expression (active versus inactive genes) that does not involve changes to the underlying DNA sequence; a change in phenotype without a change in genotype. Epigenetics is the study of cellular and physiological phenotypic trait variations that are caused by external or environmental factors that switch genes on and off and affect how cells read genes instead of being caused by changes in the DNA sequence. Wondering why identical twins aren’t actually, well, identical? Epigenetics!

Neurotransmitter Effects Variation results in Dopamine Motor control, arousal, motivation, pleasure, attention. Low levels = ADHD and Parkinson’s.   High levels = schizophrenia. Serotonin Mood, appetite, sleep, impulsive/aggressive behaviour. Low levels = depression and anxiety disorders. Acetylcholine Attention, learning, memory, muscle stimulation. Low levels = Alzheimer’s.

Psychoactive Drugs. Define psychoactive drug, depressant, stimulant and hallucinogen. the psychological and physiological effects of depressants, stimulants and hallucinogens Know examples of each category of drug.

Definitions Psychoactive drug: a chemical substance that acts primarily upon the central nervous system where it alters brain function, resulting in temporary changes in perception, mood, consciousness and behavior.

Definitions Psychological effect is in relation to mental functions and behaviours Physiological effect is in relation to the structure and functions of the body.

Drug categories Depressants - Calm the activity of the nervous system and slow body functions. eg…. Stimulants - Excite the nervous system and arouse bodily functions. Eg…. Hallucinogens - Change our perceptions and give us sensory images without input from the senses Eg…..

Stimulants Identify if the following would be considered psychological or physiological. Increased feelings of excitement Higher energy level Speed up activity in the CNS Increased confidence Increased breathing and heart rate Dilated pupils

Depressant Identify if the following would be considered psychological or physiological. Reduced activity in the CNS decreased breathing and heart rate Feel less stressed/calmer Relieves anxiety Reduced coordination

Hallucinogens Identify if the following would be considered psychological or physiological. Increased heart rate and breathing rate Disrupted cognition Dilated pupils Increased body temperature Altered perceptions Hallucinations Increased blood pressure Mood swings Play caffeine video!!!