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Description
Flashcards by Julia Romanów, updated more than 1 year ago
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Created by Julia Romanów
almost 9 years ago
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| Question | Answer |
| What is a neuron? | A specialised cell that receives, processes and transmits information (signals) to other neurons as well as muscles and organs. |
| There are 3 types of neurons... | Sensory Motor Connector ( or relay) |
| Sensory neuron functions? | Located in 'sense organs'. Carry messages from sense organ to the CNS (central nervous system) |
| Motor neuron functions? | These carry messages from the spinal cord and brain (CNS) to muscles. |
| Relay neurons | Only found in CNS. Connect neurons with other neurons. represent 95% of all neurons. mostly located in the brain. |
| 1. Dendrite 2. Cell body 3. Node of Ranvier (indentations) 4. Axon terminal 5. Nucleus 6. Axon 7. Myelin Sheath (8. Schwann cell) | |
| Axon: A long extension from the cell body which nerve impulses are sent through. Myelin sheath: fatty material that surrounds, insulates and protects the axon. | Axon terminal: End of the axon; releases neuro transmitters to communicate with other neurons. Dendrites: Receive signals from adjacent neurons and process the information received. |
| Synaptic cleft: a gap between axon terminals and dendrites. Signals cross this gap in the form of neurotransmitters. | Node of Ranvier: small indentions in the myelin sheath. speeds up the process of transmitting. |
| Briefly describe synaptic transmission | -Messages sent across axon as electrical impulses -cross the synapse in the form of chemical neurotransmitters -Each neurotransmitter then has ac specific receptor site on the other neuron / dendrites |
| The nervous system has many divisions... | |
| the sympathetic and parasympathetic Ns's work in opposition... physiological changes due to sympathetic NS state.... | increased heart rate increased breathing rate dilated pupils inhibited digestion/saliva production contracted muscles |
| physiological aspects of parasympathetic ns state... | decreased (normal) heart/breathing rate constricted pupils digestion/saliva production continues muscles relax |
| Made up of glands that secretes chemicals called hormones into the blood stream. | The endocrine system |
| Examples: Pituitary gland Thyroid Adrenals Testes Ovaries | -controls release of hormones from other -glands in the body -Thyroxine -adrenaline for 'fight or flight mode' -testosterone -oestrogen and progesterone |
| Briefly describe the process of 'fight or flight mode'... | -stressful event -autonomic NS changes it's normal state into the sympathetic state -pituitary gland in the hypothalamus releases ACTH -ACTH stimulate adrenals to produce adrenaline -adrenaline triggers physiological changes of SNS state (body is now ready for action) |
| Strengths of this approach | -Objective -Scientific -Lab experiments = lots of control -Has many applications in real life (drugs for mental illnesses as they're caused by chemical imbalances in the brain) |
| Weaknesses of this approach | -Deterministic (what about free will? ) -Reductionist (behaviour = atoms? aren't we all unique??) -Ethical issues - can we play with genetics? -Ignores environmental factors/experiences (overly simplistic) |
| What are twin studies? | To test whether a certain characteristic is caused by genetics twin studies are carried out that look for degrees of similarity. |
| Monozygotic twins (identical) 100% shared genes same sex develop from one egg/embryo that splits | Dizygotic twins (separate) 50% shared genes Any sex combination Two eggs released and developed |
| Twin studies are evaluated based on their concordance rates (%) | Concordant if both twins develop the same studied trait/characteristic Discordant if only one twin develops the trait/characteristic. |
| If Mz twins have a genetically hereditary trait that only one seems to have it could be caused by the environmental factors. why? | Although 100% DNA is shared... certain phenotypes will only be expressed under certain conditions |
| Phenylketonuria (PKU) this condition illustrates the importance of environmental factors (on the phenotype) | affects 1 in 10,000 although a person can posses the genotype for the condition it's possible to avoid it by not consuming a certain amino acid throughout the individuals life since birth. Environment > biology (?) |
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