WACE Human Biology Year 2016 Mark 80.20 Pages 19 Published Jan 30, 2017 Human Biology WACE 2016 Units 3 & 4 By Sheryar (99.85 ATAR)
Your notes author, Sheryar. Sheryar achieved an ATAR of 99.85 in 2016 while attending Canning Vale College Currently studying Radiation therapy at Curtin University of Technology Sheryar says: Graduated in 2016 winning the Science and Innovation Award at CVC for the highest aggragate from an ATAR Physical Science and and ATAR biological Science subject Subjects in Year 12: Maths Methods Phyiscs Chemistry Human Biology English Integrated Science Future plans to study at Curtin University in Radiation Therapy (requires 90 ATAR) and to also try to achieve a good UMAT score and transfer into Medicine also at Curtin in 2018 Powered by TCPDF (www.tcpdf.org)
Human Biology Notes Homeostasis Endocrine Glands- secrete hormones into the extracellular fluid, transported by the blood Hormones- substances secreted by endocrine glands Hormone Types Comparison Protein (Amine) -Water soluble (binds to receptors on the membrane) -Secondary messengers diffuse through the cell -Activates particular enzymes in the cytoplasm -Fast acting (within seconds or minutes) Steroid (Sex Hormones) -Lipid soluble (binds to receptors in the cytoplasm) -Enzymes activated inside the nucleus -Genes activated to form specific proteins -Slow acting (hours or days) Hormones Effects - Activate genes Turn enzymes on or off Alter rate of enzyme production Hormones Cascading- cascading effect one hormones molecule can trigger production of billions of enzymes After hormones as produced the required effect they are broken down and excreted through bile/urine Hypothalamus vs Pituitary Hypothalamus Pituitary -Links endocrine and nervous systems -Master Gland (Produces GH, FSH, TSH etc. in anterior lobe) -Controls release of hormones from pituitary -Release hormones which may control other endocrine glands -Regulates bodily function, maintains homeostasis Linked together by the infundibulum (neurosecretory cells to posterior lobe, blood vessels to anterior lobe) Pituitary Lobes Comparison Posterior Lobe -Hormones produced by the hypothalamus (ADH & Oxytocin) are passed along axons to the posterior lobe from the hypothalamus -These hormones are stored in the posterior lobe until released via nervous stimulation from the hypothalamus Anterior Lobe -Hormones produced in the anterior lobe include (GH, LH, Prolactin etc.) Inhibiting & releasing factors secreted by the hypothalamus Paracrine- local hormones, secreted by cells to communicate with adjacent cells Main Endocrine Glands Gland Pituitary Pineal Pancreas Adrenal Thyroid Parathyroid Thymus Ovaries Testes Hormone secreted example (may be more) Growth Hormone Insulin Cortisol Thyroxine Parathyroid Hormone Thymosins Oestrogen Androgens
Types of Neurons - Multipolar: one axon, multiple dendrites (interneurons and motor neurons) Bipolar: one axon, one dendrite Unipolar: one extension, an axon, cell body to one side Nerve Transmission Axons of a neuron have a resting polarized state due to distribution of Na+ and K- ions, resting with a negative a negative charge on the inside and positive charge on the outside. When a stimulus is applied the membrane sodium channels open and sodium ions move across the membrane into the cells and potassium ions move out and the membrane becomes depolarised (only occurs if stimuli exceeds the threshold, 15mV, all-or-none response). Active transport moves the sodium ions back out restoring potential difference, this is repolarisation. The act of depolarisation and repolarisation is the action potential. As the membrane polarity changes, neighboring channels open. As sodium ions are moved back into the cell through active transport the same section of the axon cannot be re-stimulated thus ensuring the nerve transmission propagates only in one direction (refractory period). Synapse Transmission- synapse is the gap between neurons, impulse reaches axon terminal, triggers neurotransmitters to be released from vesicles, these diffuse across the synapse and bind to receptors on the post synaptic neuron, causes channels to open triggering action potential, continuing transmission. Myelinated vs Unmyelinated Unmyelinated -Impulse travels the whole length of the axon -Slow (2m/s) Myelinated -Insulated by myelin sheath except at nodes of Ranvier -Impulse has to jump from node to node -Fast (140m/s)
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