Reviewer-jiah.docx

I. THE NERVOUS SYSTEM 1. The Nervous System controls and coordinates all essential functions of the human body. 2. The Nervous System RECEIVES and RELAYS information about activities within the body and Monitors and Responds to INTERNAL and EXTERNAL CHANGES. 3. The Nervous System has TWO Major Divisions. A. The Central Nervous System (CNS) consist of the Brain and the Spinal Cord. The Spinal Cord carries messages from the body to the Brain, where they are analyzed and interpreted. B. The Peripheral Nervous System (PNS) consists of the neurons NOT Included in the Brain and Spinal Cord. 4. The Neuron is the Basic Functional Unit of the Nervous System. 5. Neurons can be classified into THREE TYPES: a. sensory (receptor) neurons- carry impulses from the sense organs (receptors) to the brain and spinal cord. b. motor neurons - carry impulses from the brain and spinal cord to muscles or glands. c. interneurons - connect sensory and motor neurons and carry impulses between them. 8. whatever their specific function, all neurons have the same physical parts: the cell body, dendrites and one axon. a. cell body - the largest part, contains the nucleus and much of the cytoplasm b. dendrites – picked stimulus (action potentials) and impulses from the environment or from other neurons and carry them toward the cell body. c. axon - a long fiber that carries impulses away from the cell body. II. THE ENDOCRINE SYSTEM 1. The endocrine system is a collection of ductless glands that secrete chemical messages, known as hormones. 2. Pituitary gland – is inside the brain. It can bring about a change in hormone production somewhere else in the system by releasing its own ‘stimulating’ hormones. a. follicle-stimulating hormone(FSH), and luteinizing hormone (LH) affect the gonads by stimulating gamete formation and production of sex hormones b. Prolactin is secreted near the end of pregnancy and prepares the breasts for milk production. c. Oxytocin maintains lining of the uterus necessary for successful pregnancy d. Growth hormone (GH): GH is essential in early years to maintaining a healthy body composition and for growth in children. e. Thyroid-stimulating hormone (TSH): TSH stimulates the thyroid gland to produce hormones. f. Adrenocorticotropic hormone (ACTH): ACTH stimulates the adrenal glands to produce hormones.

3. Thyroid gland –It releases thyroid hormon which is required for metabolism and body homeostasis. 4. Parathyroid gland have the sole purpose of secreting parathyroid hormone to regulate the calcium level in our bodies. 5. Adrenal glands – The adrenal glands are two glands that sit on top of your kidneys that are made up of two distinct parts. a. The adrenal cortex—the outer part of the gland— produces hormones that are vital to life, such as cortisol (which helps regulate metabolism and helps your body respond to stress) and aldosterone (which helps control blood pressure). b. The adrenal medulla—the inner part of the gland— produces nonessential (that is, you don’t need them to live) hormones, such as adrenaline (which helps your body react to stress). 6. Pancreas – an organ of digestion which is inside the abdomen. Insulin lowers the amount of sugar in the bloodstream while Glucagon raises your blood glucose levels. 7. Ovaries – are inside the female pelvis. They make female sex hormones like estrogen which stimulates development of sex characteristics, preparation of uterus for fertilization and fetal development and stimulates bone growth. It has also progesterone which prepares the endometrium for the potential of pregnancy after ovulation. 8. Testes – they hang in the male scrotal sack. They secrete male sex hormones like testosterone which stimulates development of secondary sex characteristics, spermatogenesis 9. ANDROGENS promotes growth spurt in adolescence, secondary characteristics and libido in both sexes. 10. Puberty- the period of becoming first capable of reproducing sexually that is brought on by the production of sex hormones and making active reproductive cell 11. Homeostasis – Maintaining a near-constant internal environment 11. Negative feedback – It leads to a stable homeostatic system. 12. Positive feedback - is a process in which the end products of an action cause more of that action to occur in a feedback loop 13. To restore a high body temperature, we can do the following : shivering thermogenesis, sweating, flattening of skin hair and redistribution of blood flow to the periphery. III. Menstrual Cycle 1. Seminiferous tubules – produced male hormone, testosterone. 2. Fallopian tube – fertilization of human egg by sperms takes place. 3. Uterus - is the hollow organ in the female reproductive system that holds a fetus during pregnancy

4. Menstruation – shedding of the inner lining of the uterus 5. Ovulation – occurs after about 14 days. This period is the most hospitable environment for sperm passage. IV DNA replication 1. DNA contains a DEOXYRIBOSE sugar while RNA contains a RIBOSE sugar, while both nucleic acids contains phosphate. DNA has the following nitrogenous bases, cytosine paired with guanine, thymine paired with adenine while RNA has the following nitrogenous bases, cytosine paired with guanine, uracil paired with adenine. In terms of strands DNA has double strands while RNA has single strand. DNA is found only in nucleus while RNA is found in nucleus, cytoplasm, and some part of ribosome. There is only one type of DNA while there are 3 types of RNA namely mRNA, tRNA, and rRNA. DNA is replicated DNA while RNA is transcribed from DNA. 2. RNA: is a nucleic acid used is various body functions that uses Uracil instead of thymine to save energy to manufacture. 3. DNA replicates by making a complementary strand to each original strand. 4. DNA helicase is an enzyme that breaks down the hydrogen bonds during replication process IV. Transcription and Translation and Mutation 1. The central Dogma is DNA  RNA  Protein 2. The genetic code is initially transferred from DNA to RNA, in the process of transcription. Once transferred to RNA, the genetic code exists as triplet codons, which are sets of three nucleotides in which each nucleotide is one of the four kinds of ribonucleotides composing RNA. 3. Transcription results in the production of mRNA by using DNA as a template and occurs only in the nucleus. 4. The Process of translation decodes the information in mRNA, leading to the synthesis of polypeptide chains, or protein. 5. Mutation is a change in the base sequence of DNA. Mutations may affect only one gene, or they may affect whole chromosomes 6. Mutations in eggs or sperm may affect future generations by transmitting these changes in the offsprings. Mutations in non-sex (somatic) cells only are not hereditary. 7. Substitution mutations are situations where a single nucleotide is changed into another. In organisms having double-stranded DNA or RNA, this usually means that the corresponding base pair is also altered. For example, an A:T base pair could be mutated into a G:C base pair or even a T:A base pair. 8. Insertions are mutations in which extra base pairs are inserted into a new place in the DNA. For example CTGGAG  CTGGGAG

9. Deletions are mutations in which a section of DNA is lost, or deleted. For example CTGAG  CTAG 10. “Cri du chat” is caused by the deletion of part of the short arm of chromosome 5. 11. Down’s syndrome is usually caused by an extra copy of chromosome 21(trisomy 21). Characteristics include decreased muscle tone, stockier build, asymmetrical skull, slanting eyes and mild to moderate mental retardation. 12. Jacobsen syndrome is also called terminal 11q deletion disorder. VI. Biodiversity and Evolution 1. Evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection. 2. Patterns in animal development suggest that some organisms may have one common ancestor. 3. Evidence in structure and molecular studies suggests that organisms are related with one another. 4. Fossils are the remains of plants and animals. These are impression of dead plants and animals in rocks in a form of mold or cast. Most of the fossils found on sedimentary rocks. 5. Jean Baptiste de Lamarck proposed The Theory of Need, The Theory of Use and Disuse and The Theory of Acquired Characteristics. 6. Charles Darwin presented the Theory of Evolution based on natural selection. 7. FIVE evidences for evolution a. Fossil records - The remains of an organism preserved in petrified form. b. Homologous Structures- Having similar structure and anatomical position in different organisms suggesting a common ancestor c. Analogous Structures - Structures having a similar appearance, but not coming from a common ancestor d. Vestigial structures - A structure on the body that is greatly reduced in size from the original ancestor e. Embrylogical structures - A structure found during the development stage of the embryo VII. Ecosystem - Biodiversity • Biodiversity benefits people in many ways. It can be of economic, ecological or aesthetic value. • Greater biodiversity promotes a more stable ecosystem. • The more recent loss of biodiversity has been attributed primarily to human activities such as overfishing, overhunting, and loss of habitat. • Population growth gives us an idea on how fast a population changes over time. • Population growth can be affected by densitydependent or density independent limiting factors. • Changes in the habitat may cause an increase or decrease in biodiversity. • Humans are obliged to take responsibility in maintaining a clean and healthy state of the ecosystem.