Week 1 Bioscience PDF

 Week 1 bioscience The basics Endocrine system  The basics of biological terms Human anatomy : which is studies that are about the structure of the human Human physiology: studies that explain now the human body is able to surviveand reproduce Directional terms U...

 Week 1 bioscience The basics Endocrine system  The basics of biological terms Human anatomy : which is studies that are about the structure of the human Human physiology: studies that explain now the human body is able to surviveand reproduce Directional terms Used to compare the location of body parts relative to each other Anterior (ventral) – front or direction towards the front of the body Posterior (dorsal) – back or direction towards the back of the body Superior (cranial) – above or higher than another part of the body Inferior (caudal) – below or lower than another part of the body Eukaryotic cells Directional terms continued Humans are made up of trillions of Distal – a position in a limb farther to eukaryotic cells the point of attachment/trunk of the Cells are bound by a plasma/cell body membrane, that acts as a barrier to Proximal - a position in a limb nearer the extracellular environment and to the point of attachment/trunk of the controls the passage of substances into body or out of the cell Medial – middle or direction towardsthe middle of the Cells generally contain a nucleus and Lateral – side or direction towards the other membrane bound organelles, side of the body each of which has a specific function, Superficial – a position closer to the with a thick fluid called cytoplasm surface of the body Approximately 200 types of cells Deep – a position farther from the Different cells contain a different surface of the body number and type of organelles depending on their function. Tissues are groups of similar cells that work together to do a specific job in the body. Let’s break it down in a simple way: 1. Epithelial Tissue This type of tissue forms the lining on both the inside and outside of body organs, like your skin or the lining of your stomach. When it lines the inside of blood and lymph vessels, it's called endothelium. 2. Connective Tissue Connective tissue gives support to organs and protects them. It's the most common tissue in the body. Examples include cartilage, bone, and blood (yes, blood is a tissue!). 3. Muscle Tissue Muscle tissue is special because it can contract (tighten up), which helps move parts of your body. It controls movements like walking or the movement of your bowels (which helps digest food) and blood vessels(which helps regulate blood pressure). 4. Nerve Tissue Nerve tissue is made of two main cell types: neurons and glial cells. It's the main part of the nervous system and is responsible for controlling activities in your body, like muscle movements and sending signals to other parts of your body.  Endocrine system What's endocrine The systems works with the nervous system and is responsible in maintaining the internal environment - homeostasis When there is a change in production or hormone release it may be because of the nervous system How are hormones transported? By the bloodstreams. hormone originates from the Greek word hormao meaning “to set in motion” or “I excite”… Hormones set in motion/excite/stimulate parts of the body to bring about actions including sleep, hunger, metabolism, conception, moods, stress response. Role of the Endocrine System in Reproduction The endocrine system plays an important role in controlling reproduction by using hormones, which are like chemical messengers in your body. Here’s how it works: 1 Menstrual Cycle and Ovulation ◦ Hormones help control the menstrual cycle, which prepares a woman’s body for pregnancy. ◦ These hormones also trigger ovulation, which is when an egg is released from the ovaries. ◦ The hormones then prepare the uterus (the organ where a baby develops) to be ready if the egg is fertilized. 2 Pregnancy and Labour ◦ During pregnancy, many hormone levels increase a lot. ◦ Labour (the process of giving birth) is also believed to be started by hormones, which prepare the body to deliver the baby. 3 Lactation (Milk Production) ◦ After the baby is born, the endocrine system controls the production and release of milk (called lactation) for breastfeeding. Hormones help start and continue milk production Hormones are produced by the following endocrine glands throughout the body or in endocrine cells within tissues in the body: Hypothalamus Pituitary gland Pineal gland Thyroid gland 4 parathyroid glands Thymus gland 2 adrenal glands Endocrine cells within organs, such as the ovaries, testes, placenta, and pancreas Hypothalamus ' Thyroid ' Found in the diencephalon Major integrating link between the brain and Butterfly shaped gland in neck endocrine function Largest adult endocrine gland (10-20g) Receives information from other parts of the Produces & secretes 2 thyroid brain or the body and alters function by either hormones: nerve impulses or releasing its own hormones 1. Thyroxine (T4) Produces hormones, including 2. Triiodothyronine (T3) Gonadotrophin Releasing Hormone Essential for maintenance of normal (GnRH), thyroid releasing hormone and metabolism prolactin releasing hormone, that act on Thyroid hormones are important in the pituitary gland by either stimulating an regulating ovulation, preventing increase or decrease in hormone secretion miscarriage and aiding fetal brain developmen I Hormones are produced by the following Pancreas endocrine glands throughout the body or in Part of the digestive system endocrine cells within tissues in the body: Lies behind stomach Hypothalamus Two types of tissue: exocrine and Pituitary gland endocrine Pineal gland Small collections of specialised cells called Thyroid gland islets of Langerhans are found 4 parathyroid glands throughout Thymus gland Islets contain 2 adrenal glands o Alpha cells which secrete the hormone Endocrine cells within organs, such as glucagon (converts glycogen to glucose) the ovaries, testes, placenta, and o Beta cells which secrete the hormone pancreas insulin (converts glucose to glycogen) Pituitary gland Role of the Ovaries -The ovaries are important organs in the female reproductive system. They produce hormones and help with reproduction. Here’s a breakdown of what they do: Hormones Secreted by the The anterior lobe is part of the pituitary gland, a small gland in your brain that produces hormones, which are like chemical messengers. These hormones control many important processes in the body. Let’s go over some of the key Ovaries hormones produced here: The ovaries mainly release two hormones: oestrogen and progesterone. 1 Follicle Stimulating Hormone (FSH) These hormones help control the menstrual cycle and are important for pregnancy. Response to FSH and LH ◦ FSH helps the ovary create a Graafian follicle, which contains a mature egg (called an ovum) ready for ovulation. ◦ The ovaries respond to Follicle Stimulating Hormone (FSH) and Luteinising Hormone (LH), which are 2 Luteinising Hormone (LH) produced by the brain (pituitary gland). These hormones help control the release of eggs and hormone ◦ LH triggers ovulation, which is when the mature egg is released from the ovary. production in the ovaries. ◦ It also helps maintain the corpus luteum, which is important for early pregnancy. 3 Prolactin Oestrogen’s Role ◦ Prolactin is responsible for starting and continuing the production of breast milk after a baby is Development of female sexual characteristics (like breasts) during puberty. born. The maturation of the dominant Graafian follicle (the part of the ovary that holds the egg) during the 4 Thyroid Stimulating Hormone (TSH) menstrual cycle. ◦ TSH tells the thyroid gland (located in the neck) to produce thyroid hormones, which help control metabolism (how your body uses energy). Corpus Luteum Homeostasis and the Hypothalamus After the egg is released during ovulation, a structure called the corpus luteum forms in the ovary. To keep the body balanced (a state called homeostasis), the anterior pituitary releases hormones based The corpus luteum produces oestrogen and progesterone, which help prepare the uterus for a possible on signals from the hypothalamus, another part of the brain that monitors levels of various chemicals in the body pregnancy. If fertilization happens (the egg is fertilized by sperm), the corpus luteum keeps producing these Role of the Placenta hormones to support the pregnancy until about 12 weeks when the placenta takes over. Progesterone’s Role he placenta is a special organ that develops during pregnancy and plays a crucial role in Progesterone also helps prepare the breasts for producing milk after childbirth. supporting the growing baby (fetus). Here’s what the placenta does: Inhibin and Relaxin 1 Hormone Production-The placenta produces many hormones that help adjust the The corpus luteum also produces: mother’s body to create the best environment for the baby’s development. Inhibin, which along with oestrogen and progesterone, stops the release of FSH and LH to prevent more eggs from developing while a pregnancy is happening. 2 Human Chorionic Gonadotropin (hCG) -hCG is a hormone secreted by the trophoblast Relaxin, which relaxes the pelvic muscles and ligaments, helping the body prepare for labour by (the part of the placenta that connects to the uterus).It helps keep the corpus allowing the pelvis to expan luteum (a structure in the ovary) active for about 3-4 months, making sure it continues producing oestrogen and progesterone, which are needed to support the early.puritary Posterior lobe stages of pregnancy -The presence of hCG in the blood or urine is what pregnancy Two hormones are secreted by the posterior obe: tests look for as a marker of pregnancy. 1. Oxytocin – “love hormone” released during touch, sex, orgasm, birth and breastfeeding 3 Human Placental Lactogen (hPL)-hPL helps prepare the mammary glands (breasts) for 2. Anti-diuretic hormone (ADH) – milk production after the baby is born. released in response to a decrease in fluid volume in the blood to reduce reabsorptionof water by the kidney Both hormones are produced by the Relaxin -The placenta also produces relaxin, a hormone that helps relax and loosen the hypothalamus but stored and released by the posterior pituitary gland pelvic muscles and ligaments in preparation for childbirth. Feedback negative Positive feedback