Unit 04 Biology PDF

Lesson of Sunday Homeostasis A a onstant...

Lesson of Sunday Homeostasis A a onstant internal environment is maintained which C to the external environment. process by despite continuous changes - - most homeostatic mechanisms work on a negative feedback loop meaning the "System" only needs to work if the "pre-set" conditions is not being kept. - All homeostatic mechanisms require three functional Components : 1 Monitor that notes receptor any change. : a. 2 Center : Interprets the monitor to put regulators into action. Co-ordinating.. 3 Regulator : utilizes organs , hormones and chemicals to effect Various parts to return to the pre-set Condition. Classic Examples of Homeostatic Mechanisms 1. furnace at home your MonitorColdairreturnopair Circulating in thatoni s. 3 Regulator : furnace itself.. 2 Thermoregulation muscle tissue expands Blood Vessels Dilate Sweat Pants Blood Informs the Hypothalamus Expand Surface area TOOt 37C Internal temperature Toold fetal position Blood informs the Shiver Hypothalamus Blood Vessels Hair Stands up constrict Muscles Tissue Constrict  Lesson 02 Sunday Urinary System - Waste filtered by the kidneys goes to the bladder Via Ureter. F M recent at 200mL full to = urge pee - Kidney - at 400mL full = Panic - at 600mL full = auto-release # Ureter Bladder Urethra The Kidneys Cortical Renalortet fist) blood vessel - Born with two each 150g in weight (about the Size of your m Minor calyx - Together hold 25 % of your blood at a Single Moment. Interloblar - filters 200L per day (equivalent to amount of a bathtub blood vessels Major Renal calyx artery The kidneys are bean shaped and Reddish-Brown in colour. The concave side of each kidney has a depression where renal artery enters and a renal vein and a ureter exit the kidney. Renal vein It has three regions:- the renal cortex is an outer layer that dips down into an inner layer called the renal medulla. The renal medulla contains cone-shaped tissue masses. Ureter Medula The renal pelvis is a central space, or cavity, that is continuous with the ureter. Capsule Kidney and Urinary system parts and their function Two Kidneys: This Pair of purplish-brown organs is located below the ribs toward the middle of the back. They:- Remove waste products and medicines from the body. Balance the Body's fluids. Balance a variety of electrolytes. Release hormones to Control blood pressure. Release a hormone to Control RBC production. Help with bone health by controlling Calcium and phosphorus. Facts about urine Normal, healthy urine is a pale straw or clear yellow color. Darker yellow or honey-colored urine often means you need more water. A darker, brownish color may mean a liver problem or severe dehydration. Pinkish or red urine may mean blood in the urine.  Nephron Filtration : Movement of fluids from the blood into the nephron. * Each nephron has its own blood supply. * Dissolved Solutes pass from the walls of the glomerulus into the Bowman's Capsule. * HO , NaCI , Glucose , Amino acids and He pass through. * RBC WBC , , Platelets and plasma proteins are not to pass through. * 600m) of fluid passes through the kidneys per Minute. * 20 % (120m) of that filters into the Bowman's Capsule. * The Rest of the nephron tries to recover a 119m) of that. Reabsorption : - Proximal tubule has numerous Mitochondria - Actively transports Nations out > - this Causes Cl and HCO ions to follow. There is threshold after that some "Salts" > a max so get through By Moving > "Salt" out water naturally follows - 80 % of H2O is returned immediately via the proximal Convoluted to be Active transport. to salt "diffusion. " Descending loop of Henle is permeable - - Loop of Henle > - Narrows to build up pressure (like hydraulics). - Ascending loop of Henle - first half is passively transporting Salt. > - Second half "Actively transport"If Salt Content is still high. - Distal Convoluted Tubule - effected by Various hormones and chemical messengers to Capture extra H2O if needed (10-15% more possible) Glomerular filtration water Salt nutrient molecules , and , , waste molecules move from the glomerular Capsule these small molecules. are called the glomerular filtrate. Tubular Reabsorption prom e Nutrient molecules sodium solutes are actively , ions reabsorbed from the , and other proximal - tubule into the peritubular Capillary Network Distal while water flows passively. tubule Tubular Section Certain Substance (eg : -It and penicillin) are actively secreted from the peritubular Capillary network into the distal tubule. peritubular ~ capillary network Loop Water Henle of Reabsorption H20 Urea Water is reabsorbed from the collecting duct Uric Acid by Osmosis. Water reabsorption in the collecting Salts duct Increases the Concentration of the filtrate. NHI Creatinine  The kidneys remove urea from the blood through tiny filtering units called nephrons. Each nephron consists of a ball formed of small blood capillaries (glomerulus) and a small tube called a renal tubule. Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney. Renal Medulla Renal Cortex The nephrons are responsible for filtering various substances from blood, transforming it into urine. To perform this function, Each nephron is organized into three main regions:- Filter Ascending Descending loop Henle of Tubule loop of Henle Collecting duct Filter: Tubule: the filter action structure at the top of each nephron is a cap like the Bowman’s capsule is connected to a small, long narrow tubule that is twisted formation called the Bowman’s Capsule. back on itself to form loop. Each Capsule, the renal artery enters and splits into a fine The tubule has three section: the proximal tube, the loop of Henle, and the distal network of capillaries called a Glomerulus. tubule. The walls of glomerulus act as a filtration device and they are This tubule absorbs substances that are useful to the body, such as glucose and a impermeable to proteins, other large molecules, and red blood cells, variety of ions, from the filtrate passing through it. so these remain within the blood. Water, small molecules, ions, and urea—the main waste products of metabolism—pass through the walls and proceed further into Duct: the nephron. the tubule empties into a large pipe-like channel called a collecting duct. The filtered fluid that proceeds from the glomerulus into the It function as a water conversation device, reclaiming water from the filtrate Bowman’s capsule of the nephron is referred to as filtrate. passing through it so that very little water is lost from the body. lesson3 monday Blood Pressure If - your Bp is too low due to blood loss , dehydration or internal bleeding , the BP detector in the glomerulus called juxtaglomerular apparatus turns on. - This Causes the release of Renin directly into the Bloodstream. - Renin is a water Soluble protein-based hormone. - Renin in your bloodstream changes angiotensinogen into angiotensin - Angiotensin does 2 things 1 Constricts blood Vessels. 2 Releases Aldosterone from the Adrenal glands. - Aldosterone has a direct line to the kidneys toCause the nephron to increase Nat absorption in ALL active transport locations. Water Balance - Antidiuretic hormone (ADH) helps regulate Osmotic pressure and body fluid Volume. - Aldosterone regulates body fluid Volume. ADH and aldosterone work feedback Via negative -. - Osmoreceptors in the hypothalamus Shrink when body fluid levels are low (dehydrated). - Hypothalamus Shrinkage Sends Signal a to the pituitary gland. Pituitary gland releases ADH. - ADH heads to the distal Convoluted tubule (DCT) to Increase uptake of tion any -. - ADH alsoCreates the thirst response.  Blood Sugar Regulation - Body maximizes blood Sugar uptake for efficient ATP Production. two Insulin and - Controlled by major hormones glycogen. - Receptors in the pancreas monitor. - Hypothalamus Sets the limit. Insulin : Released if BS is too high. Produced by Beta Cells -. - Converts Extra BS into Glycogen. Glycogen : - Produced by Alpha Cells in the pancreas. - targets the liver. - Converts glycogen back to glucose > - Released into blood stream. Pancrease Receptors Insulin stimulated Released Cells take into Detected by phosphorylation and Limit threshold Hypothalamus passive transport To O Liver Converts extra high to Glycogen Glylagon converted Blood Sugar Norm (is also threshold) a back to glucose TOO Little Liver Stimulated Detected by glucagon Pancrease Hypothalamus Released stimulated  Thyroid Gland Hyoid bone M - Butterfly shaped found below the larynx. Controls metabolism - and growth. Hypothalamus Thyroid cartilage Superior thyroid artery Thyroid Releasing Hormone Isthmus of the thyroid Hypothyroidism Common Anterior Pituitary carotid arteries Symptoms : - Cold Intolerance Trachea threshold level Inhibits TRH Thyroid Stimulating Hormone - too little Ty - weight gain Thyroid - Dry Skin Moody tired , - Thyroxine Calcitonin - Iodine Deficiency Ty T3 (works with Parathyroid) - Goitre Hyperthyroidism Symptoms : - Parathyroid Gland weight loss - - Excessive Sweating -four Smaller glands embedded In the thyroid gland. - Protruding Eyes - Controls Calcium levels. - Sensitive to heat - Always hungry. Blood Cat levels Too high Too low - Hypothalamus detects - Hypothalamus Detects stimulated - thyroid - Parathyroid Detects - Calcitonin Released - Parathyroid Hormone Released - Bones take in more Cast - Bones give back Catt Intestines hunt + for Ca2 Aided - by absorb Cast - Kidneys Sunlight. ↳ Larynx Parathyroid glands Right thyroid Left thyroid gland gland ↑ W Trachea  Lesson 04 Monday Adrenal Gland - located at the top of the kidneys. - Composed of 2 layers. Layer-Inner Medulla - Short term Stress. - Hypothalamus has a direct Neural line. - Causes the release of Epinephrine. Heart rate , breathing rate. Blood pressure. Blood flow to extremities. liver function. Pupils dilate other senses dulled. Layer - Outer Cortex - Hypothalamus stimulates the pituitary gland to Release ACTH Cause Adrenal Gland to release 1 Cortisol ↑ Blood level. : Sugar. ↓ Inflammation. ↓ Immune System Response ↳. - Inhibitive Connective tissue. Adrenal & gland. Aldosterone 2 : ↑ Nat Absorption at DCT ↑ Blood pressure i - feel Bloated > The Concern New thresholds established for :- # Blood levels 1 Sugar Adult Onset Diabetes Left Blood pressure Stroke kidney a too high = 3 Heart Rate too Much = Heart Attack  Pituitary Gland Cerebral cortex Central sulcus B Frontal lobe Parietal lobe Lateral ventricles Hypoth alamus Corpus callosum Thalamus Temporal lobe Arbor Vitae Fourth Pituitary ventricle gland Cerebellum Pons Cerebellar Medulla cortex Spinal cord - 1 cm in diameter. - found at the bottom of the hypothalamus. - Composed of 2 lobes. Posterior Lobe Anterior Lobe Stores and Releases. following produces and stores for release the ! - - 1. ADH-antidiuretic hormone 1. HGH-human Growth hormone.. 2 Oxytocin - 1 of the few positive feedback hormones. 's met rate proteinSynthesis , cell division growth plate Causes Uterine Contractions metabolism , breakdown adipose (Brown) tissue. Gives birth. 1 2. TSH-thyroid Stimulating Hormone.. 2 Expulsion of the endometrium 3 ACTH. - Adrenocorticotropic Hormone-Adrenal. 4. FSH-follicle Stimulating Hormone.. 5 LH-Iutenizing Hormone. Prolactin Hormone. 6. -lactating TSH: activates your thyroid to release thyroid hormones. It is crucial during metabolism. ACTH: stimulates your adrenal glands to produce Cortisol and other hormones. FSH: involves with estrogen secretion and the growth of egg cells in women. It is also important for sperm cell production in men. LH: Production of estrogen both men and women. ADH: it helps your body conserve water and prevent dehydration.  Lesson os Reproduction System Tuesday Male Hypothalamus ↑ [GnRH] Gonadotropin Releasing Hormone Inhibition Anterior Pituitary 1-ve feedback) FSH LH Testes Sertoli cells Interstitial Cells Sperm production Testosterone -ve Feedback female ↑ progesterone Shuts off System Hypothalamus the feedback Gonadotropin Releasing Hormone cause LI to be released ↑ Estrogen Anterior Pituitary #SHfolicle - ve Feedback LH varis Corpus It Growing is Progesterone What happens during Pregnancy - Egg is fertilized GnRH tell fSH - pituitary gland to release more LH and less Placenta produces - more estrogen and progesterone. - Relaxin is released Allows Skin to Stretch. for Labour. Relaxes ligaments - Intestines absorb more H2O and nutrients (get that Glow) - Prolactin released Milk ducts increase in number and Size (Breasts en large - Eventually Oxytocin is released and keeps Increasing (almost exponentially female Reproductive System follicle Development Phase Name : flow follicular Ovulation luteal Phase Days : 1-5 6-14 14 15 - 28(29 34) -  Lesson 06 Nervous System Wednesday Types of Neurons Nucleus Axon 1. Sensory Neurons - Photoreceptors-Eye Hillock Axon - Chemoreceptors-Nose Axon Node of terminal - Thermoreceptor-Fingers Myelin ranvier Scwann cell - Mechanoreceptors-Ear - Nocioreceptor-Lips Dendrite 2. Interneuron (Spine) Soma Brain motor Neurotransmitter Substance 3. Motor Neuron multi-polar Acetylcholine is most neuron mostAbundant Most Abundant The Nerve Cells Come in Various Designs : How a Nerve Signal Works The Key there is an electrical difference across the membrane of a neuron. Internally of the neuron, there is a -70mV charge. The -70mV is referred to as the resting potential. This negative charge is created by 3 key factors. How the -70mV is created Large integral proteins are embedded throughout the membrane with their negatively charged end putting inwards to the inside of the neuron Potassium channels are open allowing potassium to freely move out The sodium/potassium pumps work by removing three sodium ions for every two potassium ions brought in How a Nerve Signal Travels 1. A stimulus threshold must be reached. If it is a sensory neuron you must register the sensation. An example is you do not feel the bacteria on you right now because it does not register. 2. Once a stimulus is ‘noticed’ the all or none principle begins. This means once it starts you can not stop it. Every tried to stop your leg from kicking when you are tapped on the knee by your doctor with that little triangular hammer. Can’t be done. 3. Once perceived voltage-gated sodium channels open quickly allowing sodium to rush in. A positive charge has rushed in. If -70mV is called a polarized neuron then this rush of sodium elevates the inner charge to +40mV which is called depolarized. 4. At +40mV the sodium channels reclose and this in turn causes the potassium channels to open because they are also voltage gated. Once open potassium flies out of there so much so that the neuron overshoots the -70mV and goes to -90mV. This is called hyperpolarization. 5. This new charge of -90mV causes the ATP induced active transport proteins to begin to bring two potassium back in as it kicks three sodium back out. This is called repolarization. 6. There is a brief rest period before any new stimulation can occur called a refractory period. The time for this is relatively quick 3 milliseconds.  Lesson of Wednesday The Synapse and Neurotransmission The Synapse is the Functional connection between two neurons where information transfer occurs. Parts of a Synapse: Presynaptic neuron: Sends the chemical message. Postsynaptic neuron: Receives the chemical message. Synaptic cleft: Space between presynaptic and postsynaptic neurons. Types of Synapses: Electrical synapse: Direct electrical connection; rare in mammals. Chemical synapse: Most common; allows for flexibility in signaling. Chemical synapses are the most common in mammals, as they allow for greater flexibility. While a synapse can occur between different neuronal structures, the most common one is between axon and dendrite, called axodendritic. Key Components most common Neurotransmitters: Chemicals released by neurons (e.g., acetylcholine, dopamine, serotonin, GABA). Synaptic vesicles: Contain neurotransmitters in the presynaptic neuron. Receptors: Proteins on the postsynaptic neuron where neurotransmitters bind. Ions: Charged molecules (e.g., calcium, sodium) involved in synaptic transmission. Important stages of Neurotransmission: 1. Synthesis: Neurotransmitters are synthesized in the neuron, and packaged into vesicles. 2. Release: In response to an action potential, calcium mobilizes the neurotransmitters to be released into the synaptic cleft via exocytosis. 3. Receptor action: the neurotransmitter crosses the synaptic cleft and binds to a receptor on the postsynaptic neuron, altering its activity. 4. Inactivation: the neurotransmitter is separated from the receptors and is either diffused away, converted into inactive chemicals, taken back into the presynaptic neuron, or take up by glial cells. Chemical Synaptic Transmission (Step-by-Step) 1. An action potential reaches the axon and depolarizes the area. 2. The depolarization causes the voltage gated calcium channels to open. 3. Calcium floods in. 4. Calcium causes neurotransmitter vesicles to migrate to the presynatic cleft membrane. 5. Vesicle ruptures via exocytosis flooding the synapse with the neurotransmitter held within. Only one type of neurotransmitter in a vesicle But you have numerous vesicles.. 6. Neurotransmitter binds to ligand gated receptors (allosteric sites) on the post synaptic membrane aka dendrite. 7. Causes ligand gated sodium channels to open and sodium floods in. 8. Causes depolarization of the dendritic area. 9. Eventually neurotransmitter is released from the receptor and the sodium channel closes. 10. Neurotransmitter now faces one of three fates: - Degraded by an enzyme - in the case of acteylcholine it is broken down by acetylcholineestearse. - Allowed to slowly diffuse through out the body to naturally breakdown. - Reabsorbed back into the axon by reuptake channels where it is repackaged into a vesicle. Neurotransmitters and Their Effects Effects of Drugs on Synapses Acetylcholine (ACh): Involved in muscle movement Drugs can: and memory. Mimic neurotransmitters. Dopamine: Associated with pleasure, reward, and Block neurotransmitter receptors. motivation. Inhibit reuptake or degradation of neurotransmitters. Serotonin: Regulates mood, sleep, and appetite. Affect neurotransmitter synthesis or release. GABA (gamma-aminobutyric acid): Major Example: Caffeine blocks adenosine receptors, which delays sleepiness inhibitory neurotransmitter; reduces neural activity. Synaptic Plasticity Synapses can strengthen or weaken over time, which is critical for memory, learning, and behavior changes.  Lesson Og Tuesday Brain Frontal Parietal lobe · lobe Occipital lobe Central lobule Superior cerebellar Lingula * peduncle 4th Temporal Cerebellar ventricle lobe peduncle Spinal Nodule cord Cerebellum Flocculus Uvula Cerebellum vermis Peduncle Cortex Pyramid Vallecula of flocculus Tonsil Key Brain Structures and Functions of vermis 1. Cerebrum Largest part of the brain, divided into left and right hemispheres. Controls voluntary actions, emotions, reasoning, and sensory processing. 2. Cerebral Cortex Outer layer of the cerebrum, responsible for higher-level functions like memory, language, and consciousness. Contains different lobes for specific tasks. 3. Lobes of the Brain: Frontal Lobe: Planning, decision-making, personality, motor control, speech production, and emotional regulation. Parietal Lobe: Processes sensory input (touch, spatial reasoning, navigation). Temporal Lobe: Hearing, memory formation, language comprehension, and emotional responses. Occipital Lobe: Vision and visual processing. Cerebellum: Coordination, balance, posture, and motor learning. Deep Dive into Lobes 1. Frontal Lobe Functions: Voluntary movements. 4. Temporal Lobe Functions: Speech and language production. Auditory processing (hearing). Reasoning, problem-solving, planning. Storing long-term memories. Regulating emotions and social behaviors. Emotional interpretation and language Personality and impulse control. understanding. 5. Cerebellum Functions: 2. Parietal Lobe Functions: Maintains balance and posture. Integrates sensory data (touch, taste, smell). Coordinates voluntary muscle movements. Processes spatial awareness and proprioception. Facilitates motor learning (e.g., sports, music). Helps in reading maps, numerical reasoning, and object orientation. Plays a role in cognitive functions like language. 3. Occipital Lobe Functions: Main center for visual processing. Helps interpret shape, distance, and color.  lesson 09 Thursday Cerebral cortex Central sulcus B Frontal lobe Thalamus Parietal lobe · Occipital lobe Lateral ventricles ypothalamus Corpus callosum Thalamus Temporal lobe Arbor Vitae Pineal gland Fourth ventricle Hypothalamus Pituitary gland Cerebellum Pons Cerebellar Medulla cortex Spinal cord 1. Pineal Gland Regulates sleep-wake cycles by producing melatonin. 2. Thalamus Acts as a relay station for sensory information to the cerebral cortex. 3. Basal Ganglia Controls voluntary motor movements, procedural learning, and habits. 4. Hippocampus Key for memory formation and spatial navigation. 5. Amygdala Processes emotions, especially fear and pleasure. 6. Cingulate Gyrus Involved in emotion regulation and linking behavior to motivation. 7. Pons Connects brain regions and regulates breathing, sleep, and facial movements. 8. Medulla Oblongata Controls vital functions like heartbeat, breathing, and blood pressure. 9. Corpus Callosum Connects the left and right hemispheres of the brain for communication. 10. Nucleus Accumbens Central to reward, pleasure, and addiction pathways. Function of Hypothalamus The hypothalamus serves as the brain’s control center for homeostasis, maintaining the body’s internal balance: 1. Regulation of Autonomic Nervous System: Controls involuntary functions like heart rate, blood pressure, digestion, and breathing. 2. Endocrine System Control: Connects the brain to the endocrine system via the pituitary gland. Produces releasing and inhibiting hormones that regulate the pituitary gland. 3. Thermoregulation: Monitors and regulates body temperature. 4. Hunger and Thirst: Controls appetite and hydration signals. 5. Sleep-Wake Cycle: Regulates circadian rhythms in partnership with the pineal gland. 6. Emotional and Behavioral Responses: Influences mood, stress responses, and sexual behaviors. Function of Pituitary gland The pituitary gland is often called the “master gland” because it controls Hypothalamic several other endocrine glands: Third ventricle M Supraoptic of brain 1. Anterior Pituitary Hormones: nucleus Growth Hormone (GH): Stimulates growth and cell reproduction. Optic chiasm Thyroid-Stimulating Hormone (TSH): Regulates thyroid function. Superior Hypothalamic Adrenocorticotropic Hormone (ACTH): Stimulates adrenal hypophyseal neurons artery glands. Hypophyseal Hypothalamic hypophyseal portal veins Prolactin: Stimulates milk production. tract Follicle-Stimulating Hormone (FSH) & Luteinizing Hormone Inferior hypophyseal Anterior artery (LH): Regulate reproduction. pituitary 2. Posterior Pituitary Hormones: Posterior pituitary Oxytocin: Controls uterine contractions and milk ejection. Venue Secretory cells of Antidiuretic Hormone (ADH/Vasopressin): Regulates water adenohypophysis balance and blood pressure. Cranial Nerves 1 through 12 1. Olfactory (I): Smell. 2. Optic (II): Vision. 3. Oculomotor (III): Eye movement, pupil constriction. 4. Trochlear (IV): Eye movement (superior oblique muscle). 5. Trigeminal (V): Facial sensations, chewing. 6. Abducens (VI): Eye movement (lateral rectus muscle). 7. Facial (VII): Facial expressions, taste (anterior tongue). 8. Vestibulocochlear (VIII): Hearing, balance. 9. Glossopharyngeal (IX): Taste (posterior tongue), swallowing. 10. Vagus (X): Autonomic control of heart, lungs, digestion. 11. Accessory (XI): Shoulder and neck muscles. 12. Hypoglossal (XII): Tongue movement.  Meninges Protective layers covering the brain and spinal cord. Dura Mater: Tough outer layer. Arachnoid Mater: Middle layer; web-like appearance. Pia Mater: Thin inner layer adhering closely to the brain. Glial Cells Supportive cells in the nervous system. Astroglia: Support neurons, maintain the blood-brain barrier. Oligodendroglia: Produce myelin in the central nervous system. Ependymal Cells: Line ventricles, produce cerebrospinal fluid. Microglia: Act as immune cells in the brain. Key Brain Terms 1. Forebrain: Includes the cerebrum, thalamus, and hypothalamus; responsible for sensory processing, thinking, and emotions. 2. Hindbrain: Includes the cerebellum, pons, and medulla; controls basic functions like movement and breathing. 3. Midbrain: Processes auditory and visual information and controls reflexive actions. 4. Limbic System: Emotional and memory-processing system; includes the hippocampus and amygdala. 5. Crocodile Brain: Refers to the brainstem; controls primitive survival functions. 6. Cerebral Cortex: Outer layer of the brain; involved in higher-order functions like thinking, memory, and decision-making. 7. Cerebellum: Coordinates movement, balance, and posture. 8. Blood-Brain Barrier: Protective barrier that prevents harmful substances in the blood from entering the brain.