Aparatos y sistemas. Apparatus and systems.

T1  Scale of Univ. Inner life of the cell.  //  Margulis entrevista. Y otra entrevista.  
[Atoms (Bioelements CHONPS)-> molecules (Water, mineral salts & carbohydrates, proteins, lipids, nucleic acids) -> organelles -> CELLS (Life!) -> tissues (muscle, nerve, bone...)-> organs (heart, kidney)-> systems (circulatory, excretory...)-> organisms.] 

Living beings are classified in 5 groups (Kingdoms):
AnimalsPlantsFungiProtoctists (protozoos + algae) [All EUKARYOTAE] and 
Monera (Bacterias) [prokaryotae].

2A) The membrane is composed of phospho-lipids and proteins. 
2B) The membrane is a boundary, selective barrier & protects the cell. 
2C) Phospholipids are amphipathic (they have polar & apolar regions). Polar molecules attract polar, and apolar attract apolar. 
The membrane is fluid, dynamic. The membrane can merge (capture vesicles) and separate (exocytosis or cell division). 
2D) Plant cells have a layer of cellulose (cell wall) over the membrane. 
Plants structure is possible thanks to the cellulose walls and to the hydro-skeletonIMG
3) Cells have 3 parts: a membrane, a cytoplasm and DNA (chromosomes in the nucleus). 
The cytoplasm contains: organelles, hyaloplasm, cytoskeleton and inclusions. 
4) Ribosomes make proteins. They get the "recipe" in a RNA molecule (copy of a small region of DNA from the nucleus). 

Animal cell vs Plant cell .

2 important organelles related with the ENERGY are: Mitochondria and Chloroplasts. 
Both of endosymbiotic origin. 

5A) Mitochondria💥Cell respiration <)2
Generates energy. Use glucose as fuel. With Oxygen, generate 36 ATP per glucose molecule. 
         1 glucose (C6H12O6)+ 6 O2   -->   6 CO2 + 6 H2O + 36 ATP (energy)

OUT of the mitochondria, withOUT Oxygen, in the cytoplasm, cells can break down glucose in --> 2 molecules of lactic acid and get 2ATP, or --> 2 alcohol + 2 CO2 + 2ATP

6A) The Golgi apparatus modifies proteins (add sugars) & generates vesicles full of them. 
6C) Vesicles enter the Golgi through the cis side and leave by the trans side.
7) Types: lysosomes (cell digestion of wastes, pathogens and damaged cells), peroxisomes (detoxification) and vesicles (transport).  
8) RER (with ribosomes -> make proteins) & SER (REL en español, metabolism of lipids).  
9) Chloroplast
💥(only in plants and algae, and some protozoos). 
Photosynthesis <)9. Generates glucose. Uses light energy. 
         6 CO2 + 6 H2O + ATP (from light energy) --> glucose + 6 O2 

10) Plasmodesmata:  facilitate the movement of molecules between cells, ranging from small photosynthetic products to large proteins and mRNA. IMG
11) Centrosome:  is a cellular structure involved in the process of cell division.
12) CytoskeletonIMG13AyB) The nucleus and its parts. Structure and function.  
13C,D,E) The DNA is usually part of a chromatin fibre, unless the cell prepares for cell division, in which case, the chromatin condenses into chromosomes to facilitate the separation in 2 equal halves. 
             2. Osmosis and Tissues ANSWERS




Effect of osmosis could be different on plant cells when compared to its  effect on animal cells. Why? | Socratic

IMG Elodea Turgid and plasmolysed. 

--> Types of tissues in animals (IMG): Atlas Michigan 

--> Systems in the human bodyIMG



T3 Nutrition
Nutrients have different caloric values: Fat and alcohol provide 9 kcal/g, carbohydrates 3.75 kcal/g. proteins 4 kcal/g. [1 Caloría = 4.18 Julios].
- Nutrients & Their functions <)17  - You Are What You Eat: Crash Course #1 
- Metabolism & Nutrition. Part 1. <)10 & Part 2. <)10Crash C. Anatomy & Physiol #36&37  

Some advice for a healthy diet 💥(pg 30-31 book)
A- Eat a variety of foods. 
B-  Have several meals a day. The meals should not be very big, and avoid having one or two very big meals a day. 
C- Eat fresh vegetables: These provide your daily vitamin requirements. 
D- Avoid convenience foods including ready meals and preserved foods. 
E- Include unsaturated fats in sufficient proportions in your diet and reduce your consumption of foods that are rich in saturated fats and cholesterol. 
F- Eat fibre-rich foods daily (vegetables, fruits, whole grains,etc).

10-15% protein; 55-60% carbs; 30% fats (max 300 mg cholesterol, more than 25 g fibre, 2l of water). 


Basal Metabolic Rate (BMR) refers to the minimum amount of energy that your body needs on a daily basis. 
Men: BMR = 88,36 + (13,39 x weight in kg) + (4,79 x height in cm) – (5,67 x age in years).
Women: BMR = 447,59 + (9,247 x weight in kg) + (3,09 x height in cm) – (4,33 x age in years).

The food wheel groups different foods according to the nutrients they contain as well as the function they perform in our bodies. In a balanced diet we should include foods from all groups but in the proportions recommended in the food pyramid.




Deficiencies and diseases.

The lack of certain vitamins & minerals may cause deficiency diseases such as of:
Iron --> anaemia. Symptoms: tiredness and shortness of breath.
Vitamin A --> may result in blindness.
Vitamin C --> scurvy (escorbuto). Symptoms include bleeding gums, bulging eyes and scaly skin.
Vitamin D --> Rickets: Thin, malleable, and brittle bones.
Kwashiorkor, Protein deficiency --> often results in swollen, puffy skin and muscle wastage.
Marasmus implies a TOTAL lack of food (a protein-caloric malnutrition), common of war zones.

Some disorders are:
Type II Diabetes --> An inadequate diet full of fats for a long time. Symptoms are fruity breath, polyuria (peeing in excess), constant thirst, headache, warm and dry skin, blurred vision. You can prevent its advancement having a balanced diet, doing exercise, and taking metformin.
Anorexia is rooted in dysmorphia, an obsessive desire to be very thin, fear of gaining weight, and emotional issues due to unresolved traumas --> pattern of behaviour resulting in a need to control what they eat, never reaching the desired image, that is never thin enough.
Bulimia, rooted in anxiety, and giving too much importance to the weight or the shape of the body (narcissism). An unresolved stressor disbalances the patient, who loses control while eating, and binges the food without hunger as a decontrolled coping mechanism. After that, regret and worry lead to corrective behaviours such as vomiting, laxatives, or overexertion. 
Food intolerance --> Lack of the proper enzyme to digest that food into nutrients.
Food allergy --> The inmune system reacts against a nutrient that is not harmful. Digestive cramps, pain, vomit, swelling of the mouth and gastrointestinal tract, itching, tingle in the mouth, red color, and urticaria, and lastly may lead to anaphylactic shock. Need for antihistaminic and corticoids. 
Food poisoning --> The food contains toxins, many times generated by bacteria such as: botulism, salmonella or cholera. Symptoms: like a gastroenteritis: diarrhoea (with foetid faeces), gastrointestinal cramps, pain, vomiting, fever, lack of hunger, pale and yellowish skin, and general discomfort. Salmonella grows in raw food, botulism in rotten or canned food and cholera is typical of contaminated water.

List of vitamins and sources:

Carbohydrateslipids and proteins <)21. (🥷) (& Many summaries from Bio🥷).




T4  Digestion 💥

Digestion is the process of breaking down food into smaller molecules that can be absorbed by the body. It may be mechanical or chemical. 

It begins in the mouth with mechanical mastication, grinding food into smaller pieces with saliva. Chemical digestion begins in the mouth with the action of enzymes like the salivary amylase, which breaks down starch into disaccharides (maltose). The salive also contains lysozyme that kills bacteria and mucin to lubricate the bolus. 

That bolus (ground food + saliva) is swallowed and travels down the oesophagus with peristaltic movements to the stomach, where it is mixed with gastric juices containing hydrochloric acid and pepsin to become the chyme (bolus + gastric juices). Hydrochloric acid kills harmful bacteria and lowers the pH for the pepsin to break down proteins into smaller polypeptides. (Disaccharides are digested into monosaccharides: maltose -> 2 glucose; sucrose -> glucose + fructose; lactose -> glucose + galactose).

From the stomach, the chyme moves to the duodenum (first part of the small intestine), where it is further broken down by enzymes from the pancreas, liver (gall or bile), and small intestine itself. Here the pH increases to 8, to inactivate the gastric enzymes and activate the new ones. Pancreatic enzymes break down carbohydrates, proteins, and lipids. Bile from the liver, which is stored in the gallbladder, has lipase that breaks down lipids. And the chyme becomes the chyle. 

The chyle (chyme + bile + pancreatic juices) contains carbohydrates broken down into monosaccharides, proteins broken down into amino acids and lipids broken down into fatty acids and glycerol. The DIGESTION is done.

The ABSORPTION: That mixture will move on to the 2nd and 3rd part of the small intestine: jejunum and ileum, where most of the nutrients are absorbed into the bloodstream and then transported to the liver. (The liver will release nutrients slowly along the rest of the day, as they are needed).

The rest continues into the large intestine or colon, which is colonised by bacteria (intestinal flora). They protect us, ensure the mineral balance for the water absorption, and release vitamin K (for coagulation) and B. The waste products will eventually be excreted from the body as faeces, through the rectus and anus. Bacteria also produce gases (methane and others). 

Key terms:

Enzyme: A protein that speeds up a chemical reaction.
Intestine: A long, coiled tube that is part of the digestive system.
Nutrient: A substance that provides energy, builds and repairs tissues, or regulates body functions.
Saliva: A fluid produced in the mouth. It has lysozyme to kill bacteria, mucin to lubricate and amylase.
Small intestine: The longest part of the intestine. Duodenum (digest) + Jejunum + Illeum (absorpt).
Large intestine: The last part of the intestine: ascendent colon, transverse colon and descending colon.


T5  Respiratory system 

The Respiratory System: A Journey of Gas Exchange

The respiratory system, a remarkable network of intricate structures, is responsible for the crucial process of gas exchange, ensuring the continuous supply of oxygen to every cell in our bodies and the removal of carbon dioxide, a waste product of cellular respiration. This elaborate system, composed of the respiratory airways, lungs, and muscles, orchestrates the movement of air into and out of the body, enabling the exchange of these life-sustaining gases.

The Respiratory Airways: A Pathway for Air Intake: The journey of air into our bodies begins with the nostrils, the external openings that act as gateways for inhaled air. The air then passes through the nasal passages, where it is warmed, moistened, and filtered, removing dust particles and other impurities. Next, the air enters the pharynx, a common passageway for both air and food. From here, it moves into the larynx, commonly known as the voice box, where vocal cords vibrate to produce sounds.

Following the larynx, the air enters the trachea, a rigid tube supported by cartilaginous rings, which help keep it open during inhalation. The trachea branches into the right and left bronchi, which further divide into smaller bronchioles, eventually terminating in microscopic air sacs called alveoli.

The Movements of Intercostal Muscles and Diaphragm: A Symphony of Breath: The process of breathing, the rhythmic movement of air into and out of the lungs, is orchestrated by a coordinated interplay of muscles. The intercostal muscles, located between the ribs, play a crucial role in expanding and contracting the chest cavity. As the intercostal muscles contract, they raise the ribs, increasing the volume of the chest cavity, thereby creating a partial vacuum that draws air into the lungs during inhalation.

In contrast, during exhalation, the intercostal muscles relax, allowing the ribs to fall back down. This decrease in chest cavity volume pushes air out of the lungs. Simultaneously, the diaphragm, a dome-shaped muscle at the base of the lungs, also plays a vital role in breathing. The diaphragm contracts during inhalation, flattening and expanding the chest cavity further, aiding in the intake of air.

Gas Exchange: The Oxygen and Carbon Dioxide Exchange at the Alveoli: The alveoli, the tiny air sacs at the end of the bronchioles, serve as the primary sites for gas exchange. Surrounded by a network of capillaries, the smallest blood vessels in the body, the alveoli provide an ideal interface for the diffusion of gases.

As oxygen-rich air enters the alveoli during inhalation, it diffuses across the thin walls of the alveoli and the capillaries, entering the bloodstream. Simultaneously, carbon dioxide, a waste product produced by cellular respiration, diffuses in the opposite direction, leaving the bloodstream and entering the alveoli. This exchange of gases ensures that our cells receive the oxygen they need for energy production and that the carbon dioxide produced is removed, preventing harmful buildup.

Gas Exchange in the Rest of the Body: The Delivery of Oxygen and Elimination of Carbon Dioxide: 

The oxygen that enters the bloodstream in the alveoli is transported by red blood cells, which contain hemoglobin, a protein that binds tightly to oxygen. As blood circulates through the body, oxygen is released from hemoglobin and diffuses into the cells, providing them with the oxygen they need for energy production.

In contrast, carbon dioxide, the waste product of cellular respiration, is carried back to the lungs by the bloodstream. In the alveoli, carbon dioxide diffuses from the capillaries into the alveoli and is exhaled during exhalation. This process of gas exchange ensures that oxygen is delivered to every cell in the body and carbon dioxide is removed, maintaining the delicate balance of gases required for cellular function.

In conclusion, the respiratory system, a marvel of intricate design and coordination, plays a vital role in maintaining life by facilitating the exchange of gases, ensuring the continuous supply of O2 to our cells and the removal of CO2. The respiratory airways, muscles, and alveoli work in harmony to orchestrate this essential process, enabling us to breathe and sustain life.


T6  Circulatory system 💥

Circulatory system.
A Journey of Oxygen and Nutrients (by Miguel Servet 1511 and, later, William Harvey 1578. Servet was a Spanish doctor and theologian, burned at the stake by the Swiss Calvinist inquisition because of his writings on the Trinity.) The circulatory system, a complex network of vessels and organs, is responsible for transporting oxygen and nutrients to every cell in our bodies and removing waste products, hormones, vitamins and others.

  •   Systemic circulation: The Journey of Oxygenated Blood

    The blood gets oxygenated in the lungs, and arrives into the left atrium. Then is pumped during the auricular systole into the left ventricle, (the most powerful muscular pumping chamber of the heart) through the bicuspid -Mitral valve. From here, the blood is forcefully ejected (ventricular systole) into the aorta artery, the main artery of the body. The aorta (and the pulmonary artery) has a semilunar valve to avoid the return of the blood to the ventricle. 

The aorta branches into smaller arteries, delivering oxygen-rich blood to all parts of the body: the hepatic (to the liver), mesenteric (to the intestine villi), hepatic portal (from intestines to the liver to store the absorbed nutrients), renal (for the kidneys, where the blood is cleaned from nitrogen wastes and others), etc. The arteries, become capillaries, for the exchange of O2 for CO2 (gases and nutrients between the blood and the cells. Oxygen diffuses from the capillaries into the cells, providing them with the energy they need for their functions. Simultaneously, carbon dioxide, a waste product of cellular respiration, diffuses from the cells into the capillaries and is carried back to the heart.). The capillaries are microscopic vessels that form an intricate network throughout the body's tissues. 

The circulatory system also plays a crucial role in delivering nutrients to the body's cells. After digestion, nutrients are absorbed from the villi of the intestines and transported by the hepatic portal vein to the liver. The liver processes and stores nutrients, ensuring that they are distributed to the body's cells in a controlled manner. It also removes harmful substances from the blood and synthesizes proteins and other essential molecules.

The Return of Oxygen-Deprived Blood: Veins and Valves. The capillaries fuse to make venues and veins that return to the heart. These veins carry deoxygenated blood back to the heart, completing the pulmonary circulation. As the blood travels through the veins, it encounters a series of half-moon valves that prevent backflow and ensure unidirectional blood flow. These valves are essential for maintaining the continuous circulation of blood throughout the body towards the heart. Venous valves are crucial for maintaining the circulation of blood back to the heart, preventing it from pooling in the lower extremities and causing swelling.

All those veins eventually converge into two large vessels, the superior vena cava and the inferior vena cava, which carry deoxygenated blood back to the heart (right atrium), that is relaxed (diastole), and down to the ventricle. 

  • The Pulmonary Circulation. Blood that needs to refill O2.

The remains of deoxygenated blood from the right atrium enter (auricular systole) the right ventricle, the pumping chamber of the right side of the heart through the tricuspid valve. This ventricle pumps the blood into the pulmonary artery, which carries the blood to the lungs. Sigmoid valves prevent the back flow of the blood in the arteries. 

In the lungs, the blood passes through a network of capillaries surrounding the alveoli, the tiny air sacs where gas exchange occurs: O2 for CO2. As the oxygen-rich air from the lungs diffuses into the capillaries, it replaces the carbon dioxide that was exhaled from the lungs. This freshly oxygenated blood then travels back through the pulmonary vein to the left atrium, completing the pulmonary circulation.


The heart is a muscular pump that circulates blood throughout the body. It consists of four chambers: two atria (upper chambers) and two ventricles (lower chambers). Check this video: <)1 Anatomy of the heart.

Diastole:

  • During diastole, the atria and ventricles relax and are filled with blood from the veins.
  • The atrioventricular valves (mitral and tricuspid) are open, allowing blood to flow from the atria into the ventricles.
  • The papillary muscles are relaxed, not contributing to the filling of the ventricles.

Systole:

  • During systole, the atria contract, squeezing more blood into the ventricles.
  • The atrioventricular valves close, preventing blood from flowing back into the atria (1st cardiac noise).
  • The ventricles contract forcefully, pumping blood out of the heart.
  • The sigmoid valves (pulmonary and aortic) open, allowing blood to flow from the ventricles into the arteries. And close then to avoid the back flow. (2nd cardiac noise).
  • The papillary muscles contract, pulling the chordae tendineae tight and preventing the atrioventricular valves from prolapsing.

Pulse

The force of the ventricles contracting causes a momentary dilation of the arteries that can be felt as a pulse at the wrist or other points where an artery is close to the skin.

  • The pulse rate is an indication of the heart rate.


Heart beat and Nerve control

Nerve cells, also known as neurons, play a pivotal role in orchestrating the heart's

electrical activity and rhythm. They are responsible for generating electrical signals that initiate and coordinate the heart's contractions, ensuring a steady and efficient pumping action.

The sinoatrial (SA) node, a cluster of specialized nerve cells residing at the top of the right atrium, serves as the heart's inherent pacemaker. These cells autonomously generate electrical impulses at a consistent rate, igniting the heartbeat and disseminating throughout the heart's chambers.

As the electrical impulse approaches the atrioventricular (AV) node, a group of nerve cells positioned at the base of the right atrium, it undergoes a slight delay, guaranteeing that the atria have ample time to fully contract before the ventricles commence their contraction. This delay is crucial for proper heart coordination.

From the AV node, the electrical impulse travels along the bundle of His, a specialized bundle of nerve fibers that traverses the heart's septum (the wall separating the right and left ventricles). This bundle further branches into Purkinje fibers, which disperse the electrical signal throughout the ventricles, stimulating their forceful contraction.

The role of nerve cells in the heart's electrical activity extends beyond triggering and coordinating contractions. They also participate in regulating the heart rate and adjusting it to meet the body's demands. The vagus nerve, a prominent nerve in the parasympathetic nervous system, dispatches inhibitory signals to the SA node, slowing down the heart rate whenever necessary.

In essence, nerve cells are indispensable for the heart's electrical activity, ensuring a regular rhythm, coordinated contractions, and the ability to adapt the heart rate to the body's requirements. They serve as the heart's natural pacemaker and play a critical role in maintaining cardiovascular health.

You may measure your blood pressure and check if the values are similar to those on the table:


The Lymphatic System: A Network of Cleansing and Defense

The circulatory system transports O2 (red cells), wastes, nutrients, hormones and vitamins through the blood. 

The lymphatic system is a network of vesselsnodes, and organs that move lymph by muscular contractions. It ensures the fluid balance (1), the removal of waste products (2), transport of lipids (3), and the immune function (4)(white cells).

(1) As fluid leaks out of blood vessels into tissues, it is collected by lymphatic capillaries and transported back into the bloodstream. This process helps prevent fluid buildup and swelling, a condition known as edema.

(2) The Lymphatic system helps in the removal of waste products, filtering and processing waste particles, dead cells, cellular debris, and excess proteins.  

(3) The lymphatic system transports fats (triglycerides), from the small intestine to the bloodstream. After dietary fat is broken down (into triglycerides and glycerol) and absorbed into the intestinal cells, it is packaged into chylomicrons, which are large lipoprotein particles. These chylomicrons enter the lymph vessels. As lymph, containing chylomicrons, circulates through the lymphatic vessels, it encounters lymph nodes, which are small bean-shaped structures that act as filters. Lymph nodes trap and remove any pathogens or other foreign substances that may be present in the lymph. Once filtered, the lymph enters larger lymphatic ducts, which eventually converge into the thoracic duct. The thoracic duct, the largest lymphatic duct, carries lymph up to the neck, where it empties into the left subclavian vein. This is where the chylomicrons enter the bloodstream, where they can be transported to other tissues and organs for utilization or storage.

The lymphatic system's role in lipid transport is essential for maintaining healthy lipid levels in the body. By efficiently transporting triglycerides from the intestines to the bloodstream, the lymphatic system prevents excess fat from accumulating in the digestive tract and reducing the risk of developing cardiovascular diseases. If we have a bad diet, with too many sat fats, we may have Atherosclerosis: 
HDL (😊) Good cholesterol, sent to the liver and made bile. (Fats from plants). 
LDL (💣) Bad cholesterol, sent to tissues and blood -> Atherome plaque -> infarct -ictus (from animals). 

(4) Lymph nodes filter the lymph searching for bacteria, viruses, and cancer cells. They house immune cells (lymphocytes), which produce antibodies to fight off infections. Lymphocytes, born in the bone marrow, mature in the spleen (Bazo) and thymus (Timo), are responsible for recognizing and responding to invading pathogens

Primary organs for development of B and T lymphocytes: Bone marrow (or fetal liver) (in birds is the bursa of Fabricius for B-cells) and the thymus (that atrophy at puberty)

Secondary lymphoid organs for lymphocyte maturation: lymph nodesspleen, Peyer’s patches, appendix and tonsils (amígdalas). They efficiently trap antigens for exposure to T and B cells and prepare the response. 
When a foreign substance is identified, lymphocytes activate and multiply, producing antibodies that specifically target the invading agent. These antibodies bind to the pathogen's surface, marking it for destruction by other immune cells. 

The lymphatic system also plays a role in tissue repair and cancer prevention
. Lymphocytes monitor the body for abnormal cells, such as cancer cells, and initiate immune responses to eliminate them before they can spread.

Maintaining a Healthy Lymphatic System: Regular exercise, maintaining a healthy weight, and avoiding excessive alcohol consumption can help to keep the lymphatic system functioning effectively. Eating a balanced diet rich in fruits, vegetables, and whole grains provides the body with essential nutrients that support lymphatic function. Regular consumption of probiotics, beneficial bacteria found in fermented foods, can help maintain a healthy balance of gut flora, which is linked to immune function. Regular deep breathing exercises can also stimulate lymphatic flow and enhance the body's ability to remove waste products. Massage therapy can further promote lymph flow and reduce fluid buildup, especially in areas prone to swelling, such as the legs and ankles.


T7 Excretory system 💥





T8 Endocrine system



Nervous system




T9 Reproductive system 💥




El ciclo femenino.  
El ciclo menstrual, de unos 28 días, regula la preparación del cuerpo para el embarazo. Las hormonas FSH y LH, producidas por la hipófisis, son las directoras de orquesta:

*Fase folicular (días 1-14):

- FSH: La pituitaria libera FSH que induce el crecimiento de folículos en los ovarios, cada uno con un óvulo.
- Estrógenos: Producidos por los folículos ováricos, engrosan el revestimiento uterino y preparan el cuerpo para la implantación, y dan señal a la pituitaria para que libere LH.

*Fase ovulatoria (en torno al día 14):

- LH: Induce la liberación del óvulo maduro del folículo dominante, la formación del cuerpo lúteo, y este liberará progesterona. 

*Fase lútea (días 14-28):

- Progesterona: Producida por el cuerpo lúteo (folículo remanente), mantiene el revestimiento uterino engrosado.

Si no hay embarazo los niveles de FSH, LH, estrógeno y progesterona disminuyen y el revestimiento uterino se desprende como menstruación (días 1-5).
Si hay fecundación se inhibe la liberación de FSH. Se produce una fase lútea modificada: la progesterona se aumenta significativamente, principalmente por el cuerpo lúteo y luego por la placenta. Es crucial para mantener el revestimiento uterino engrosado y prevenir la menstruación. 
Además, el embrión producirá gonadotropina coriónica humana (hCG) para avisar a la madre de su presencia y estimular la producción continua de progesterona por parte del cuerpo lúteo y la placenta. Los niveles de estrógeno también se mantienen elevados, principalmente producidos por la placenta, para apoyar el crecimiento del útero y la placenta.


Desarrollo embrionario: "Inmediatamente después de la fecundación empieza el desarrollo del embrión, dividiéndose continuamente. Unas 30 horas después de la fecundación, el embrión es bicelular.
A la vez que se va dividiendo el embrión se va trasladando por la trompa hacia el útero gracias a las vellosidades y movimientos que esta produce. En ese momento del desarrollo el embrión se denomina mórula, por el gran parecido que guarda con una mora.
Sobre el quinto día el embrión llega al útero, y aproximadamente un día después comenzará a penetrar en el espesor del endometrio donde anidará. Antes, el embrión experimenta una reorganización celular: las células más pequeñas emigran hacia el exterior y formarán la placenta; las más voluminosas se agrupan en el centro para formar el embrioblasto; entre ellas queda el blastocele, una cavidad llena de líquido. En este momento del desarrollo el embrión recibe el nombre de blástula. La anidación terminará aproximadamente a los 14 días de la fecundación."
Una vez anidado, la placenta desarrolla unas ramificaciones arborescentes capaces de ir captando los nutrientes necesarios de los vasos sanguíneos de la madre. El embrioblasto, que dará lugar al cuerpo del embrión, adquiere forma de disco: es el disco germinativo. Además, se formará la cavidad amniótica, rellena de líquido amniótico, que rodea al embrión para protegerlo y favorecer su crecimiento.

La placenta y el embrión están conectados por el cordón umbilical, formado por vasos sanguíneos capaces de transportar las sustancias nutritivas de la madre hacia el feto y sustancias de desecho en sentido inverso. Al comienzo del tercer mes ya están formados los diferentes órganos y sistemas del embrión, al que se empieza a denominar feto." [Texto. de Sexualidad, vida y salud. © lgnacio Gómara, lnmacuIada Serrano y Jokin de lraIa.]





















Locomotive system 
💥


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GCSE revision book/ Worksheets bio                                   
Term I 
T1  T1SOL   Cells & organelles <)10        (1oxf[ppt.]       
T2  T2SOL   Transport across membrane. <)10 Tissues, organs, systems. <)4  
T3  T3SOL   Nutrition. <)17 <)10 <)10  
Term II
T4  T4SOL   Digestive system. <)6 [<)4]  
T5  T5SOL   Respiratory system. <)8 [<)4]   Entrega semana del 8/Ene (Exam T1-5)
T6  T6SOL   Circulatory <)6 Lymphatic systems <)6   
Term III
T10 Geology - Ecology: Presentations  
T9  Reproductive system. From conception to birth
T7  T7SOL   Excretory system - urinary <)10
T8  Endocrine <)7 <)18- Nervous <)8 - (Senses)(eye-ear-taste-smell-touch) Senses Ex (pain <)16)
  

Practical activities bio year 9
Posters
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Book BIO  (Answers old 22-23)                                







- Guía de RCP.

- Página interactiva sencilla que ayuda a estudiar todos los aparatos y sistemas. (ENG).

- Funcionamiento de la nefrona (ENG). video 







- Algunos libros acerca de planteamientos en torno a la sexualidad.

- Joseph B. Stanford, M.D., es Profesor Adjunto de medicina Preventiva y de Familia en la Universidad de Utah. Ha sido Presidente de la Academia Americana de Planificación Familiar Natural, del Comité Asesor de Medicina Reproductiva de la United States Food and Drug Administration y, en la actualidad, es Miembro del Consejo de Administración del Instituto Internacional de Medicina Reproductiva Restaurativa. Algunas partes de este trabajo están adaptadas de un trabajo que apareció en “Physicians Healed (One More Soul)”. En este escrito habla de Naprotecnología, lleva por título "Sexo, naturalmente".

Get Body Smart.

Types of blood cells.

BLOOD VESSELS & CIRCULATION PHYSIOLOGY

Composición de las células de la sangre (ENG).

- Enfermedades:
Angina pectoris.