What is "Buy nothing day"
viernes, 26 de noviembre de 2021
martes, 16 de noviembre de 2021
Diet Analysis
1. Write a food diary of a normal day in your life. Analize all your meals and look for the Nutrition Facts using the labels or internet.
2. Compare the Recommended Dietary Allowance (RDA) or Adequate Intake (AI) with the amount of nutrients of your diet. Just the following nutrients:
a. Calories
b. Total fat.
c. Saturated fat.
d. Cholesterol
e. Sodium
f. Total Carbohydrate
g. Protein
h. Vitamins A, C y D
i. Calcium
j. Iron
3. Describe the lack or the excess of the previous nutrients.
4. Describe a disease that you can suffer because of the lack or the excess of nutrients
5. Create a healthy plate using Harvard's Healthy Eating Plate as a guide.
lunes, 15 de noviembre de 2021
Trabajo sobre Nutrición 3º ESO C
Teniendo en cuenta las siguientes tablas:
2. Compara la información nutricional analizada en el punto anterior con la ingesta diaria recomendada para los siguientes elementos:
a) Valor energético
b) Grasas totales y grasas saturadas
c) Hidratos de carbono y azúcares
d) Proteínas
e) Sal
f) Vitaminas A, C y D
g) Calcio
h) Hierro
3. Determina las carencias o excesos de tu alimentación respecto a las ingestas recomendadas
4. ¿Qué enfermedad podrías tener debido a esas carencias o excesos si tu alimentación fuera todos los días similar a la analizada?
5. Elabora un plato saludable siguiendo las recomendaciones del plato de Harvard
jueves, 11 de noviembre de 2021
miércoles, 10 de noviembre de 2021
Alimentación saludable
Todo lo que sabes sobre alimentación puede ser mentira
Plato de Harvard de la alimentación
¿Qué son las Grasas trans? Hace referencia a la posición de las moléculas en el doble enlace
¿Qué son las grasas saturadas? Sin dobles enlaces. ¿En qué alimentos se encuentran y cuáles son las consecuencias para la salud?
viernes, 22 de octubre de 2021
jueves, 7 de octubre de 2021
miércoles, 6 de octubre de 2021
La sangre: Tejido conectivo
La sangre es considerada por numerosos autores como un tipo especializado de tejido conectivo compuesto de elementos celulares (células y fragmentos celulares) y una matriz extracelular líquida denominada plasma. Sería el único tejido con matriz extracelular líquida.
La cantidad de sangre en el cuerpo humano depende del tamaño corporal; una persona de unos 70 Kg tiene 5 o 6 litros de sangre. La temperatura de la sangre en el cuerpo humano es de 38 ºC, un grado más que el cuerpo
Funciones:
Transporte. La sangre sirve para transportar nutrientes y oxígeno desde el aparato digestivo y los pulmones, respectivamente, al resto de las células del organismo, y productos de desecho hasta el riñón, el hígado y los pulmones.
Homeostasis. Contribuye a la homeostasis general o regulación del estado general del cuerpo. Contribuye a matener una temperatura corporal homogénea.
También mantiene un pH tisular estable, así como es el principal encargado de regular la cantidad de agua de las células del cuerpo.
Defensa. Tiene una función de protección frente a heridas mediante su capacidad de coagulación, evitando así que el organismo pierda su sangre, y de defensa frente a patógenos externos o células malignas internas gracias a las células del sistema inmunitario, los leucocitos
Elementos celulares
Las células sanguíneas se clasifican en dos tipos: eritrocitos o glóbulos rojos y leucocitos o glóbulos blancos (Figuras 1 y 2). La sangre también contiene fragmentos celulares denominados plaquetas.
martes, 5 de octubre de 2021
Connective tissues
Connective Tissues
They show a remarkable extracellular matrix, which is a scaffolding (andamiaje) made up of collagen and elastic fibers, and other molecules.
The type and proportion of these components in the extracellular matrix set the structural, mechanical and biochemical properties of the different connective tissues.
Extracellular matrix features and cell types define the variety of connective tissues.
Functions
- they connect and keep together many organs of the body,
- they provide mechanical support to different parts of the body and to the whole body as well,
- and protect and isolate many organs.
- Furthermore, they allow communication between different parts of the body.
Types:
CONNECTIVE PROPER
The Connective tissue proper contains several types of cells and a variable amount of extracellular matrix made up of fibers and ground substance (sustancia fundamental)
This tissue is widespread throughout the body. It fills spaces between organs (Figure 2), for example between the skin and muscles, and surrounds blood vessels, nerves and several organs
ADIPOSE TISSUE
It can be regarded as a rather unusual connective tissue since it has very little extracellular matrix.
Adipocytes are the cells that form the adipose tissue, and they have the ability of synthesizing and storing large lipid droplets in the cytoplasm.
These fat depots provide lipids that are used by other tissues to produce energy or just heat
Adipose tissue is not just for lipid storage. It is also involved in the control of the body metabolism by releasing several hormones,
Two types of adipose tissue are found:
white fat (or unilocular) with adipocytes containing a large lipid droplet, and
brown fat (or multilocular) with adipocytes containing many small lipid droplets.
Cartilage is a semi-rigid structure that maintains the shape of several organs, covers the surface of bones in the joints, and is the main supporting tissue during embryonic development, when bones are not yet present. During development, bone substitutes cartilage by endochondral ossification
Ccartilage is mostly an avascular tissue, lacking blood and lymphatic vessels, and without nerve terminals.
Cells that form the cartilage are called chondrocytes. They are located through the tissue in scattered small cavities known as lacunae
BONE
Bones support the soft parts of the body and protect organs like the brain, lungs and heart. They also work as a lever used by muscle to produce movement.
As a metabolic center, bones store calcium and phosphorous, and regulate their metabolism. In addition, in the internal cavities of bones, the bone marrow is made up of many stem cells (hematopoietic cells) that differentiate into blood cells, a process referred as hemaotopoiesis.
Osteocytes are the most abundant cell type in the mature bone. They are locked in extracellular matrix cavities (bone lacunae
Two types
2. Trabecular bone
Trabecular or spongy bone (Figure 2) has large inner spaces known as vascular cavities.
Compact bone
Compact or cortical bone has no vascular cavities, and the extracellular matrix is organized into bone lamellae, which can be arranged straight and parallel (lamellar compact bone) or concentrically around a canal (osteonic compact bone).
Blood is regarded by many authors as a specialized type of connective tissue composed of cells, cell fragments and a liquid extracellular matrix known as blood plasma
BLOOD
Blood has many functions. The following are three salient functions.
1) Communication pathway. Blood transports nutrients and oxygen from intestine and the lungs, respectively, to the rest of the body. Wasting products are transported to the kidney and lungs. It is also the main communication pathway for chemical signals, like hormones, between distant cells in the body.
2) Homeostasis. Blood contributes to the general body homeostasis. For example, it keeps relatively constant the body temperature and pH of tissues.
3) Defense. Blood contributes in the repairing of wounds by sealing the damages with erythrocytes, platelets and plasma, i.e., blood clotting (coagulación). It also contains the cells of the immune system, that use the circulatory system to be transported and attack pathogen in any tissue of the body.
1. Blood cells
Blood cells are classified in two groups: erythrocytes or red cells, and leukocytes or white cells (Figures 1 and 2). There are also cell fragments in the blood referred as platelets.(plaquetas)
Plasma
Plasma is the liquid part of the blood and accounts for more than half of the blood volume. It is 90 % water, and the rest is composed of proteins, ions, amino acids, lipids, and gases. Plasma is the main transporter of nutrients and waste products.
lunes, 4 de octubre de 2021
viernes, 1 de octubre de 2021
jueves, 30 de septiembre de 2021
Epitelium
Covering epitelium
Covering epithelium shows almost :
- no extracellular matrix and
- epithelial cells are tightly attached to one another by macromolecular adhesion complexes.
- Some epithelia show a high rate of cell turnover where cell death and cell proliferation are frequent.
- Some epithelial cells can have apical specializations that allow them to function as sensory receptors, and some animals show complex structures in their epithelial layer, such as hair, feathers or scales.
Epithelia are usually classified according to two features: the number of cell layers and the shape of the cells of the more superficial layer
- Simple epithelia are single cell layers where all the cells contact the underlying basal lamina and have an apical free surface. The shape of the cells can be flat (wider than high), cuboidal (as wide as high), or columnar (higher than wide).
- Pseudostratified epithelia are simple epithelia where all cells contact the basal lamina, but not all cells reach the superficial layer because some are shorter than the others. Thus, this is a simple epithelium that looks stratified.
- Stratified epithelium contains two or more layers of cells. Only cells of the deeper layer are in contact with the basal lamina and only cells of the upper layer show free surfaces.
squamous,
cuboidal and
columnar, depending on the shape of the cells of the upper layer when observed in transverse view.
Epithelium.
KERATINIZED STRATIFIED SQUAMOUS
Basal lamina: The basal lamina is a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits.Glandular epithelium
Secretion is the release of substances from cells to the extracellular milieu, having these substances a physiological purpose. Secretory cells are usually grouped to from glands, although it is not always so.
Exocrine glands release their products to the external surfaces of the body (for example, skin, respiratory ducts and digestive duct).
If the products are released into inner tissues and blood stream they are called endocrine glands.
Exocrine glands release their products to internal cavities or to the exterior of the body.
The classification of living organisms: Taxonomy
Human taxonomy
What are the characteristics of a scientific name?
The scientific name of a species is formed by the combination of two terms The first name (capitalized) is the genus of the organism, the second (not capitalized) is its species…. The genus name is written first. The genus name is always underlined or italicized. The first letter of the genus name is always capitalized.
What does a scientific name tell you?
Scientific names are also designed to tell you something about the animal’s relationships with other animals. The scientific name of each species is made up of a generic name (generic epithet) and a specific name (specific epithet). Scientific names are often descriptive also, suggesting something about the animal.
What two characteristics must a useful scientific name have?
A useful scientific name must have two characteristics: Each name must refer to only one species. Everyone must use the same name.
Hybridization
Speciation: is the evolutionary process by which populations evolve to become distinct species
martes, 28 de septiembre de 2021
Intercambio de sustancias con el ambiente
Sin gasto de energía: Transporte pasivo
Difusión: Simple o facilitada
Ósmosis
Transporte Activo
Endocitosis : Entrada de sustancias
Exocitosis
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