Sistem Sirkulasi Darah Manusia

Darah manusia adalah cairan di dalam tubuh yangberfungsi untuk mengangkut oksigen yang diperlukan oleh sel-sel di seluruh tubuh. Darah juga menyuplai jaringan tubuh dengan nutrisi, mengangkut zat-zat sisa metabolisme, dan mengandung berbagai bahan penyusun sistem imun yang bertujuan mempertahankan tubuh dari berbagai penyakit. Hormon-hormon dari sistem endokrin juga diedarkan melalui darah.

Darah manusia berwarna merah, antara merah terang apabila kaya oksigen sampai merah tua apabila kekurangan oksigen. Warna merah pada darah disebabkan oleh hemoglobin, protein pernapasan (respiratory protein) yang mengandung besi dalam bentuk heme, yang merupakan tempat terikatnya molekul-molekul oksigen.

Manusia memiliki sistem peredaran darah tertutup yang berarti darah mengalir dalam pembuluh darah dan disirkulasikan oleh jantung. Darah dipompa oleh jantung menuju paru-paru untuk melepaskan sisa metabolisme berupa karbon dioksida dan menyerap oksigen melalui pembuluh arteri pulmonalis, lalu dibawa kembali ke jantung melalui vena pulmonalis. Setelah itu darah dikirimkan ke seluruh tubuh oleh saluran pembuluh darah aorta. Darah membawa oksigen ke seluruh tubuh melalui saluran halus darah yang disebut pembuluh kapiler. Darah kemudian kembali ke jantung melalui pembuluh darah vena cava superior dan vena cava inferior.

Darah juga mengangkut bahan bahan sisa metabolisme, obat-obatan dan bahan kimia asing ke hati untuk diuraikan dan dibawa ke ginjal untuk dibuang sebagai air seni.

[sunting]Komposisi

Darah terdiri daripada beberapa jenis korpuskula yang membentuk 45% bagian dari darah, angka ini dinyatakan dalam nilai hermatokrit atau volume sel darah merah yang dipadatkan yang berkisar antara 40 sampai 47. Bagian 55% yang lain berupa cairan kekuningan yang membentuk medium cairan darah yang disebut plasma darah.

Korpuskula darah terdiri dari:

• Sel darah merah atau eritrosit (sekitar 99%).

Eritrosit tidak mempunyai nukleus sel ataupun organela, dan tidak dianggap sebagai sel dari segi biologi. Eritrosit mengandung hemoglobin dan mengedarkan oksigen. Sel darah merah juga berperan dalam penentuan golongan darah. Orang yang kekurangan eritrosit akan menderita penyakit anemia.

• Keping-keping darah atau trombosit (0,6 - 1,0%)

Trombosit bertanggung jawab dalam proses pembekuan darah.

• Sel darah putih atau leukosit (0,2%)

Leukosit bertanggung jawab terhadap sistem imun tubuh dan bertugas untuk memusnahkan benda-benda yang dianggap asing dan berbahaya oleh tubuh, misal virus atau bakteri. Leukosit bersifat amuboid atau tidak memiliki bentuk yang tetap. Orang yang kelebihan leukosit akan menderita penyakit leukimia, sedangkan orang yang kekurangan leukosit akan menderita penyakitleukopenia.

Susunan Darah. serum darah atau plasma terdiri atas:

1. Air: 91,0%
2. Protein: 8,0% (Albumin, globulin, protrombin dan fibrinogen)
3. Mineral: 0.9% (natrium klorida, natrium bikarbonat, garam dari kalsium, fosfor, , kalium dan zat besi,nitrogen, dll)
4. Garam

Plasma darah pada dasarnya adalah larutan air yang mengandung :-

• albumin
• bahan pembeku darah
• immunoglobin (antibodi)
• hormon
• berbagai jenis protein
• berbagai jenis garam

Demikian juga dengan darah Hewan, juga mengandung:air, protein ((Albumin, globulin, protrombin dan fibrinogen),mineral (natrium klorida, natrium bikarbonat, garam dari kalsium, fosfor, , kalium dan zat besi,nitrogen, dll).

Source : http://id.wikipedia.org/wiki/Darah

Untuk lebih lengkap mengenal tentang darah, bisa dengan mendownload file disini

Hortatory Exposition

Hortatory Exposition.

Watch your Kids While Watching TV

Television becomes one of the most important devices which takes place in almost houses. It can unite all members of the family as well as separate them. However, is it important to know what your kids are watching? The answer is, of course, absolutely “Yes” and that should be done by all parents. Television can expose things you have tried to protect the children from, especially violence, pornography, consumerism and so on.

Recently, a study demonstrated that spending too much time on watching TV during the day or at bedtime often cause bed-time disruption, stress, and short sleep duration.

Another research found that there is a significant relationship between the amount of time spent for watching television during adolescence and early adulthood, and the possibility of being aggressive.

Meanwhile, many studies have identified a relationship between kids who watch TV a lot and being inactive and overweight.

Considering some facts mentioning above, protect your children with the following tips:

• Limit television viewing to one-two hours each day
• Do not allow your children to have a TV set in their own bedrooms
• Review the rating of TV shows which your children watch

Watch television with your children and discuss what is happening in the show

Generic Structure dari Hortatory Exposition.

• Thesis - Berisi permasalahan yang di bahas.
• Argument - Berisi alasan - alasan atau berupa fakta untuk memperkuat thesis.
• Recomendation - Berisi saran dan masukkan agar pembaca dapat menyelesaikan masalah tersebut.

Source : http://www.zimbio.com/Indonesian+language/articles/9E7_Huov9Bc/Contoh+Teks+Analytical+Exposition+dan+Hortatory

Analytical Exposition

Analytical Exposition.

Writing for Money Online

The emergence of the internet has given internet entrepreneurs many ways to make money. Writers are one group that have benefited from their talents as a result in the rise of internet based jobs.

Blog writing is an increasingly popular way to earn money online determined by the owner of the blog. They are very popular because of tBlogs are usually written on a certain subject area but can vary as its content is heir simplicity to get up and running. There are many free websites out there that will help you set up your own blog if you choose to go that route because blog plus advertisement is a potential money

Article writing is also good money to earn money online. Make sure to gear your articles to promote and advertise you own business ventures. These articles are a free way to market the products and services you offer for free. The most effective advertising with these articles comes from the dialogue box that is inserted at the end of each article. These dialogue boxes contain links to basically any website you would like to drive traffic to. For instance, you might have one link in your dialogue box to a product you are selling and one to a blog where you are promoting a discussing other products.

Writing takes some time to gain credibility through but once it’s done’ earning potential can become very powerful.

Generic Structure dari Analytical Exposition.

·         Thesis - Berisi masalah yang akan di bahas.

·         Argument - Berisi alasan - alasan atau berupa fakta untuk memperkuat thesis.

·         Retteration - Berisi tentang kesimpulan dari semua pembahasan.

Source : http://www.zimbio.com/Indonesian+language/articles/9E7_Huov9Bc/Contoh+Teks+Analytical+Exposition+dan+Hortatory

Descriptive Text

Descriptive Text

- Descriptive text is a text to describe something.

- The generic structure are :

.     Identification -> A part To introduce something in general (Who, Where, When )

.     Description ->A part To describe something more details.

-  Descriptive text use simple present tense

- The example :

            Gery is one of my rabbits. It’s a male rabbit.

            Gery likes carrots if the carrots in small pieces. He likes spinach too sometimes. He has gray skin and black eyes. His ears are down when he’s hungry.  I like to watch him when he act funny. He loves to play in the yard. He often run away from me. That act is so funny for me.

Narrative Text

Narrative Text 

·        Narrative text is a text that tell about fiction story happened in the past.

·        The generic structure are :
1.     Orientation -> A part To introduce a person, place, and time
2.     Complication -> A part tell the conflict
3.     Resolution -> A part solve the conflict
4.     Re-Orientation -> A part that have a conclusion and moral value 

·        Narrative text uses simple past tense

 ·        The example :
            Once upon a time, there was a girl named Cinderella. She lived with her stepmother and her stepsisters. They treated her very bad. She had to do all homeworks.
           One day an invitation about a dance party in the palace came to Cinderella and her family. Her stepsisters didn’t allow her to go. She was very sad. The stepsisters went to the palace and left Cinderella alone.
           Suddenly, a fairy godmother came and helped her to go to the palace. The prince was spellbound with the beauty of Cinderella. He asked to dance with her and they danced untill 12 A.M. The bell was ringed and Cinderella left the prince alone. One of Cinderella’s glass slipper left on the stairs when Cinderella ran away. The prince found it and asked his servant to searched the owner from that glass slipper.
         The servant came to Cinderella and her family’s house and he found the owner from that glass slipper here. That was Cinderella. The prince was very happy and then he married her. They lived happily ever after.