Anatomi Dan Fisiologi Manusia - Digestive Sistem Sistem Pencernaan

ANATOMI & FISIOLOGI MANUSIA

SISTEM PENGHADAMAN

What is Digestion?

• Digestion is a catabolic process in which large complex molecules (carbohydrates, lipids, proteins, nucleic acids) are broken down into simpler monomers (monosaccharides, glycerol and fatty acids, amino acids, and nucleotides) which can be absorbed by the body.

Function

• Digestion– Breakdown of ingested food– Absorption of nutrients into the blood

• Once the nutrients are absorbed by the digestive system they are transported by the blood to the tissues for metabolism.– Production of cellular energy (ATP)– Constructive and degradative cellular activities

Types of Digestion• There are two forms of digestion:

a. mechanical: In mechanical there is no chemical change in the food. The food is simply broken down into smaller pieces and mixed with digestive juices secreted in the body. Ex. Mastication (chewing)

b. chemical: In chemical digestion the is a chemical change in the food. The polymers are broken down into monomers commonly by hydrolysis reactions carried out by enzymes contained within the digestive juices.

Proses Pencernaan

Ingestion

Propulsion

Mechanical

Digestion

Chemical

Digestion

Absorption

Defecation

Six Processes of Digestion

1.Ingestion – getting food into the mouth2.Propulsion – moving foods from one region of

the digestive system to another3.Mechanical digestion– Mixing of food in the mouth by the tongue– Churning of food in the stomach– Segmentation in the small intestine

4.Chemical Digestion– Enzymes break down food molecules into their building

blocks– Each major food group uses different enzymes• Carbohydrates are broken to simple sugars• Proteins are broken to amino acids• Fats are broken to fatty acids and alcohols

5.Absorption– End products of digestion are absorbed in the blood or lymph– Food must enter mucosal cells and then into blood or lymph

capillaries6.Defecation– Elimination of indigestible substances as feces

Digestive Processes

Divisions of Digestive System Organs

• Two main groups1.Alimentary canal – continuous coiled hollow tube

that runs from the mouth to the anus2.Accessory digestive organs – secrete digestive

juices by ducts (exocrine glands) into the alimentary canal.

Alimentary Canal Organs

• Mouth• Pharynx• Esophagus• Stomach• Small intestine• Large intestine• Anus

Accessory Digestive Organs

• Salivary glands• Teeth• Pancreas• Liver• Gall Bladder

Mouth Oral Cavity (Ac)

• Mastication (chewing) of food

• Mixing masticated food with saliva

• Initiation of swallowing by the tongue

• Allowing for the sense of taste

Salivary Glands (Ac)

Salivary Glands:• Saliva-producing glands– Parotid glands – located anterior to ears– Submandibular glands– Sublingual glands

Saliva:• Mixture of mucus and serous fluids• Helps to form a food bolus• Contains salivary amylase to begin starch digestion• Dissolves chemicals so they can be tasted

Teeth (Ac)• The role is to masticate (chew)

food• Humans have two sets of teeth

– Deciduous (baby or milk) teeth– 20 teeth are fully formed by age

two• Permanent teeth

– Replace deciduous teeth beginning between the ages of 6 to 12

– A full set is 32 teeth, but some people do not have wisdom teeth

• Types of teeth:Incisors - cuttingCanines - tearingPremolars – shearing, shreddingMolars - grinding

Tooth Structure• Crown – exposed part

– Outer enamel– Dentin– Pulp cavity

• Neck– Region in contact with the

gum– Connects crown to root

• Root– Periodontal membrane

attached to the bone– Root canal carrying blood

vessels and nerves

Pharynx (Al)

• Serves as a passageway for air and food

• Food is propelled to the esophagus by two muscle layers– Longitudinal inner layer– Circular outer layer

• Food movement is by alternating contractions of the muscle layers (peristalsis)

Esophagus (Al)

• Runs from pharynx to stomach through the diaphragm

• Conducts food by peristalsis (slow rhythmic squeezing)

• Passageway for food only (respiratory system branches off after the pharynx)

Liver and Gall Bladder (Accessory Organs)• Largest gland in the body• Connected to the gall bladder

via the common hepatic duct• Composition

– Bile salts– Bile pigment (mostly bilirubin

from the breakdown of hemoglobin)

– Cholesterol– Phospholipids– Electrolytes

• Stores bile from the liver by way of the cystic duct

• Bile is introduced into the duodenum in the presence of fatty food

• Gallstones can cause blockages

Alimentary Canal Organ Structure and Tissue Arrangement

• Mucosa– Innermost layer– Moist membrane

• Surface epithelium• Small amount of connective tissue

(lamina propria)• Small smooth muscle layer

• Submucosa– Just beneath the mucosa– Soft connective tissue with blood

vessels, nerve endings, and lymphatics

• Muscularis externa – smooth muscle– Inner circular layer– Outer longitudinal layer

• Serosa– Outermost layer – visceral peritoneum– Layer of serous fluid-producing cells

Stomach (Al)• Located on the left side of the abdominal cavity• Food enters at the cardioesophageal sphincter• Regions of the stomach

– Cardiac region – near the heart– Fundus– Body– Pylorus – funnel-shaped terminal end

• Food empties into the small intestine at the pyloric sphincter

• Rugae – internal folds of the mucosa• External regions

– Lesser curvature– Greater curvature

Stomach (Al)

• Acts as a storage tank for food

• Site of food breakdown• Chemical breakdown of

protein begins• Delivers chyme

(processed food) to the small intestine

Pancreas (Ac)

• Produces a wide spectrum of digestive enzymes that break down all categories of food

• Enzymes are secreted into the duodenum• Alkaline fluid introduced with enzymes

neutralizes acidic chyme• Endocrine products of pancreas– Insulin– Glucagon

Large Intestine (Al)

• Larger in diameter, but shorter than the small intestine

• Frames the internal abdomen• Cecum – saclike first part of the

large intestine• Appendix

– Accumulation of lymphatic tissue that sometimes becomes inflamed (appendicitis)

– Hangs from the cecum• Colon

– Ascending– Transverse– Descending– S-shaped sigmoidal

• Rectum• Anus – external body opening

Functions of Large Intestine• Absorption of water• Eliminates indigestible food from the body as feces• Does not participate in digestion or absorption of

digested food• Goblet cells produce mucus to act as a lubricant• Site of production of Vitamin K by symbiotic bacteria

which live off the remains of food that have not been digested or absorbed in the small intestine. These bacteria produce over 50% of fecal matter.

Small Intestine (Al)

• The body’s major digestive organ all digestion of food is completed in this organ

• Site of nutrient absorption into the blood• Muscular tube extending form the pyloric sphincter to the

ileocecal valve• Suspended from the posterior abdominal wall by the

mesentery• Duodenum (25cm = 10 inches) “12 finger widths long”

– Attached to the stomach– Curves around the head of the pancreas– Where bile and pancreatic juices enter the alimentary canal

• Jejunum (2.5m = 8 feet) “empty”– Attaches anteriorly to the duodenum

• Ileum (3.6m = 12 feet) “twisted”– Extends from jejunum to large intestine

Small Intestine (Internal Structure)• Villi are small fingerlike

structures formed by the mucosa

• Give the small intestine more surface area for absorption

• Fold in the intestine are called circular folds or plicae circulares

• Deep folds of the mucosa and submucosa

• Do not disappear when filled with food

• The submucosa has Peyer’s patches (collections of lymphatic tissue)

Villi Internal Structure and Function

• Absorptive cells are found on the surface epithelium which are simple columnar microvilliated epithelium

• Blood capillaries are below the surface epithelium and this is where monosaccharides, amino acids, and nucleic acids enter into the blood stream and are taken to the liver for processing

• Lacteals (specialized lymphatic capillaries) where lipids are absorbed and eventually re-enter the blood stream to be taken to the liver for processing.

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter26/animation__organs_of_digestion.html

PENGHADAMAN DAN PENYERAPAN

Digestion, Absorption and Transport

1. Chemical breakdown of organic molecules into their component parts 2. After digest;

- some diffuse through the intestinal wall- transported across the intestinal wall

Carbohydrates

1. Polysaccharides (split) to disaccharides by salivary and pancreatic amylases2. Disaccharides (breakdown) to monosaccharides by disaccharides - surface of intestinal epithelium3. Monosaccharides absorbed - blood, carried by portal veins to liver4. Glucose - carried and enter into the cells by facilited diffusion.5. Insulin increases the rate of glucose transport

Lipids

1. Bile salts is emulsify lipids2. Pancreatic lipase (breakdown) lipid3. Products - micelles4. Lipids are stored in the adipose and in the liver5. Lipids release when it needed by the body

Proteins

1. Proteins (split) - small polypeptides by enzymes (stomach and pancreas2. Peptidases complete the digestive process3. Amino acids (absorbed) - intestinal epithelial cells4. Amino acid actively transported - growth hormon and insulin5. Amino acid - build new proteins and energy

Water and Minerals

1. Water can move - ‘osmotic condition’2. 99 % water absorbed3. Most minerals are actively transported

Pengenalan Metabolisma Selular

PENGENALAN METABOLISMA SELULAR

• Metabolisma atau bahasa inggerisnya metabolism adalah kadar pembakaran glukos dalam sel badan kita.

Laluan Metabolik

• Metabolism is the set of chemical reactions that occur in living organisms in order to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories. Catabolism breaks down organic matter, for example to harvest energy in cellular respiration. Anabolism, on the other hand, uses energy to construct components of cells such as proteins and nucleic acids.

METABOLISMA SELULAR

Metabolisme sel = perubahan tenaga,dari satu bentuk ke bentuk yang lain.

The process by which living cells process nutrient molecules and maintain a living state; metabolism in cells can be characterized in two distinct divisions: anabolism, in which a cell uses energy and reducing power to construct complex molecules and perform other life functions such a creating cellular structure; and catabolism, in which a cell breaks down complex molecules to yield energy and reducing power.

KARBOHIDRAT

• Karbohidrat adalah biomolekul yang paling banyak terdapat di alam. Setiap tahunnya diperkirakan kira-kira 100 milyar ton CO2 dan H2O diubah kedalam molekul selulosa dan produk tanaman lainnya melalui proses fotosintesis.

• Nama karbohidrat (carbohydrate) diambil dari komponen penyusunnya yang terdiri dari karbon, hidrogen.

Rumus : Cn(H2O)n dengan perbandingan C : H : O adalah 1 : 2 : 1. Sebagai contoh glukosa C6H12O6 yang juga dapat ditulis dengan C6(H2O)6. Walaupun demikian beberapa karbohidrat memiliki nitrogen, fosfor dan sulfur. Karbohidrat digolongkan kedalam monosakarida, disakarida dan polisakarida.

KARBOHIDRAT

Monosakarida• Karbohidrat yang paling sederhana adalah

monosakarida dan sebagai unit pembentuk disakarida,dan polisakarida. Monosakarida memiliki gugus aldehid atau keton dengan satu atau lebih gugus hidroksil.

• Monosakarida glukosa dan fruktosa memiliki enam gugus hidroksil. Atom karbon tempat pengikatan gugus hidroksil disebut sebagai pusat kiral.

• Glukosa merupakan monosakarida yang paling penting dalam metabolisme tubuh. Glukosa yang terkandung dalam nutrisi masuk ke dalam sistem sirkulasi atau ke dalam darah untuk dipindah ke sel-sel tubuh yang memerlukannya atau diubah pada hati menjadi molekul yang lain. Glukosa adalah sumber tenaga utama bagi sel-sel haiwan, dan merupakan satu-satunya sumber tenaga bagi manusia.

METABOLISME KARBOHIDRAT • Metabolisme merangkumi sintesis (anabolisme)

dan penguraian (katabolisme) molekul organik kompleks. Metabolisme biasanya terdiri atas tahap-tahap yang melibatkan enzim, yang dikenal pula sebagai jalur metabolisme. Jumlah metabolisma merupakan semua proses biokimia di dalam organisma. Metabolisme sel merangkumi semua proses kimia di dalam sel. Tanpa metabolisme, makhluk hidup tidak dapat bertahan hidup. KARBOHIDRAT merupakan hidrat dari unsur karbon (C). Peristiwa ini banyak dijumpai pada tubuh makhluk hidup, baik tumbuhan, haiwan, atau manusia.

DISAKARIDA• Disakarida seperti maltosa, laktosa dan sukrosa

terdiri dari dua unit monosakarida yang terbentuk melalui suatu ikatan yang disebut ikatan glikosida.

• Ikatan glikosida ini mudah dihidrolisis oleh asam(asid).

• Oleh kerana itu diskarida dapat dihidrolisis dengan mudah dengan memanaskannya dalam larutan asam(asid). Bentuk ikatan glikosida.lanya terbentuk antara gula dengan atom N (ikatan N-glikosil) yang ditemukan pada seluruh nukleotida.

POLISAKARIDA• Sebahagian besar karbohidrat yang dijumpai di bumi

terdapat dalam bentuk polisakarida, iaitu polimer dengan berat molekul yang tinggi dan sering juga disebut dengan glikan atau glukan.

Struktur umum polisakarida

METABOLISMA LIPID• Lipids are the most diverse group of

biochemicals. Their main structural uses are as part of biological membranes such as the cell membrane, or as a source of energy.[6] Lipids are usually defined as hydrophobic or amphipathic biological molecules that will dissolve in organic solvents such as benzene or chloroform.[7]

The fats are a large group of compounds that contain fatty acids and glycerol; a glycerol molecule attached to three fatty acid esters is a triacylglyceride.[8] Several variations on this basic structure exist, including alternate backbones such as sphingosine in the sphingolipids, and hydrophilic groups such as phosphate in phospholipids. Steroids such as cholesterol are another major class of lipids that are made in cells.

Lipid

METABOLISMA PROTEIN

• Proteins are made of amino acids arranged in a linear chain and joined together by peptide bonds. Many proteins are the enzymes that catalyze the chemical reactions in metabolism.

•Other proteins have structural or mechanical functions, such as the proteins that form the cytoskeleton, a system of scaffolding that maintains the cell shape.[5] Proteins are also important in cell signaling, immune responses, cell adhesion, active transport across membranes and the cell cycle.

METABOLISMA NUKLEIK ASID

• Asid nukleik merupakan merupakan sejenis makromolekul yang terdiri daripada rantaian nukleotida. Dalam biokimia molekul ini mampu membawa maklumat atau membentuk struktur dalam sel.

• Asid nukleik yang biasa termasuk asid deoksiribonukleik (DNA) dan asid ribonukleik (RNA). Asid nukleik terdapat dalam semua benda hidup, kerana mereka terkandung dalam segala sel. Asid nukleik juga terdapat di dalam virus.

• Nucleic acid metabolism is the process by which nucleotides are synthesized and degraded. Nucleic acid synthesis is an anabolic mechanism generally involving chemical reaction of phosphate, pentose sugar, and a nitrogenous base. Destruction of nucleic acid is a catabolic procedure generally involving enzyme reactions.

METABOLISMA NUKLEIK ASID

• Asid nukleik merupakan merupakan sejenis makromolekul yang terdiri daripada rantaian nukleotida. Dalam biokimia molekul ini mampu membawa maklumat atau membentuk struktur dalam sel.

• Asid nukleik yang biasa termasuk asid deoksiribonukleik (DNA) dan asid ribonukleik (RNA). Asid nukleik terdapat dalam semua benda hidup, kerana mereka terkandung dalam segala sel. Asid nukleik juga terdapat di dalam virus.

• Nucleic acid metabolism is the process by which nucleotides are synthesized and degraded. Nucleic acid synthesis is an anabolic mechanism generally involving chemical reaction of phosphate, pentose sugar, and a nitrogenous base. Destruction of nucleic acid is a catabolic procedure generally involving enzyme reactions.

Diet dan Pemakanan

Diet • Pengambilan makanan oleh individu.

Diet Seimbang • Pengambilan makanan yang mengandungi

semua nutrien seperti protein,karbohidrat,lemak, vitamin, garam mineral, dan air serta pelawas dalam kuantiti yang diperlukan.

Pemakanan• kajian berkaitan dengan pengambilan makanan

untuk proses pertumbuhan ,pemulihan dan pengawalan kesihatan.

• Makanan berfungsi untuk membekalkan tenaga kepada manusia untuk terus hidup.

• Makanan yang dimakan setiap hari membekalkan zat-zat makanan yang diperlukan oleh tubuh badan.

Kumpulan Makanan Asas

Karbohidrat• Membekalkan tenaga utama untuk keperluan badan.• BERLEBIHAN: lebihan berat badan• KEKURANGAN: ketosis

Protein• membentuk dan membaiki tisu, membentuk enzim,

antibodi, hormon, agen pengangkut.• BERLEBIHAN: lemak mningkat, paras kalsium drh t’jejas.• KEKURANGAN: penghasilan antibodi menurun & risiko

jangkitan meningkat.

Lemak• membekalkan tenaga & pengekalan suhu, membekalkan asid

lemak perlu, penyerapan vitamin larut lemak.• BERLEBIHAN: lebihan berat badan.

Garam Galian• Dibahagikan kpd 2 kumpulan :

- Makronutrien (dp’lukan dlm Kuantiti bsr)- Mikronutrien (dp’lukan dlm kuantiti kecil)

a) Makronutrien

Kalsium• Smbr: susu, keju, ikan bilis, bijirin.• Fgsi: m’bina tlg & gigi yang kuat, mnolong pmbekuan drh, dp’lukan untk

pengecutan otot & pmindahan impuls saraf.• Ksn kkrgn: riket,osteoporosis, p’darahan b’pnjangan.

Magnesium• Bijirin,syrn hijau,susu, daging.• Menjana enzim yang diperlukan untuk mengeluarkan tenaga dalam tubuh.

Diperlukan oleh tubuh dalam pembentukan bahan genetik dan pertumbuhan tulang.

• Otot lemah

Fosforus• Susu, daging, bijirin, telur.• M’bntk tulang & gigi yang kuat, menggiatkan enzim-enzim yang

diperlukan tubuh untuk menukarkan makanan kepada tenaga.• Tulang rapuh, kerosakan gigi.

Natrium• Garam, daging, telur, susu.• Mngekalkan keseimbangan air dlm bdn, mngekalkan tknn osmosis

cecair dlm bdn.• Kekejangan otot

Kalium• Susu, daging, pisang, sayuran hijau.• Pemindahan impuls saraf, pengecutan otot.• Ganguan dlm sstm saraf.

B) Mikronutrien

Iodin• Udang, kerang, makanan laut.• M’bntk hormon tiroksina.• Goiter, kretinisme pd knk-knk.

Besi• Hati, bayam, kacang, telur kuning.• M’bntk hemoglobin.• Anemia

Florin• Air minuman, teh, sayuran.• Mengukuhkan enamel pd gigi.• Karies gigi.

Vitamin

• Kumpulan sebatian organik yang diperlukan dalam kuantiti yang kecil untuk memelihara dan mengekalkan kesihatan.

• Dikelaskan kepada 2 kumpulan :a) Larut lemak: vitamin A, D, E dan K.b) Larut air: Vitamin B kompleks dan vitamin C.

• Vitamin larut lemak tidak dapat dikumuh melalui air kencing tetapi disimpan dalam badan.

• Vitamin larut air tidak dapat disimpan dalam badan dan sebarang kuantiti berlebihan akan larut dalam air dan dikumuhkan keluar melalui air kencing.

Vitamin C• Smbr : buah-buahan.• Fgsi : memelihara tisu p’hubung, kshtn kulit & pemulihan luka yang

cepat, mngkatkan ketahanan t’hdp jgkitan.• Ksn kkrgn : skurvi ( gusi b’darah, kulit lebam, sendi bgkak)

Vitamin A :• Sumber – susu, tomato, lobak merah.• Fgsi: Membina pigmen pada retina mata untuk penglihatan jelas

pada waktu malam & memastikan p’tumbuhan sel epitelium kulit yang sihat.

• Kesan kekurangan : rabun malam, kulit tidak yang sihat.

Vitamin D • Sumber : Keju, mentega dan telur.• Fgsi : m’bantu pnyerapan kalsium & fosforus, m’bina tulang dan

gigi yang kuat.• Ksn kekurangan: penyakit riket, karies gigi.

Vitamin E• Smbr: sayuran hijau,minyak kelapa sawit.• Fgsi : memelihara kshtn sstm otot, saraf & sstm p’edaran darah,

bhn p’oksidaan bgi asid lmk tepu.• Ksn kkrgn : kemorosotan otot & saraf

Vitamin K• Smbr: hati,bayam dan kubis.• Fgsi: m’bantu dalam pembekuan darah.• Ksn kkrgn : b’darah secara berlebihan.

Air• Merupakan 70% drp berat bdn manusia.• Peranan :a) Sbg pelarutb) Medium tndk bls kimia dlm bdn.c) Medium pengangkutan bhn mknn t’cerna, oksigen,

bhn p’kumuhan.d) Pengawalaturan suhu bdn : Bila kekurangan air, suhu

tubuh akan menjadi panas dan naik. Khdiran air akan m’bntu m’stabilkan suhu bdn.

e) Sbg pelincir : mngurangkan geseran tulang pd sendi.f) P’kumuhan : urea,asid urik & grm mineral b’lebihan

dsingkirkn melalui air kencing dan peluh.