HumanBio ATAR11 - DIgestive and Elimination System

Fill out this diagram

Name all types of human teeth and their purpose

Canines - ripping

Incisors - biting

Premolars and Molars - chewing

Mechanical Digestion in the mouth

Cutting, Biting, and Chewing for the teeth, the tongue shapes the food into a ball (bolus) and swallows

Chemical Digestion in the Mouth

Saliva from Salivary Glands use saliva amylase to break down starch and complex carbohydrates into maltose

Mechanical Digestion of the Stomach

Digests food in waves by churning using a third opaque layer of muscle

Mixed with stomach juice to churn into a thick soupy liquid called chyme

Chemical Digestion of the Stomach

Secretes gastric juices from gastric glands

pH = 2-3 to give enzymes the best environment to break down the bolus, and turn pepsinogen into pepsin into polypepsin. This protects the lining of the stomachs cells.

Mechanical Digestion of the Small Intestine

Pushes the bolus through the tubes using circular muscles

Uses segmentation to break the bolus up into pieces, increasing surface area for faster digestion.

Chemical Digestion of the Small intestine

Pancreatic juices are secreted into the small intestine which digests food by breaking it down using enzymes. E.g. pancreatic lipases turns fats into fatty acid and glycerol

Intestinal juice also digests food containing enzymes such as carbohydrates, proteins and lipids.

Mechanical Digestion of the Large Intestine

Pushes through and forms faeces - made of water, undigested food, bile pigmentation, bacteria, and cell remains

Chemical Digestion of the Large Intestine

Absorbs water and other liquids + nutrients

Bacteria breaks down the remaining compounds

What are the parts of Villus

Blood capillaries, Epithelial cells, Lacteal, Micro-Villi, Amino acids and carbohydrates

Why is the Small Intestine suited for its job

The length is confined and villi gives the small intestine as much surface area as possible to digest.

Describe the role of the liver in excretion

The liver processes substances to be excreted. In order to use protein as an energy source, the amino acid NH2 must be removed from the body, so it is broken down in the liver into ammonia. Ammonia is toxic to the body, so it must be further broken down into urea, which then in excreted via urine.

Amino acid + oxygen —> carbohydrates + ammonia

ammonia + energy + carbon dioxide —> urea + water

Outline the organs involved in the excretion system and their use

Lungs: excretes carbon dioxide via respiratory system

Liver: processes substances to be excreted

Sweat glands: Sweats out by-products of metabolism (water, urea, etc)

Alimentary Glands: Excretes bile pigments

Kidney: Principle excretory system, makes urine

Describe how the kidneys and nephrons are suited for their job

Nephrons are made of unique cells to preform specific transport functions. Kidneys have these ig.

Label all parts of the excretory system

Label all parts of this diagram

What does the glomerulus filter

Water, glucose, amino acids, salt

What does the descending limb and ascending limb reabsorb

descending: reabsorbs water

ascending: diffuses Na+ and Cl-

What is reabsorbed in the distal convoluted tubule

Sodium