Human Nutrition and Digestion Basics

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Questions and Answers

What is the primary function of nutrition?

To provide energy for body processes (correct)

To assist in digestion only

To eliminate waste from the body

To support growth and repair of tissues

Which of the following is NOT a life process involved in energy provision?

Respiration

Nutrition

Excretion

Circulation (correct)

Why do we need to digest food despite having a balanced diet?

To convert food into energy directly

To increase the volume of food

To break down complex substances into simpler forms (correct)

To make food taste better

What is the approximate length of the human alimentary canal?

8-10 meters (D) Signup and view all the answers

How many teeth does an adult human typically have?

32 (D) Signup and view all the answers

What type of dentition do humans exhibit?

Diphyodont (B) Signup and view all the answers

What covers the crown of a tooth?

Enamel (D) Signup and view all the answers

What substance is primarily found in enamel?

Both A and B (D) Signup and view all the answers

What is the primary function of the pyloric sphincter?

To regulate the flow of food from the stomach to the small intestine (C) Signup and view all the answers

Which part of the small intestine follows the duodenum?

Jejunum (A) Signup and view all the answers

What is the length of the human small intestine?

About 6 meters (D) Signup and view all the answers

What is the primary role of the caecum in the human digestive system?

To host symbiotic microorganisms (D) Signup and view all the answers

What does the pulp cavity contain?

Nerves and blood vessels (B) Signup and view all the answers

Which section of the large intestine temporarily stores undigested waste material?

Rectum (C) Signup and view all the answers

What structure prevents food from entering the trachea during swallowing?

Epiglottis (A) Signup and view all the answers

Which part of the stomach surrounds the opening between the oesophagus and stomach?

Cardia (B) Signup and view all the answers

How long is the human large intestine approximately?

1.5 meters (C) Signup and view all the answers

What is the function of the anus in the human digestive system?

To expel fecal matter (C) Signup and view all the answers

What is the function of mucus in the oesophagus?

Lubricate the passageway of food (D) Signup and view all the answers

Which part of the small intestine is highly coiled and broader than the jejunum?

Ileum (D) Signup and view all the answers

What type of muscles make up the oesophagus?

Longitudinal and circular muscles (D) Signup and view all the answers

How long is the oesophagus approximately?

25 cm (C) Signup and view all the answers

What is dentition the study of?

Teeth arrangement and development (B) Signup and view all the answers

Which part of the pharynx opens into the oesophagus?

Oropharynx (C) Signup and view all the answers

Study Notes

Human Nutrition - Digestion

Nutrition is the intake of food, considered in relation to the body's dietary needs (WHO definition)
Dietary needs include carbohydrates, proteins, fats, vitamins, minerals, water, and fibre
Nutrition includes ingestion, digestion, absorption, assimilation, and egestion
Food provides energy and material for growth and tissue repair
Vitamins and minerals required in small amounts for nutrition

Human Digestive System

Digestion converts complex, non-diffusible, non-absorbable food into simple, diffusible, assimilable substances
The human digestive system comprises the alimentary canal and associated digestive glands
Alimentary canal is a 8-10 meter long tube starting from the mouth and ending at the anus
Mouth (oral/buccal cavity): Lined with mucous membrane, salivary glands open into the cavity
Teeth (32): Thecodont (in sockets), diphyodont (two sets), heterodont (different types)
Types of teeth: incisors, canines, premolars, molars
Dental formula for adult humans: 2(I 2/2, C 1/1, PM 2/2, M 3/3)

Mouth and Teeth

Mouth - oral cavity; buccal cavity
Side walls made of cheek, roof of palate, floor by tongue
Salivary glands open into the buccal cavity
32 teeth in the adult human buccal cavity
Teeth are thecodont, diphyodont and heterodont
Two sets of teeth in human life – milk teeth, permanent teeth
4 types of teeth: incisors, canines, premolars, molars

Pharynx

The pharynx is a short passage common for food and air
Upper region of pharynx is trachea (openings - glottis) is guarded by epiglottis
Epiglottis closes during swallowing to prevent food from entering trachea
Lower region of pharynx is oropharynx, leads to oesophagus

Oesophagus

A thin muscular tube that lies behind the trachea
About 25 cm long
Passes through the neck, rib cage, pierces diaphragm, and connects to the stomach
Lined with mucus cells to lubricate food passage
Peristalsis (rhythmic muscle contractions) moves food through the oesophagus

Stomach

Located in the upper left portion of the abdominal cavity
J-shaped, 25-30 cm long
Divided into cardiac region (top) and pyloric region (bottom)
Temporarily stores food, mixes it with gastric juice
Cardiac sphincter prevents reflux of food into oesophagus
Pyloric sphincter controls release of food into small intestine

Small Intestine

About 6 meters long, coiled within abdominal cavity
Held together by mesenteries (supports blood vessels, lymph vessels, and nerves)
Divided into three parts: duodenum, jejunum, ileum
Duodenum: 'U' shaped, receives digestive secretions from pancreas and liver, responsible for early stages of digestion
Jejunum and Ileum: responsible for absorption of nutrients

Large Intestine

1.5 meters long, wider than small intestine
Larger in diameter, shorter than small intestine
Comprised of caecum, colon, and rectum
Caecum: small, blind sac with vermiform appendix
Colon: ascending, transverse, and descending sections; responsible for water absorption
Rectum: stores waste materials temporarily
Anus: terminal opening, expulsion of faeces (egestion)

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Description

Discover the essential components of human nutrition, including the processes of ingestion, digestion, absorption, and egestion. This quiz covers the anatomy of the digestive system as well as the roles of various nutrients needed for bodily functions. Test your knowledge on how food transforms from complex substances into forms the body can use.