Lesson Notes By Weeks and Term v3 - Primary 4
Human Body (The mouth)
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Human Body (The mouth)
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Subject: Basic Science
Class: Primary 4
Term: 2nd Term
Week: 9
Theme: Living And Non-Living Things
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Watch on YouTubeSee Facebook postname the types of teeth in the mouth locate the relative positions of teeth in the mouth mention the uses of each type of teeth state the role of the to ngue in feeding state the role of the lips in feeding
the mouth and play several important roles: Holding Food/Liquid: They seal the mouth, preventing food and liquids from spilling out during chewing and drinking.
Example: Sipping kunu or soup without spillage.
Controlling Food Intake: They help to direct food into the mouth and control the size of bites taken.
Assisting in Speech: Lips are crucial for forming various sounds and articulating words clearly, allowing for effective communication in languages like Yoruba, Igbo, or Hausa. * Sucking: Essential for infants during breastfeeding and for drinking liquids from a cup or bottle. This section provides the core content knowledge for the teacher to deliver the lesson.
A. Parts of the Mouth Covered: The mouth is the first part of the digestive system. Key structures within the mouth that aid in feeding and speech include: Teeth: Hard, calcified structures used for tearing, cutting, grinding, and crushing food.
Tongue: A muscular organ crucial for tasting, mixing food, and speech.
Lips: Fleshy folds that form the opening of the mouth, aiding in feeding, speech, and expression.
B. Types of Teeth and Their Functions: Humans develop two sets of teeth during their lifetime:
1. Primary (Milk)
Teeth: Usually 20 in number, these begin to appear around 6 months of age and are fully developed by age 2-
3. They are eventually replaced.
2. Permanent Teeth: Around 32 in number, these start replacing milk teeth around age 6 and continue growing until early adulthood. For Primary 4, the focus is on the types and functions, regardless of whether they are milk or permanent teeth.
There are four main types of teeth:
1. Incisors: Description: These are the flat, chisel-shaped teeth located at the very front of the mouth. There are typically 8 incisors in total (4 upper, 4 lower).
Location: Front and centre of the mouth.
Function/Use: Primarily used for cutting and biting food into smaller, manageable pieces.
Example: Biting into an apple, a slice of bread, or a piece of boli (roasted plantain).
2. Canines: Description: These are the pointed, sharp teeth located on either side of the incisors. There are typically 4 canines in total (2 upper, 2 lower).
Location: Positioned next to the incisors, slightly towards the back of the mouth.
Function/Use: Designed for tearing and piercing tough or fibrous foods.
Example: Tearing meat (ponmo), tough vegetables, or fibrous fruits.
3. Premolars (Bicuspids): Description: These teeth are flatter than canines but less broad than molars, with two cusps (points) on their chewing surface. There are typically 8 premolars in total (4 upper, 4 lower).
Location: Situated behind the canines, moving further back in the mouth.
Function/Use: Used for crushing and grinding food, preparing it for the molars.
Example: Crushing groundnuts, chewing small pieces of yam, or processing slightly harder food items.
4. Molars: Description: These are the largest and broadest teeth with flat, wide chewing surfaces designed for heavy grinding. There are typically 12 molars in total (6 upper, 6 lower, including wisdom teeth which may or may not emerge).
Location: Found at the very back of the mouth.
Function/Use: Their primary role is to powerfully grind and mash food into a fine pulp before swallowing.
Example: Grinding tough meats, chewing fufu or amala, or mashing beans.
C. Role of the Tongue in Feeding: The tongue is a highly flexible muscular organ with several critical roles: Taste Perception: It contains taste buds that detect sweet, sour, salty, bitter, and umami flavours of food, allowing us to enjoy dishes like jollof rice or bitter leaf soup.
Mixing Food with Saliva: The tongue constantly moves food around the mouth, mixing it thoroughly with saliva to soften it and begin chemical digestion.
Forming Bolus: It helps to gather the chewed food and saliva into a soft, rounded mass called a bolus, which is easy to swallow.
Swallowing: The tongue pushes the bolus to the back of the mouth and down into the pharynx, initiating the swallowing reflex.
D. Role of the Lips in Feeding: The lips are the outer boundary of the mouth and play several important roles: Holding Food/Liquid: They seal the mouth, preventing food and liquids from spilling out during chewing and drinking.
Example: Sipping kunu or soup without spillage.
Controlling Food Intake: They help to direct food into the mouth and control the size of bites taken.
Assisting in Speech: Lips are crucial for forming various sounds and articulating words clearly, allowing for effective communication in languages like Yoruba, Igbo, or Hausa.
Sucking: Essential for infants during breastfeeding and for drinking liquids from a cup This section outlines the step-by-step approach for delivering the lesson.
A. Introduction (10 minutes)
Teacher Activity: Begin by engaging learners with questions about eating habits. "What do you do with your mouth when you are eating rice? What parts of your mouth do you use to chew garri?" Student Activity: Learners share their initial thoughts and observations about the mouth's role in eating.
Teacher Activity: Introduce the topic: "Today, we will learn about the different parts of our mouth – specifically our teeth, tongue, and lips – and how they help us eat and speak." Display a simple diagram of the human mouth if available, or ask students to gently touch their own mouths.
B. Development of Content (30 minutes)
Activity 1: Exploring Types and Positions of Teeth Teacher Activity: Instruct learners to use a small, clean mirror (if available) or simply use their fingers to feel inside their mouths. Guide them to identify the different shapes and positions of their teeth. "Feel the teeth at the very front. Are they sharp or flat? What do they look like?" (Incisors) "Now feel the pointed teeth next to them." (Canines) "Move your finger further back, feel the teeth behind the pointed ones. Are they flat or pointed?" (Premolars) "Finally, feel the very big, flat teeth at the back of your mouth." (Molars)
Student Activity: Learners actively explore their own mouths, feeling and observing the different teeth based on the teacher's instructions. They describe what they feel.
Teacher Activity: Introduce the proper names for each type of tooth (Incisors, Canines, Premolars, Molars) and their relative positions, writing them on the board. Reinforce by asking "Where are your incisors located?" etc.
Activity 2: Uses of Each Type of Tooth Teacher Activity: Bring a few simple, safe food items or pictures of them (e.g., a slice of apple or bread, a piece of roasted meat/fish, some groundnuts, a piece of yam).
Student Activity: Ask learners, "If you want to bite into this apple, which teeth would you use?" (Incisors). "If you want to tear this piece of meat, which teeth would help?" (Canines). "To crush these groundnuts, what teeth would you use?" (Premolars). "And to grind this yam into a pulp, which teeth are best?" (Molars). Learners demonstrate or describe the action.
Teacher Activity: Summarise and explain the specific function of each tooth type clearly on the board, connecting it to the food examples. Emphasise that all teeth work together for effective chewing.
Activity 3: Role of the Tongue and Lips Teacher Activity: Focus on the tongue. Ask learners to stick out their tongue and move it around. "What does your tongue do when you eat jollof rice? Does it help you taste it? Does it move the rice around?" (Tasting, mixing food). "When you are talking, does your tongue move? Can you say 'Lagos' without moving your tongue?" (Speech). Explain the role of the tongue in tasting, mixing food with saliva, forming the food bolus, and helping to swallow.
Student Activity: Learners experiment with their tongues, observe movements, and try speaking without tongue movement. They discuss their observations.
Teacher Activity: Focus on the lips. "What do your lips do when you drink water? What if you open your mouth wide while drinking?" (Holding liquid). "When you say 'Mama' or 'Papa', do your lips move?" (Speech). Explain the role of the lips in holding food/liquid, assisting in speech, and helping with sucking.
Student Activity: Learners demonstrate how their lips help them drink or form specific sounds.
C. Lesson Conclusion (5 minutes)
Teacher Activity: Review the key points by asking quick questions. "Can someone name the four types of teeth?" "What does the tongue help us do?" "How do our lips help when we eat?" Student Activity: Learners provide brief answers, consolidating their understanding.
Teacher Activity: Emphasize the importance of taking care of their mouth (brushing teeth) because all these parts are essential for good health and communication. These questions are designed to be worked through with teacher guidance.
Question 1: Imagine you are eating a piece of roasted chicken. Which type of tooth would you primarily use to TEAR the meat from the bone?
Solution 1: Answer: Canines.
Commentary: Canines are pointed and sharp, specifically designed for tearing tough foods like meat, making them perfect for separating chicken from the bone.
Question 2: You just put a spoonful of delicious egusi soup in your mouth. What is the main role of your tongue immediately after the soup enters your mouth?
Solution 2: Answer: The tongue will move the egusi soup around and mix it with saliva, helping you taste it fully and prepare it for swallowing.
Commentary: The tongue's flexibility is crucial for tasting and mixing food, initiating the digestion process and sensory experience.
Question 3: Your younger sibling is struggling to bite into a hard gala (sausage roll). Which type of teeth should they use to cut off the first piece?
Solution 3: Answer: Incisors.
Commentary: Incisors are the front, chisel-shaped teeth used for cutting and biting into food items like gala to break them into smaller portions.
Question 4: When you are eating fufu with soup, what part of your mouth helps to prevent the fufu and soup from spilling out while you chew and move it around?
Solution 4: Answer: The lips.
Commentary: The lips seal the mouth, forming a barrier that keeps food and liquids securely inside, preventing spillage during eating and drinking.
Oral Hygiene and Health: Emphasise the importance of brushing teeth twice daily (using local chewing stick/paste) to prevent tooth decay and gum disease, which can affect the function of all teeth. Discuss the need to visit a dentist for check-ups, if accessible, or local health centres for basic dental care. This directly connects to the role of teeth in processing local Nigerian foods, many of which are starchy or sugary.
Healthy Eating Habits and Digestion: Proper chewing, facilitated by different teeth types, ensures food is broken down adequately for easy digestion. Learners can relate this to how chewing amala or garri properly prevents stomach upset. The tongue's role in tasting helps in appreciating local delicacies like afang soup or moin-moin.
Communication and Social Interaction: The tongue and lips are crucial for speaking clearly. Practising clear articulation of words in different Nigerian languages (e.g., Igbo, Hausa, Yoruba, Efik) highlights the importance of these mouth parts for effective communication, participation in local community events, and even storytelling.