warm up 4/10 what do you know? what do you know about the digestive system? 1. write down anything...
TRANSCRIPT
WARM UP 4/10WHAT DO YOU KNOW? What do you know about the digestive
system?
1. Write down anything you know about it – parts, how it works, purpose, etc.
2. Also write down where food goes after you swallow it – all the way through the body naming the parts
PARTS OF THE DIGESTIVE SYSTEM
On your warm up, label A-F the best you can
THE DIGESTIVE SYSTEM
CHAPTER 21
4/10
WHY DO WE NEED THE DIGESTIVE SYSTEM? Food we eat is not
in a form that can be used by the cells
DIGESTION – process of altering the physical and chemical composition of food so it can be used by our cells
ALIMENTARY CANAL or GASTROINTESTINAL TRACT (GI) – tube from mouth to anus
MOUTH Buccal cavity
Lips – obicularis musclephiltrum
tubercle Oral fissure
CLEFT LIP – philtrum to the nasal cavity
CHEEKS – buccinator muscles
PALATES – top of mouth a. Hard – front (bone under) b. Soft - back
TONSILS – sides of back of mouth; fight infections
UVULA – hangs in the back of the mouth, no known function
TONGUE Skeletal muscle covered by mucous
membrane
Connected to the hyoid bone
(Hypoglossal and glossopharyngeal nerves bring impulses to and from)
Covered with PAPILLAE – bumps
LINGUAL FRENULUM – fold of tissue that helps anchor tongue to the floor of the mouth
PLICA FIMBRIATA – tissue on both undersides of the tongue; contains lingual vein
Vessels very close to surface – soluble drugs absorbed rapidly under the tongue
TONGUE FUNCTIONS
- helps in mastication (chewing) - helps in deglutition (swallowing) - helps in speech - sense of taste
SENSE OF TASTE - GUSTATION TASTE BUDS – 50-100 inside the
papillae 4 main tastes: sweet, salty, sour,
bitter Ave person has 10,000 taste buds Decrease with age, so food stronger in younger• Less taste buds in smokers
Sense of taste a. Bitter – back b. Salty – sides c. Sweet – tip d. Sour - middle
How we taste Substance dissolves and fits into a
taste bud receptor. Sends message through facial or
glossopharyngeal nerves to parietal lobe of cerebrum
Brain interprets the taste Can detect about 5,000 diff. tastes
Hot and spicy foods actually stimulate pain receptors
Smells of foods can cause stimulation of saliva
Bitter taste is actually a protection – most spoiled or toxic foods are bitter
Our genes determine the number and types of taste buds we have…that is why some people think certain foods taste good and some don’t
EX: PTC paper
OLFACTION = SMELL
Olfactory cells high in nasal cavity
SENSE OF SMELL influences taste• As you chew, chemicals released up into nose• Trigger receptors in nose• Send message to brain through olfactory nerve• Goes to temporal lobe • Brain interprets• Brain can detect about 10,000 different smells
• NOSE + TASTE BUDS = TRUE FLAVOR
(why stuffy nose = less taste – can’t get to receptors)
If same smell is detected for a period of time, body adapts to smell and no longer notice it
Ex: perfume or cologne you are wearing, chemicals working with (fingernail salons), etc.
Many smells linked to memories - mamillary body