Respiratory and Digestive System

What are the primary and secondary functions of the respiratory system?

Primary: Gas exchange

Secondary: Heat and water elimination

Acid-base balance

Assists circulation

Vocalization

Defense

Smell and taste

What are the 6 principal portions of the respiratory tract?

Nose/nasal cavity

Pharynx

Larynx

Trachea

Bronchial tree

lungs

The nose consists of a framework of ____ and ___, covered externally by the ___ and internally by a ____ membrane

Cartilage, bone, skin, mucous

Describe the nose’s structure and functions

Divided into a left and right side by the nasal septum

External nares lead into the nasal cavity from the nose, and the internal nares lead into the nasopharynx. Inhaled air swirls through the conchae and meatuses. This allows the air to be moisturized and warmed

What do sinuses do?

Make the skull lighter

Serve as resonating chambers

What are the nose and nasal cavity’s functions?

1. Air passageway

2. Warms, moisturizes, and filters incoming air

3. Defense via sneezing, hair, and mucus

4. Smell and taste

   1. Vocalization

The pharynx’s walls consist of ____ muscle with a ____ membrane. It’s a common passageway for both the ___ and ____ systems

Skeletal, mucous, respiratory, digestive

What are the pharynx’s 3 portions?

Nasopharynx

Oropharynx

Laryngopharynx

What 4 structures open to or are found in the pharynx?

Eustachian tubes

Pharyngeal tonsils

Palatine tonsils

Lingual tonsils

What are the pharynx’s 4 functions?

Air passageway

Food passageway

Vocalization

Defense

What singular cartilage is found in the larynx? And what’s it’s purpose?

Epiglottis, acts as a trap door to close off the lower respiratory tract at the larynx. Prevents solids and liquids from entering

Which cartilage is felt as the Adam’s Apple? 🍎

Thyroid

What two folds are found in the larynx?

Superior vestibular folds/false vocal cords

Inferior vocal folds/true vocal cords

What 3 functions does the larynx serve?

Air passageway

Vocalization

Defense

The trachea is anterior to the _____. It’s lined with ____ columnar epithelium. It has 16-20 ____ of _____

esophagus, ciliated, c-shaped rings, cartilage

What functions does the trachea serve?

Air passageway

Defense

Describe the bronchial tree’s branches

Trachea → Primary bronchi → Secondary bronchi → Tertiary bronchi → Bronchioles → Terminal bronchioles

What are 3 changes that happen from main bronchi dividing into smaller branches? And what could happen from this?

1. Cartilaginous rings disappear

2. The amount of smooth muscle in the walls increase

3. Mucous membrane slowly loses cilia

Smooth muscle spasms may collapse these smaller airways

What functions does the bronchial tree serve?

Air passageway

Defense

Which division of the nervous system would trigger relaxation of the smooth muscle in the walls of distal bronchioles – leading to dilation of airways?

The sympathetic division

What is the pleura and its 3 parts?

A two-walled sac surrounding the lungs.

Parietal: Attaches to the inner thoracic wall and the diaphragm

Visceral: Surrounds and is attached to the lungs

Pleural fluid: Reduces friction when the lungs inflate and deflate

The right lung is divided into a ___, ____, and ____ lobe. The left lung is divided into a ___ and ____ lobe.

Superior, middle, and inferior

Superior and inferior

The ___ bronchial divides into ____ bronchioles, which divide into ____ ducts

Terminal, respiratory, alveolar

What are alveoli?

Small pouches that make up the lungs

What is the function of the lungs?

Gas exchange between the environment and blood

What are the 3 phases of respiration

Pulmonary ventilation

External respiration

Internal respiration

What is the air flow formula?

Pressure gradient/Resistance

What is the partial pressure of a gas?

The amount of pressure that each gas contributes to the total pressure in a mix of gases.

How do individual gases move?

From areas of high partial pressures to areas of lower partial pressures

What is pulmonary ventilation?

movement of air between the lungs and the environment due to the thoracic cavity expanding and contracting

What are the two parts in ventilaiton?

Inhalation: Increasing the size of the thoracic cavity

Exhalation: Decreasing the size of the thoracic cavity

How does the thoracic cavity’s size change?

By contracting and relaxing skeletal muscles

What is the difference between external and internal respiration?

External: Involves the movement of gases between alveoli and the blood. This is an exchange for partial pressures of gases

Internal: Exchange of gases between the tissues/cells and blood. Also driven by partial pressure

In gas transport, most of the ___ is bound to ____. Most of the ___ is transported as _____ ___

oxygen, hemoglobin, carbon dioxide, bicarbonate ions

Where is the respiratory control center located?

Brain stem

What 3 parts of the brain influence respiration?

Cerebral cortex

Hypothalamus

Limbic system

____receptors in the medulla monitor levels of ___, ___, and ___ in the ____ fluid and ___

Chemo, oxygen, carbon dioxide, hydrogen, cerebrospinal, blood

What tube runs from the mouth to the @nus?

The alimentary canal

What are the major and accessory portions of the alimentary canal?

Major: Oral cavity, pharynx, esophagus, stomach, small and large intestine

Accessory: Teeth, tongue, salivary glands, liver, gallbladder, pancreas

What are the 6 principle classes of nutrients?

1. Carbs

2. Vitamins

3. Lipids/fats

4. Minerals

5. Proteins

6. Water

What are the 4 layers in the alimentary canal’s lumen?

1. Mucosa

2. Submucosa

3. Muscularis

4. Serosa

The mucosa is a ____ membrane composed of a layer of ____. Lymphatic cells known as ____ are there to help protect against disease

Mucous, epithelium, MALT

What type of vessels does submucosa contain?

Blood and lymphatic

What is the submucosal plexus?

A network of neurons that conveys motor impulses to secretory cells to the mucosal epithelium

The muscularis has two layers of ____ muscle, ___ and ____ fibers.

smooth, circular, longitudinal

What parts in the muscularis contain smooth muscle?

Mouth, pharynx, upper esophagus, and anal canal

The serosa is a ____ membrane. It’s also referred to as the ____ peritoneum

Serous, visceral

What two divisions in the nervous system influence the digestive system?

Autonomic and enteric

Neurons in the ____ division ____ digestive activity, while neurons in the ____ division ____ digestion

parasympathetic, stimulate, sympathetic, inhibit

What nerve supplies parasympathetic input?

Vagus, CN X

The enteric division consists of the ___ and ___ plexus

Myenteric, submucosal

Sensory neurons convey sensory impulses from what two receptors?

Chemoreceptors and mechanoreceptors

What do interneurons do?

They connect the neurons of the two plexuses

What do motor neurons do?

Myenteric: Trigger contraction of the muscles in the muscularis

Submucosal: Secretions into the lumen’s tract

What are the four processes in the digestive system

1. Motility

2. Secretion

3. Digestion

   1. Mechanical

   2. Chemical

4. Absorption

The ___ and ____ palates separate the oral cavity from the nasal cavity

Hard, soft

What does the uvula do?

Closes off the nasopharynx when swallowing

What is the tongue?

Consists of skeletal muscle covered with a mucous membrane

List and describe the 4 papillae

Circumvallate: 12, large, located in the back of the tongue. House hundreds of tastebuds

Fungiform: Mushroom shaped, on the lateral and superior surface. 5 buds each

Foliate: On the lateral margins, degenerate after early childhood

Filiform: Pointed and threadlike. Don’t contain tastebuds, but increase friction for food

What are the 3 salivary glands?

1. Parotid

2. Submandibular

   1. Sublingual

What division of the nervous system controls salivation?

Parasympathetic

What is saliva composed of?

99.5% water, .5% solutes

What enzymes are in saliva?

Lysozyme

Salivary amylase

What are the 3 parts of the tooth?

1. Crown (visible)

2. Neck (gum line)

   1. Root (bony socket)

What’s the difference between dentin and enamel?

Dentin: Forms most of the tooth, is slightly harder than bone

Enamel: Covers the dentin of the crown, hardest substance in the body

What are the 4 digestive processes int he oral cavity?

1. Motility: Mastication/chewing, deglutition/swallowing

2. Secretion: Saliva

3. Mechanical digestion: All nutrients if chewed

4. Chemical digestion: Salivary amylase what breaks down carbs

What do the tonsils do?

Defend against inhaled or ingested microbes

What parts of the pharynx are involved in the digestive and respiratory system?

Digestive: Oropharynx and laryngopharynx

Respiratory: Nasopharynx

Describe the process of swallowing/deglutition

Bolus (a soft mass of food mixed with saliva) is pushed back by the tongue and towards the pharynx. The muscles in the pharynx contract to propel the food into the oropharynx. The uvula closes off the nasopharynx while the epiglottis closes off the larynx. The bolus is then directed into the esophagus.

The ____ is located posterior to the trachea. It then passes through the ____.

Esophagus, diaphragm

The upper third of the muscularis of the esophagus consists of ____ muscle, and the lower third consists of ____ muscle

skeletal, smooth

What are the differences between the upper and lower esophageal sphincter?

UES: Consists of skeletal muscle, located between the laryngopharynx and esophagus

LES: Between the inferior end of the esophagus and the stomach

What does the adventitia do?

Surrounds the muscularis of the esophagus, which merges with the connective tissue of other organs in the mediastinum, anchoring the esophagus to surrounding organs

What is the digestive process in the esophagus?

Motility: Deglutition in the upper esophagus, peristalsis begins in the esophagus

What is the largest serous membrane, and what does it do?

Peritoneum, anchors most abdominal organs together

What two parts make up the peritoneum, and what do they do?

Parietal: Lines the abdominal cavity

Visceral: Covers some abdominal organs and is considered the serosa

What are the 5 major peritoneal folds?

1. Greater omentum: Draped over the transverse colon and coils of the small intestine

2. Lesser omentum: Connects the stomach and duodenum to the liver

3. Mesentery: Anchors the jejunum and ileum of the small intestine to the posterior wall

4. Mesecolon: Binds the sigmoid and transverse colon to the post. abdominal wall

5. Falciform ligament: Attaches the liver to the anterior abdominal wall and diaphragm

Where is the stomach located?

Left Upper Quadrant (LUQ)

What are the stomach’s 4 main regions

1. Cardia: Surrounds the opening of the esophagus to the stomach

2. Fundus: A rounded portion superior and to the left of the cardia

3. Body: A large central portion

4. Pyloric portion: Consists of an antrum, canal, and pylorus

What 3 types of exocrine cells make up gastric glands? And what do they secrete?

Mucous neck cells: Secrete mucus

Chief cells: Secretes pepsinogen and gastric lipase

Parietal cells: Produce hydrochloric acid and intrinsic acid, used to absorb vitamin B₁₂

The muscularis is composed of ___ layers of ____ muscles

3, smooth

Describe motility in the stomach

When food passes through the esophagus, the LES opens, allowing food into the stomach. It closes, and converts the food into a viscous liquid called chyme. Once food particles in chyme are small enough, they pass through the pyloric sphincter and into the duodenum.

Describe digestion in the stomach

Chyme continues to be mechanically digested into smaller particles. Chemical digestion handles carbs via salivary amylase. HCL activates pepsinogen and pepsin. Pepsin breaks down proteins into smaller fragments. A thick layer of mucous secretes the food

What digestive processes are found in the stomach?

Secretion: Gastric juice

Mechanical digestion: All nutrient classes

Chemical digestion: Proteins

Absorption: Weak acids

What are 3 facts about the pancreas?

Connected to the duodenum

99% of it consists of exocrine cells

Interspersed with small clusters (islets) of endocrine cells

What 3 enzymes are found in pancreatic juice?

Amylase: Digests starches

Proteases: Digests proteins

Lipase: Digests triglycerides

What is the largest gland in the body? And what does it produce?

Liver, bile

What 3 ducts are found in the gallbladder?

Common hepatic duct

Cystic duct

Common bile duct

What are hepatocytes?

Principle function cells in the liver

What is the gallbladder made of?

Simple columnar epithelium folded into rugae

Describe blood flow within the liver

Hepatocytes receive oxygen-rich blood from the hepatic artery and nutrient-rich blood form the hepatic portal vein

The ____ stores and concentrates ____

Gallbladder, bile

What are other liver functions?

• Carbohydrate metabolism - storing glycogen, releasing glucose

• Protein metabolism – plasma protein synthesis and the deamination of amino acids for use in ATP production (producing the waste product urea)

• Lipid metabolism – hepatocytes store some lipids, break down fatty acids for ATP, synthesize lipoproteins (HDL, LDL…), synthesize bile salts

• Detoxification and excretion of alcohol and drugs

• Altering or excretion of hormones such as thyroid hormones and some steroid hormones like estrogen and aldosterone.

• Phagocytosis of red blood cells, white blood cells, and some microbes

• Excretion of bilirubin from RBC breakdown (into bile)

• Activation of calcitriol, the active form of vitamin D

• Storage of vitamins (A, B12, D, E, K) and minerals (iron, copper) for use when needed elsewhere in the body

The ____, ____, and ___ are not a part of the alimentary canal, but they ____ products into the lumen of the ____

Pancreas, liver, gallbladder, secrete, lumen

What are the 3 regions in the small intestine

Duodenum: Starts at pyloric sphincter

Jejunum: Middle portion, 3 feet long

Ileum: Last portion, 6 feet long

What is villi, and what does it do?

Villi are small fingerlike projections in the small intestine’s mucosa that increase the surface area

What 4 things does intestinal juice contain?

Water,

mucous,

bicarbonate ions

brush-border enzymes

What 2 things are included in small intestine motility?

Segmentations and migrating motility complex

What is the small intestine’s primary site?

Chemical digestion of all nutrients

What macronutrients are transported through blood capillaries and the hepatic portal vein?

Monosaccharides, amino acids, lipids, fat-soluble vitamins, monoglycerides