What are tissues?
Tissues are groups of specialized cells that function together to perform specialized tasks.
What are the 4 types of tissue?
-Epithelial
-Muscle
-Nervous
-Connective
What is the function of epithelial tissue?
To form a protective barrier: covers the outer surface of the body lines body cavities such as the digestive or respiratory system
Protection
Skin tissue protects underlying tissue from mechanical injury, harmful chemicals, invading bacteria and from excessive water loss
Secretion
Glands secrete enzymes, hormones & lubricating fluids
Absorption
Cells in the small intestine absorb nutrients from digested food
What are the 3 types of muscle tissue?
Skeletal
Voluntary
Striated
Contract to pull on bones to create movement
Smooth
Involuntary
Smooth
Contract to facilitate movement of liquids and solids throughout the body
Cardiac
Involuntary
Smooth
Muscles of the heart contract to move blood throughout the circulatory system
What is nervous tissue?
-Nerve tissue can create impulses & transmit them throughout the body
-Nerve cells receive information from inside & outside the body
What is connective tissue and explain all the types
The main function is to join other tissues together.
Tendons & ligaments: connect muscles to bones
Bones: provide structural support
Cartilage: cushioning between bones
Blood:
Red Blood Cells: transport O2 and CO2
White Blood Cells: fight off infection
Platelets: form blood clots for wound healing
Adipose (fat): provides cushioning and insulation
Collagen: gives strength & support to bones, muscles, skin
What are the components of the alimentary canal?
Mouth
Pharynx
Esophagus
Stomach
Small Intestine
Duodenum
Jejunum
Ileum
Large Intestine/Colon
Cecum
Ascending Colon
Transverse Colon
Descending Colon
Sigmoid Colon
Rectum
Anus
What are the accessory organs?
Salivary glands
Liver
Gallbladder
Pancreas
What is the pharynx?
The pharynx, or throat, connects the mouth to the esophagus and trachea.
What is the esophagus and how does it push food?
The esophagus is a tube of smooth muscle that connects the pharynx to the stomach. The esophagus is able to push food along because of peristaltic muscle contractions.
What is the stomach and how does an ulcer occur?
The stomach further digests food by using enzymes and acid. An ulcer occurs when the stomach acid gets through to the actual muscle.
What is the small intestine & its role?
The small intestine uses enzymes from the pancreas and bile produced in the liver to further break down nutrients. The role of the small intestine is to absorb nutrients.
What is the large intestine & its role?
Food that cannot be further digested moves from the small intestine to the colon (large intestine).
The colon absorbs water and vitamins into the bloodstream.
What is the liver?
The liver produces bile, which is a greenish-brownish fluid that aids in digesting fats (emulsification)
What is the gallbladder?
The bile is stored in the gallbladder. The bile travels through ducts from the gallbladder to the small intestine.
What is the pancreas?
The pancreas is an accessory organ that makes enzymes that goes into the small intestine and it creates insulin, which is a hormone used to regulate blood sugar levels.
How does heartburn happen?
Heartburn is a burning sensation in the chest that is caused by the regurgitation of acid from the stomach into the esophagus.
What are goblet cells?
Goblet cells are specialized epithelial cells found in the respiratory and digestive systems. They produce and secrete mucus.
Goblet cells are primarily found in the respiratory tract, including the lining of the trachea, bronchi, and bronchioles. They are also present in the digestive system, particularly in the epithelial lining of the intestines
What are ciliated cells?
Ciliated cells are epithelial cells that possess hair-like structures called cilia on their surface. They are found in the respiratory tract, including the trachea, bronchi, and bronchioles, where their coordinated movement helps propel mucus and trapped particles out of the airways.
What are red blood cells?
Disc-shaped cells
Contain hemoglobin, a protein that binds to
oxygen and carbon dioxide
O2 enters cells via diffusion
Made in the bone marrow
What are white blood cells?
Fight infection in the blood
Also produced in the bone marrow
What are platelets?
Help blood clot to seal injuries and prevent blood loss
Result from fragmentation of large cells in the bone marrow
What is plasma?
It’s a protein-rich liquid that carries the blood cells and other dissolved components
Maintains fluid balance in the body
What are chief cells?
Chief cells are specialized cells found in the stomach lining, specifically in the gastric glands of the stomach. They are responsible for secreting pepsinogen, an inactive enzyme that is later activated to pepsin, aiding in the digestion of proteins.
What are parietal cells?
Parietal cells are specialized cells located in the stomach lining, particularly in the gastric glands. They secrete hydrochloric acid (HCl) and intrinsic factor.
What is mechanical digestion and what are the forms of it?
Mechanical digestion is the physical breakdown of food (chewing food is an example)
The actual chewing and crushing of food is known as mastication
Another form of mechanical digestion is the smooth muscle contractions, called peristalsis, that occur as the food is passed along the digestive tract
What is chemical digestion?
Chemical digestion is the chemical breakdown of food into simpler nutrients that can be absorbed. This is done with the aid of enzymes
What is segmentation?
Segmentation is when digested food is moved back and forth in short segments.
What is the chemical formula for cellular respiration?
C6H12O6 + O2 → CO2 + H20 + ATP energy
What are the circulatory system’s functions
1. Transport
O2
Nutrients
CO2
Waste
Hormones
2. Regulation
Homeostasis (steady state)
3. Protection/ Immune Response
What are the components of the circulatory system?
Blood
Blood Vessels
Arteries, Veins, Capillaries
Heart
What is the approximate composition of blood?
55% plasma, 45% RBCs, <1% WBCs and Platelets
What are arteries and what are the smaller ones called?
Arteries carry blood away from the heart
Arterioles are small arteries that
regulate blood pressure
Their walls have 3 layers:
Thin inner epithelium
Thick elastic smooth muscle layer
Outer connective tissue
Need to be thick to withstand the high pressure of the blood pumping through them
What are veins and what are the smaller ones called?
Veins carry blood toward the heart
Venules are small veins
Venule and vein walls have 3 layers
Thin inner epithelium
Thinner, inelastic smooth muscle layer
Outer connective tissue
Veins are thinner than arteries, they have less pressure
Veins that carry blood against gravity have valves to keep blood flowing toward the heart
What are capillaries?
Tiny blood vessels between arterioles and venules
Made of one layer of epithelial tissue
one cell thick
Allow for diffusion of oxygen and nutrients into cell and carbon dioxide out of the cell
What is the difference between an open and closed circulatory system?
Open circulatory systems which are commonly found in invertebrates have free flowing blood because unlike closed systems, they do not have vessels to contain them.
What are the four chambers of the heart?
Right Atrium receives oxygen-poor blood from the body
Right Ventricle pumps oxygen-poor blood into the lungs
Left Atrium receives oxygen-rich blood from the lungs
Left Ventricle pumps oxygen-rich blood into the rest of the body
Note that heart has 4 valves
What is the blood’s pathway?
Deoxygenated blood in the heart is pumped to the lungs through arteries to “pick up” oxygen
Gas exchange occurs in the lungs through capillaries
CO2 diffuses from blood into lungs
O2 diffuses from lungs into blood
Oxygenated blood returns to heart through veins
Oxygenated blood is pumped from the heart to the body through arteries
What are the largest veins and arteries called
Vena cava
Has inferior and superior to carry blood from upper and lower body
Aorta
What are pulmonary arteries and veins?
The pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the heart
The pulmonary arteries, on the other hand, are responsible for carrying deoxygenated blood from the heart to the lungs, where it undergoes oxygenation
What is the respiratory system’s main function?
Gas exchange
What are the parts of the respiratory system
Note that the larynx is also called the voice box and the trachea is often called the windpipe
What protects the respiratory tract when eating?
The uvula is a small muscle that covers the nasal cavity when swallowing food
The epiglottis is a flap that covers the opening of the trachea when swallowing, prevents choking while eating
How many lobes does each side of the lung have?
3 on the right and 2 on the left
What are alveoli?
Tiny air sacs at the end of the bronchioles
Look like bunches of grapes
Site of gas exchange
Covered in capillaries
Maximized surface area to increase diffusion
Very thin (few cells)
Shortens diffusion distance
Surfactant (mix of lipids and proteins) covers the alveoli to prevent them from collapsing during exhalation
What is the diaphragm?
The diaphragm is a skeletal muscle that separates the abdominal and thoracic cavity (chest)
Dome-shaped
Responsible for inhalation and exhalation
What happens when you inhale?
Diaphragm contracts and moves down
Rib muscles contract and move out
Air pressure in chest cavity decreases
Causes your chest cavity to fill with air as you breathe in
What happens when you exhale?
Diaphragm relaxes and moves up
Rib muscles relax and move in
Air pressure in chest cavity increases
Causes air to be pushed out during exhalation