Human Anatomy Flashcards
Mouth
The structure that ingests food and starts digestion through mechanical chewing (teeth) and chemical (saliva)
Salivary glands
3 glands in the mouth that moisten food and begin chemical digestion of starches
Tongue
a muscular organ that moves food around the mouth; helps in the mechanical chewing and positioning of food
Uvula
a flap of tissue which hangs down inside the back of the mouth to prevent large chunks of food from going down the esophagus (choking / gag response)
Esophagus
a muscular tube which takes food to the stomach using an action called peristalsis
Epiglottis
a flap of tissue that covers the upper trachea when food and liquids are swallowed to prevent them from entering the lungs
closes off airway when swallowing food
Stomach
a bag-like organ which digests food using both chemical (HCl and Pepsin) and mechanical (muscles)
Liver
A large lobed organ which: produces bile detoxifies blood from food and drink stores excess glucose and iron breaks down amino acids and RBC Stores vitamins a, d, e and k Stores glycogen bile breaks down fat globules into droplets, and activates lipases to break down the droplets
Gallbladder
a small organ which stores bile produced by the liver
-contains chemicals such as cholesterol an bile salts involved in the breakdown of fats
Pancreas
A smaller organ which produces many enzymes including insulin
-releases a basic solutions to change the pH of chyme when it enters the duodenum
Small intestine
the longest section of the digestive system which removes nutrient value from the food through the action of villi
What are the 3 sections of the digestive system?
duodenum
jejunum
ileum
Colon/large intestine
reabsorbs water from digested food
appendix
a small structure at the start of the colon, which has no known use, - it is believed it once digested cellulose
Rectum
tube at the end of the colon which stores waste
Anus
Opening at the end of the digestive system, through which waste is excreted
Ingestion
the process of taking in food
digestion
the separation of large food pieces into individual molecules with the help of internal organs
absorption
occurs to the food molecules after digestion as they diffuse into the blood so that they may be transported to the appropriate cells
egestion
occurs to parts of the food that are not absorbed, but eliminated
Nutrients
Chemicals that an organism need to grow, build tissues, repair tissues, and to produce energy
Catabolism
the metabolic reactions that break down larger molecules to into smaller subunits
anabolism
the metabolic reactions that use energy to produce larger molecules from smaller subunits
Metabolism
the set of chemical reactions that occur in living organisms that are necessary to maintain life
Alimentary canal
- tube within the body
- food goes from the mouth through the various parts as it is processed
- food egested never enters the cells of the organism
extracellular digestion
digestion occuring outside the cells (eg. in the stomach, intestines etc.) - most digestion occurs this way
Excretion
products which have been a part of the body’s chemical reactions are given off (eg: urine, CO2)
What ae the two main criteria animals eat?
- endothermic (warm blooded) or ectothermic (cold blooded)
2. Body size
metabolic rate of an animal depends on (5)
- body size - more energy for larger animals
- physical activity - higher activity required for larger animals
- sex - males require more energy (more muscle mass, often larger)
- Age - metabolic rates decrease w age
- hereditary factors - some naturally have a higher rate (humming bird)
Set point
a level which remains close to constant when you eat the amount required by the body
Enzymes
speed up chemical reactions
act on particular substrate (molecules)
end in ‘ase’
example: lactase works on the substrate lactose
Hormones
regulate digestive secretions
in the lining of the stomach which regulates the secretion of mucin to lubricate food and protect the walls of the stomach , pepsin, HCl, and lipases
Peristalsis
wave like action of smooth muscle along the esophagus
Nutrients
elements or compounds an organism needs but cannot manufacture itself
what are the 3 major groups of nutrients?
protein, carbohydrates, and fats
duodenum
lined with thousands of villi and micovilli
the lacteal vessels carry fat particles
Jejunum
contains more folds and intestinal glands than the duodenum, breaks down proteins and carbohydrates
Ileum
contains fewer villi, absorbs the remaining nutrients and
Nasal Passages
filters, warms, and moistens air
Oral cavity
a hollow space for an alternate gas exchange route; warms and moistens the air
Pharynx
Chamber which connects the oral and nasal cavities to the larynx
Larynx
flexible membranes that vibrate when air passes through; responsible for voice sounds
Trachea
Passage of air to the lungs’ bronchi; has cartilaginous rings for protection
Bronchi
2 smaller passageways from the trachea to the bronchioles; one enters each lung
Bronchiole
further branched tubes to increase surface area from the bronchi to the alveoli
alveoli
site of gas exchange; the membranes are one cell thick and surrounded by capillaries
diaphragm
very thin, muscular structure to increase and decrease the volume of the chest cavity
External respiration
transfer of O2 by blood to living cells
Internal respiration
when O2 is in its intended cell for combination with glucose
What are the 4 factors affecting gas exchange?
- presence of moist diffusing surfaces
- surface area for diffusion (greater = faster)
- concentration difference (greater = faster)
- diffusion distance (shorter = faster)
Inhalation
intercostal muscles (between the ribs) and diaphragm contract to expand the thoracic (chest) cavity
Exhalation
intercostal muscles (between the ribs) and diaphragm relax causing a decrease in thoracic volume leading to increased pressure compared to outside
What are the 2 major requirements of a respiratory system?
- surface area for gas exchange must be large enough to meet the needs of the organism
- there needs to be a moist environment so that oxygen and CO2 can be dissolved
What are the 4 methods of Gas exchange?
- simple diffusion
- skin respiration
- gills
- tracheal
Simple diffusion
- protists, fungi, bacteria
- membrane is always moist so O2 and CO2 can dissolve
- all cells can receive O2 through diffusion
Skin respiration
- earthworm
- skin must remain moist, survive only in water or damp soil
- capillary vessels make contact with surface, so gases are able to diffuse in and out
Gills
aquatic organisms
- some have protective coating that does not allow for diffusion
- structural changes enables the organism to ventilate the surface
Tracheal respiration
During breathing air will move from a region of higher pressure to a region of lower pressure until an equilibrium is reached
The role of blood
- Transport of O from capillaries outside the lung alveoli to the mitochondria in all living cells
- Transport CO2 from the capillaries outside the cells which have carried out cellular respiration to the alveoli for exhalation
Cardiac
Supplies blood to the heart
Pulmonary
Blood flow through the lungs to pick up O2 and drop off CO2
Systemic
Blood flow through the body cells
RBC
small, manufactured in red bone marrow, function is to carry oxygen and CO2 to and from cells
WBC: leucocytes
Largest, manufactured in red bone marrow, function is to engulf foreign particles
WBC: lymphocytes
Large, manufactured in the spleen / lymph glands, its function is to play a role in the formation of antibodies
Platelet
smallest, manufactured in red bone marrow / lungs, its function is to play a role in the clotting of blood
Arteries
- carry blood away from the heart at high pressure
- structure is more muscular to withstand pressure
- blood moved to smaller arteries (arterioles) and loses pressure as it travels further from the pump towards the capillaries
Veins
- Carry blood towards the heart
- structure is less muscular
- contains valves which ensure blood travels in one direction only
- blood moves with outside pressure from surrounding skeletal muscles
Capillaries
- connect arterial and venous systems
- close t every cell in the body to ensure the quickest diffusion rate
- structure is very small allowing only 1 RBC though at a time
Atrium
accepts blood
Ventricle
responsible for pumping blood out of the heart
Right side of the heart
accepts low oxygen blood from the vena cavae, and pumps it to the lungs
Left side of the heart
received high oxygen blood via the pulmonary vein and pumps it out of the heart via the aorta
Pericardium
sac made of epithelium and fibrous tissue which protects the heart
heart valves
control blood flow, making sure none flows backwards or mixes
systole
strongest part (contraction) of the heart beat
diastole
weakest part (relaxation) of the heart beat
