animals: structure and function Flashcards
Mouth
Mechanical digestion by teeth and chemical digestion
pH (of mouth)
6-7 (neutral)
Salivary glands
Produce saliva
Saliva
Lubricates food, stimulates taste buds, contains salivary amylase to digest carbs
Epiglottis
Lid that covers your trachea when you’re swallowing
Esophagus
Connects mouth to stomach
Structure: Hollow tube lined with involuntary smooth muscles and mucosa
Peristalsis: Wave- like involuntary muscle movements to push food down
Stomach
Mechanical digestion because of churning and chemical digestion by HCL assisted by enzymes
pH (of stomach)
1-3
Sphincters
Drawstring - like valves at the beginning and end of the stomach (cardiac and pyloric)
Cardiac sphincter
Esophagus to stomach
Pyloric sphincter
Stomach to small intestine
Gastric Juices
Pepsin: Digests Protein
HCl: Breaksdown fibrous tissues in food, kills bacteria, activates pepsingen into pepsin
Mucus: Protects stomach lining from being digested
Small intestine
Final digestion and absorption
pH (of small intestine)
8
Villi
Small, finger-like projections along the walls of the small intestine to increase surface area for absorption
Mircrovilli
Further increase Surface area
Large intestine
Water absorption, removal of undigested waste
Asending, transverse, descending
Accessory Organs
Liver, gallbladder, bile duct, pancreas, pancreatic duct
Liver
Detoxifies harmful substances, products bile, converts glucose to glycogen and stores it in the gallbladder
Gallbladder
Stores bile
Bile Duct
When fat is present in the Small Intestine, cholecystokinin causes gallbladder to release bile to the Small intestine, which then breaks down the fat present
Pancreas
produces insulin, secretes pancreatic fluid
Structure: Spongy, tucked under between stomach and Small intestine
Pancreatic Duct
Secretes pancreatic fluid into the small intestine
Carbohydrates
Short term energy
Starts in the mouth by the salivary amylase. Ends in the small intestine by carbohydrates and pancreatic amylase into monosaccharides.
Lipids
Long term energy, insulation
Starts in the small intestine emulsified by bile and digested by pancreatic lipase into glycerol and fatty acids
Proteins
Structues and support, muscle movement
Starts in the stomach by pepsin. Ends in the Small intestine by protease (trypsin, chymotrypsin) and peptidase into amino acids
Heart
Double Pumping organ, made of cardiac muscle tissue
Septum
Muscle Seperating the left and right pump
Pericardium
Fluid filled membrane protecting the heart
Atria
Thin-walled “receiving” chambers
Ventricles
Thick walled,”Pumping” chambers
Vena Cava
Carries de-oxygenated blood from head and lower body to right atrium
Aorta
Carries oxygenated blood from the heart to the body
Pulmonary Artery
Carries de-oxygenated blood away from lung to heart
Pulmonary vein
Carries oxygenated blood from the lungs to the heart
Coronary artery
Supply blood to the heart
Atrioventricular Valves
Atria to ventricle. Prevent backflow of blood from ventricles to atria
- Tricuspid: Right atrium to right ventricle
- Bicuspid: Left atrium to left ventricle
Semilunar valves
Ventricle to artery. Prevents backflow of blood from arteries to ventricles.
- Pulmonary: Right ventricle to pulmonary artery.
- Aortic: left ventricle to aorta.
Blood vessels
Arteries: Carry oxygenated blood away from the heart. ‘Blood supply’
- Thick walls for high-pressure. High elastic to allow the artery to expand when blood surges.
- Arterioles: Small arteries
Veins: Carry deoxygenated blood to heart. ‘Collect blood’
- Thin walls for low-pressure. One -way valves to prevent backflow of blood.
- Venules: Small veins
Capillaries:Connects artieries and veins
- One cell thick
- Site of fluid and gas exchange
Circuits
Pulmonary circuit: Right side of the heart. Deoxygenated blood came from the body and pumped to the lungs to pick up O2.
Systemic Circuit: Left side of the heart. Oxygenated blood came from the lungs and pumped the body to provide O2.
Blood flow
- Vena cava to the right atrium to the tricuspid valve to the right ventricle to pulmonary arteries to lungs to pick up O2.
- Lungs to pulmonary veins to left atrium to bicuspid valve to left ventricle to aortic valve to aorta to body.
Plasma
Fluid portion of blood 55%
- 90% water, 10% materials
Red blood cells (erythrocytes):
Transport O2 and CO2, 44% of blood
White blood cells (leukocytes):
Destroy invaders by phagocytosis, form antibodies, 1% of blood.
Atrioventricular node:
Located at the base of the interatrial septum.
- Transmits signals to the bundle of His, relaying to purkinjie fibres and initiates ventricular contraction.
The heartbeat
Parts of the heartbeat:
- Systole: Ventricle contraction
- Diastole: Ventricle Relaxation
Heart sounds
- Lubb: AV valves (tricuspid and bicuspid) close
- Dubb: Semilunar valves pulmonary and aortic) close
Heart beat
BPM
Electrocardiograph
Graph made by tracing from an ECG
- P wave: SA node fires artia contraction
- QRS complex: AV node stimulates ventricular contraction
- R: AV valves close (lubb)
- T wave: Ventricles relax. Semilunar valves close (dubb)
Bradycardia
Slower than normal heart rate
Tachycardia
Faster than a normal heart rate
Blood Pressure
the force that blood exerts on blood vessel walls
Cardiac Output
Amount of blood pumped from each ventricle/ min.
- A high BP occurs when the heart pumps more blood with each contraction (Stroke volume) or beats more frequently, causing a greater force on vessel walls.
Arteriolar resistance
Blood encounters resistance when they contact vessel walls. A greater resistance can be caused by vessel diameter and length and blood viscosity. When you have a greater resistance, this makes it harder for blood to flow, therefore blood has to increase pressure in order to flow.
Vessel elasticity
Blood vessels expand and recoil in order to absorb the shock of systolic pressure. Hardened ateries (atherosclerosis or atherosclerosis) do not expand. This narrows your vessels, causing blod pressure to increase in order to flow.
Blood volume
An increase in blood volume leads to a greater amount of blood pumped by the heart, resulting in increaed stroke volume and cardiac output, raising BP.
