Anatomy And Physiology Flashcards
What are the three layers of a standard blood vessel
Tunica intima
Tunica media
Tunica externa
What is tunica intima
Deepest layer of the blood vessel
Endothelium
Basement membrane
What is tunica media
Middle layer of blood vessel
Smooth muscle
Elastic connective tissue
What is the tunica externa?
Outer most layer of the blood vessel
Dense irregular connective tissue
Vasa vasorum to keep the vessel alive
Where do arteries take the blood
Away from the heart
What are the two types of arteries
Elastic
Muscular
Elastic arteries
More elastic fibers feather than smooth muscle
Allow for stretch against the intense pressure as blood gets ejected from the heart
PULMONARY AND AORTA
*found close to the heart
Muscular arteries
Small-medium peripheral arteries
More muscle to help direct flow
Can constrict and dilate
* further away from the heart
Arteries often form regions of watershed called what
Anastomoses
What are anastomeses
Complex interwoven vascular structures form alternate routes through which blood can flow to a structure through collateral circulation. These are important in our vital to life organs such as the brain, heart, and lungs.
*if one gets blocked, there are other ways for blood to get to the organ that way it doesn’t die
OFTEN INCOMPLETE
Where do veins take blood
They convey blood from our tissues back to the heart.
Veins vs Arteries
We have more veins than arteries and veins are
generally larger in diameter
In what three ways are veins different from arteries?
Different layers: veins have a thinner tunicae intima and media than arteries and veins also lack elastic laminae.
Valves: veins have flap-like cusps comprised of tunica interna which extend into the lumen. They prevent back flow of blood in different segments of a vein.
No muscle: veins do not have a smooth muscle layer rendering it incapable of altering its own diameter. It depends on surrounding skeletal muscle to “pump” it back to the heart
What are capillaries
Microscopic vessels that form the junction between the arterial and venous systems. They connect outflow from the heart with the return to the heart.
What are endothelial cells
Cells that form the lining of all blood vessels
They accommodate changes at their locations by physically changing their own number and arrangement. The arrangement is so thin that it provides the bulk of the support for growth, nutrition, and repair tissues
What chemicals does the endothelium produce?
Vasodilators
Vasoconstrictors
Anticoagulants
Growth factors
What are arteries composed of
Elastic connective tissue
Fibrous connective tissue
Smooth muscle
What are veins
Thin walled
Larger in diameter
Less elastic tissue in tunica externa: slower recoil after distention
May contain valves- one way blood flow to the heart
What affects blood flow
Pressure and resistance
What is pressure
Exerted by liquid in a system
Flow depends on difference in pressure between arteries and the veins
What is resistance
Opposition to force
Determined by the diameter and length of the vessel
Inversely related to blood flow
RADIUS
What is motility
Movement of food through the GI tract
What are the 4 stages of motility
Ingestion: taking food into the mouth
Mastication: chewing the food and mixing it with saliva
Deglutition: swallowing food
Peristalsis: contractions that move through the GI tract
What is secretion
Exocrine: HCL,H2O, HCO3-, bile, lipase, pepsin, amylase, trypsin, elastase, and histamine are secreted into the lumen of the GI
Endocrine: Stomach and small intestine secrete hormones to help regulate the GI system like gastrin, secretin, guanylin, somatostatin
Digestion
Breakdown of food particles into subunits (chemical structure change)
What is absorption
Process of the passage of digestion into the blood or lymph
What is storage and elimination?
Temporary storage and elimination of indigestible food
Parasympathetic nervous system effects on GI tract
Vagus and spinal nerves
Stimulate motility and GI secretions
Sympathetic nervous system effects on GI tract
Postganglionic sympathetic fibers that pass through submucosal and myenteric plexuses and innervate GI tract
Reduce peristalsis and secretory activity
Mastication
Mixes food with saliva which contains amylase
Enzyme that can catalyze the partial digestion of starch
Deglutition (swallowin)
-Oral phase is voluntary
-pharyngeal and esophageal phases are involuntary
-larynx is raised
-epiglottis covers the entrance to respiratory tract
Esophagus
Connects pharynx to stomach
Top:skeletal muscle
Middle:mixture of skeletal and smooth
Bottom: smooth
What are the functions of the stomach
*Most dispensable part of the GI tract
Stores food
Initiates digestion of proteins
Kills bacteria
Moves food into the small intestine
What does the contractions of the stomach do?
Church chyme
Mix chyme with gastric secretions
Push food into the intestine
What about digestions and absorption in the stomach?
Proteins partially digested by pepsin
Carbohydrate digestion by salivary amylase is soon inactivated by acidity
Alcohol and aspirin are the only commonly ingested substances absorbed
What is absorbed in the duodenum and jejunum
Carbs, amino acids, lipids, iron, and calcium
What is absorbed in the ileum
Bile salts
Vitamin b12
Electrolytes
Water
What about absorption in the large intestine
Most nutrients has already been absorbed, but the ascending colon absorbs whatever is remaining and water
Absorbs water, electrolytes, vitamin b complex, vitamin k, and folic acid
Defecation
Waste material passes to the rectum
Rectal pressure arises and external anal sphincter relaxes
Defecation reflex
Longitudinal rectal muscles contract to increase rectal pressure
Excretion is aided by contractions of abdominal and pelvic skeletal muscles
What is included in the upper respiratory tract
Nasal passages
Sinuses
Nasopharynx
Pharynx
Larynx
Tonsils
Glottis
What is a part of the lower respiratory tract
Lower trachea
Right and left bronchus
Bronchial tree
Lungs
Pleural membranes
Alveolar ducts
Alveoli
Mediastinum
What about air movement
Blood in upper airways warms and humidifies air and removes particles from the air
What pulls air into the lungs
Contraction of diaphragm pulls air into the lungs
Inhalation-active
Exhalation-passive
Pressure changes of the lungs
Inhale- pressure outside is greater than pressure inside
Exhale-pressure inside is greater than pressure outside
What is the dead space in the alveoli of the lungs
Ventilation but little or no circulation
What is shunt in the alveoli of the lungs
Circulation but little to no ventilation
What is lung compliance
More compliance: easier to expand, inflate, the lungs
Less compliance: difficult to inflate the lungs-either the lungs or chest walls
Elastic recoil
Lungs expand and then passively return to normal during exhalation
Surfactant
Decreases surface tension in the alveoli so they can expand during inhalation
Primary digestive organs
Mouth/oral cavity
Esophagus
Small intestine
Large intestine
What are the accessory organs of GI
Liver
Gallbladder
Pancreas
What are the layers of the eye
Sclera
Choroid
Retina
Sclera
White dense connective tissue
No blood vessels
Clear portion in front is the cornea
Choroid
Lots of blood vessels and pigment
Attached to the iris- controls pupil size
Behind the pupil is an elastic lens- focuses light
Retina
Transforms light waves into nerve impulses
What is the anterior chamber of the eye
Filled with aqueous humor
-made in the ciliary body
-makes it way through the trabecular mesh work
-drained through the canal of schelmm
What is the posterior chamber
Vitreous humor
When the pupil dilates what happens to the iris
It gets smaller/contracgs
When the pupil constricts, the depth of the iris gets
Larger/dilates
What happens to the pupil and miosis in strong light
Parasympathetic NS activation
Circular sphincter muscle contracts
Radial/dilator muscle relaxes
Pupil diameter decreases
Less light enters
What happens to the pupil in weak/no light
Sympathetic NS activation
Radial/dilator muscle contracts
Circular sphincter muscle relaxes
Pupil diameter increases (mydrasis)
More light enters
What are the main organs of the urinary system
Kidneys
Ureters
Urinary bladder
Urethra
Prostate
Two ureters
Narrow tubes, 10-12 inches long
Drain urine from renal pelvis to bladder
Bladder
Reservoir for urine
Normal output is 1500mL
Urethra
Small muscular tube from bladder neck to meatus
Female=1-2 inches
Male= 8-10 inches long
