ASAP V2 Flashcards
Tunica Intima
Innermost layer of blood vessels, composed of endothelial cells, providing a smooth surface for blood flow.
Tunica External
Outermost layer of blood vessels, composed of connective tissue, providing support and protection to the vessel.
Tunica Media
Middle layer of blood vessels, primarily consisting of smooth muscle cells, responsible for vessel tone and diameter regulation.
Elastic vs Musuclar arteries
Elastic closer to heart, larger, higher elastin content
Muscular have internal elastic laminar and assists in directing blood flow to regions
3 arteries off the aortic arch
Brachiocephalic
left common Carotid
left Subclavian
Haemostasis
1.vasoconstriction to reduce blood flow
2.formation of temporary platelet plug at injury site
3.coagulation cascade
4.Fibrinolysis, clot dissolves after tissues repaired
Haematopoiesis (formation of blood cells)
-Occurs in red bone marrow (soft,spongy bone in middle)
Blood flow through heart
SVC/IVC
Right atrium
Tricuspid valve
Reign ventricle
Pulmonary valve
Pulmonary artery
Lung
Pulmonary vein
Left atrium
Mitral Valve
Left ventricle
Aortic valve
Aorta
Layers of heart
Endocardium (innermost)
Myocardium (middle muscular layer)
Epicardium (CT for lubrication and protection)
Conduction system of the heart
-SA node=natural pace maker causes atria contractions
-AV node=delays signal from SA then ventricle contraction
-Bundle of His= pathways for electrical signals to travel from AV node to ventricles
-Purkinje fibres= terminal branches of bundle of his
Starling forces
Capillary/Hydrostatic (pressure exerted by fluid in capillary outwards)
Interstitial (pressure exerted by fluid outside capillary, inwards)
Plasma Colloid Osmotic (pressure exerted by proteins such as albumin pulling fluid towards capillary)
Interstitial fluid colloid osmotic (pressure exerted by proteins such as albumin pulling fluid towards the interstitial fluid)
Hormonal extrinsic pathway of cardiac regulation
-Adrenaline and noradrenaline released from adrenal medulla and bind too extracellular receptors on the surface of target cardiac cells
-target cells initiate a response acting to increase of decrease cardiac function
-stimulation of sympathies nerves innervating the adrenal medulla results in the released of adrenaline (80%) and noradrenaline (20%)
-stimulates alpha receptors within blood vessels and beta receptors in the myocardium, having a chronotropic (Heart beats with less force) or ionotropic (heart beats with more force)
Aortic murmurs
Where, When, what
2nd ICS, right sternal adge
Aortic regurgatation - blowing diastolic mumrmur
Aortic stenosis- high pitched, midsystolic (can cause dyspnea, and angina)
Mitral stenosis and regurgitation
5th ICS midclavicular line
Stenosis- low pitched mid diastolic murmur loudest over apex
Regurgitation- systolic murmur heart at apex
Where to Ausculate pulmonary valve
2nd ICS left sternal edge
Where to ausculate tricuspid valve
4th ICS left sternal edge
Cardiac output at rest
4-5L/min
Cumulative incidence
Number of new events divided by total population at risk
Respiratory membrane/blood air barrier
Fused basal lammina between two pops of epithelial cells, the alveolar epithelium and endothelium of pulmonary cavities
Anatomical dead space resp
Where gas exchange does not occur
Tidal volume, total ventilation
Tidal volume is the amount of air that is inhaled or exhaled
Total ventilation is volume of air moved per minute (tidal volume times resp rate)
Peptide hormones
-short Half life
-bind to cell surface receptors
Steroid hormones
-derived from cholesterol
-made in smooth ER and mitochondria
-not stored
-longer half life
-modulate gene expression (by activating or repressing gene transaction)
Amine hormones
-Amino acid derived
-Stored in vesicles until needed
-short half life
-cell surface receptors
Upregulation and down regulation for hormone stimulation
High levels of hormone causes target cells to produce receptors, low levels mean they lose receptors
Factors effecting plasma conc of hormone
Rate of secretion, rate of binding to carrier proteins, and rate of metabolism
Pancreas- Alpha cells
Produce glucagon —> increase blood sugar levels
Pancreas - Beta cells
Produce insulin —> decrease blood sugar levels
Pancreas - Delta cells
produce somatostatin —> inhibits the release of other hormones eg insulin and glucagon
Pancreas - PP cells
Produce pancreatic peptide —> regulate appetite and digestion
Stimulation of insulin secretion
Occurs through glucose-stimulated insulin secretion (GSIS)
•When blood glucose levels rise, glucose molecules are transported into pancreatic beta cells via glucose
transporters (GLUT2).
• Inside the beta cells, glucose undergoes metabolism through glycolysis, leading to an increase in intracellular
ATP levels.
• This rise in ATP levels triggers the closure of ATP-sensitive potassium channels (KATP channels), depolarising
the cell membrane and leading to the opening of voltage-gated calcium channels.
• The influx of calcium ions (Ca2+) triggers the exocytosis of insulin-containing vesicles, releasing insulin into the
bloodstream, thus promoting the uptake and storage of glucose by cells throughout the body.
Autonomic NS regulation of insulin secretion
Sympathetic —> inhibits secretion when low blood glucose levels
Parasympathetic —> stimulated secretion in response to high plasma glucose
Insulin actions
-Facilitates glucose uptake, stimulates glycogenesis, inhibits gluconeogenesis
-Increases conversion of glucose to fatty acids in adipose tissues, decrease lipolysis
-promotes activ transport of amino acids into muscle, increases protein synthesis
Diabetes mellitus complications
-Micro and Macro-vascular changes (stroke, hypertension, Atherosclerosis)
-Peripheral Neuropathy (impaired reflexes, incontinence , pain/numbness)
HPA (Hypothalamic-Pituitary-Adrenal) Axis
Hypothalamus
-Regulates body functions including sleep, temp, hunger and thirst
-link between nervous system and endocrine system
Pituitary Gland
-“Master Gland” regulates other endocrine glands
-Anterior pituitary (adenohypophysis) is made of glandular tissues, has a vascular connection to hypothalamus
-Posterior pituitary (neuropophysis) is made of nerve fibres and glial cells, has a neural connection to hypothalamus
What is released from anterior pituitary
-TSH (Thyroid Stimulating Hormone)
-Prolactin
-ACTH (Adrenocorticotrophic Hormone)
-LH (Luteinizing Hormone)/FSH (Follicle Stimulating Hormone)
-GH (Growth Hormone)
What is released by the Posterior pituitary
-ADH (Anti-diuretic Hormone AKA Vasopressin)
-Oxytocin (for milk ejection and uterine contraction)
-NB: these are stored here, but produced in the hypothalamus
TSH do what
Stimulates thyroid gland to release thyroxine —> regulates metabolism, temp, weight
Prolactin do what
Stims breast for lactation
ACTH do what
-Stimulates adrenal gland —> releases cortisol and other steroid hormones
-released by corticotrophs
ADH/Vasopressin do what
Regulates water balance by promoting water reabsorption in the kidneys and vasoconstriction
GH do what
-effects bone, tissues and liver
-Countercts insulin
-released by somatotrophs
-AKA somatotropin
-interacted with tyrosine kinase linked receptors in cell surface
Hypophysiotropoic hormones
-released by hypothalamus to either stimulate or suppress the secretion of anterior pituitary hormones
-two types, releasing hormone, inhibiting hormone
EG: Gonadotropin-releasing hormone (GnRH) stimulates the release of FSH and LH
Somatostatin
-AKA Growth Hormone Inhibiting hormone
-released by hypothalamus
IGF-1 and IGF-2
-IGF-1 Peptide hormone that stimulates cell growth and proliferation in various tissues.
-IGF-2 Growth-promoting hormone primarily involved in foetal growth and development.
Thyroid hormones (types and description)
-T3, regulates metabolism, growth and development
-T4 (thyroxine), regulates metabolism and energy balance
-Caclitonin, regulates calcium levels in blood, and bone metabolism (also —> parathyroid hormone production)
Thyroid disorders
-Hashimotots disease (hypothyroidism due to inflammation and destruction)
-Graves’ disease (hyperthyroidism due to antibody production)
Hypo and hyper calciumia
Hyper—> weakness, fatigue, kidney stones, bone pain (Fixed by Calcitonin and Vitamin D aka calcitrol)
Hypo—> muscle spasms and tetany and seizures (fixed by parathyroid hormone)
Cortisol
-released from the adrenal glands
-increases BP and HR
-suppresses immune function
-regulates glucose metabolism, and promotes gluconeogenesis
-inhibits hone formation and bone resorption
-influences mood, cognition and stress response
Cushing’s syndrome
Hypercortisolsim
Catecholamine hormones
-made by adrenal glands
-use g coupled protein receptors
Upper GI tract
-Mouth (for chewing)
-Oesophagus
-Stomach (mechanical digestion and small amount of absorption)
-Duodenum (digestion due to arrival of bile and pancreatic juice + absorption)
GI tract wall
-Mucosa (innermost layer of epithelium, lamina proprietor and muscularis mucosa)
-Submucosa (blood vessels, lymph tissue and nerves for support and nutrition of mucosa)
-Muscularis externa (provides rhythmic contractions that propel food)
-Seboas (outermost layers secretes a slippery fluid to reduce friction)
Motility in GI tract
-smooth muscle contractions
-Propulsive movements = peristalsis
-Mixing movement = segmentation
-gradient of segemntation also helps
Liver and gallbladder secretions GI tract
Bile (bile salts, alkaline secretions, bilirubin)
What does exocrine pancreas secrete
Digestive enzymes eg; lipase, amylase, trypsin
What does the small intestine secrete
-Succus entericus, enzymes
CCK hormone
-secreted from duodenum
-regulates lipid and protein digestion
Emesis (vomiting) mech
1.Coordinated by the vomiting centre in the medulla of the brainstem
2.Deep inspiration; glottis is closed; uvula is raised
3.Stomach, oesophagus, and gastroesophageal sphincter is relaxed
4.Respiratory muscles (diaphragm and abdominal) are contracted; stomach is squeezed between descending diaphragm and increasing intra-abdominal pressure
5.Sensation of nausea, salivation, sweating, rapid heart rate is regulated by the ANS
6.Excessive vomiting results in the loss of fluids and acids
MMC (migrating motility complex)
-starts after most nutrients are absorbed