fisio

Functions of the digestive system are: ingestion,secretion, mixing, propulsion, digestion, absoprtion and defecation.

The mucosa is the innermost layer of the GI tract, Serosa the outer.

The Serosa is called visceral peritoneum in the portions of the GI that are suspended if the abdominopelvic cavity

The Serosa is called Adventicia in the esophagus

The Lower portion of the large intestines receives parasympathetic innervations from spinal nerves in the Vagus Nerve region.

The parotid salivary glands are located anterior and inferior in the ears.

Sympathetic stimulation Decreases salivation

Sublingual and submandibular glands, innvervated by the facial nerve

The opening of the folds on inner surface stomach are called gastric pits

ECF like cells in the gastric epithe secrete Histamine and Serotonine

Trypsin is the enzyme that activates other zymogens of pancreatic juice

bilirubin is produced as a derivative of the heme group in haemoglobins

The enterokinase is attached to the membrane  of the brush border cells

STOMACH= Histamine, chief cells ( pepsinigen + gastric lipase), ECF, Dcells ( somatostatin ), gastric juice, Parietal cells (intrinsic factor + HCL), gastric pits. G cells (gastrin)

Duodenum= Enterokinase

Jejunum= Important control of stomach emptying.

Ileum= Release of CCK, CCK inhibits gastric emptying by inhibiting pyloric pump. (bile salts, Vit B12, water+electro)

Pancreas= Trypsin, elastase, bicarbonate. Sinusoids large pores (fenestrae), secretes insulin + glucagon.

Gallbladder; Stores and concentrates bile.

Funcion Kidney: Regulate extracellular fluid-formation of urine, maintain blood pH, blood pressure anc conc.

Afferent arterioles: Deliver blood into glomeruli

Cortical Neph: Renal corp lie in outer position, short loop of henle, peritubular capillaries, 80%

Juxta Neph: Renal corp lie deep in the cortex, Long loop henle, Peritubu cap and vasa recta, dilute urine, 20%

Glomerular filt – Tubular reabsoprt + Tubular secretion:

– Glom filt: H20 + solutes in bllod plasma move across the wall of glomerular capilaries into glomerular capsule

– Tubular reabsop: Mov of water and solutes from the tubules to the peritubullar cap and vasa recta

– Tubular secre: Secretion os wastes from blood to urine.

Inner layer of glome corpu presents cells called podocytes.

Sympath nerv effect: Increas symp, stimu constric of afferent arterioles (todo baja GHP, NET FR, URINE VOLUM, GFR)

Renal autoregulation: 2 mechani; Myogenic Mecha- streching triggers contraction of smooth muscles in afferent arterioles. rises BP, rises GFR

 2. Tubuloglomerular feedback= macula densa + juxtaglo cells.

Principal cells: ADH + Aldosterone

Intercalated cells: Homeostasis of blood pH

Bowmans capsule: Filtration

Proximal convoluted tubule: Aquaporin1 and reabsorption of water

Desc loop henle: Never permeable water, aquaporin1

Ascen loop henle: Primary active transp of NaCl

Distal convol tubule: Permeab water depend of bodys needs, secretion of H+, aldosterone, intercalated cells and principal cells

he kidneys are located in the Retroperitoneal space

The entrance of the kidney is called Hilum

Part always permeable to water: Proximal convoluted Tubule

Outermost covering of the kidney is: Cortex

Each minor calyx receives urine from: Renal Papillae

Basic functional unit of tye kidney is called: Nephron

The last part of the Nephrons are: convoluted duct

Urine to flow from the kidney to the bladder by: Peristalsis

Under voluntary control: External sphincter

Bile salts are needed for the absoption of: Lipids

The liver is the principal site of: Iron storage and Albumin.

Increase in distension of duodenum decreases G emptying.

Parietal cells, release substance for absopt of Vit B12

The pancreas arises from the embry germ layer: endoderm.

Pepsin is more likely to be found in a patientr suffer reflux

Colon: Mucus secreted to lucricate+Fecal transit inverse related to fiber contents.

Path bile salts: Liver, Gallb, duode, jejunum, ileum, liver.

Proteins+Polypeptide: Anterior and posterior pituitary gland hormones, pancreas, parathyroid gland.

Steroids: Adrenal cortex, ovaries, testes and placenta

Tyrosine derivatives: Thyroid and adrenal medulla.

Polypeptide and protein hormones

synthesized in endoplasmic reticulum (prohormones formed, active finally)

Receptors: plasma membrane

Steroid hormones

Synthesized from cholesterol, soluble in lipds

Receptors: Cytoplasm   Pregnonolone rate limit step

Amine Hormones derived from tyrosine

Thyroid: synthesized + stored in thyroid gland

Adrenal medullary: Epinephrine, norepi, stored as vesicles.

Receptors: Nucleus    Produces: T4,T3 and calcitonin

Calmodulin: Binds to Ca2+, 4 Ca2+ sites, act/inact prot kinas.

Parathyroid hormone increases Ca and phosp absopt bone.

Pituitary Gland

Pituitary secretion by Hypothal,connects via pitu stalk.

3 Hypotha regions: Anterior (supraoptic), middle (tuberal)  and posterior (mammillary)

Magnocellular cells: Release ADH, oxytocinin and cRH

Anterior pituitary hormones

GH: Target liver   ACTH: target adrenal cortex, action is cortisol secretion,  TSH: Target thyroid gland

PRL: Target Mammary gland, inhibited by dopamine

FSH: Target ovaries +testes LH same as FSH

MSH: Target Brain   all secreted by anterior.

Posterior Pituitary hormones:  ADH and oxytocinin

Suppreses GnRH, FSH, LH: Estrogen femal, testos males

progesterone inhibit: GnRH

GnRH controls the secretion of FSH

Thryroid hormones

located below larynx on each side anterior trachea

Thryroxine = T4  Triodothyronine = T3  iodine from diet.

Formation: Iodine trapping, synthesis thyroblogulin, oxidat of iodine, Iodination tyrosine, coupling T1 and T2, secretion thyroid hormone, stored in target cells. 

TSH (Thyrotropin): INCREASE: Act iodide pump, iodinat thyrosine, proteolysis of thyroglob

TRH: tripept, affects ant pitu increase output of TSH

Action mechanism: Activate nuclear transciption.

Funct: Increa ATP, stim fat metab, effect on endocrine gland

ADRENAL GLANDS

Adrenal cortex: Produced steroid hormones

Adrenal medulla: Produces three catecholamines

Adrenal cortex; 3 zones;

1. zona glomeru(outer); secrete mineralcort, aldost, secret controlled by ECF conc of angiot II and K+

2. Zona fascio(middle); Cortisol, secret controll cRH-ACTH

3. Zona reticu(inner); ACTH regulat, weak androgens, estroge.

Mineralcorticoids: Aldosterone, regult blood P, Vol, promote excretion H+ in urine and levels of Na, K+ and H+

Glucocorticoids regul:  CRH stim secret of ACTH, controls product of cortisol- negative feedback effects.

PANCREAS HORMONES

A cells secrete glucagon, B cells secrete insulin, D cells secrete somatostatin which inhib insu and gluca, F cells secrete pancreatic polypep

What increases insulin: Acetylcholin, GIP, Arginine and leucin.

What increases Glucagon Secretion: Exercise, meat with prot.

Mechanorecep: Mecha compress recept tissues adjac.

Thermorecep: Changes in temp

Nociceptors: Damage or potencial damage (No adapt)

Electromag: Light    Chemorecept: Taste, smell, CO2

Exterocept: external surf body, info about environm

Interocept: Locat blood vessels, muscles, intern environm

Propriocept: Muscles, tendons, joints, inner ear, Body posit.

Process sensations: 1. Stim sensory recep 2. transduct of stim

3. Generat nerv impul: First order neuron 4. Integration

Generat poten: Free nerve endings of 1st order (pain,therm), encapsulated 1st order(pressu, vibrat,touch), Action potencial reached if is large enough to reach threshold.

Recept poten: Separat cells from synap with 1st order sensory neuron ( hearing, equilibrium). This trigger release of neurotransm, produces PSP and triggers action potencial.

Tonic recept: Transm impulses to brain, status muscle contraction, pain, position, chemical composition

Phasic recept: React strongly. predictive funcion. 

PAIN

subjective

Acute: protection, well localized, reliable for diagnosis

Chronic: Not localiz, Peripheral, central sensitazion.

Nocicept: Thermal, Mechanical and Polymodal, Sensitized by: Decre threshold, Increa respon, develp spont activity

Hyperalgesia: Exaggerat response to noxi stim

Allodynia: Respon stim that are normally innocuous

EYES AND VISION

Cornea = Transparent coat, curved and helps focus light

Sclera = Opaque, fibrous, protective outer, Shape, provides attachment surfaces for extrinsic eye muscles.

Choroid = Highly vascular to supply nutrients and remov waste prod. Melanin absorbs light rays, prevents reflect.

Ciliary body= Secretes aqueous humor, cont ciliary muscles, enable lens to change shape. Focus on near and distant obj.

Iris = Pigm musc struct, control the amount of light enter eye.

Pupil = Hole, middle ear, light allowed continue passage

Lens= Transp, flexi, curved struct. Focus using refract propert.

Retina = Layer sens neurons, photoreceptors (rods and cones)

Fovea= Responsible for good visual acuity

Blind spot= Bundle sens fibres form the optic nerve.

Cones: Day vis, Colour vis, High acuity, low sensi, plasma memb fold back+forth, little converg, 3 types, reading

Rods: night vis, shades grey, low acuity, high sensit, opsin and retinene, rhodopsin, free floating disc, Much convergence.

For near vision, the ciliary muscle contracts so that the suspensory ligaments become slack. This allows the lens to round up which increases the strength of the lens

HEARING

3 functional parts: External captures mechanical energy, middle transmits to recept organ, Inner transduces into electrical signal.

External: Auricle, Ext audi canal, eardrum  Middle: air filled, auditory osciles (Mall,Inc, Stap) Inner; labyrinth and perilym.