hormon dan pertukaran darah.ppt

Abu Bakar

Gbr. 011

Analisa Gas Darah pH 7,35 – 7,45 pO2 80 – 100 mmHg pCO2 35 – 45 mmHg HCO3־ 22 – 26 mEg/L BE -2 - +2 Saturasi ≥ 95%

PEMBACAAN

Asidosis 7,45 Alkalosis7,35 pH

pCO2

HCO3

Berlawanan Respiratorik4535

SearahMetabolik 22 26

Berlawanan Respiratorik

SearahMetabolik

INTEPRETASI HASIL GDA

Ketidak Seimbangan

pH pCO2 HCO3 BE

Asidosis Respiratorik ↓ ↑ N N

Asidosia Metabolik ↓ N ↓ ↓Alkalosis Respiratorik ↑ ↓ N N

Alkalosis Metabolik ↑ N ↑ ↑

Darah Lengkap ALBUMIN

Mempertahankan Tekanan Osmotik

ERITROSITJumlah Sel Darah Merah

HEMATOKRITMengetahui Viskositas Darah

• TROMBOSITElemen Koagulasi

• HEMOGLOBINPengikat O2

• LEUKOSITPertahanan Tubuh

Hormon Pengatur Kardio There are several hormones that control

the resistance of the vascular system. These hormones are released directly in response to changes in blood pressure, in response to neural stimulation, or both

Norepinephrine and Epinephrine Norepinephrine and epinephrine are

released from the adrenal medulla in response to activation of the sympathetic nervous system.Vasoconstrictionvasodilation of arteriolesincrease heart rate

Renin-Angiotensin System Changes in blood pressure are sensed

by the renal baroreceptors. If blood pressure is high, release of the hormone renin is decreased. If blood pressure decreases, renin release increases. Renin release is also stimulated by sympathetic nerves to the kidney. Renin controls the production of another hormone, angiotensin II.

Angiotensin II is a powerful vasoconstrictor that primarily causes constriction of the small arterioles. This causes an increase in resistance to blood flow and an increase in blood pressure.

Aldosterone Aldosterone circulates to the kidney and

causes cells of the distal tubule to increase sodium reabsorption. Under many circumstances, reabsorption of water follows that of sodium, leading to an increase in plasma volume. An increase in plasma volume increases stroke volume, and hence cardiac output. It also causes increased blood pressure.

Antidiuretic Hormone Antidiuretic hormone (ADH), also called

vasopressin, is released from the posterior pituitary in response to increased plasma osmolality (decreased water concentration) or decreased blood pressure.

ADH is a potent vasoconstrictor with the potential to increase blood pressure by increasing the resistance to blood flow.

Atrial Natriuretic Peptide Atrial natriuretic peptide (ANP) is a

hormone released from cells of the right atrium in response to an increase in blood volume. ANP acts on the kidney to increase the excretion of sodium ion (natriuresis). Because water will follow sodium in the urine, ANP serves to decrease blood volume and blood pressure.

Other Chemical Mediators Influencing Blood Flow Various other chemicals are released by

the blood vessels or by mediators of inflammation or healing, which affect blood flow to an area.

Nitric Oxide Endothelial cells of the small arteries and

arterioles respond to the binding of various vasoactive substances such as acetylcholine with the production of the vasodilator nitric oxide (previously called endothelial-derived relaxing factor). Nitric oxide release also occurs with increased blood flow through a vessel, allowing local dilation of the microvasculature to be matched by dilation of the small arteries and arterioles.

Endothelin Endothelial cells also release

endothelin, a 21–amino acid peptide that acts as a potent constrictor of vascular smooth muscle. Endothelin release is stimulated by angiotensin II, ADH, thrombin, cytokines, reactive oxygen species, and shearing forces acting on the vascular endothelium.

Serotonin Serotonin (5-hydroxytryptamine) is

primarily released by platelets drawn to an area of injury or inflammation. Effects of serotonin may be vasodilatory or vasoconstricting, depending on the site of release. Serotonin's ability to vasoconstrict and decrease blood flow appears to be one mechanism whereby platelets control or reduce bleeding.

Bradykinin Bradykinin, like all members of the kinin

family, is a small polypeptide that acts as a potent vasodilator of arterioles and as a mediator to increase capillary permeability.

The effects of bradykinin are increased local blood flow, increased capillary permeability, and decreased vascular resistance. These effects

Prostaglandins There are many different types of

prostaglandins. Some cause dilation of the vascular system and some cause constriction. Arachidonic acid is present in all cell membranes and is released with tissue injury. Prostaglandins work to control local blood flow. They may circulate to affect distant cells.