10-1 e. Pressure must be regulated to control flow (1) Cardiovascular system (fast) (a) cardiac output increase c.o., increase pressure (b) peripheral resistance increase p.r., increase pressure vasoconstriction of arterioles compress veins by smooth or striated muscle contraction

10-2 (2) Osmoregulatory system (slow, kidney, liver) pHy >> pOs: fluid leaves blood, blood volume drops, pressure drops pOs >> pHy: fluid enters blood, blood volume increases, pressure increases Retaining water or salt in blood will increase pressure

10-3 f. Mechanisms of Pressure Regulation (1) Autonomic reflex arcs (a) Baroreceptor Reflex baroreceptors in aortic/carotid bodies in arteries increased blood pressure causes increased a.p.s to medulla activates PSNS, deactivates SNS slows heart, increases vasodilation

10-4 (b) Chemoreceptor Reflex chemoreceptors in circulation and CNS monitor pH, CO 2, O 2 information relayed to medulla to regulate SNS, PSNS Medulla integrates sensory information Generates output to ANS to control cardiac output and vascular smooth muscle activity Direct flow to tissues with highest metabolic demand

10-5 (2) Local (intrinsic) control in vessels Smooth muscle activity modified by local environment Results of metabolic activity cause vasodilation decreased blood O 2 increased blood K + increased temperature Endothelium produces vasodilators: NO Activity promotes blood flow to tissues: Active Hyperemia

10-6 g. Regulate pressure to maintain homeostasis (1) Response to postural changes in gravitational field lie down: mean = 100 mm in all arteries stand up: gravity causes pooling in lower limbs Reaction: activation of SNS peripheral vasoconstriction in lower extremities, both arterial and venous

10-7 Arterial mean pressure: legs:180 mm heart:100 mm head:62 mm Forces flow from legs to above heart But over time, still pooling in extremities Force blood up by skeletal muscle contraction

10-8 (2) Exercise/stress Must adjust flow to supply most active tissue Activation of SNS increase heart rate and strength (beta) vasoconstriction of viscera (alpha) vasodilation in muscle (beta, local) redirection to drive flow to muscle

Brain Resting Human

Heart Brain Resting Human

Heart Brain Muscle Resting Human

Heart Brain Muscle Skin Resting Human

Heart Brain Muscle Skin Kidney Resting Human

Heart Brain Muscle Skin Kidney Abdomen Resting Human

Heart Brain Muscle Skin Kidney Abdomen Other Resting Human

,000 Heart Brain Muscle Skin Kidney Abdomen Other Resting Human

,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise

,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise

, ,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise

, ,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise

, ,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise

, ,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise

, ,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise 600

, , ,000 Heart Brain Muscle Skin Kidney Abdomen Other Strenuous Exercise 600

10-25 h. Increased blood pressure adaptive (1) Increases flow therefore capillary filtration and exchange (2) Increases nutrient, O 2 supply, waste removal

10-26 VII. ENDOCRINE SYSTEM A. Basics of Hormonal Communication 1. Chemical communication All cells communicate via diffusable chemicals

Secretion: the controlled release of chemicals by a cell can occur in several ways OUTSIDE ECF BLOOD Duct

Secretion: the controlled release of chemicals by a cell can occur in several ways AutocrineParacrine Exocrine Endocrine ACCESS TO ALL CELLS

10-29 Neurotransmitters are paracrine, require direct cellular contact with controlled target tissue Endocrine system chemical control without direct cellular contact use circulatory system as delivery mechanism endocrine communication slower, more general than nervous

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Organs of system: Endocrine Glands Specific secretory tissues producing hormones 4. Hormone: organic chemical agent secreted into the circulation by a specific living tissue (endocrine gland) acting in minute amounts at a distance from its source to modify the activity of a distinct target resulting in coordinated activation of target cells

Types of hormone molecules a. Proteins and peptides tripeptides to glycosylated proteins protein synthesis, vesicle storage and release to capillaries by exocytosis

10-39 b. Lipids steroids: built from cholesterol prostaglandins: C 20 fatty acids enzymatic synthesis type produced depends on enzymes active lipid soluble, so can’t be stored in vesicles immediate release by diffusion

10-40 c. Amino acid derivatives enzymatic modification of amino acids catecholamines, thyroid hormones, indoleamines released from vesicles