Blood and clotting Erythrocytes is a biconcave disc which has a very shallow center. The shape optimizes the ratio of surface area to volume, which facilitates gas exchange. It also enables them to fold up as they move through narrow blood vessels.

circulation Blood flow refers to the movement f blood through a vessel, tissue, or organ Resistance is a phenomenon that impedes blood flow or slows it down Hydrostatic pressure is the force exerted by a fluid due to gravitational pull, usually against the wall of a container Blood pressure is

CIRCULATION The main functions of the lymphatic system are to carry excess fluids into the bloodstream and to filter pathogens out of the blood. The immune system is the complex collection of cells and organs that destroys or neutralizes pathogens that would have otherwise caused disease or death.

circulation Resistance is directly proportional to the viscosity of blood and the length of blood vessel. Resistance is inversely proportional to the radius to the fourth power. Blood volume is directly proportional to blood pressure and flow. As blood volume increases, blood pressure and flow increase.

circulation Hydrostatic pressure: Blood hydrostatic pressure Intersitial fluid hydrostatic pressure Osmotic pressure: Blood colloidal pressure Intersitial fluid colloidal osmotic pressure Pc = Capillary hydrostatic pressure Increase Pc factors favors filtration OUT of the capillary into the interstitial space Determined by arterial venous pressures and resistance Higher at the arteriolar end of the capillary than at the venous end Pi = Intersitial hydrostatic pressure Increase in Pi opposes filtration out of the capillary.

circulation Pulmonary circuit: Systemic circuit: RV: Right ventricle; LA: left atrium; LV: left ventricle; RA: right atrium We can initially view the circuits from the point of view of gases. The pulmonary circuit transports blood to and from the lungs, where it picks up oxygen and delivers carbon dioxide for exhalation.

Neural and endocrine signaling communication is a process in which a sender transmits signals to one or more receivers, which control and coordinate actions in the human body. Two major organ systems participate in relatively long-distance communication. These are the nervous system and the endocrine system.

Hypothalamus is a structure of the diencephalon of the brain, which is located anterior and inferior to the thalamus. The hypothalamus has both neural and endocrine functions, producing and secreting many hormones. Hypothalamus is anatomically and functionally related to the pituitary gland.

The parathyroid glands are four tiny round structures, usually found embedded in the posterior surface of the thyroid gland. A thick connective tissue capsule separates the glands from the thyroid tissue. Most people have fourth parathyroid glands, but occasionally there are extra glands in tissues of the neck and chest (see the image).

Mnemonic for anterior pituitary hormones: FLAT PIG, The posterior pituitary only produces ADH and oxytocin.

The thyroid gland basically wraps around the trachea, which is just inferior to the larynx and anterior to the trachea. Each of the thyroid lobes are embedded within the parathyroid glands on their posterior surfaces. This close proximity of the thyroid to the parathyroid glands is important because during the thyroidectomy, many times the surgeon will also remove the parathyroid glands.

endocrine physiology The adrenal glands or the suprarenal glands are located in the posterior abdomen, between the kidneys and the diaphragm. The adrenal gland consists of an outer connective tissue capsule, an outer cortex, and an inner medulla. The adrenal glands have a rich blood supply and experience one of the highest rates of blood flow in the body.

GASTROINTESTINAL Digestion includes mechanical and chemical processes. Physical process of breaking down food For example: mastication Breakdown of complex molecules into smaller substances Examples: proteins into amino acids The small intestine is where most of the digestion and absorption happens in the GI tract.

gastrointestinal physiology GI tract is also called the alimentary canal. It begins at the mouth and ends at the anus. Each of these ends open to the external environment. GI tract consists of the mouth, pharynx, esophagus, stomach, small and large intestines, and anus.

membrane physiology The functions of the nervous system depend on the function of the neurons underlying these pathways. The basis of neural communication is the action potential, which demonstrates how changes in the membrane can constitute a signal. Most cells in the body make use a charged particle such as ions to build up a charge across the membrane.

membrane physiology Composed of phospholipids and proteins. Phospholipids: Integral Proteins Imbedded into cell membrane via hydrophobic interactions Examples: ion channels, transport proteins, receptors, and GTP-binding proteins Peripheral Proteins Loosely attached to the cell membrane via electrostatic interactions Lipid soluble subtances can cross the cell membrane because they can dissolve in the hydrophobic lipid bilayer.

membrane physiology One of the great wonders of the cell membrane is its ability to regulate the concentration of substances inside the cell. These substances include ions, such as calcium sodium potassium and chloride. It also includes nutrients such as sugars fatty acids and amino acids and waste products such as carbon dioxide, which has to leave the cell.

membrane physiology Action potential is a property of excitable cells, such as neurons and muscle cells. Resting membrane potential describes the steady cell state of the cell. The resting membrane potential will not change, so in order to get an electrical signal, the membrane potential has to change.

metabolism The human digestive system is a series of organs that converts food into essential nutrients which are then absorbed into the body. The digestive organs also move unused waste material out of the body. Carbohydrates are compounds consisting of carbon, oxygen, and hydrogen that are classified as either simple or complex sugars.

physiology Bundles of muscle fibers, called fascicles, are covered by the perimysium. Muscle fibers are covered by the endomysium (see the image). A skeletal muscle fiber is surrounded by a plasma membrane (sarcolemma), which contains sarcoplasm (cytoplasm). Each muscle fiber contains bundles of myofibrils, surrounded by sarcoplasm reticulum and invaginated by transverse tubules.

nervous system The precentral gyrus is the primary motor cortex. Cells from this region of the cerebral cortex are the upper motor neurons (UMNs) that instruct cells in the spinal cord to move skeletal muscles. Anterior to this region are a few areas that are associated with planned movements.

nervous system The nervous system produces a response on the basis of the stimuli perceived by sensory structures. Responses include things like the neural control of glands, production and secretion of sweat, lower the body temperature, etc. Responses can be divided into voluntary (conscious) and involuntary (unconsciously).

nervous system Several terms to understand: CNS: brain + spinal cord PNS: cranial nerves and spinal nerves Sensory / afferent Motor / efferent Autonomic nervous system (ANS). ANS is splitted into sympathetic nervous system and parasympathetic nervous system. sympathetic nervous system is regulated by norepinephrine and epinephrine while the parasympathetic nervous system is regulated by acetylcholine.

REPRODUCTION After conception, the zygote is referred to as an embryo up until the eighth week of life. At week 9, the developing human is referred to as a fetus until gestation. The completion of fetal development results in a newborn or an infant who although still immature in very many ways, is capable of surviving outside of the womb.

reproduction Chromosomes are located in the nucleus. Chromosomes are composed of DNA and protein. Each somatic cell contains 23 pairs of chromosomes. The genetic instructions that are used to build and maintain an organism are arranged in an orderly manner in strands of DNA.

Female reproductive system functions to produce gametes and reproductive hormones. Unlike its male counterpart the female reproductive system is located primarily inside the pelvic cavity. The female reproductive system is also responsible for supporting and developing fetus. The ovaries are the female gonads.

reproduction Fertilization occurs when a mature sperm cell and a mature oocyte combine. During this integration, their nuclei fuse together, creating one diploid zygote. A zygote is a single, diploid cell that contains 23 chromosomes from mom and 23 chromosomes from dad. Pregnancy is also referred to as gestation.

reproduction The structures of the male reproductive system include: The testicles are located in the scrotum. The testes are where sperm is created. Spermatogenesis: creation of mature spermatozoa or sperm. Spermiogenesis: transformation of spermatids to spermatozoa Gamete: specialized sex cell with 23 chromosomes (haploid) Males: spermatogonium Females: oocyte Spermatogonia: stem cells (the least mature) Sperm count: the total number of sperm a man produces Spermatogenesis occurs in the seminiferous tubules.

respiration The purpose of the respiratory system is to perform gas exchange in the respiratory zone. The respiratory zone consists of the respiratory bronchioles and the alveolar ducts and sacs. Gas exchange occurs at the respiratory membrane where the alveolar and capillary walls meet.

respiration The lungs are the major organs of the respiratory system.

RESPIRATION The goals of the respiratory system are to deliver oxygen to the tissues and gas exchange. It Is trying to deliver oxygen to the tissues. It provides oxygen for use by the body cells during cellular respiration and eliminates carbon dioxide, which is a waste product of cellular respiration from the body.

respiration The lungs are pyramid-shaped paired organs that are connected to the trachea via the right and left bronchi. The inferior surface of the lungs is bordered by the diaphragm. Diaphragm is a flat dome-shaped muscle located at the base of the lungs. The thoracic cavity is enclosed by pleura, which are attached to the mediastinum.

respiration Breathing usually occurs unconsciously, although sometimes we can consciously control breathing, such as in swimming, singing, or when trying to blow a bubble. The respiratory rate, or the amount of breath per minute, is controlled by the respiratory center in the medulla oblongata.

Special senses Sensory receptors help us understand the environment around us or the state of our internal environment. Stimuli from varying sources and of different types are received and changed into electrochemical signals of the nervous system. This occurs when a stimulus changes the cell membrane potential of a sensory neuron.

The differences between eukaryotes and prokaryotes are: Prokaryotes have a more rudimentary nucleus Eukaryotes have mitochondria Eukaryotes have membrane-enclosed nucleus Prokaryotes have flagella, which give motility Cytosol: jelly like substance that provide fluid medium necessary for biochemical reactions to occur Nucleus: central organelle that contains the cell's genetic material Three major organelles together form a system within the cell, called the endomembrane system.

Nucleus is the control center of the cell. It contains the genetic material that determines the entire structure and function of a cell. Like most other cellular organelles, the nucleus is surrounded by a membrane called the nuclear envelope. It is a membrane that surrounds the nucleus; consists of a double-lipid layer.

Cardiac output is a measurement of the amount of blood pumped by each ventricle in one minute. Remember these formulas: MAP: mean arterial pressure; TPR: total peripheral resistance; EDV: end diastolic volume; ESV: end systolic volume Average resting heart rate is about 60-100 beats per minute. However, everybody has a different baseline.

(See the diagram) Aorta 🡪 Right coronary artery, left coronary artery Left coronary artery 🡪 left anterior descending, circumflex, posterior descending (8% population) Right coronary artery 🡪 posterior descending (92% population), marginal branches (See the images) Heart has a dedicated complex and extensive coronary circulation because of the critical and nearly ceaseless activity of the heart throughout life.

Cardiac muscles contract spontaneously and display a rhythmic beat. They can branch to form connections with adjacent cells. Cardiac muscle contain one centrally located nucleus and glycogen granules. The sarcoplasm contains myoglobin. There are thin and thick filaments that are arranged into myofibrils. Cardiac muscles have cross-banding patterns, similar to skeletal muscles.

Cardiac shunt is a pattern of blood flow in the heart that deviates from the normal circuit of the circulatory system. There are two common shunts: Right ventricle has lower pressure than the left ventricle. In the right to left shunt, blood is flowing from either the right atrium to the left atrium or right ventricle to left ventricle.

There's about 5 liters of blood in the human body. The heart acts as a pump since its contraction develops the pressure that ejects blood into the major vessels. The blood is distributed to the remainder of the body.

Blood goes like this: IVC: inferior vena cava; SVC: superior vena cava RA: right atrium; RV: right ventricle; LA: left atrium; LV: left ventricle PA: pulmonary artery; PV: pulmonary vein The cardiac cycle is made of systole and diastole. This cycle begins with the contraction of atria and ends with ventricular relaxation.

URINARY SYSTEM Identify the body's main fluid compartments. Explain the importance of water in the body. Compare and contrast the difference between intracellular fluid and extracellular fluid. Define plasma osmolality and identify two ways in which plasma osmolality is maintained.

URINARY SYSTEM Clearance is defined by (Clearance in mL/min or mL/24 hour; urine concentration in mg/mL; urine volume in mL/min; plasma concentration in mg/mL) The plasma concentration of a substance X is 140 mEq/L. The urine concentration of substance X is 700 mEq/L. The urine flow rate is 1 mL/minute.

urinary system pH is the acid-base balance or the level of acids and bases in the blood. Normal pH of blood is 7.35-7.45. A buffer is a chemical system that prevents a radical change in fluid pH by dampening the change in hydrogen ion concentrations.

URINARY SYSTEM Some ions assist the transmission of electrical impulses along the cell membranes in neurons and muscle while other ions help stabilizing protein structures and enzymes or aid in releasing hormones from the endocrine glands.

URINARY SYSTEM Some important organs to remember: Kidneys: produces urine Ureters: transport urine from the kidney to the bladder Bladder: stores the urine Urethra: transports urine from the bladder out of the body Some important terms to remember: Reabsorption: reabsorbed back into the blood from the urine filtration Filtration: filtered from the glomerular capillaries into the urine Secretion: secreted from the peritubular capillaries into the urine Excretion: excreted out of the body via the urine Reabsorption is the amount of solute reabsorbed back into the blood.