Unit One Flashcards
What Is Human Anatomy the study of?
It is the scientific study of the body’s structures
Where does the Root word of Anatomy come from?
Greek root that means “To cut apart”
Gross Anatomy (Anatomy specialization)
The study of the larger structures of the body, those visible without the aid of magnification
- Macro = large meaning gross anatomy is referring to macroscopic anatomy
Microscopic anatomy
The study of structures that can be observed only with the use of microscope
- micro = small includes cytology, histology
Regional Anatomy
The study of interrelationships of all of the structures in specific body region.
- Etc. Abdomen
- Helps appreciate interrelationships of body structures such as muscles, nerves, blood vessels working together to serve particular body part
Systemic Anatomy
Study of the structures that make up a discrete body system. A group of structures working together to perform unique body function.
- etc. systemic study of muscular system will consider all of the skeletal muscles of the body
Physiology
Is the scientific study of the chemistry and physics of structures of the body and the ways in which they work together to support functions of life
What does physiology centre towards
Homeostasis
Homeostasis?
The state of the steady internal conditions maintained by living things
Organization of Human Body Order? From smallest to largest
Subatomic particles, atoms, molecules, organelles, cells, tissues, organs systems, organisms and biosphere
Cell?
The smallest independently functioning unit of living organism
All matter in the universe…
Is composed of one or more unique pure substance called elements, familiar examples of which are hydrogen, oxygen carbon, nitrogen, calcium and iron
Functions of the human life: in order
Organization, metabolism, responsiveness movement, development, reproduction
Organization
The body maintains distinct internal compartments to keep body cells separated from external
environmental threats and to keep the cells moist and nourished
Examples for organziation
Integumentary system which the largest organ system. Includes the skin and associated structures,(hair, nails). It is a barrier that protects internal structures and fluids from potentially harmful microorganisms and other toxins.
Organization examples pt 2.
The intestinal tract, for example, is home to more bacterial cells than the total of all human cells in the
body, yet these bacteria are outside the body and cannot be allowed to circulate freely inside the body.
Compartment example
In the chest and abdomen, a variety of internal membranes keep major organs such as the lungs, heart, and kidneys separate from others.
Metabolism
Thus, organisms consume energy and molecules in order to convert it into fuel for movement, sustain body functions, and build and maintain body structures.
Two types of reactions that accomplish to obtain energy
Anabolism, catabolism
Anabolism
process whereby smaller, simpler molecules are combined into larger, more complex
substances.
Catabolism
process by which larger more complex substances are broken down into smaller simpler
molecules. Catabolism releases energy.
First law of thermodynamics
Energy can neither be created nor destroyed
Every cell in the body makes uses…..?
Adenosine Triphosphate(ATP)
The cell stores energy in synthesis of ATP, Then moves the ATP molecules to the location where energy is needed to fuel cellular activities
Anabolism
ATP is broken down and controlled amount of energy is released, which is used by the cell to perform a particular job
Catabolism
Catabolism(Energy)
Releases energy
Anabolism
Requires energy
Responsiveness
The ability of an organism to adjust to changes in its internal and external environment
Responsiveness example
Changes in an organism’s internal environment, such as increased body temperature, can
cause the responses of sweating and the dilation of blood vessels in the skin in order to
decrease body temperature.
Development
Development: is all of the changes that the body goes through in life.
Growth
is the increase in body size by increasing the:
• number of existing cells • amount of non-cellular material around cells (such as mineral deposits in bone) • size of existing cells (within very narrow limits)
Reproduction
formation of a new organism from parent organisms. In humans,
reproduction is carried out by the male and female reproductive systems.
Requirements of human life
- Oxygen 2. Nutrients 3. Temperature 4. Pressure
Oxygen
Key component of the chemical reactions that keep the body alive, including the reactions that produce ATP
Atmospheric air is about…
20 percent oxygen
Brain cells are very sensitive to lack of oxygen? Why
Because of their requirement for a high and steady production of ATP
Brain damage is likely within
5 minutes without oxygen and death is likely within 10 minutes
Nutrients
Nutrient is a substance in foods and beverages that is essential to human survival
Three basic classes of nutrients are
- Water(macronutrient)
- Energy-yielding and body-building nutrients(Macronutrient)
- Micronutrients(Vitamins and minerals)
Nutrients - Water
Depending on the environmental temperature and our state of health, we may be able to survive for only a few days without water.
Facts of the nutrient water
The body’s functional chemicals are dissolved and transported in water. • Chemical reactions of life take place in water. • Moreover, water is the largest component of cells, blood, and the fluid between cells. • Water makes up about 70 percent of an adult’s body mass. • Water also helps regulate our internal temperature. • Water cushions, protects, and lubricates joints and many other body structures.
Nutrients - Energy- yielding and body-building nutrients
Carbohydrates, lipids while proteins mainly supply the amino acids that are the building blocks of body itself
The digestive system breaks these down into molecules small enough to be absorbed. • Although you might feel as if you are starving after missing a single meal, you can survive without consuming
the energy-yielding nutrients for at least several weeks.
Nutrients – Micronutrients (vitamins and minerals)
Vitamins and minerals participate in many essential chemical reactions and processes, such as nerve
impulses, and some, such as calcium, also contribute to the body’s structure.
The body can store some micronutrients in tissues, and draw on those reserves if needed. • Other micronutrients, however, such as vitamin C and most of the B vitamins, are water-soluble and cannot
be stored, so they need to be consumed every day or two.
Narrow range of temperature
Many chemical reactions upon which the body depends can only take place within a narrow range of body
temperature, from just below to just above 37°C.
When body temperature rises well above or drops well below normal, certain proteins (enzymes) that
facilitate chemical reactions lose their normal structure (denature) and their ability to function and the
chemical reactions of metabolism cannot proceed.
Narrow Range of Temperature
• Short-term exposure to cold:
Shivering (random muscle movement that generates heat)
• Increased breakdown of stored energy to generate heat. When that energy reserve is depleted,
however, and the core temperature begins to drop significantly, red blood cells will lose their ability to give up oxygen, denying the brain of this critical component of ATP production.
• This lack of oxygen can cause confusion, lethargy, and eventually loss of consciousness and death.
The body responds to cold by reducing blood circulation to the extremities, the hands and feet, in order to prevent blood from cooling there and so that the body’s core can stay warm.
• Even when core body temperature remains stable, however, tissues exposed to severe cold,
especially the fingers and toes, can develop frostbite when blood flow to the extremities has been much reduced. This form of tissue damage can be permanent and lead to gangrene, requiring amputation of the affected region.
Narrow Range of Temperature
• Short-term exposure to heat:
Sweating. As sweat evaporates from skin, it removes some thermal energy from the body, cooling it.
• Adequate water (from the extracellular fluid in the body) is necessary to produce sweat, so
adequate fluid intake is essential to balance that loss during the sweat response. • The sweat response is much less effective in a humid environment because the air is already
saturated with water. Thus, the sweat on the skin’s surface is not able to evaporate, and internal
body temperature can get dangerously high.
Controlled hypothermia
Hypothermia is the clinical term for an abnormally low body temperature • Controlled hypothermia is clinically induced hypothermia performed in order to reduce the
metabolic rate of an organ or of a person’s entire body • Controlled hypothermia often is used, for example, during open-heart surgery because it
decreases the metabolic needs of the brain, heart, and other organs, reducing the risk of
damage to them • Some emergency department physicians use controlled hypothermia to reduce damage
to the heart in patients who have suffered a cardiac arrest
Narrow range of atmospheric pressure
Pressure is a force exerted by a substance that is in contact with another substance. • Atmospheric pressure is pressure exerted by the mixture of gases (primarily nitrogen and oxygen) in the
Earth’s atmosphere. This pressure keeps gases within your body, such as the gaseous nitrogen in body fluids,
dissolved. • The ability to breathe—that is, to take in oxygen and release carbon dioxide—also depends upon a precise
atmospheric pressure. • Altitude sickness occurs in part because the atmosphere at high altitudes exerts less pressure, reducing the
exchange of these gases, and causing shortness of breath, confusion, heada
Decompression sickness (DCS)
Occurs when gases dissolved in the blood or in other body tissues are no longer dissolved following
a reduction in pressure on the body. Gases that were dissolved in the blood come rapidly out of
solution, forming bubbles in the blood and in other body tissues.
• The most common symptoms of DCS are pain in the joints, with headache and disturbances of
vision occurring in 10 percent to 15 percent of cases.
• This condition affects underwater divers who surface from a deep dive too quickly, due to the
relatively rapid decrease of pressure as divers rise from the high-pressure conditions of deep water
to the low, by comparison, pressure at sea level.
• DCS can also affect pilots flying at high altitudes in planes with unpressurized cabins. At high
altitude, barometric pressure is much less than on Earth’s surface because pressure is produced by
the weight of the column of air above the body pressing down on the body.
Humans have the most urgent need for a continuous supply of
Oxygen
Homeostasis - Set point
A set point is the physiological value around which the normal range fluctuates. A normal range is
the restricted set of values that is optimally healthful and stable.
• For example, the set point for normal human body temperature is approximately 37°C.
Physiological parameters, such as body temperature and blood pressure, tend to fluctuate
within a normal range a few degrees above and below that point.
Control centers in the brain and other parts of the body monitor and react to deviations from
homeostasis using negative feedback. • Negative feedback is a mechanism that reverses a deviation from the set point. Therefore, negative
feedback maintains body parameters within their normal range. • The maintenance of homeostasis by negative feedback is continuous.
Negative feedback
A negative feedback system has three basic components:
• A sensor, also referred to a receptor, is a component of a feedback system that monitors a
physiological value • The control center is the component in a feedback system that compares the value to the normal
range • An effector is the component in a feedback system that causes a change to reverse the situation and
return the value to the normal range
Negative feedback - Heat
When the brain’s temperature regulation center receives data from the sensors indicating that the body’s temperature exceeds its normal range, it stimulates a cluster of brain cells referred to as the “heat-loss center.” • This causes blood vessels in the skin to dilate allowing more blood from the body core to flow to the surface of the
skin allowing the heat to radiate into the environment. • As blood flow to the skin increases, sweat glands are activated to increase their output. As the sweat evaporates
from the skin surface into the surrounding air, it takes heat with it. • The depth of respiration increases, and a person may breathe through an open mouth instead of through the nasal
passageways. This further increases heat loss from the lungs.
• In contrast, activation of the brain’s heat-gain center by exposure to cold reduces blood flow to the skin,
and blood returning from the limbs is diverted into a network of deep veins
Negative feedback - Cold
When the brain’s temperature regulation center receives data from the sensors indicating that the body’s temperature is low, it stimulates a cluster of brain cells referred to as the “heat-gain center.” • This reduces blood flow to the skin • Diverts blood from the limbs into the deep veins • Activates shivering • The thyroid gland is activated and releases thyroid hormone to increase metabolic activity • Adrenal glands release epinephrine to breakdown glycogen into glucose.
Negative feedback system pathway
Stimulus, sensor, control, effector, response,
Therefore body temperature exceeded 37 Celsius, nerve cells in skin and brain, temperature regulatory center in brain, sweat glands throughout body, increased heat loss
Physiological parameters
When a stimulus moves a physiological parameter beyond its normal range (that is, beyond homeostasis), it
is “heard” by a specific sensor.
• For example, in the control of blood glucose, specific endocrine cells in the pancreas detect excess glucose
(the stimulus) in the bloodstream. These pancreatic beta cells respond to the increased level of blood
glucose by releasing the hormone insulin into the bloodstream.
• The insulin signals skeletal muscle fibers, fat cells (adipocytes), and liver cells to take up the excess glucose,
removing it from the bloodstream.
• As glucose concentration in the bloodstream drops, the decrease in concentration—the actual negative
feedback—is detected by pancreatic alpha cells, and insulin release stops. This prevents blood sugar levels
from continuing to drop below the normal range.
Positive feedback
Positive feedback intensifies a change in the body’s physiological condition rather than
reversing it • A deviation from the normal range results in more change
• Thus, the system moves farther away from the normal range
• Positive feedback in the body is normal only when there is a definite end point
• Childbirth and the body’s response to blood loss are two examples of positive feedback
loops that are normal but are activated only when needed
Positive feedback loop child birth
The first contractions of labor (the stimulus) push the baby toward the cervix (the lowest part of the uterus).
1. The cervix contains stretch-sensitive nerve cells that monitor the degree of stretching (the sensors).
2. These nerve cells send messages to the brain, which in turn causes the pituitary gland at the base of
the brain to release the hormone oxytocin into the bloodstream. 3. Oxytocin causes stronger contractions of the smooth muscles in of the uterus (the effectors), pushing
the baby further down the birth canal. 4. This causes even greater stretching of the cervix. 5. The cycle of stretching, oxytocin release, and increasingly more forceful contractions stops only when
the baby is born. At this point, the stretching of the cervix halts, stopping the release of oxytocin.
Positive feedback – Blood loss
Following a penetrating wound, the most immediate threat is excessive blood loss.
• Less blood circulating means reduced blood pressure and reduced perfusion (penetration of
blood) to the brain and other vital organs. • If perfusion is severely reduced, vital organs will shut down and the person will die.
• The body responds to this potential catastrophe by releasing substances in the injured blood vessel
wall that begin the process of blood clotting.
• As each step of clotting occurs, it stimulates the release of more clotting substances. This
accelerates the processes of clotting and sealing off the damaged area. Clotting is contained in
a local area based on the tightly controlled availability of clotting proteins. This is an adaptive,
life-saving cascade of events.
After a meal, nerve cells in the stomach respond to the distension in the walls resulting from the food. These cells relay this information to the __________.
Control centre
Anatomical position
The standard body anatomical position, is that of the body:
• Standing upright
• Feet at shoulder width and parallel
• Toes forward
• Upper limbs held out to each side
• Palms of hands face forward
A body that is lying down is described ? And what are the two definitions
Prone describes a face-down orientation,
and supine describes a face up orientation.
Anterior (or ventral
describes the front or direction toward the front of the body. The toes are
anterior to the foot.
Posterior (or dorsal
describes the back or direction toward the back of the body. The popliteus
is posterior to the patella.
Superior (or cranial)
describes a position above or higher than another part of the body proper.
The orbits are superior to the oris.
Inferior (or caudal)
describes a position below or lower than another part of the body proper;
near or toward the tail (in humans, the coccyx, or lowest part of the spinal column). The pelvis is
inferior to the abdomen.
Lateral
describes the side or direction toward the side of the body. The thumb (pollex) is lateral to
the digits.
Medial
describes the middle or direction toward the middle of the body. The hallux is the medial
toe.
Proximal
describes a position in a limb that is nearer to the point of attachment or the trunk of the
body. The brachium is proximal to the antebrachium.
Distal
describes a position in a limb that is farther from the point of attachment or the trunk of the
body. The crus is distal to the femur.
Superficial
describes a position closer to the surface of the body. The skin is superficial to the
bones.
Deep
describes a position farther from the surface of the body. The brain is deep to the skull.
plane
A plane is an imaginary two-dimensional surface that passes through the body. There are three planes commonly referred to in anatomy and medicine.
Sagittal plane
The sagittal plane is the plane that divides the body or an organ vertically into right and left sides.
• If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into
unequal right and left sides, it is called a parasagittal plane or less commonly a longitudinal section.
frontal plane
The frontal plane is the plane that divides the body or an organ into an anterior (front) portion and a
posterior (rear) portion. The frontal plane is often referred to as a coronal plane. (“Corona” is Latin for
“crown.”)
transverse plane
The transverse plane is the plane that divides the body or organ horizontally into upper and lower portions.
Transverse planes produce images referred to as cross sections.
Body cavities and serous membranes
The body maintains its internal organization by means of membranes, sheaths, and other
structures that separate compartments.
The dorsal (posterior) cavity and the ventral (anterior) cavity are the largest body compartments.
These cavities contain and protect delicate internal organs, and the ventral cavity allows for
significant changes in the size and shape of the organs as they perform their functions. • The lungs, heart, stomach, and intestines, for example, can expand and contract without
distorting other tissues or disrupting the activity of nearby organs.
Subdivisions of the posterior (dorsal) cavity
In the posterior (dorsal) cavity, the cranial cavity houses the brain, and the spinal cavity (or
vertebral cavity) encloses the spinal cord.
Just as the brain and spinal cord make up a continuous, uninterrupted structure, the cranial and
spinal cavities that house them are also continuous. • The brain and spinal cord are protected by the bones of the skull and vertebral column and by
cerebrospinal fluid, a colorless fluid produced by the brain, which cushions the brain and spinal
cord within the posterior (dorsal) cavity.
Subdivisions of the anterior (ventral) cavity
The anterior (ventral) cavity has two main subdivisions: the thoracic cavity and the
abdominopelvic cavity.
The thoracic cavity is the more superior subdivision of the anterior cavity, and it is
enclosed by the rib cage.
• It contains the lungs and the heart, located in the mediastinum. • The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic
cavity.
• The abdominopelvic cavity is the largest cavity in the body.
• Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the
abdominal cavity, the division that houses the digestive organs, and the pelvic cavity, the division that houses the organs of reproduction.
Region approach:
Subdivides the cavity with one horizontal line immediately inferior to the ribs and one immediately
superior to the pelvis, and two vertical lines drawn as if dropped from the midpoint of each clavicle (collarbone).
Quadrant approach:
Subdivides the cavity with one horizontal and one vertical line that intersect at the patient’s umbilicus
(navel).
Regions and quadrants of the peritoneal cavity
Hypochondriac, Epigastric, Umbilical, Lumbar, iliac
Membranes of the anterior (ventral) body cavity
A serous membrane (serosa) is a thin membrane that cover the walls and organs in the thoracic and abdominopelvic cavities. The serous membranes form fluid-filled sacs, or cavities, that are meant to cushion and reduce friction on internal organs when they move, such as when the lungs inflate or the heart beats.
The parietal layers of the membranes line the walls of the body cavity.
• The visceral layer of the membrane covers the organs.
• Between the parietal and visceral layers is a very thin, fluid-filled serous space, or cavity. Both the
parietal and visceral serosa secrete the thin, slippery serous fluid located within the serous cavities.
Membranes of the anterior (ventral) body cavity
There are three serous cavities and their associated membranes: 1. The pleura is the serous membrane that encloses the pleural cavity; the pleural cavity surrounds the lungs.
• Reduces friction between the lungs and the body wall 2. The pericardium is the serous membrane that encloses the pericardial cavity; the pericardial cavity
surrounds the heart.
• Reduces friction between the heart and the wall of the pericardium.
3. The peritoneum is the serous membrane that encloses the peritoneal cavity; the peritoneal cavity surrounds
several organs in the abdominopelvic cavity.
• Reduces friction between the abdominal and pelvic organs and the body wall.
Serous membrane (Heart)
Visceral pericardium, pericardial cavity, perietal pericardium
Serous membrane lines the pericardial cavity and reflects back to cover the heart—much the same way that an underinflated balloon would form two layers surrounding a fist.
The lumbar region is
Inferior to umbilical region
X-Rays
The X-ray is a form of high energy electromagnetic radiation with a short wavelength
• Can penetrate solids and ionizing gases • X-rays depict a two-dimensional image of a body region from a single angle
The X-ray is a form of high energy electromagnetic radiation with a short wavelength
• Can penetrate solids and ionizing gases • X-rays depict a two-dimensional image of a body region from a single angle
X-Rays – Risks
Like many forms of high energy radiation, X-rays can damage cells and initiate changes that can lead
to cancer. • Unfortunately, this danger of excessive exposure to X-rays was not fully appreciated for many years
after their widespread use. • Refinements and enhancements of X-ray techniques have continued throughout the twentieth and
twenty-first centuries. • Although the X-Ray has been replaced more and more with other, more sophisticated imaging
techniques, the X-ray remains a regular staple in medical imaging, especially for viewing fractures
and for dentistry. • The disadvantage of irradiation to the patient and the operator is now attenuated by proper
shielding and by limiting exposure.
Computed tomography (CT scan)
Noninvasive imaging technique that uses computers to analyze several cross-sectional X-
rays in order to reveal small details about structures in the body. • The technique was invented in the 1970s and is based on the principle that, as X-rays
pass through the body, they are absorbed or reflected at different levels. • In the technique, a patient lies on a motorized platform while a computerized axial
tomography scanner rotates 360 degrees around the patient, taking X-ray images. • The main disadvantage of CT scanning is that it exposes patients to a dose of radiation
many times higher than that of X-rays.
Magnetic resonance imaging (MRI
Noninvasive medical imaging technique based on a phenomenon of nuclear physics
discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was
found to emit radio signals.
The early MRI scanners were crude, but advances in digital computing and electronics
led to their advancement over any other technique for precise imaging, especially to
discover tumors.
Functional MRIs (fMRIs), which detect the concentration of blood flow in certain parts of the body, are increasingly being used to study the activity in parts of the brain during various body activities. This has helped scientists learn more about the locations of different brain functions and more about brain abnormalities and diseases
MRI – Drawbacks
High cost • Patient discomfort due to :
• Enclosure in a metal tube-like device for the entire scan (can be up to 30 minutes)
• Requirement to stay still
• Noise made by the machine • These problems have been overcome somewhat with the development of “open” MRI scanning, which does
not require the patient to be entirely enclosed in the metal tube. • Patients with iron-containing metallic implants (internal sutures, some prosthetic devices, and so on) cannot
undergo MRI scanning because it can dislodge these implants.
Positron emission tomography (PET scan)
Positron emission tomography is a medical imaging technique involving the use of so-
called radiopharmaceuticals, substances that emit radiation that is short-lived and
therefore relatively safe to administer to the body. • Although the first PET scanner was introduced in 1961, it took 15 more years before
radiopharmaceuticals were combined with the technique and revolutionized its potential. • PET is widely used to diagnose a multitude of conditions, such as heart disease, the
spread of cancer, certain forms of infection, brain abnormalities, bone disease, and
thyroid disease.
A main advantage to PET is that it can illustrate physiologic activity—including nutrient
metabolism and blood flow—of the organ or organs being targeted, whereas CT and MRI scans
can only show static images.
Ultrasonography
Uses the transmission of high-frequency sound waves into the body to generate an echo signal that is
converted by a computer into a real-time image of anatomy and physiology. • Ultrasonography is the least invasive of all imaging techniques, and it is therefore used more freely in
sensitive situations such as pregnancy. • The technology was first developed in the 1940s and 1950s. • Ultrasonography is used to study heart function, blood flow in the neck or extremities, certain conditions
such as gallbladder disease, and fetal growth and development. • The main disadvantages of ultrasonography are that the image quality is heavily operator-dependent and
that it is unable to penetrate bone and gas.
Medical imaging techniques
a) The results of a CT scan of the head are shown as
successive transverse sections. • (b) An MRI machine generates a magnetic field around
a patient. • (c) PET scans use radiopharmaceuticals to create
images of active blood flow and physiologic activity of
the organ or organs being targeted. • d) Ultrasound technology is used to monitor
pregnancies because it is the least invasive of imaging
techniques and uses no electromagnetic radiation. • (credit a: Akira Ohgaki/flickr; credit b: “Digital
Cate”/flickr; credit c: “Raziel”/Wikimedia Commons;
credit d: “Isis”/Wikimedia Commons
Which of the following medical imaging techniques is best to study the uptake of nutrients by rapidly multiplying cancerous cells?
PET
