Anatomy and Physiology (Bio 120) chapter 1

Human anatomy

the scientific study of the body's structures

dissected

to be cut apart in order to observe physical attributes and their relationships to one another.

Gross anatomy (macroscopic anatomy)

the study of the larger structures of the body, those visible without the aid of magnification

microscopic anatomy

the study of structures that can be observed only with the use of a microscope or other magnification devices

cytology

study of cells

histology

study of tissues

Regional anatomy

the study of the interrelationships of all of the structures in a specific body region, such as the abdomen.

helps us appreciate the interrelationships of body structures, such as how muscles, nerves, blood vessels, and other structures work together to serve a particular body region.

systemic anatomy

the study of the structures that make up a discrete body system—that is, a group of structures that work together to perform a unique body function.

ex: study of the muscular system would consider all of the skeletal muscles of the body

Human physiology

the scientific study of the chemistry and physics of the structures of the body and the ways in which they work together to support the functions of life

includes observation, both with the naked eye and with microscopes, as well as manipulations and measurements.

Homeostasis

the state of steady internal conditions maintained by living things.

neurophysiology

study of the brain, spinal cord, and nerves and how these work together to perform functions as complex and diverse as vision, movement, and thinking

levels of organization

subatomic particles, atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms and biosphere

atom

smallest unit of any element

subatomic particles

protons, neutrons, electrons (make up atoms)

molecule

two or more atoms held together by covalent bonds

the chemical building blocks of all body structures.

cell

smallest independently functioning unit of a living organism

cytoplasm

water-based cellular fluid

organelles

Structures specialized to perform distinct processes within a cell

tissue

a group of many similar cells (though sometimes composed of a few related types) that work together to perform a specific function

organ

an anatomically distinct structure of the body composed of two or more tissue types.

Each one performs one or more specific physiological functions

organ system

a group of organs that work together to perform major functions or meet physiological needs of the body

Why is assigning organs to organ systems imprecise?

organs that "belong" to one system can also have functions integral to another system

Integumentary System

Encloses internal body structures; Site of many sensory receptors; body's largest organ system

ex: hair, skin, nails

Skeletal System

Supports the body; Enables movement (with muscular system

ex: cartilage, bones, joints

Muscular System

Enables movement (with skeletal system); Helps maintain body temperature

ex: skeletal muscles, tendons

Nervous System

Detects and processes sensory information; Activates bodily response

ex: brain, spinal cord, peripheral nerves

Endocrine System

Secretes hormones; Regulates bodily processes

ex: pituitary gland, thyroid, pancreas, adrenal gland, testes, ovaries

Cardiovascular System

Delivers oxygen and nutrients to tissues; Equalizes temperature in the body

ex: heart, blood vessels

Lymphatic System

Returns fluid to blood; Defends against pathogen

ex: thymus, lymph nodes, spleen, lymphatic vessels

Respiratory System

Removes carbon dioxide from the body; Delivers oxygen to blood

ex: nasal passage, trachea, lungs

Digestive System

Processes food for use by the body; Removes wastes from undigested food

ex: stomach, liver, gallbladder, small intestines, large intestines

Urinary System

Controls water balance in the body
Removes wastes from blood and excretes the

ex: kidneys, urinary bladder

Male Reproductive System

Produces sex hormones and gametes; Delivers gametes to female

ex: epididymis, testes

Female Reproductive System

Produces sex hormones and gametes; Supports embryo/ fetus until birth; Produces milk for infant

ex: mammary glands, ovaries, uterus

organism

highest level of organization

a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life

internal compartments

keep body cells separated from external environmental threats and keep the cells moist and nourished.

also separate internal body fluids from the countless microorganisms that grow on body surfaces, including the lining of certain passageways that connect to the outer surface of the body.

first law of thermodynamics

Energy cannot be created or destroyed--it can only change form

Anabolism

process whereby smaller, simpler molecules are combined into larger, more complex substances.

Using energy, your body can assemble the complex chemicals it needs by combining small molecules from the foods you eat

consumes energy

Catabolism

larger more complex substances are broken down into smaller simpler molecules.

releases energy

complex molecules found in foods are broken down so the body can use their parts to assemble the structures and substances needed for life

releases energy

Metabolism

the sum of all anabolic and catabolic reactions that take place in the body

anabolic and catabolic reactions occur simultaneously and continuously

Adenosine Triphosphate (ATP)

used to store and release energy

How is ATP used?

1. The cell stores energy in the synthesis (anabolism) of ATP, then moves the ATP molecules to the location where energy is needed to fuel cellular activities.

2. Then the ATP is broken down (catabolism) and a controlled amount of energy is released, which is used by the cell to perform a particular job.

Responsiveness

is the ability of an organism to adjust to changes in its internal and external environments

ex: moving toward sources of food and water and away from perceived dangers.

Human movement

actions at the joints of the body, but also the motion of individual organs and even individual cells

ex: action of entire muscle groups to enable you to move air into and out of your lungs, to push blood throughout your body, and to propel the food you have eaten through your digestive tract; consciously, you contract your skeletal muscles to move the bones of your skeleton to get from one place to another

Development

all of the changes the body goes through in life, including differentiation, growth, and repair

Differentiation

unspecialized cells become specialized in structure and function to perform certain tasks in the body

Growth

the increase in body size

How do all multicellular organisms grow?

by increasing the number of existing cells, increasing the amount of non-cellular material around cells (such as mineral deposits in bone), and, within very narrow limits, increasing the size of existing cells.

Reproduction

the formation of a new organism from parent organisms

Why are brain cells especially sensitive to lack of oxygen?

Oxygen is required to produce ATP and they need a high-and-steady production of it.

Lack of oxygen can cause confusion, lethargy, and eventually loss of consciousness and death.

Brain damage is likely within 5 minutes without oxygen, and death is likely within 10 minutes.

nutrient

a substance in foods and beverages that is essential to human survival.

3 basic classes of nutrients

water, the energy-yielding and body-building nutrients, and the micronutrients (vitamins and minerals)

What is the most critical nutrient? Why?

Water

The body's functional chemicals are dissolved and transported in water, and the chemical reactions of life take place in water. Water is the largest component of cells, blood, and the fluid between cells, and water makes up about 70% of an adult's body mass. Also helps regulate our internal temperature and cushions, protects, and lubricates joints and many other body structures.

What are the energy-yielding nutrients?

What are the body-building nutrients?

primarily carbohydrates and lipids

proteins

amino acids

the building blocks of the body itself, supplied by proteins

How are energy-yielding and body-building nutrients involved in ATP?

digestive system breaks them down into molecules small enough to be absorbed. The breakdown products of carbohydrates and lipids can then be used in the metabolic processes that convert them to ATP.

what is considered a macronutrient? Why?

Water and the energy-yielding nutrients, because the body needs them in large amounts.

What are micronutrients? What do they do?

vitamins and minerals; they participate in many essential chemical reactions and processes, such as nerve impulses, and some, such as calcium, also contribute to the body's structure.

Does the body store micronutrients?

some micronutrients can be stored in tissues and drawn on as needed, but others (vitamin C and most of the B vitamins) are water-soluble and cannot be stored, so you need to consume them every day or two.

What range of temperature can the body function at?

just above or below 37°C (98.6°F)

What happens when body temperature is out of its needed range?

certain proteins (enzymes) that facilitate chemical reactions lose their normal structure and their ability to function and the chemical reactions of metabolism cannot proceed.

How does sweating work? What does it need? When does it not work as well, and what happens?

sweat evaporates from the skin, removing some thermal energy from the body to cool it.

Adequate fluid intake is essential to balance that loss during the sweat response.

much less effective in a humid environment because the air is already saturated with water. The sweat on the skin's surface is not able to evaporate, and internal body temperature can get dangerously high.

Responses to cold temperatures

1. shivering (random muscle movement that generates heat.)
2. increased breakdown of stored energy to generate heat
3. reducing blood circulation to the extremities

What happens in cold temperatures when the body's energy reserve is depleted 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, eventually leading to death.

It will reduce blood circulation to the extremities, in order to prevent blood from cooling there and so that the body's core can stay warm.

frostbite

form of tissue damage from extremely low temps that can be permanent and lead to gangrene, requiring amputation of the affected region.

Hypothermia

the clinical term for an abnormally low body temperature

What is controlled hypothermia? How does it work?

clinically induced hypothermia performed in order to reduce the metabolic rate of an organ or of a person's entire body

ex: during open-heart surgery to decrease the metabolic needs of the brain, heart, and other organs, reducing the risk of damage to them.

How: patient is given medication to prevent shivering, body is cooled to 25-32°C (79-89°F), heart is stopped and an external heart-lung pump maintains circulation, The heart is cooled further and is maintained at a temperature below 15°C (60°F) for the duration of the surgery

Pressure

a force exerted by a substance that is in contact with another substance

Atmospheric pressure

pressure exerted by the mixture of gases (primarily nitrogen and oxygen) in the Earth's atmosphere

keeps blood gasses dissolved

Altitude sickness

the atmosphere at high altitudes exerts less pressure, reducing the exchange of these gases, and causing shortness of breath, confusion, headache, lethargy, and nausea

Decompression Sickness

condition in which gases dissolved in the blood or in other body tissues are no longer dissolved following a reduction in pressure on the body

happens when divers resurface too quickly or airplane cabins aren't pressurized

blood pressure

pressure exerted by blood as it flows within blood vessels, must be great enough to enable blood to reach all body tissues, and yet low enough to ensure that the delicate blood vessels can withstand the friction and force of the pulsating flow of pressurized blood.

set point

the physiological value around which the normal range fluctuates.

normal range

the restricted set of values that is optimally healthful and stable.

Negative feedback

a mechanism that reverses a deviation from the set point (maintains body parameters within their normal range)

goes on throughout the body at all times

What are the 3 basic components of negative feedback?

1. sensor (receptor), 2. control center, 3. effector

sensor (receptor)

a component of a feedback system that monitors a physiological value that is reported to the control center

control center

the component in a feedback system that compares the value to the normal range. If the value deviates too much from the set point, then the control center activates an effector

effector

the component in a feedback system that causes a change to reverse the situation and return the value to the normal range

Explain negative feedback for regulating blood sugar

1. specific endocrine cells in the pancreas detect excess glucose (the stimulus) in the bloodstream.
2. These pancreatic beta cells respond to the increased level of blood glucose by releasing the hormone insulin into the bloodstream.
3. The insulin signals skeletal muscle fibers, fat cells (adipocytes), and liver cells to take up the excess glucose, removing it from the bloodstream.
4. 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.

Explain negative feedback for regulating temperature when hot

1. the brain's temperature regulation center receives data from the sensors indicating that the body's temperature exceeds its normal range
2. it stimulates a cluster of brain cells referred to as the "heat-loss center." [has 3 major effects: (1) Blood vessels in the skin dilate, allowing more blood from the body core to flow to the surface of the skin allowing the heat to radiate into the environment.
   (2) 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.
   (3) 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.]

Explain negative feedback for regulating temperature when cold

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 to trap heat closer to the body core and restricts heat loss.

If heat loss is severe, the brain sends random signals to skeletal muscles causing shivering to release heat using ATP

brain triggers the thyroid gland in the endocrine system to release thyroid hormone, which increases metabolic activity and heat production in cells throughout the body.

also signals the adrenal glands to release epinephrine (adrenaline), a hormone that causes the breakdown of glycogen into glucose, which can be used as an energy source, resulting in increased metabolism and heat production

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, and the system moves farther away from the normal range. ONLY happens when there is a definite end point

ex: child birth, the body's response to blood loss

How is child birth an example of positive feedback?

1. The first contractions of labor (the stimulus) push the baby toward the cervix
2. The cervix contains stretch-sensitive nerve cells that monitor the degree of stretching (the sensors).
3. These nerve cells send messages to the brain, which in turn causes the pituitary gland to release the oxytocin into the bloodstream. 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. The cycle of stretching, oxytocin release, and increasingly more forceful contractions stops only when the baby is born.
5. At this point, the stretching of the cervix halts, stopping the release of oxytocin.

the root of an anatomical term

often refers to an organ, tissue, or condition

the prefix or suffix of an anatomical term

often describes the root

Prone

a body lying down in a face-down orientation

supine

a body lying down in 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.

section

two-dimensional surface of a three-dimensional structure that has been cut

plane

an imaginary two-dimensional surface that passes through the body.