ap chap 1

anatomy

• is the scientific discipline that investigates the structure of the body

• examines the relationship between the structure of a body part and its function

dissect, or cut apart and separate, the parts of the body for study

word anatomy means to

• systemic anatomy

• regional anatomy

two basic approaches to the study of anatomy:

systemic anatomy

• — is the study of the body by systems, such as the cardiovascular, nervous, skeletal, and muscular systems.

• It is the approach taken in this textbook.

regional anatomy

• — is the study of the organization of the body by areas.

• Within each region, such as the head, abdomen, or arm, all systems are studied simultaneously.

surface anatomy and anatomical imaging

Anatomists have two general ways to examine the internal structures of a living person:

surface anatomy

— is the study of external features, such as bony projections, which serve as landmarks for locating deeper structures.

anatomical imaging

— involves the use of x-rays, ultrasound, magnetic resonance imaging (MRI), and other technologies to create pictures of internal structures (such as when determining if a bone is broken or a ligament is torn.)

physiology

• the study of nature

• is the scientific discipline that deals with the processes or functions of living things

1. examining the body’s responses to stimuli

2. examining the body’s maintenance of stable internal conditions

2 major goals when studying physiology

human physiology

study of humans

cellular physiology

— focuses on processes inside cells such as the manufacturing of substances, including proteins

systemic physiology

— focuses on the functions of organ systems

1. chemical level

2. cell level

3. tissue level

4. organ level

5. organ system level

6. organism level

Levels of Organization for the Human Body

atom

The simplest level of organization in the human body is the --

chemical level

• involves how atoms, such as hydrogen and carbon, interact and combine into molecules.

• This is important because a molecule’s structure determines its function

cells

are the basic structural and functional units of organisms, such as plants and animals

organelles

• Most cells contain smaller structures inside them, called —

• carry out particular functions, such as digestion and movement, for the cell

tissue

is a group of similar cells and the materials surrounding them.

1. epithelial

2. connective

3. muscle

4. nervous

many tissues that make up the body are classified into four primary types:

organ

is composed of two or more tissue types that together perform one or more common functions

organ system

is a group of organs that together perform a common function or set of functions.

1. :integumentary

2. skeletal

3. muscular

4. nervous

5. endocrine

6. cardiovascular

7. lymphatic

8. respiratory

9. digestive

10. urinary

11. reproductive

11 major organ systems

integumentary system

provides protection, regulates temperature, prevents water loss, and helps produce vitamin D

skeletal system

provides protection and support, allows body movements, produces blood cells, and stores minerals and adipose tissue

muscular system

• produces body movements, maintains posture, and produces body fat

• consists of — attached to the connective tissue sheets or the skeleton by tendons

nervous system

a major regulatory system that detects sensation and controls movements, physiological processes, and intellectual functions

endocrine system

a major regulatory system that influences metabolism, growth, reproduction, and many other functions

cardiovascular system

transports nutrients, waste products, gases, and hormones throughout the body; plays a role in the immune response and the regulation of body temperature

lymphatic system

removes foreign substances from the blood and —, combats disease, maintains tissue fluid balance, and absorbs dietary fats from the digestive tract

respiratory system

exchanges oxygen and carbon dioxide between the blood and air and regulates blood Ph

digestive system

performs the mechanical and chemical processes of digestion, absorption of nutrients, and elimination of waste

urinary system

removes waste products from the blood and regulates blood ph, ion balance and water balance

organism

is any living thing considered as a whole, whether composed of one cell, such as a bacterium, or of trillions of cells

1. organization

2. metabolism

3. responsiveness

4. growth

5. development

6. reproduction

six essential characteristics of life

organization

— refers to the specific interrelationships among the individual parts of an organism, and how those parts interact to perform specific functions.

metabolism

is the ability to use energy to perform other vital functions, such as growth, movement, and reproduction

responsiveness

is an organism’s ability to sense changes in the external or internal environment and adjust to those changes.

growth

refers to an increase in the size or number of cells, which produces an overall enlargement in all or part of an organism, cell size, or the amount of substance surrounding cells.

development

includes the changes an organism undergoes through time, beginning with fertilization and ending at death.

differentation

involves changes in a cell’s structure and function from an immature, generalized state to a mature, specialized state.

reproduction

• is the formation of new cells or new organisms.

• allows for growth and development.

• Formation of new organisms prevents extinction of species

homeostasis

is the maintenance of a relatively constant environment within the body.

variables

• Body temperature is one of our body’s —

• These changes in body conditions are called —because their values are not constant.

homeostatic mechanisms

the — that maintain normal body temperature include sweating or shivering to maintain body temperature near an ideal normal value

set point

near an ideal normal value

normal range

• body temperature increases and decreases slightly around the set point, producing a — of values.

• As long as body temperatures remain within this —, homeostasis is maintained.

98.6°F or 37°C

Our average body temperature is —

negative-feedback mechanism

• is when any deviation from the set point is made smaller or is resisted.

• does not prevent variation but maintains variation within a normal range.

maintenance of normal body temperature

is an example of a negative-feedback mechanism

1. receptor

2. control center

3. effector

Most negative-feedback mechanisms have three components:

receptor

which monitors the value of a variable, such as body temperature, by detecting stimuli

control center

such as part of the brain, which determines the set point for the variable and receives input from the receptor about the variable

effector

such as the sweat glands, which can adjust the value of the variable when directed by the control center, usually back toward the set point

stimulus

A changed variable is a— because it initiates a homeostatic mechanism

positive-feedback mechanisms

— occur when a response to the original stimulus results in the deviation from the set point becoming even greater

1. many disease states result from the failure of negative-feedback mechanisms to maintain homeostasis

2. some positive-feedback mechanisms can be detrimental instead of helpful.

Two basic principles about homeostatic mechanisms to remember

anatomical position

refers to a person standing upright with the face directed forward, the upper limbs hanging to the sides, and the palms of the hands facing forward

supine

A person is —when lying face upward

prone

A person is — when lying face downward

Directional terms

— describe parts of the body relative to each other

superior or dorsal

above

anterior or ventral

toward the front of the body

posterior or dorsal

toward the back of the body

proximal

closer to a point of attachment

distal

father from a point of attachment

lateral

away from the midline of the body

medial

toward the middle or midline of the body

superficial

toward or on the surface

deep

away from the surface, internal

head, neck, and trunk

the central region of the body consists of the

the thorax, the abdomen, and the pelvis

trunk can be divided into three regions:

thorax

— is the chest cavity where the heart and lungs are located

abdomen

— contains organs such as the liver, the stomach, and the intestines

pelvis

contains the bladder and reproductive organs

upper limb

is divided into (1) the arm, (2) the forearm, (3) the wrist, and (4) the hand

arm

extends from the shoulder to the elbow

forearm

extends from the elbow to the wrist

lower limb

is divided into (1) the thigh, (2) the leg, (3) the ankle, and (4) the foot.

thigh

extends from the hip to the knee

leg

extends from the knee to the ankle

1. the right-upper quadrant

2. the left-upper quadrant

3. the right-lower quadrant

4. the left-lower quadrant

abdomen is often subdivided superficially into four quadrants:

1. epigastric

2. right hypochondria

3. left hypochondria

4. umbilical

5. right lumbar

6. left lumbar

7. hypogastric

8. right iliac

9. left iliac

the abdomen is sometimes subdivided into nine regions:

planes

• it is useful to describe the body as having imaginary flat surfaces, called — passing through it

• — divides, or sections, the body, making it possible to “look inside” and observe the body’s structures

sagittal plane

separates the body or a structure into right and left halves.

“the flight of an arrow”

word sagittal means—and refers to the way the body would be split by an arrow passing anteriorly to posteriorly.

median plane

is a sagittal plane that passes through the midline of the body, dividing it into equal right and left halves.

transverse plane

runs parallel to the ground, dividing the body into superior and inferior portions.

frontal or coronal plane

divides the body into front (anterior) and back (posterior) halves

longitudinal section

is a cut along the length of the organ, similar to the cut along a hot dog bun

transverse section

cuts completely through an organ, similar to cutting a hot dog or banana into round pieces

oblique section

If a cut is made diagonally across the long axis, it is called an —

dorsal body cavity and ventral body cavity

body contains 2 types of internal cavities

dorsal body cavity

encloses the organs of the nervous system, the brain and spinal cord.

cranial cavity and vertebral canal

2 subdivisions of the dorsal body cavity

cranial cavity

dorsal body cavity that houses the brain

vertebral cavity

dorsal body cavity that houses the spinal cord

meninges

Both the brain and spinal cord are covered by membranes called

ventral body cavity

houses the vast majority of our internal organs,

viscera

internal organs