Download Physiology Ch 1

Essentials of Human Anatomy and Physiology
Chapter 1 The Human Body: An Orientation
anatomy
- study of the structure of the body
gross anatomy
- study of whole body or large body structures
microscopic anatomy - study of cells and tissues of the body using a microscope
physiology
- study of how the body functions
levels of structural organization
chemical level (simplest level)
atoms - tiny building blocks of matter
- combine to form molecules
molecules
- combine to make up cells
cellular level
cell
- smallest units of all living things
- cells vary in size and shape depending on their function
- group together to form tissues
tissue level
tissue - group of similar cells with a common function
- 2 or more tissue types combine to form an organ
organ level
organ - made of 2 or more tissue types
- performs a specific function for the body
organ system level
organ system - group of organs that work together to perform a certain job
- 11 of them
organismal level (highest level)
organism
- the living body
11 organ systems
integumentary system - external covering of the body (skin)
- functions: waterproofs body
cushions and protects deeper tissues
excretes materials
helps regulate body temperature
has nerve receptors for detecting temperature, pressure, and pain
produces vitamin D
skeletal system
- bones, cartilage, ligaments, joints
- functions: supports body
provides framework for muscles to use for movement
protects organs
forms blood cells (hematopoeisis)
stores minerals
muscular system
- skeletal muscles (large muscles attached to bones)
- function:
contract (shorten) to cause movement
nervous system
- fast-acting control system (brain, spinal cord, nerves, sensory receptors)
- function:
responds to stimuli from outside and inside the body by
activating appropriate muscles or glands
endocrine system
- slower control system (endocrine glands)
- function:
regulates body activities
- hormones - chemicals released by endocrine glands into
bloodstream and carried throughout body
cardiovascular system - heart, blood vessels
- function:
transports blood which carries oxygen, carbon dioxide,
nutrients, wastes, etc.
lymphatic system
- lymphatic vessels, lymph nodes, spleen
- function of vessels: return fluid leaked from the blood to the blood vessels
- function of lymph nodes: cleanse blood
house white blood cells involved in immunity
respiratory system
- nasal passages, pharynx, larynx, trachea, bronchi, lungs
- function:
supplies body with oxygen and gets rid of carbon dioxide
digestive system
- mouth, esophagus, stomach, small and large intestines, rectum
- also liver and pancreas
- functions: break down food and deliver nutrients to blood
eliminate undigested food through anus as feces
urinary system
- sometimes called excretory system
- kidneys, ureters, bladder, urethra
- function:
removes wastes from blood
produce urine to eliminate these wastes
maintains a water and salt balance
maintains an acid-base balance
reproductive system
male reproductive system
- testes, scrotum, penis, accessory glands, duct system
- function:
production of offspring
sperm produced by testes
female reproductive system - ovary, uterine tubes, uterus, vagina
- functions: production of offspring
eggs (ova) produced by ovaries
uterus provides site for development of fetus
necessary life functions
maintaining boundaries
- an organism’s “inside” must remain distinct from its “outside”
- examples: cells have cell membranes
body enclosed by skin
movement
- activities promoted by the muscular system including:
walking, swimming, etc.
manipulating environment with fingers
- aided by skeletal system
- also includes propelling substances through body (blood, food, urine, etc.)
responsiveness- aka irritability
- ability to react to changes in environment (stimuli)
- involves nervous system mostly
digestion
- breaking down food into simple molecules which can be absorbed into the bloodstream
- involves digestive system
metabolism - chemical reactions that occur within body cells
- includes breaking down complex substances into simpler building blocks, making
larger molecules from smaller ones, using nutrients and oxygen to make ATP for energy
excretion
- removing wastes from the body
- involves digestive and urinary systems
reproduction - producing offspring
- cellular reproduction - cell divides into2 identical daughter cells
- reproduction of organism - making a whole new person
- involves reproductive and urinary systems
growth
- increase in size
- usually involves an increase in the number of cells
survival needs
nutrients
- chemicals used for energy and cell building
- include:
carbohydrates - main energy source for cells
proteins
- used for building cell structures
fats
- used for energy and building cell structures, and cushion organs
vitamins/ minerals - used in chemical reactions in cells
oxygen
- needed for the chemical reactions that release energy from foods
water
- most abundant chemical in the body (60-80% of body weight)
- fluid base for body secretions and excretions
- lost by evaporation from lungs and skin and in excretions
stable body temperature
- about 37oC (98oC)
- metabolic reactions slow down as body temp drops and speed up as
temp increases
atmospheric pressure - must be appropriate for oxygen and carbon dioxide exchange to occur
homeostasis
- body’s ability to maintain stable internal conditions even when outside conditions
change
- internal conditions may change slightly but stay within a narrow range
- maintaining homeostasis is controlled mainly by nervous and endocrine systems
(electrical signals and hormones)
variable
- condition being regulated
components of homeostatic control mechanisms:
receptor
- a sensor that responds to changes in environment (stimuli)
- sends information to control center
control center - determines level at which a variable is to be maintained
- analyzes incoming information and determines appropriate response
effector
- responds to influence the stimulus (feeds back)
negative feedback mechanism
- net effect is to shut off or reduce original stimulus
- example:
thermostat
- examples in body: regulating body temperature, heart rate,
blood pressure, breathing rate, and levels
of glucose, oxygen, and carbon dioxide in
blood
positive feedback mechanism
- net effect is to increase the original stimulus
- rare in the body
- involved in blood clotting and child birth
homeostatic imbalance
- often results in disease
Language of Anatomy
anatomical position
- body is erect
- feet parallel
- arms at sides with palms forward
directional terms
superior (cephalad)
inferior (caudal)
anterior (ventral)
posterior (dorsal)
medial
lateral
intermediate
proximal
distal
- toward head or toward the upper part; above
- away from the head or toward the lower part; below
- at the front of the body; in front of
- at the back of the body; behind
- toward or at the body’s midline; inner side
- away from the midline; outer side
- between a more medial and a more lateral structure
- close to the body part’s point of attachment
- farther from the body part’s point of attachment
superficial (external) - toward or at the body surface; external
deep (internal)
- away from the body surface; internal
regional terms
anterior landmarks:
abdominal
acromial
antecubital
axillary
brachial
buccal
carpal
cervical
coxal
crural
digital
femoral
fibular
inguinal
nasal
oral
orbital
patellar
pelvic
pubic
sternal
tarsal
thoracic
umbilical
posterior landmarks:
calcaneal
cephalic
deltoid
femoral
gluteal
lumbar
occipital
olecranal
popliteal
sacral
scapular
sural
vertebral
inferior landmark:
plantar
- anterior trunk below ribs
- point of shoulder
- anterior elbow
- armpit
- arm
- cheek
- wrist
- neck
- hip
- leg
- fingers, toes
- thigh
- lateral leg
- groin
- nose
- mouth
- eye
- anterior knee
- area in front of pelvis
- genital region
- breastbone
- ankle
- chest
- navel
- heel
- head
- shoulder
- thigh
- buttock
- posterior back between ribs and hips
- back of head
- posterior elbow
- posterior knee
- between hips
- shoulder blades
- calf
- spine
- sole of foot
section
plane
- a cut
- imaginary line through which a cut is made
sagittal section
- divides body into right and left parts
midsagittal section - aka median section
- cut is made down median plane of body
frontal section
- aka coronal section
- divides body into anterior and posterior parts
transverse section
- aka cross section
- divides body into superior and inferior parts
body cavities:
dorsal body cavity
ventral body cavity
- 2 subdivisions:
cranial cavity - space inside skull
- contains brain
spinal cavity - extends from cranial cavity to end of
vertebral column
- contains spinal cord
- contains all structures within chest and abdomen
- 2 subdivisions separated by diaphragm (dome-shaped muscle):
thoracic cavity
- superior to diaphragm
- contains lungs, heart, etc.
- protected by ribcage
mediastinum - central region in thoracic cavity
- separates right and left lungs
- contains heart, trachea, etc
abdominopelvic cavity
- inferior to diaphragm
- 2 subdivisions:
abdominal cavity
- contains stomach, liver,
intestines, etc.
these organs are most
vulnerable to trauma because
they are not protected by bones
pelvic cavity - contains reproductive organs,
bladder, and rectum
abdominal cavity
- divided into 4 quadrants:
right upper quadrant (RUQ)
left upper quadrant (LUQ)
right lower quadrant (RLQ)
left lower quadrant (LLQ)
- divided into 9 areas by another system
umbilical region
- surrounds navel
epigastric region
- superior to umbilical region
hypogastric (pubic) region - inferior to umbilical region
right inguinal or iliac region - right of pubic region
left inguinal or iliac region - left of pubic region
right lumbar region - right of umbilical region
left lumbar region
- left of umbilical region
right hypochondriac region - right of epigastric region
left hypochondriac region
- left of epigastric region