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A&P 8/22/05

 

Anatomy & Physiology

 

The study of the human body must encompass both anatomy and physiology because structures, functions, and processes are interwoven

 

 

Anatomy

 

1)     Anatomy – structure as it relates to function

a)     Developmental anatomy – changes that occur between conception and adulthood

b)     Embryology – a sub specialty of developmental anatomy. Changes from conception to the end of the 8th week of development

i)        Most birth defects occur during this stage

c)      Cytology – study of structural features of cells

i)        Pap smear

d)     Histology – examines tissues – which are the cells and the materials surrounding them

2)     Gross anatomy – study of structures which can be seen without the aid of microscope

3)     Systemic anatomy – body is studied system by system.

a)     System is a group of structures that have 1 or more common functions

i)        Circulatory system

4)     Regional anatomy – body studied area by area. Usually the med school approach

a)     I.e.: studying the head or arms

5)     Surface anatomy – study of external form of the body and its relationship to deeper structures

a)     Ribs and sternum help define where to best hear heart sounds

 

 

1)     Anatomical imaging – seeing into the body without being invasive

a)     Radiographs – x-rays

b)     MRI – uses magnets – the water in the body helps give the image

c)      CAT scans – x-rays – computed axial tomography

d)     CT scans – x-rays – computed tomography

e)     Ultrasound – sound waves – probe bounces sound waves off organs

f)        Nuclear medicine – physiologic – shows active metabolism

i)        Injection with isotopes

ii)      bone scan

2)     abnormal anatomy – refers to abnormal anomalies – anatomical anomalies

a)     extra finger – harmless

b)     horseshoe kidney – attached kidneys so there’s just one – harmless

c)      blue baby syndrome – transposition of great vessels – the aorta and pulmonary arteries – lethal

 


 

Physiology

 

  1. Physiology – is the scientific investigation of the processes or functions of living things
    1. Major goals are to understand and predict the responses of the body to stimuli and to understand how the body maintains conditions within a narrow range of values in a constantly changing environment
    2. Often examines systems rather than regions because portions of a system in more than one region can be involved in a given function
  2. cell physiology – examines the processes occurring in cells
  3. systemic physiology – considers the functions of the organ systems
  4. neurophysiology – focuses on the nervous system
  5. cardiovascular physiology – deals with the heart and blood vessels
  6. pathology – the medical science dealing with all aspects of disease
  7. exercise physiology – focuses on changes in function, but also structure caused by exercise

 

 

 

Structure and Function Organization

6 levels – page 5

 

1)     chemical level – atomic or molecular level atoms combine to form molecules

a)     fats

b)     proteins

c)     nucleic acids

d)     carbohydrates

2)     cell level – cells are the basic units of all living things

a)     molecules combine to form organelles – the small structures that make up cells

i)        nucleus – contains hereditary info

ii)      mitochondria – provide energy – the powerhouse – makes ATP

3)     Tissue level – tissue is a group of similar cells and the materials which surround them characteristics of cells and materials determine the tissue function. 4 tissue types:

a)     epithelial

b)     connective

c)     muscle

d)     nervous

4)     organ level – organ is composed of two or more tissue types that perform one or more common functions

a)     heart

5)     organ system level – group of organs that have a common function or set of functions and are therefore viewed as a unit

a)     11 major organ systems

b)     Integumentary

c)     Skeletal

d)     Muscular

e)     Nervous

f)       Endocrine

g)     Cardiovascular

h)     Lymphatic

i)        Respiratory

j)        Digestive

k)     Urinary

l)        reproductive

6)     organism level – an organism is any living thing considered as a whole, whether composed of one cell or trillions of cells

 

 

 

11 Major Organ Systems  page 7

 

1)     integumentary system – hair, skin, and skin appendages (nails, and sweat glands)

a)     provides protection

b)     regulates temp

c)      prevents water loss

d)     helps metabolize Vitamin D

2)     skeletal system – consists of bones, cartilages, ligaments, and joints

a)      provides protection and support

b)      allows body movement

c)      produces blood cells

d)     stores fats and minerals

3)     muscular system – consists of muscles attached to the Skelton by tendons

a)     produces body movements

b)     maintains posture

c)      produces body heat

d)     consists of muscles attached to the Skelton by tendons

4)     lymphatic system –consists of lymphatic vessels – thoracic duct is the largest – lymph nodes, and other lymphatic organs such as the spleen and thymus

a)      removes foreign substances from the blood and lymph

b)      combats disease

c)       maintains tissue fluid balance

d)      absorbs fats from digestive tract

5)     respiratory system – consists of the lungs and respiratory passages – trachea, larynx, sinuses, and nasal passages

a)     exchanges O2 and CO2 between the blood and air

b)     regulates blood PH (acid base regulation)

6)     digestive system – consists of mouth, esophagus, stomach, intestines, and accessory organs

a)     performs mechanical and chemical processes of digestion

b)      absorption of nutrients

c)       elimination of wastes

7)     nervous system – one of two major regulatory systems –consists of brain, spinal cord, nerves, and sensory receptors

a)      detects sensations

b)      controls movements

c)      physiological processes

d)     intellectual functions

8)     endocrine system – one of two major regulatory systems –consists of glands such as pituitary, that secrete hormones

a)     influences metabolism

b)      growth, reproduction

c)       other functions

9)     Cardiovascular system – Consists of heart, blood vessels, and blood

a)     transports nutrients and waste products, gases, and hormones throughout body.

b)     Plays a role in immune response

c)      regulation of body temp

10) Urinary system – Consists of kidneys, urinary bladder, and ducts that carry water

a)     removes waste products from blood

b)      regulates blood PH

c)      ion balance

d)     water balance

11) Female reproductive system – Consists of ovaries, vagina, uterus, mammary glands, and associated structures.

a)     produces oocytes

b)     is the site of fertilization and fetal development

c)      produces milk for newborn

d)     produces hormones that influence sexual functions and behavior

12) Male reproductive system – Consists of testes, accessory structures, ducts, and penis

a)     produce and transfer sperm cells to the female

b)     produces hormones that influence sexual function and behavior

 


The Human Organism – Characteristics of life

 

All living things are highly organized and the organized parts all interact with each other.

 

  1. organization – the condition in which the parts of an organism have specific relationships to each other and the parts interact to perform specific functions.
    1. All organisms are composed of 1 or more cells.
    2. Cells are composed of highly specialized organelles which depend on the precise organization of large molecules
    3. Disruption of the organized state can lead to loss of function or even death
  2. metabolism – is all the chemical reactions that occur within an organism
    1. the breakdown of nutrients so energy can be utilized
    2. takes raw materials digested and makes them into itself
    3. necessary for vital functions such as responsiveness, growth, development, and reproduction
  3. responsiveness – the ability of the organism to sense changes in external/internal environment and adjust
    1. external – a plant leaning into the light
    2. internal – sweating if hot
  4. growth – happens when cells increase in size or number, which produces an overall enlargement of all or part of an organism
    1. cells can multiply or cells can get larger – a baby is one cell that becomes millions
    2. exercise can make muscles bigger.
    3. material surrounding the cells can increase – as bones grow they increase the material between the cells.
  5. development – includes the changes an organism undergoes through time. Begins with fertilization and ends at death.
    1. Differentiation – change in cell structure and function from generalized to specialized.
    2. Morphogenesis – the change in the shape of tissues, organs, and the entire organism
  6. reproduction – formation of new cells or organisms
    1. without reproduction, growth and development are not possible
    2. species would become extinct

 

NOTE:  some entities do not meet all 6 requirements. So there’s some controversy as to if they are alive. Viruses fit this category.

 

 


 

 

Homeostasis

 

Homeostasis is the existence and maintenance of a relatively constant environment within the body.

 

  1. variables –  conditions that must remain within a narrow range
    1. the volume
    2. temp
    3. chemical content of the fluid surrounding the cells
  2. set point – ideal normal value
    1. homeostatic mechanisms such as shivering or sweating normally maintain body temp at the set point
  3. normal range
    1. body temp increases and decreases slightly around to set point to produce a normal range of values
    2. it changes during exercise to meet the new demands
    3. as long as body temp remains in the normal range, homeostasis is maintained
  4. negative feedback – regulates most body systems
    1. negative means any deviation from the set point is made smaller or is resisted
    2. three components

                                                              i.      receptor – monitors the value of a variable

                                                            ii.      control center – establishes the set point around which the variables are maintained

                                                          iii.      effector – which can change the value of the variables.

    1. Stimulus – a deviation from the set point
    2. Response – produced by effector – tends to turn the variable back to set point.
    3. The receptor detects the stimulus and informs the control center, which analyzes the input. It sends output to the effector and the effector produces a response which tends to turn the variable back to set point.
    4. BP increases and a receptor in the aorta alerts the brain – the control center – the brain tells the heart – the effector – to slow down so BP is lowered
  1. positive feedback – not homeostatic and rare in healthy individuals
    1. when a deviation from a normal value occurs, the system response is to make the deviation greater.
    2. Creates a cycle leading away from homeostasis
    3. Non-homeostatic – If BP drops due to blood loss, the heart doesn’t beat properly – beats slower – which drops BP even further. Can result in death if not stopped.
    4. Homeostatic – Child birth is an exception. It’s a normal to have positive feedback as the uterus stretches to accommodate

 

 

 

Terminology and the Body Plan

 

 

Etymology – the derivation of words – where they originate from.

 

 

Body positions and terms pages 13-17

 

  1. anatomical position – standing erect with face directed forward, upper limbs hanging to sides, and palms face forward
    1. supine – lying face upward
    2. prone – lying face down
  2. directional terms – describe parts of the body relative to each other.
    1. Right – toward the right side of the body
    2. Left – toward the left side of the body
    3. Superior – up – a structure above another
    4. Inferior – down – a structure below another
    5. Anterior – front – the front of the body
    6. Posterior – back – the back of the body
    7. Cephalic – superior or closer to the head than another structure
    8. Caudal – inferior or closer to the tail than another structure
    9. Ventral – belly – toward the belly
    10. Dorsal – back – toward the back
    11. Proximal – nearest – closer to the point of attachment to the body than another structure
    12. Distal – to be distant – farther from the point of attachment to the body than another structure
    13. Lateral – side – away from the midline of the body
    14. Medial – middle – toward the midline of the body
    15. Superficial – toward the surface – toward or on the surface of the body
    16. Deep – away from the surface, internal
  3. body parts and regions
    1. upper limb divided into

                                                              i.      arm – extends from the shoulder to elbow

                                                            ii.      forearm – extends from elbow to wrist

                                                          iii.      wrist

                                                          iv.      hand

    1. lower limb divided into

                                                              i.      thigh – extends from hip to knee

                                                            ii.      leg – extends from knee to ankle

                                                          iii.      ankle

                                                          iv.      foot

    1. central region consists of

                                                              i.      head

                                                            ii.      neck

                                                          iii.      trunk

    1. trunk divided into

                                                              i.      thorax – chest

                                                            ii.      abdomen – between thorax and pelvis

                                                          iii.      pelvis  -- inferior end of the trunk associated with hips

  1. subdivisions of the abdomen
    1. 4 quadrants – divide the abdomen superficially by 2 lines, horizontal and vertical that intersect the navel

                                                              i.      right upper – gallbladder and liver

                                                            ii.      left upper – spleen and stomach

                                                          iii.      right lower – appendix

                                                           iv.      left lower – small bowel and large bowel

    1. 9 regions – divide the abdomen by 4 lines, 2 horizontal and 2 vertical. They create an imaginary tic-tac-toe on the abdomen.  Used as reference points for locating underlying organs

                                                              i.      Right hypochondriac -- liver

                                                            ii.      Epigastric – stomach and liver

                                                          iii.      Left hypochondriac -- stomach

                                                           iv.      Right lumbar --

                                                             v.      Umbilical -- navel

                                                           vi.      Left lumbar --

                                                         vii.      Right iliac --

                                                       viii.      Hypogastric --

                                                           ix.      Left iliac --

  1. Planes – imaginary flat surfaces passing through the body, making it possible to look “inside” and observe the body’s structures.
    1. Sagittal plane – runs vertically through the body and separates it into right and left portions.

                                                              i.      Sagittal means “the flight of an arrow”

    1. Median plane – a Sagittal plane that passes through the midline and divides the body into equal left and right halves
    2. Transverse or horizontal plane – runs parallel to the ground and divides the body into superior and inferior portions
    3. Frontal or coronal plane – runs vertically from left to right and divides the body into anterior and posterior portions
    4. Longitudinal section – when an organ is cut through the long axis
    5. Cross or transverse section –  when an organ is cut at right angles to the long axis
    6. Oblique section – when an organ is cut at other than a right angle to the long axis

 

 

Body parts and regions

 

Front

 

  1. cephalic – head
    1. frontal – forehead
    2. orbital – eye
    3. nasal – nose
    4. oral – mouth
    5. otic – ear
    6. buccal – cheek
    7. mental – chin
  2. trunk
    1. thoracic – thorax

                                                              i.      pectoral – chest

                                                            ii.      sternal – breastbone

                                                          iii.      mammary -- breast

    1. abdominal – abdomen
    2. umbilical – naval
    3. pelvic – pelvis
    4. inguinal – groin
    5. pubic – genital
  1. upper limb
    1. clavicular – collar bone
    2. axillary – arm pit
    3. brachial – arm
    4. antecubital – front of elbow
    5. antebrachial – forearm
    6. carpal – wrist
    7. manual -- hand

                                                              i.      palmar – palm

                                                            ii.      digital – fingers

  1. lower limb
    1. coxal – hip
    2. femoral – thigh
    3. patellar – kneecap
    4. patellar – kneecap
    5. crural – leg
    6. pedal – foot

                                                              i.      talus – ankle

                                                            ii.      dorsum – top of the foot

                                                          iii.      digital – toes

 

 

Back

 

  1. cranial – skull
    1. occipital – base of skull
    2. nuchal – back of neck
  2. trunk
    1. dorsal – back
    2. scapular – shoulder blade
    3. vertebral – spinal column
    4. lumbar – loin
  3. sacral – between hips
  4. gluteal – buttock
  5. perineal – perineum
  6. upper limb
    1. acromial – point of shoulder
    2. olecranon – point of elbow
    3. dorsum – back of hand
  7. lower limb
    1. popliteal – hollow behind knee
    2. sural – calf
    3. plantar – sole
    4. calcaneal -- heel

 

Body cavities

 

some open to outside and some do not

 

  1. trunk – or ventral body cavity or coelom – has 3 large cavities that do not open to the outside
    1. thoracic cavity – surrounded by rib cage. Diaphragm separates it from abdominal cavity

                                                              i.      divided into left and right by a median partition, the mediastinum or middle wall

                                                            ii.      mediastinum contains: heart

1.      thymus gland

2.      trachea

3.      esophagus

4.      blood vessels

5.      nerves

                                                          iii.      lungs are on either side of mediastinum

                                                           iv.      pericardial cavity – surrounds heart

                                                             v.      pleural cavity – surrounds lungs

    1. abdominal cavity – enclosed primarily by abdominal muscles

                                                              i.      stomach

                                                            ii.      intestines

                                                          iii.      liver

                                                           iv.      spleen

                                                             v.      pancreas

                                                           vi.      kidneys

    1. pelvic cavity – encased by pelvic bones –

                                                              i.      urinary bladder

                                                            ii.      part of the large intestine

                                                          iii.      internal reproductive organs

    1. abdominopelvic cavity – term used for the abdominal and pelvic cavities sometimes as they are not physically separated

 

 

serous membranes

 

cover the organs of the trunk cavities and line the trunk cavities and decrease friction of the organs.

2 types:

  1. visceral – covers the organ
  2. parietal – lines the cavity
    1. the space between the visceral and parietal membranes is normally filled with a thin, lubricating film of serous fluid produced by the membranes

 

 

  1. thoracic cavity contains 3 serous lined membrane cavities
    1. pericardial cavity –

                                                              i.      surrounds the heart

1.      contains pericardial fluid

2.      located between the visceral and parietal pericardium

a.      visceral pericardium – covers the heart, which is contained within a connective tissue sac lined with the parietal pericardium

 

    1. pleural cavity –

                                                              i.      surrounds each lung which is covered by visceral pleura

1.      located between the visceral and parietal pleurae

2.      contains pleural fluid

                                                            ii.      parietal pleura line the inner surface of the thoracic wall, the lateral surfaces of the mediastinum, and the superior surface of the diaphragm

    1. abdominopelvic cavity 

                                                              i.      peritoneal cavity – lined with serous membranes

1.      visceral peritoneum covers many organs

2.      located between the visceral and parietal peritonea

3.      contains peritoneal fluid

                                                            ii.      parietal peritoneum lines the wall of cavity and inferior surface of diaphragm

  1. mesenteries
    1. consist of two layers of peritoneum fused together
    2. connect the visceral peritoneum of some abdominopelvic organs to the body wall – anchors them
    3. or to the visceral peritoneum of other organs
    4. provides pathway for nerves and blood vessels to reach organs
  2. retroperitoneal – behind the peritoneum
    1. organs without mesenteries.
    2. More closely attached to body wall
    3. Organs covered by parietal peritoneum
    4. Includes:

                                                              i.      Kidneys

                                                            ii.      Adrenal glands

                                                          iii.      Pancreas

                                                           iv.      Parts of intestines

                                                             v.      Urinary bladder