Anatomy and Physiology 1 Chapter 1

Science

Method of observing and measuring natural phenomenon in order to explain them

Human anatomy

Study of structure of human body

Human physiology

Study of body’s functions

Characteristics of Living Organisms

Cellular composition: cells are basic units of life

Metabolism: chemicals - substances with unique molecular composition; used in or produced by chemical reactions; living organisms carry out chemical reactions, collectively known as metabolism. Metabolism can build up or break down substances

Growth: building outweighs breaking down processes; either increase in size of individual cells or increase in numbers of cells

Excretion: elimination of potentially harmful waste products created by metabolic processes

Responsiveness or irritability: sensing and reacting to changes or stimuli in environment

Movement of entire organism/individual cells within organism and materials within or between cells or organisms

Reproduction: two forms in multicellular organisms; individual cells reproduce during growth and to replace damaged or old cells; organisms itself reproduces

Levels of Structural Oragnization

Body is constructed from series of progressively larger “building blocks”; each type of block is structural level of organization

Chemical level

smallest level or organization

foundation for each successive level

ranges from tiny atoms to complex chemical structures (molecules) composed of thousands of atoms

Cellular level

groups of many different types of molecules combined in specific ways to form cellular structures

Tissue level

two of more cell types cooperate to perform common fucntios

two components: cells and surrounding extracellular matrix

Organ level

Two or more tissue types combined to form organ

recognizable shape/performs specialized task

Organ system level

organs grouped into organ systems

two or more organs together carry out broad function

ex: cardiovascular system (heart and blood vessels) transports blood

Organism level

organ systems function together to make up working human body, an organism

Organ systems

human body has 11 organ systems

Integumentary system

hair, skin, and nails

protects the body from external environment

produces hitman D

retains water

regulates body temperature

Skeletal System

bones and joints

supports the body

protects internal organs

provides leverage for movement

produces blood cells

stores calcium salts

Muscular System

skeletal muscles

produces movements

controls body openings

generates heat

Nervous System

brain, spinal cord, and nerves

regulates body functions

provides for sensation, movement, automatic functions, and higher mental functions via nerve impulses

Endocrine System

pineal gland, hypothalamus, pituitary gland, thyroid gland, thymus gland, adrenal glands, pancreas, ovaries, and testes

regulates body functions

regulates the functions of muscles, glands, and other tissues through the secretion of chemicals called hormones

Cardiovascular System

blood vessels and heart

pumps and delivers oxygen-poor blood to the lungs and oxygen-rich blood to the tissues

removes waste from the tissues

transports cells, nutrients, and other substances

Lymphatic System

tonsils, lymph nodes, thymus, spleen, and lymphatic vessels

returns excess tissue fluid to the cardiovascular system

provides immunity (protection against disease)

Respiratory System

nasal cavity, pharynx, larynx, trachea, lungs

delivers oxygen to the blood

removes carbon dioxide from the body

maintains the acid-base balance of the blood

Digestive System

mouth, salivary glands, esophagus, liver, stomach, gallbladder, pancreas, large intestine, small intestine

digests food

absorbs nutrients into the blood

removes food waste

maintains fluid, electrolyte, and acid-based balance

Urinary System

kidneys, ureters, urinary bladder, urethra

removes metabolic wastes from the blood

maintains fluid, electrolyte, and acid-base balance

stimulates blood cell production

Reproductive System

prostate gland, ductus deferens, testis, penis

produces and transports sperm

secretes hormones

sexual function

Reproductive System

mammary glands, uterine tube, ovary, uterus, vagina

produces and transports oocytes (eggs)

site of fetal developmental, fetal nourishment, childbirth, and lactation

secretes hormones

sexual function

Types of Anatomy and Physiology

systemic anatomy: examines human body by individual organ systems

regional anatomy: divides body into regions of study (such as head and neck)

surface anatomy: studies surface markings of body

gross anatomy: examines structures that can be seen with unaided eye

microscopic anatomy: studies structures that can only be seen with aid of microscope; includes histology (study of tissues) and cytology (study of cells)

physiology: subfields classified by organ or organ system being studied (i.e. neurophysiology studies brain and nerves, cardiovascular physiology studies heart and blood vessels)

What do anatomists study?

relationships among parts of the body

structure of individual organs, tissues, and cells

i.e. focus on the form, structure, and location of the small intestine; describe the composition of the wall

Microscopic & Macroscopic Anatomy

microscopic anatomy: examines structures not seen by unaided eye (i.e. cytology and histology)

gross anatomy (macroscopic): investigates structures visible to the unaided eye (i.e. systemic anatomy, regional anatomy, surface anatomy, comparative anatomy, and embryology)

Form and Function are interrelated

structure and function are inseparable; together, they provide the basis for understanding health and human performance

integrating the disciplines is the easiest way to learn about both; both disciplines must use information from the other field

Anatomical Positon

body standing upright, feet are shoulder width apart, with upper limbs at sides of trunk and head and palms facing forward

“right” and “left” always refers to sides of body being described, not our own

Prone

laying face down flat

Supine

laying face up

Anterior (ventral)

front in humans

Posterior (dorsal)

back

can refer to body as a whole or to body part

superior (cranial)

towards head

used to refer to positions on head, neck, and trunk only

inferior (caudal)

used to refer to positions on head, neck, and trunk only

towards tail

used to refer to positions on head, neck, and trunk only

proximal

closer to point of origin

distal

more distant from point of origin

medial

closer to midline

lateral

further away from midline of body

superficial

closer to the surface of the body

deep

further away from surface

axial

head, neck and trunk

appendicular

upper and lower limbs or appendages

Planes of Section

three primary places of section

means of studying form and function of body region by dividing body or a body part for examination

Sagittal Plane

divides body or body part into right and left sections

Midsagittal plane (median plane)

divides body or body part into equal left and right sections

Parasagittal plane

divides body or body part into unequal right and left sections

Frontal Plane (Coronal Plane)

divides body or body part into anterior and posterior sections

Transverse Plane (Horizonal Plane)

divides body or body part into superior and inferior sections or proximal and distal sections for structures of appendicular region

Oblique plane

less standardized plane; taken at angle; useful for structures that are difficult to examine using only three primary planes of section

Cavity

any fluid-filled space without body

axial region is divided into several cavities

protect internal organs and allow them to move and expands as necessary to perform functions

major cavities include posterior and anterior cavities and their subdivisions

Posterior Body Cavity

largely on the posterior side of body

Cranial cavity (posterior body cavity)

within the skull; protects the brain

Vertebral (spinal) cavity (posterior body cavity)

within the vertebral column

protects spinal cord

subdivisions are continuous

filled with cerebrospinal fluid (CSF)

bathes and protects brain and spinal cord

Anterior Body Cavity

separated into two divisions by diaphragm (thoracic cavity and abdominopelvic cavity)

Thoracic cavity

superior to diaphragm

divided into pleural cavities, mediastinum, and pericardial cavity

Pleural cavities

each surround either left or right lung

Mediastinum

between pleural cavities; houses heart, great vessels, trachea, and esophagus

not within serous membrane

Pericardial cavity

within mediastinum

within serous membrane that surrounds heart

Abdominopelvic cavity

inferior to diaphragm

subdivided into superior abdominal cavity (diaphragm to bony pelvis) and pelvic cavity (within bony pelvis)

contains organs from several systems (digestive, lymphatic, reproductive and urinary)

Peritoneal Cavity

abdominal sub cavity found within the serous membrane

Abdominopelvic quadrants

imaginary lines cross at umbilicus divide cavity into four quadrants

right upper quadrant

right lower quadrant

left upper quadrant

left lower quadrant

can also divided into 9 regions

Serous membranes

thin sheets of tissue; for cavities in ventral cavity, surround heart, lungs and many abdominal organs

single, continuous layer of tissue; folds over itself to create a double layered structure

• visceral layer: in contact with underlying organ

• parietal layer: outermost layer attached to surrounding structures

Serous fluid

within cavity between two membrane layers; extremely thin layer of fluid

• watery, slippery lubricant

• fills space between membrane layers

• produced by cells of membrane

• prevents friction from movement of organs

Body Cavities

body has three serous body cavities formed by three main serous membranes

• pleural membranes

• pericardial membranes

• peritoneal membranes

Pleural Membranes

consists of outer parietal pleura (followers contours of thoracic wall) and inner visceral pleura (rungs along surface of lungs)

pleural cavities: thin space enclosed by pleural membranes

Pericardial membranes

consists of outer parietal pericardium (separates heart from mediastinum) and inner visceral pericardium (lies directly on heart muscle)

pericardial cavity: space created by pericardial membranes

Peritoneal membranes

surrounds some of abdominal organs

consists of outer parietal peritoneum and inner visceral peritoneum

peritoneal cavity: space between layers

doesn’t cover every organ; kidneys lie outside of and behind parietal peritoneum; thus retroperitoneal organs

Medical Imaging

used to look inside patients without surgery; different forms of radiation form images of internal structures

examples of imaging techniques; sections of body planes

• x-ray: ionizing radiation

• computed tomography scan (CT): also ionizing radiation; 3-d imagine is computer generated from data

• magnetic resonance imaging (MRI): body is places within magnetic field; computer complies data producing 3D image

Physiological processes operate to maintain body’s homeostatis

homeostatic imbalances: disturbances in homeostasis can lead to disease and death if uncorrected

body’s internal environment: results of a wide range of coordinated processes or variables (i.e. temperature, chemical composition of blood and other body fluids)

to prevent imbalance, most variables are controlled and maintained within a narrow range, close to a normal value (set point)

Negative feedback loops

oppose initial change in regulated variable; reduce output

• when regulated variable is outside normal range, stimulus is detected by receptor

• stimulus is sent to control center (nervous or endocrine system) and determine variable is outside of set point

• control center signals effectors, which cause physiological responses that return variable to normal homeostatic range

ends once variable returns to normal

Positive Feedback Loop

less common

• effector activity increases and reinforces initial stimulus

• shuts off when conditions return to normal range

i.e. formation of a blood clot

• injury to blood vessels leads to blood loss

• activates receptors on platelets

• release chemical that attract and activate more platelets to stick together and plug wound

• additional platelets attract and activate more platelets, and so on, until blood vessel is sealed by a blood clot

childbirth - labor occurs by positive feedback

• body’s head stretches cervix (stimulus); data is sent to brain (control center); signals uterus (effector); uterus produces oxytocin; oxytocin stimulates uterine contractions (response)

• contractions move body’s head, causing more cervical stretching; stimulates release of more hormone; effect continues to be amplified until baby is born

• Pitocin (syntenic oxytocin): induces labor; stimulates uterine contractions, initiating feedback loop

Structure and Function Core Principle

complementarity of structure and function

• form of structure is always such that it best suits its function

• states simply that form follows function; applies to each level of organization even down to chemical level

Gradient Core Principle

gradient: present any time more of something exists in one area than another, where two areas are connected

gradients drive many physiological processes (respiration, nutrient exchange, formation of urine)

common gradients in human body

• temperature gradient: temperature difference between two connected regions

• concentration gradient: concentration difference between two connected regions

• pressure gradient: pressure difference between two connected regions

Cell-Cell Communication

cells in body must work in coordinated fashion to maintain homeostasis of entire organism

usually via chemical messengers or electrical signals; one cell triggers a response from another cell

electrical signals are usually transmitted between neighboring cells; chemical messengers can affect neighboring cells or travel to distant cells to cause effect