Chapter 1 Introduction to the Human Body

The term "anatomy" means

"'to cut apart""

Physiology defined

'nature' -the study of the functioning of living organisms -studies the functions of the body, in other words, how the body parts work and carry life-sustaining activity; underlines anatomy. - how the functions work and keep us alive.

water

- 50-60% our body weight -Most abundant chemical in body; provides the watery environment needed for chemical reactions -Also is fluid base for secretions and excretions

Movement

- muscular system allows movement -change in position of the body or of a body parts via skeletal muscles - motion of an internal organ. -cardiac muscle (blood), - smooth muscle, foodstuff (digestive) and urine (urinary system) contractility - refers to movement at the cellular level, self-contraction, ability to shorten forcibly when stimulated

1.2 Levels of Organization

Learning Objectives 1. Name the different levels of structural organization that make up the human body, and explain their relationships. 2. List the 11 organ systems of the body, identify their components, and briefly explain the major function(s) of each system.

*Tissue Level

are groups of similar types of cells that have common function Classes of Tissue 1. epithelial tissue 2. connective tissue 3. muscle tissue 4. nervous tissue

*chemical level

atom, molecules and organelles atoms- fundamental building blocks of matter (chemicals.) molecules- atoms combined in specific ways, such as water and proteins Organelles- basic components of cells, that carries specific functions within a cell.

The two fundamental divisions of our body are

axial part and appendicular

variables

factors that can change (blood sugar, body temperature, blood volume, etc.)

Palpation

feeling organs with your hands

subdivisions of Anatomy

gross, macroscopic, anatomy

why this matters

learning and understanding anatomical terminology helps us to communicate with our colleagues in the health science

Systemic Anatomy

looks a specific system (just one system) of the body; -For example, when studying the cardiovascular system, you would only examine the heart and the blood vessels of the entire body.

regional anatomy

looks all the structures in particular part of the body; muscles, bones, blood vessels, nerves etc in a particular region of the body such as the abdomen or leg, are examined at the same time.

surface anatomy

looks at internal structures as they relate to the overlying skin surface ex: visible muscles and veins - clinic get blood work done uses that

Microscopic anatomy

looks at structures too small to be seen with the naked eye; example: tissues + cells Subdivisions of microscopic anatomy include cytology and histology

*Organ Level

organ- two or more types of tissues that work together to perform specific functions for the body

Cardiovascular system

organs found: blood vessels, heart function: transports nutrients, chemical messengers, gases and wastes in blood; the heart pumps blood

Skeletal system

organs found: bones and joints ligaments, associated cartilages function; supports the body organs, and provides a framework the muscles use to cause movement. blood cells are formed within bones. bones store minerals

Nervous system

organs found: brain, spinal cord, nerves function: controls cell function with electrical signals

Urinary system

organs found: kidneys, ureters,urinary bladder, urethra function; removes wastes, maintains body fluid volume, pH and electrolyte levels.

Respiratory system

organs found: nasal cavity, pharynx, larynx, trachea, lungs, bronchus function: exchanges oxygen and carbon dioxide between air and blood in the lungs, pH regulation, sound production

Digestive system

organs found: oral cavity, esophagus, liver, stomach, small intestine, large intestine, rectum, anus function: digest food , absorbs nutrients

Endocrine system

organs found: pineal gland, pituitary gland, thyroid gland, thymus, adrenal gland pancreas, ovary, testis function: secretes hormones that regulate body functions; control cell function with hormones

Male Reproductive system

organs found: prostate, penis, testis, scrotum, ductus deferens function: produces sperm and transmit to female vagina during intercourse

Lymphoid system

organs found: red bone marrow, thymus, lymphatic vessels, thoracic duct, spleen, lymph nodes function; returns fluid to cardiovascular system, detects, filters, and eliminates disease causing organisms.

Integumentary system

organs found: skin, hair, nails,associated glands function: forms the external body covering and deeper tissues from injury and helps regulate body temperature

Muscular system

organs found: smooth muscular tissue, skeletal tissue, cardiac muscle function: moves the body and body parts such as facial expression, maintains posture and produces heat

Female Reproductive system

organs found; mammary glands, ovary, uterus, vagina uterine tube function: produces sperm and male sex hormone, enables birth of infant, mammary glands breasts produce

*Organ System Level

organs that work closely together to make up an organism system Organs that work together to accomplish a common purpose

muscle tissue

provides movement

Homeostatic control of variables involves three components:

receptor, control center, and effector

Contractility

refers to movement at cellular level ability to shorten forcibly when stimulated

Excretion

removes of wastes from metabolism and digestion urinary system: Urea (from breakdown of proteins), cellular respiration: carbon dioxide (from metabolism), digestive system: feces (unabsorbed foods)

Body Planes and Sections

sagittal plane, frontal (coronal) plane, transverse (horizontal) plane Sections: Cuts or sections made along a body plane Named after plane, so a sagittal cut results in a sagittal section

Developmental anatomy

studies anatomical and physiological development that occur in body throughout life span Embryology a subdivision

pathological anatomy (gross)

studies structural changes caused by disease

Cytology

study of cells

Histology

study of tissues

connective tissue

supports and protects body organs

Observation

the action or process of observing something or someone carefully or in order to gain information.

What is the correct structural order for the following terms: tissue, organism, organ, cell?

the order in the structural hierarchy is cell, tissue, organ, and organism

Gross or macroscopic, anatomy

the study of the large body structures, visible to the naked eye such as heart, lungs and kidneys -studies preserved animals or their organs are dissected (cut up) to be examined.

Variable of Homeostatic Control

are factors that can change (blood sugar, body temperature, blood volume, etc.)

subdivions of developmental anatomy

Embryology

Two complementary branches of science

anatomy and physiology—provide the concepts that help us to understand the human body.

manipulation

- move diff parts of body to diagnose/ help p feel better - to access movement and flexibility - therapeutically for joint and spine problems.

nervous tissue

A body tissue that carries electrical messages back and forth between the brain and every other part of the body.

epithelial tissue

A body tissue that covers the surfaces of the body, inside and out

Reproduction

- At the cellular level, reproduction involves division of cells for growth or repair - two identical daughter cells - At the organismal level, reproduction is the production of offspring

Homeostatic Control

- Body must constantly be monitored and regulated to maintain homeostasis --Nervous and endocrine systems, as well as other systems, play a major role in maintaining homeostasis -Variables are factors that can change (blood sugar, body temperature, blood volume, etc.)

Nutrients

- Chemicals substances used for energy and cell building Carbohydrates: major source of energy Proteins: needed for cell structures building and cell chemistry Fats: long-term energy storage Minerals and vitamins: involved in chemical reactions as well as for structural purposes

control center

- Determines set point at which variable is maintained - Receives input from receptor - Determines appropriate response

homeostatic imbalance

- Disturbance of homeostasis --Increases risk of disease --Contributes to changes associated with aging ---Control systems become less efficient --If negative feedback mechanisms become overwhelmed, destructive positive feedback mechanisms may take over ---Heart failure

Normal body temperature

- If body temp falls below or goes above 37°C (98.6°F), rates of chemical reactions are affected - the muscular system generates most body heat.

Anatomy defined

- Latin:"to cut up" -the study of the structure of living organisms; studies the structure of the body parts and their relationship to one another. it's concrete; body structures can be seen, felt, and examined closely.

Essential tools for studying anatomy

- Mastery of anatomical terminology - Observation - Manipulation - Palpation - Auscultation

Negative feedback mechanisms

- Most-used feedback mechanism in body - Response reduces or shuts off original stimulus - Variable changes in opposite direction of initial change Examples Regulation of body temperature (a nervous system mechanism) Regulation of blood glucose by insulin (an endocrine system mechanism) - regulate heart rate, blood pressure, the rate and depth of breathing, and blood levels of oxygen, carbon dioxide, and minerals

positive feedback mechanisms

- Response enhances (increase) or exaggerates the original stimulus - May exhibit a cascade or amplifying effect as feedback causes variable to continue in same direction as initial change - Usually controls infrequent events that do not require continuous adjustment, for example: - Enhancement of labor contractions by oxytocin (oxytocin causes the contractions to become more painful and more powerful until the baby is born. The birth ends the stimulus for oxytocin release and shuts off the PFB) Platelet plug formation and blood clotting

Maintaining boundaries

- Separation between internal and external environments must exist - Plasma membranes separate inside cell and outside cell - Skin separates organism from environment (integumentary job to protect whole external body)

Atmospheric pressure

- Specific pressure of air is needed for adequate breathing and gas exchange in lungs (760 mm Hg at sea level)

medical technology sophisticated tools

- X-ray - Computed Tomography (CT) Scans -Digital Subtraction Angiography -Positron Emission Tomography (PET) Scansaphy - Magnetic Resonance Imaging (MRI) -Ultrasound Imaging

Receptor

- a sensor that monitors the environment - Responds to stimuli (things that cause changes in controlled variables)

Digestion

- breaking down of ingested foodstuffs to simple molecules that can be absorbed into the blood.

Metabolism

- combination of all chemical reactions that occur in body cells - Sum of all catabolism (breakdown of molecules) and anabolism (synthesis of molecules) as it carries out its life processes - Metabolism is regulated largely by hormones secreted by endocrine system glands

Auscultation

- listening to sounds within the body - (listening to organ sounds with a stethoscope)

Homeostasis

- the maintenance of relatively stable internal conditions despite continuous changes in environment - A dynamic state of equilibrium, always readjusting as needed -Maintained by contributions of all organ systems

Oxygen

-Essential for release of energy from foods -The body can survive only a few minutes without oxygen - 20% of the air we breathe is oxygen

effector

-Receives output (data) from control center -Provides the means to respond -Response either reduces stimulus (negative feedback) or enhances (faster) stimulus (positive feedback)

principle of complementarity of structure and function.

-The relationship between a structure and its function; i.e structure determines function - function always reflects structure Anatomy and physiology are inseparable Function always reflects structure What a structure can do depends on its specific form - Bones can support and protect body organs because they contain hard mineral deposits. - Blood flows in one direction through the heart because the heart has valves that prevent backflow.

Humans are multicellular

-To function, must keep individual cells alive -organs are designed to service cells -All cells depend on organ systems to meet their survival needs (11 organs)

Neurophysiology

-explains the workings of the nervous system

gross anatomy approaches

-regional anatomy -systemic anatomy -surface anatomy - Microscopic anatomy -developmental anatomy -Radiographic anatomy - pathological anatomy

*Cellular Level

-single cell -Cells- basic structural and functional units of the body -All cells share some common functions, but individual cells vary widely in size and shape, reflecting their unique functions in the body.

cardiovascular physiology

-the function of the heart, blood, and blood vessels

Describe the levels of organization in the human body.

1. Chemical level 2. Cellular level 3. Tissue level 4. Organ level 5. Organ system level 6. Organismal level

1.1 Form (anatomy) determines function (physiology)

1. Define anatomy and physiology and describe their subdivisions. 2. Explain the principle of complementarity.

1.4 Homeostasis is maintained by negative feedback

1. Define homeostasis and explain its significance. 2. Describe how negative and positive feedback maintain body homeostasis. 3. Describe the relationship between homeostatic imbalance and disease.

1.5 Anatomical terms describe body directions, regions, and planes

1. Describe the anatomical position. 2. Use correct anatomical terms to describe body directions, regions, and body planes or sections.

List the 11 major organ systems of the body and functions for each organ system.

1. Integumentary system 2. Skeletal system 3. muscular system 4. nervous system 5. endocrine system 6. lymphatic system 7. respiratory system 8. digestive system 9. urinary system 10. reproductive system 11. Cardiovascular system

1.3 What are the requirements for life?

1. List the functional characteristics necessary to maintain life in humans. 2. List the survival needs of the body.

List the Functional Characteristics necessary to maintain life in humans

1. Maintaining boundaries 2. Movement, 3. Responsiveness or excitability 4. Digestion, 5. Metabolism, 6. Excretion, 7. reproduction, 8. Growth.

Survival needs of the body; Humans need several factors for survival that must be in the appropriate amounts; too much or too little can be harmful:

1. nutrients 2. oxygen 3. water 4. normal body temp 5. atmospheric pressure

Topics of Physiology subdivisions:

1. renal physiology, 2.neurophysiology, 3.cardiovascular physiology

*Organismal Level

All organs system combined to make a whole organism and keep us alive

Growth

Is an increase in size of a body part or the organism. it is usually accomplished by increasing the number of cells. However, individual cells also increase in size when not dividing.

axial part

Makes up the main axis of our body, includes the head, neck, and trunk.

example of negative feedback

Receptors sense increased blood glucose (blood sugar) Pancreas (control center) secretes insulin into the blood Insulin causes body cells (effectors) to absorb more glucose, which decreases blood glucose levels

Radiographic Anatomy (gross)

Studies internal structures as visualized by X-ray images or specialized scanning procedures

Embryology

Study of developmental changes that occur before birth

anatomical position

To stand erect with arms at the sides and palms of the hands turned forward and thumbs point away from the body

Anatomical Terminology

a set of vocabulary used by health professionals to refer to parts, regions, directions, and planes on the human body

The image below shows tissue cells and part of a blood vessel. The cells' nutrients and wastes are exchanged across an important boundary between two fluid compartments. Name the boundary (a) and the fluid in the compartments (b and c). Be specific.

a) plasma membrane b) intracellular fluid c)extracelullar fluid

Responsiveness, or excitability

ability to change and respond to stimuli -Withdrawal reflex prevents injury (glass, cut finger) -Control of breathing rate, which must change in response to different activities (ex: blood rises to high level)

Directional Terms

allow us to explain where one body structure is in relation to another Direction is always based on standard anatomical position Right and left refer to the body being viewed, not right and left of observer

Physiology often focuses on

cellular and molecular level of the body

Renal Physiology

concerns kidney function and urine production and balance fluid, electrolytes, blood pH, etc. often focuses on cellular and molecular cells of the body

Appendicular part

consists of the appendages, or limbs (legs and arms), which are attached to the body's axis

Subdivisions of microscopic anatomy includes:

cytology and histology

Regional Terms

designate specific areas within major body divisions