Chapter 1- An introduction to the human body Flashcards
Anatomy
The study of form/structure
- Means “a cutting open”
-The study of the internal and external structures of the body & the physical relationships among body parts
Anatomy can be divided into
Gross Anatomy
Microscopic Anatomy
Gross (macroscopic) Anatomy
Involves the examination of relatively large structures and features usually visible with the unaided eye
What is gross anatomy broken down into
Surface anatomy
Regional Anatomy
Systemic Anatomy
Surface Anatomy
The study of surface features of the body
-Surface anatomy deals with anatomical features that can be studied by sight, without dissection.
-These are the form and proportions of the human body and the surface landmarks which correspond to deeper structures hidden from view, both in static pose and in motion.
Regional Anatomy
The study of structures that contribute to specific body regions
Example of regional anatomy
The thoracic region encompassing the chest
The mammary region encompassing each breast
The sternal region encompassing the sternum
The abdominal region encompassing the stomach area
The umbilical region is located around the navel
The coxal region (hip region) encompassing the lateral (side) of hips
The pubic region encompassing the area above the genitals1.
Systemic Anatomy
Study of the structures that contribute to specific body systems
Example of systemic anatomy
A systemic anatomical study of the muscular system would consider all of the skeletal muscles of the body
Ex:
-The skin and its appendages belong to the integumentary system
-All structures involved in digestion to the digestive system
-All bones of the body to the skeletal system.
In systemic anatomy, the systems are studied one by one (as opposed to regional anatomy).
Microcscopic Anatomy
Delas with structures that cannot be seen without magnification, & thus the equipment used establishes the boundaries of what can be seen
Microscopic Anatomy is broken down into
Cytology
Histology
Cytology
The study of cells
Histology
The study of tissues
Dissecting Microscope
Tissue Structure
Light Microscope
Basic details of cell structure
Electron Microscope
Individual molecules that are only a few nanometers apart
Physiology
The study of functions
-How living organisms perform their vital functions
(Functions are complex and much more difficult to examine than most anatomical structures)
Basic Principles of Cell Theory
1) Cells are structural building blocks of all plants and animals
2) Cells are produced by the divisions of pre- existing cells
3) Cells are the smallest structural units that perform all vital functions
Responsiveness
Indicates that the organism recognizes changes in its internal or external environment
-Required for adaptability
Adaptability
Changes the organism’s behavior, capabilities or structure
-Required for survival in a constantly changing world
Growth and Development
Inherited patterns for growth (an increase in size) and development (changes in structure and function) produce organisms characteristic of their species
-Growth and development to maturity is controlled by inherited instructions in the form of DNA
Development
All of the changes the body goes through in life
-The processes of growth and repair, both of which involve cell differentiation
Differentiation
Development includes the process of differentiation, in which unspecialized cells become specialized in structure and function to perform certain tasks in the body
Growth
The increase in body size
-Humans grow by increasing the number of existing cells, increasing the amount of non-cellular material around cells (mineral deposits in bones, and (within very narrow limits) increasing the size of existing cells
Reproduction
The formation of a new organism from parenting organisms
Levels of organization
1) Chemical
2) Cellular
3) Tissue
4) Organ
5) Organ System
6) Organism
Chemical Level
Atoms bond to form molecules with three dimensional structures
Cellular Level
A variety of molecules combine to form the fluid and organelles of a body cell
Tissue Level
A community of similar cells form a body tissue
Organ Level
Two or more different tissues combine to form an organ
Organ system level
Two or more organs work closely together to perform the functions of a body system
Organism level
Many organ systems work harmoniously together to perform the functions of an independent organism
4 requirements for human life
-oxygen
-nutrients
-narrow range of temperature
-Narrow range of atmospheric pressure
Molecules
2 or more atoms combine to form a molecule
-The chemical building blocks of all body structures
Climax
Climactic condition
Cell
The smallest independentely functioning unit of a living organism
Organelles
Flexible membranes that enclose cytoplasm, a water based cellular fluid together with a variety of tiny functioning units
Tissue
A group of many similar cells that work together to perform a specific function
Organ
An anatomically distinct structure of the body composed of 2 or more tissue types
Organ system
A group or organs that work together to perform major functions or meet physiological needs of the body
Lymphatic system
-Returns fluid to blood
-Defends against pathogens
Thymus
Lymph Nodes
Spleen
Lymphatic vessels
Respiratory system
-Removes carbon dioxide from the body
-Delivers oxygen to blood
Nasal Passage
Trachea
Lungs
Muscular system
-Enables movement (with skeletal system)
-Helps maintain body temperature
Skeletal muscles
Tendons
Nervous System
-Detects and processes sensory information
-Activates bodily responses
Brain
Spinal cord
Peripheral nerves
Integumentary system
-Encloses internal body structures
-Site of many sensory receptors
Hair
Skin
Nails
Skeletal system
-Supports the body
-Enables movement (with muscular system)
Cartilage
Bones
Joints
Endocrine system
-Secretes hormones
-Regulates bodily processes
Pituitary gland
Thyroid Gland
Adrenal Glands
Pancreas
Testes
Ovaries
Cardiovascular System
-Delivers oxygen and nutrients to tissues
-Equalizes temperature in the body
Heart
Blood Vessels
Digestive system
-Processes food for use by the body
-Removes wastes from undigested food
Stomach
Liver
Gall bladder
Large Intestine
Small intestine
Urinary System
-Controls water balance in the body
-Removes wastes from blood and excretes them
Kidneys
Urinary bladder
Male Reproductive System
-Produces sex hormones and gametes
-Delivers gametes to females
Epididymis
Testes
Female reproductive system
-Produces sex hormones and gametes
-Supports embryo/fetus until birth
-Produces milk for infant
Mammary glands
Ovaries
Uterus
Metabolism
The sum of all anabolic and catabolic reactions that take place in the body
Anabolism
The process where smaller, simpler molecules are combined into larger, more complex substances
Example of anabolism
Your body can assemble, by utilizing energy, the complex chemicals it needs by combining small molecules derived from the foods you eat
Catabolism
The process by which larger more complex substances are broken down into smaller simpler molecules.
-Releases energy
Example of catabolism
The complex molecules found in foods are broken down so the body can use their parts to assemble the structures and substances needed for life
Anabolic reactions (short definition)
Building reactions and consume energy
Catabolic reactions (short definition)
Break down materials and release energy
4 requirements for human life
-Oxygen
-Nutrients
-Narrow range of temperatures
-Atmospheric pressure
Homeostasis
The presence of a stable internal environment
-Maintaining homeostasis is vital to an organism’s survival
-Failure to maintain homeostasis soon leads to illness and death
Homeostatic regulation
The adjustment of physiological systems to preserve homeostasis in environments that are often inconsistent, unpredictable, and potentially dangerous
Maintaining homeostasis requires:
A receptor
A control center
An effector
Set point
(homeostasis)
The physiological value around which the normal range fluctuates
-Maintaining homeostasis requires that the body continuously monitor its internal conditions. From body temp to BP to levels of certain nutrients, each physiological condition has a particular set point.
Normal range
(homeostasis)
The restricted set of values that is optimally healthful and stable.
Example of normal range in homeostasis
The set point for normal human body temperature is approximately 37 degrees C or 98.6 degrees F. Physiological parameters such as body temp and BP tend to fluctuate within a normal range a few degrees above and below that point
Ex of negative feedback in homeostasis
The regulation of blood glucose levels. If blood glucose levels continue to rise it may result in diabetes.
Control centers in the brain and other parts of the body monitor and react to deviations from homeostasis using negative feedback
Negative feedback (homeostasis)
A mechanism that reverses a deviation from the set point
-Neg feedback maintains body parameters within their normal range
Sensor (aka receptor)
A component of a feedback system that monitors physiological value.
-The value is reported to the control center
Control Center
The component in a feedback system that compares the value to the normal range
-If the value deviates too much from the set point, then the control center activates an effector
Effector
The component in a feedback system that causes a change to reverse the situation and return the value to the normal range
Negative feedback system
A stimulus (a deviation from a set point) is resisted through a physiological process that returns the body to homeostasis
-Temperature is regulated by negative feedback
5 basic parts of negative feedback system
1) Stimulus
2) Sensor
3) Control
4) Effector
5) Response
Positive feedback
-Results in a change in the bodys status, rather than a return to homeostasis. (intensifies a change in the bodys physiological condition rather than reversing it).
-A deviation from the normal range results in more change and the system moves farther away from the normal range.
-Positive freedback in the body is only when there is a definite end point.
Examples of positive feedback loop
-Childbirth (the extreme muscular work of labor and delivery)
- The body’s response to blood loss
These are normal but activated only when needed
Anatomical position
The body standing upright, with the feet at shoulder width and parallel, toes forward. The upper limbs are held out to each side, and the palms of the hands face forward
2 essential functions of body cavities:
1)Protects organs from shocks and impacts
2) Permit changes in size and shape of organs
Serous membrane
The serous membrane, or serosal membrane, is a thin membrane that lines the internal body cavities and organs such as the heart, lungs, and abdominal cavity
The serous membrane allows for frictionless movement in a number of vital organs
-visceral, parietal
-pericardium, pleural membrane, peritoneal membrane
X-ray
A form of high energy electromagnetic radiation with a short wavelength, capable of penetrating solids and ionizing gases
Computed Tomography (CT)
A noninvasive imaging technique that uses computers to analyze several cross-sectional X-rays
X-ray machine
Allows the internal structures of a body, such as bones, to be seen in x-rays (ex: x-ray of a hand)
Magnetic resonance imagine (MRI)
Generates a magnetic field around a patient
- A noninvasive medical imaging technique based on a phenomenon in which matter exposed to magnetic fields and radio waves was found to emit radio signals.
Positron Emission Tomography (PET) scans
Use radiopharmaceuticals to create images of active blood flow and physiologic activity of the organ or organs being targeted
-Can illustrate physiologic activity (including nutrient metabolism and blood flow) of the organs being targeted
Ultrasound technology
An imaging technique that uses the transmission of high-frequency sound waves into the body to generate an echo signal that is converted by a computer into a real- time image of anatomy and physiology.
It is used to monitor pregnancies because it is the least invasive of imaging techniques and uses no electromagnetic radiation.
Anterior/ or ventral
The front or direction towards the front of the body
ex: the toes are anterior to the foot
Posterior/ or dorsal
The back or direction toward the back of the body
ex: the popliteus is posterior to the patella
Superior/ or cranial
A position above or higher than another part of the body proper
ex: the orbits are superior the the oris
Inferior/ or caudal
A position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx or lowest part of the spinal column)
ex: the pelvis is inferior to the abdomen
Lateral
The side or direction toward the side of the body
ex: The thumb (pollex) is lateral to the digits
Medial
The middle or direction toward the middle of the body
ex: the hallux is the medial toe
Proximal
A position in a limb that is nearer to the point of attachment or the trunk of the body
ex: The brachium is proximal to the antebrachium
Distal
A position in a limb that is farther from the point of attachment or the trunk of the body
ex: The hand is distal to the shoulder
Superficial
A position closer to the surface of the body.
ex: The skin is superficial to the bones
Deep
A position farther from the surface of the body
ex: The brain is deep to the skull
Section
A two-dimensional surface of a three- dimensional structure that has been cut
Plane
An imaginary two-dimensional surface that passes through the body.
-There are three planes (sagittal, frontal, and transverse)
Sagittal plane
Divides the body or an organ vertically into right and left sides
-AKA parasagittal plane or a longitudinal section
Frontal plane
Divides the body or an organ into an anterior (front) portion and a posterior (rear) portion.
-AKA coronal plane
Transverse plane
Divides the body or organ horizontally into upper and lower portions
-Transverse planes produce images referred to as cross sections
Reproduction
The formation of a new organism from parenting organisms.
- In humans, reproduction is carried out by the male and female reproductive systems
Nutrient
A substance in foods and beverages that is essential to human survival.
Pressure
a force exerted by a substance that is in contact with another substance
Atmospheric pressure
Pressure exerted by the mixture of gases (primarily nitrogen and oxygen) in the earth’s atmosphere).
-Constantly pressing down on your body
- The pressure keeps gases within your body (such as gaseous nitrogen in body fluids) dissolved.
Physiology
The study of function and how living organisms perform their vital functions
Human physiology is the scientific study of the chemistry and physics of the structures of the body and the ways in which they work together to support the functions of life.
Neurophysiology
The study of the brain, spinal cord, and nerves and how these work together to perform functions as complex and diverse as vision, movement, and thinking.
The structures of the body in terms of fundamental levels of organization that increase in complexity
Subatomis particles, atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms and biosphere
Cell physiology
All living structures of human anatomy contain cells, and almost all functions of human physiology are performed in cells or are initiated by cells.
Development
All of the changes the body goes through in life
-Also includes the process of growth and repair, both of which involve cell differentiation
Differentiation
Unspecialized cells become specialized in structure and function to perform certain tasks in the body.
Systemic phisiology
A branch of physiology that deals with the study of specific organ systems, such as how they function.
-This would include the details of how the digestive system works to accomplish the roles of ingestion, digestion, absorption, and excretion
Subatomic particles
A particle smaller than an atom or a cluster of such particles
Atom
A particle of matter that uniquely defines a chemical element
Organism
The highest level of organization.
A living being that has a cellular structure and that can independently perform all physiologic functions necessary for life.
Differentiation
Process by which unspecialized cells become specialized in structure and function
Examples:
-A single-celled zygote developing into a multicellular embryo with various cell types.
-Lung cells and brain cells performing different functions in the body.
-Skeletal tissue containing different types of bone cells.
-Epithelial tissue lining the small intestine and absorbing nutrients.
Functions
Complex and much more difficult to examine than most anatomical structures
Anatomy (Form/ structure)
Means “a cutting open,” is the study of the internal and external
structures of the body and the physical relationships among body
parts.
Can be divided into Gross and Microscopic Anatomy
Characteristics of living organisms
Responsiveness
Adaptability
Growth and development
Reproduction
Movement and locomotion
Respiration
Circulation
Digestion
Excretion
Responsiveness
Indicates that the organism
recognizes changes in its
internal or external environment
-Required for adaptability
Adaptability
Changes the organism’s
behavior, capabilities, or
structure
-Required for survival in a
constantly changing world
Development and Growth
Inherited patterns for growth (an increase in size) and
development (changes in
structure and function) produce organisms characteristic of their
species.
-Growth and development
to maturity is controlled
by inherited instructions in the form of DNA
Reproduction
Produces the next generation
-Sexual reproduction between two parents produces offspring with varied characteristics
Movement and Locomotion
Distributes materials throughout large organisms
Respiration
Usually refers to oxygen
absorption and utilization, and carbon dioxide generation and release
-Oxygen is required for chemical processes that
release energy in a usable form/ carbon dioxide is released as a waste product
Circulation
Movement of fluid within the
organism; may involve a pump and a network of special vessels
-The circulation provides an
internal distribution network
Digestion
The chemical breakdown of
complex materials for
absorption and use by the
organism
-The chemicals released can be used to generate energy or to support growth
Excretion
The elimination of chemical
waste products generated by the organism
-The waste products are often toxic, so their removal is essential
Ventral body cavity
Includes the thoracic and abdominopelvic cavities and their subdivisions
Dorsal body cavity
Includes the cranial and spinal cavities
Extracellular vs intracellular
The intracellular fluid (ICF) compartment is the system that includes all fluid enclosed in cells by their plasma membranes.
Extracellular fluid (ECF) surrounds all cells in the body)
Mechanisms (cause-effect changes) examples
1) The hypothalamus determines the set point for body temp (around 37 degrees C or 98.6 degrees F)
2) Specialized cells in the pancreas determine the set point for blood glucose (around 70-100 mg/dL)
Threshold
The value of the membrane potential which, if reached, leads to the all-or-nothing initiation of an action potential
Cranial cavity
In the posterior cavity, the cranial cavity houses the brain
Spinal cavity
In the posterior cavity, the spinal cavity (or vertebral cavity) encloses the spinal cord
Thoracic cavity
The more superior subdivision of the anterior cavity, and it is enclosed by the rib cage.
-Contains the lungs and the heart, which is located in the mediastinum.
-The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity.
Abdominopelvic cavity
The largest cavity in the body.
-Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the abdominal cavity, the division that houses the digestive organs, and the pelvic cavity, the division that houses the organs of reproduction.
A characteristic of homeostatic control mechanisms
Oscillation (movement back and forth at regular speed) around the set point
ex: picture from (AC turns on, AC turns off)
Example of responsiveness to internal stimuli
Changes in an organism’s internal environment, such as increased body temperature, can cause the responses of sweating and the dilation of blood vessels in the skin in order to decrease body temperature, as shown by the runners in
Example of responsiveness to external stimuli
-Moving toward sources of food and water and away from perceived dangers.
-Organisms may respond to environmental shifts through anatomical changes, such as growing heavy winter coats in areas where temperatures vary significantly season to season
