lecture 1 - introduction-week 1
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Human Anatomy and Physiology ITRANSCRIPT
Biology 250
Human Anatomy and Physiology
Instructor: Dr. Frank Sauer
Anatomy and Physiology
• Anatomy: studies the structure of body parts and their rela:onships to one another.
• Physiology: concerns the func:on of the body. • How do body parts work and carry out their life-‐sustaining ac:vi:es.
• Gross-‐Anatomy: • Study of large body structures visible to the naked eye.
• Microscopic anatomy: • Study of structures too small to be observed with the naked eye.
• Developmental anatomy: • Study of structural changes during the en:re life cycle of an organism.
Topics of Anatomy
• Gross-‐Anatomy: Gross or macroscopic anatomy.
• Different approaches: • Regional anatomy: all structures in a parEcular region of the body are examined at the same Eme (e.g., leg). • Systemic anatomy: body structures are studies system by system (e.g., cardiovascular system). • Surface anatomy: study of internal structures as they relate to the overlying skin (e.g., idenEfy muscles under skin).
Topics of Anatomy
• Microscopic anatomy: • Cytology (cells). • Histology (:ssues).
• Developmental anatomy: • Study of structural changes during the en:re life cycle of an organism. • Embryogenesis: Study of structural changes occurring in the embryo before birth.
Topics of Anatomy
• Different subdivisions: Most of them study the acEvity/operaEon of specific organs.
• Renal physiology = kidney funcEon and urine producEon • Neurophysiology = funcEons of nervous system • Cardiovascular physiology = heart and blood vessel
• Physiology oRen focuses on cellular and molecular level. The body’s abiliEes/acEviEes depend on individual cells and the chemical reacEons that occur in the cells.
• Physiology rests on the principles of physics, molecular biology, cell biology and (bio-‐)chemistry.
Topics of Physiology
Anatomy and Physiology are closely connected because
funcEon always reflects structure
Principle of complementarity of structure and funcEon
• Range: From atom to the enEre organisms. • Different levels of structural organizaEon:
• Chemical level: Atoms, combine to form molecules that associate in specific ways to form cell organelles.
• Cellular level: Cells are basic building blocks (units) of living things. All cells have common func:on and organiza:on but differ in size, shape, and func:on to full-‐fill specific role in the body.
OrganizaEon of the Body
• Tissue level: Tissue = groups of similar cells that have a common func:on. • Four basic types of :ssue: Epithelium, muscle, connec:ve :ssue, and nervous :ssue.
• Organ level: Organ = discrete structure composed of at least two :ssue types that performs a specific func:on for the body (e.g., liver, brain, blood vessel. At the organ level, extremely complex func:ons become possible. Stomach: lining is composed of epithelium, the wall of muscle, and nerve fibers increase diges:ve ac:vity by s:mula:ng muscles.)
• Organ system level: Organs that work together to accomplish a common task/purpose make up an organ system, e.g., heart and blood vessels of the cardiovascular system.
• Organismal level: sum of all structural levels working together to keep organism (us) alive.
OrganizaEon of the Body
Which are the necessary life funcEons ??
• Humans maintain their boundaries, move, respond to environmental changes, take in and digest nutrients, carry out metabolisms, dispose of waste, reproduce, and grow.
Necessary life funcEons
• Every living organism must maintain its boundaries so that internal the environment remains different from the external environment.
• Single-‐celled organisms: cell membrane.
• Organisms: integumentary system (skin): protects internal organs from drying out, bacteria, heat and sunlight.
Maintaining Boundaries
integumentary system
• Muscular system: running, swimming, and when blood, food, and urine are propelled through internal organs of cardiovascular, diges:ve, and urinary systems.
• Skeletal System: provides bony framework that the muscles pull on.
• Cellular level: muscle cells ability to move by shortening is termed: contrac:lity.
Movement
Muscular system Skeletal System
• Ability to sense changes in the environment and then respond to them. • Nervous system (all cells are excitable).
Responsiveness
DigesEon
• Diges:on (breakdown) of food to single molecules that are absorbed into the blood.
• Diges:ve system (all cells are excitable). • Single-‐celled (e.g., amoeba) = diges:on factory.
Metabolism
• Term that describes all chemical reacEons within body cells. • Diges:ve system (all cells are excitable). • Single-‐celled (e.g., amoeba) = diges:on factory • Catabolism: breakdown of substances into simpler building blocks • Anabolism: synthesis of complex cellular structures from building blocks. • Cellualr respira:on: cellular combus:on of nutrients with oxygen to produce cellular energy in form of ATP.
• Metabolism involves: diges:ve, respiratory, cardiovascular, and endocrine system.
ExcreEon
• Removing wastes (or excreta) from body. • Diges:ve system. • Urinary system. • Respiratory system
ReproducEon
• Reproduc:on: • Cellular: cell division. • Human: • Reproduc:ve system (male/female). • Endocrine (hormone) system.
Growth
• Growth: Increase in size of a body part or the organism as a whole.
• Generally achieved by increasing the number of cells. • Cell growth: size of individual cells can increase.
What does the human body need to survive?
Survival Needs
• Nutrients (food, diet), oxygen, water, appropriate temperature, and atmospheric pressure. • Nutrients (diet): contains chemical substances for energy and cell building. • Carbohydrates (sugars): energy source. • Proteins: building block for cell structures. • Fat: emergency energy source and essen:al for cell structure. • Minerals: e.g., calcium (bone).
• Oxygen: Essen:al for energy produc:on in cellular respira:on.
• Water: 50-‐60% of body weight. Provides environment of cellular reac:ons and a fluid base for secre:ons and excre:ons.
Survival Needs
• Temperature: normal (human) 37oC (98.6oF). Op:mized for all metabolic reac:ons. • Too high or too low = death. • Muscular system generates most body heat.
• Atmospheric pressure: force that air exerts on surface of body. • Breathing and gas exchange depend on appropriate atmospheric pressure. • High al:tude (Mount Everest) pressure is too low to support adequate gas exchange.
Homeostasis
Ability of the body to maintain relaEvely stable internal condiEons in the presence of constantly changing
environmental condiEons
• All organ systems are involved in homeostasis. • Communica:on within the body is essen:al for homeostasis: nervous system and endocrine system.
• All homeosta:c control mechanisms regulate event or factor (termed variable) and contain three components: • Receptor • Control center • Effector
Homeostasis
• Homeosta:c control mechanisms:
• Receptor: some type of sensor that monitors the environment and responds to changes (s:muli) by sending informa:on to the control center via afferent pathway.
• Control center: determines the set point, which is the level or range at which a variable (e.g., blood oxygen) is to be maintained. Analyzes input received from receptor. • Sends informa:on to effector via efferent pathway. • Effector: provides means to control control center’s response. Results feed back to influence the effect of s:mulus (either shut off/reduc:on or enhancement)
NegaEve feedback mechanisms
• Nega:ve feedback: output (effector) shuts-‐off or reduces effect of the original s:mulus. Variable changes in the direc:on opposite to that of the ini:al change (s:mulus) to return to “set” value.
NegaEve feedback mechanisms
NegaEve feedback mechanisms
PosiEve feedback mechanisms
• Posi:ve feedback: output (effector) enhances original s:mulus. Posi:ve because changes enhance original effect and proceed in the same direc:on as the ini:al change (s:mulus). Variable deviates further and further from set value or range.
PosiEve feedback mechanisms
Anatomical Terms
• Anatomical posi:ons describe body direc:on, regions, and planes.
• Standard anatomical posi:on (anatomical reference point): “standing at aden:on”: body erect, with feet slightly apart.
• Lef right refer to sides of the person or the cadaver being viewed – not those of the observer.
• Direc:onal terms: allow us to explain where one body structure is in rela:on to another. (ears are lateral to the nose; instead of ears are on each site of the head and lef and right of the nose).
Anatomical Terms
Anatomical Terms
Anatomical Terms
Regional Terms
Axial Part: • main axis of the human body • includes head, neck and trunk Appendicular Part: • includes appendages or limbs, which are
adached to the body’s axis.
Regional Terms
© 2016 Pearson Education, Inc. Human Anatomy and Physiology, Tenth Edition, by Elaine N. Marieb and Katja Hoehn
Figure 1.7 Regional terms used to designate specific body areas.
(a) (b)
Cervical
Cephalic Frontal Orbital Nasal Oral Mental
Thoracic Sternal Axillary Mammary
Abdominal Umbilical
Pelvic Inguinal (groin)
Anterior/Ventral
Pubic (genital)
ThoraxAbdomen
Back (Dorsum)
Upper limb Acromial Brachial (arm) Antecubital Olecranal Antebrachial (forearm) Carpal (wrist)
Manus (hand) Metacarpal Palmar Pollex Digital
Lower limb Coxal (hip) Femoral (thigh) Patellar Popliteal Crural (leg) Sural (calf) Fibular or peroneal
Pedal (foot) Tarsal (ankle) Calcaneal Metatarsal Digital Plantar Hallux
Cervical
Back (dorsal) Scapular
Vertebral
Lumbar
Sacral
Gluteal
Perineal (between anus and external genitalia)
Cephalic Otic Occipital (back of head)
Posterior/Dorsal
Body Planes and SecEons
• For anatomical studies, the body is ofen cut (sec:oned) along a flat surface
• Flat surface = plane
• Most frequent planes: sagi]al, frontal, and transverse planes, which lie in right angles to one
• Sec:ons are named for the plane along which they are cut.
Sagi]al Plane
Sagi]al plane: ver:cal plane that divides body into lef and right parts.
• Median plane: Sagidal plane exactly in the middle • Parasagi]al planes (para = near): all other sagidal
planes that offset from the midline.
Frontal Plane
Frontal (coronal) plane: ver:cal plane that divides body into anterior and posterior parts.
Transverse or horizontal plane
Transverse or horizontal plane: divides body into inferior and superior parts.
• Transverse secEon = cross secEon
Body Planes
• Different sec:ons reveal different structures and details.
Oblique secEons
• Sec:ons based on cuts made diagonally between horizontal and ver:cal planes
• Seldom used, because sec:ons are difficult to interpret
Membrane-‐lined body caviEes
• Two sets of internal body cavi:es • Dorsal body cavity • Ventral body cavity
• Cavi:es are closed to the outside and provide different degrees of protec:on to the organs within them.
• Dorsal and ventral cavity differ in developmental origin and lining.
• Dorsal cavity is not recognized in many anatomical references.
Dorsal body cavity
• Dorsal Cavity protects the fragile nervous system organs.
• Two subdivisions: • Cranial cavity: located in the skull, encases the brain.
• Vertebral (spinal) cavity: runs within the bony vertebral column and encloses the spinal cord.
• Cranial and vertebral caviEes are conEnuous
(connected).
• Brain and spinal cord are covered by membranes called meninges.
Ventral body cavity
• Ventral Cavity protects internal organs. • Two subdivisions: • Thoracic cavity: located in the skull, encases the brain
• Abdominopelvic cavity: runs within the bony vertebral column and encloses the spinal cord.
• Ventral body cavity houses viscera or visceral
organs = Internal organs in a body cavity.
Ventral body cavity: the thoracic cavity
• Thoracic cavity is surrounded by ribs and muscles of the chest.
• Thoracic cavity is subdivided into: • Lateral pleural caviEes, which house the lungs. • Medial mediasEnum: • Contains pericardial cavity, which encloses the heart and surrounds thoracic organs (e.g., esophagus, trachea).
Ventral body cavity: the abdominopelvic cavity
• Abdominopelvic and thoracic cavi:es are separated by diaphragm (dome-‐shaped muscle involved in breathing).
• Abdominopelvic cavity is subdivided into two parts, which are not physically separated by muscle or membrane:
• Superior porEon = Abdominal cavity: contains e.g., stomach, intes:nes, spleen, liver. • Inferior porEon = Pelvic cavity: located in bony pelvis and contains urinary bladder, reproduc:ve organs, and the rectum.
Membranes of the the Ventral body cavity
• Walls of ventral body cavity and outer surfaces of organs covered with thin, double-‐layered membrane, the serosa (or serous membrane).
• Part of membrane lining the cavity walls is called the parietal serosa.
• Part of membrane lining the organs is called the visceral serosa.
Membranes of the the Ventral body cavity
• Parietal serosa folds on itself to form visceral serosa.
Note: Parietal serosa always fused to cavity wall .
Parietal and visceral serosa are separated by fluid, called serous fluid
• Serous fluid allows the organs to slide without fric:on across cavity wall and one another. • Especially important for moving organs, e.g., heart and stomach.
Naming serous membranes
• Parietal pericardium lines the pericardial cavity. • Folds back to form visceral pericardium.
• Parietal pleurae line walls of thoracic cavity, visceral pleurae cover the lungs • Parietal peritoneum associated with walls of the abdominopelvic cavity,
visceral peritoneum covers most organs within the cavity.
Naming serous membranes
• Parietal pleurae line walls of thoracic cavity, visceral pleurae cover the lungs
• Parietal peritoneum associated with walls of the abdominopelvic cavity, visceral peritoneum covers most organs within the cavity.
Abdominopelvic Regions and Quadrants
• Abdominopelvic cavity is large and contains several organs.
• Medical personnel use scheme consis:ng of a transverse and ver:cal plane passing through the umbilicus at right angles.
Abdominopelvic Regions: Nine Regions
• Anatomists use scheme consis:ng of two transverse • and two parasagidal planes.
Abdominopelvic Regions: Nine Regions
• Anatomists use scheme consis:ng of two transverse • and two parasagidal planes.
epi = upon Gastri = belly Hypo = below Iliac = superior part of the hip bone Lumbus = loin Chondro = car:lage
Abdominopelvic Regions: Nine Regions
• Umbilical region: centermost region deep to and surrounding the umbilicus. • Epigastric region: superior to umbilical region. • Hypogastric (pubic) region: located inferior to the umbilical region
• Right and lef iliac, or inguinal regions: located lateral to the hypogastric region.
• Right and lef lumbar region: lateral to the umbilical region.
• Right and lef hypochandriac region: lateral to the epigastric region and deep to the rips
Abdominopelvic Regions: Nine Regions
• Anatomists use scheme consis:ng of two transverse • and two parasagidal planes.
Other Body CaviEes
• Oral (mouth) and digesEve cavity • Oral cavity contains teeth and tongue • Oral cavity con:nuous with Diges:ve cavity, which consists of diges:ve organs, and opens to the body exterior at the anus.
• Nasal cavity: located in the posterior of the nose, part of respiratory system passageways. Open to exterior.
• Orbital caviEes: located in the skull and present eyes to outside.
• Middle ear caviEes: located in the skull just medial to eardrum and contain :ny bones that transmit sound. . Open to exterior.
• Synovial caviEes: joint cavi:es, enclosed within fibrous capsules that surround freely movable joints (elbow, knee joints).. Membranes surrounding synovial cavi:es secrete a lubrica:ng fluid that reduces fric:on as bones move across one another.