Introduction to Anatomy

Anatomy is… The study of structure We study what it is, what it’s shaped like, what it’s made of “What is does” is left for physiology next semester

Microscopic vs. Gross Anatomy Microscopic Structures that cannot be viewed with the naked eye Gross AKA macroscopic anatomy anything that can be seen with the naked eye

Approaches to gross anatomy Comparative anatomy examines similarities and differences of different species

Approaches to gross anatomy Developmental anatomy investigates the changes in structure from conception through maturity Embryology is specifically concerned with development before birth

Approaches to gross anatomy Regional anatomy examines structures in a particular region of the body (e.g., skin, bones, muscles) Surface anatomy examines superficial anatomic markings and internal body structures as they relate to the skin covering them Systemic anatomy studies gross anatomy of each system in the body (ex. digestive, urinary)

Structural organization of the body Simplest level of organization is chemical level atoms: the smallest units of matter molecules: two or more atoms bounded together Simplest level of LIFE is cellular level

How did we get here? In the primordial soup, atoms bound together to make molecules Then fat molecules bound together to make a fat ball with nucleotides inside Then the nucleotides bound together into a chain and replicated themselves Let this repeat itself over a billion years, and viola! Life!

Organization Most basic level of life: cellular level of organization Most basic organisms are unicellular Not necessarily old species

Cellular level of organization In multicellular organisms, different types of cells have different functions different functions have different shapes osteocytes make bone muscle cells many types of cells in skin neurons red and white blood cells

Tissue level of organization Cells with a common function are organized into tissues One tissue may contain several types of cells In some organisms, tissues not organized into organs many types of cells in skin red and white blood cells

Organ level of organization Tissues with similar functions organized into organs proboscis for feeding gut nerve net ovary “brain” teste ovariduct sperm duct seminal vesicles copulatory organ

Organ level of organization

Organ system level of development Organs with similar function work together in systems

Atom Molecule Chemical level Cells Cellular level Epithelial tissue Tissue level Small intestine Organ level Organ system level Organismal level Life starts here

What makes life? A Cell! Plasma membrane DNA and other stuff inside

What else makes life? Organization: complex structure and order Metabolism: chemical reactions including breaking down molecules into digestible particles Growth and development: increased size from assimilation of materials from the environment Responsiveness: sense and respond to changes in the environment Regulation: maintain a consistent internal environment Homeostasis is the process of maintaining a steady state inside the body Reproduction: produce new cells for growth, also replicate self

One more thing Adaptation At the population level, organisms adapt (Individuals DON’T adapt) Each generation is different from the last Each generation contains individuals whose ancestors were better at reproduction than another individual Over many generations (thousands to millions of years) populations become altered in response to their environment

Anatomic position Used when referring to parts of the body Common point of reference Standing, facing forward, feet straight head, head forward, arms at sides, palms facing forward, thumbs away from the body

Dividing the body Planes are imaginary slices that divide the body Help describe where things are in relation to other things

(b) Coronal section (c) Transverse section (d) Midsagittal section Fig. 1.5 Coronal plane vertical divides into front and back Transverse plane aka cross-sectional plane or horizontal plane perpendicular to axis of body separates into upper and lower Midsaggital plane vertical through center of body separates into right and left halves Saggital plane is to left or right of midsaggital

Fig. 1.6 Dividing the body Body parts can also be divided along planes

Anatomic directions Used to describe where things are in relation to other things Anterior = front toward the front surface of the body The coyote’s nose is anterior to its eyes Ventral = belly side of body The coyote has a ventral gray patch ventral = anterior in humans

Anatomic directions Posterior = back behind; toward the back surface The coyote’s cheek lies posterior to its grin Dorsal = booty side of body The coyote has a dorsal tail posterior = dorsal in humans The shark has a scary dorsal fin

Anatomic directions Superior = above closer to the head The coyote’s yellow eyes are superior to its tail Inferior = below closer to the feet The coyote’s tail is inferior to its ears

Anatomic directions Cranial = at the head end closer to the head The coyote’s ears are cranial to its shoulders Caudal = at the tail end closer to the tail; in humans, closer to the feet The coyote’s tail is caudal to its ears

Anatomic directions Medial = middle toward the midline of the body The coyote’s chest hair tuft is medial to the arm Lateral = side away from the midline of the body The coyote’s cheeks are lateral to the nose

Anatomic directions ipsilateral = on the same side The coyote’s tail is ipsilateral to its raised eyebrow contralateral = on the opposite side The right hand is contralateral to the left foot

Anatomic directions Proximal = closer to the point of attachment to the trunk The coyote’s knee is proximal to the foot Distal = farther from the point of attachment to the trunk The coyote’s fist is distal to the elbow

Anatomic directions Superficial = on the outside, closer to the outside The dough boy’s skin is superficial to his intestines Deep = on the inside, underneath another structure The dough boy’s heart is deep to his ribs

Medical Imaging Radiography (X-rays) X-rays (high-energy radiation) sent through body Pass through soft tissue, leaving image of hard tissues: bone, teeth, tumors

Medical Imaging Sonography (ultrasound) high-frequency sound waves penetrate body, bounce off tissues and return inexpensive, portable, no harmful radiation shows hard tissue and some soft tissue not very sharp images (getting better)

Medical Imaging Computed Tomography (CT) uses low-intensity X-rays that pass through the body Produces images of dime-thick slices of the body Produces 3-D image Sharper image that X-rays Visible Human Project

Medical Imaging Digital Subtraction Angiography (DSA) 3-D, X-rays Used to observe blood vessels Radiographs taken before and after injecting an opaque medium into blood vessel Useful in angioplasty (insertion of stent into blocked blood vessel)

Medical Imaging Dynamic Spatial Reconstruction (DSR) Uses modified CT scanners Produces 3-D images of organs provides info about movement of organ valuable for evaluating heart function

Medical Imaging Magnetic Resonance Imaging (MRI) provides image of soft tissues not clear images of hard tissues Uses magnet and causes protons in tissues to align functional MRI (fMRI) provides map of oxygen flow in the brain

Medical Imaging Positron emission tomography (PET) Analyze metabolic state of tissues Patient injected with radioactive sugar Determine which tissues are most active Can determine if cancer has metastasized