Unit 1—Organization of the Human Body

1. Unit 1—Organization of the Human Body Dr. Achilly

2. Part 1--Introduction

3. Anatomy—study of structures Physiology—study of body functions It’s important to realize that the structure of anything will determine its function. DNA Lungs Throughout the year we will look at the human body on many levels: Chemical/molecular (atoms & molecules) Cellular (cells) Tissue (group of cells working together) Organ (group of tissues working together) System (related organs) Organismal (a living individual)

4. Homeostasis • A condition of equilibrium (balance) within a living organism. • All structures in the body (from atoms to systems) contribute to keeping the internal environment within a narrow, normal range. • E.g. body temperature

5. Homeostasis • Your body regulates its internal environment using many feedback systems. • Body conditions are continually monitored, changed, re-evaluated… • In general, feedback systems have 3 components:

6. Homeostasis • Receptor—a body structure that monitors conditions & sends info to a central control center. • Control center—evaluates input from receptors & determines if conditions are within normal limits. • Effector—receives output from control center & produces a response.

7. Homeostasis • Feedback systems can be “negative” or “positive.” • Positive feedback loops strengthen or add to the detected change. • Negative feedback reverses the detected change.

8. Positive feedback

9. Negative feedback

10. Homeostasis • If homeostasis is not maintained, there can be disorder, disease or death. • Symptoms may develop (subjective changes that can’t be measured). • Signs may be observed by a clinician (these can be measured objectively).

11. Anatomical Terminology • In order for scientists or clinicians to communicate effectively about conditions of the body, a common language is needed.

12. Anatomical Terminology • Anatomical position is assumed.

13. Anatomical Terminology Planes are imaginary flat surfaces that pass thru body parts. • Sagittal—divides body into left and right sides. • Midsagittal/median • Parasagittal • Frontal/coronal—divides body into anterior & posterior parts. • Transverse/horizontal/cross section—divides body into superior and inferior parts

14. Mid sagittal transverse frontal

15. Anatomical Terminology • Prone—lying face down • Supine—lying face up • Head region = skull & face • Neck = supports head and attaches it to trunk • Trunk = chest, abdomen, pelvis • Upper limb = shoulder, armpit, arm, forearm, wrist, hand • Lower limb = buttock, thigh, leg, ankle, foot

16. Anatomical Terminology • Superior (cephalic/cranial)—toward the head. • Inferior (caudal)—away from the head • Anterior (ventral)—nearer the front of the body. • Posterior (dorsal)—nearer the back • Medial—nearer the midline • Lateral—farther from midline • Intermediate—between 2 structures

17. Anatomical Terminology • Ipsilateral—on the same side of body • Contralateral—on the opposite side • Proximal—nearer to the attachment of a limb to the trunk • Distal—farther from the attachment • Superficial—toward/on surface of body • Deep—away from the surface

19. alg—pain blast—germ/bud brachi—arm cardi/cardio—heart chondr—cartilage crani—skull cut/derma—skin ischi—hip joint kines—motion my/myo—muscle a/an—without ante—before bi—two demi/hemi—half end/endo—within Ecto/exo/extra--outside hyper/super/supra—above hypo/infra—below, under inter—between Iso—equal juxta/para—near peri—around artho—joint osteo—bone -algia—pain -itis—inflamation -pathy—disease Anatomical prefixes/suffixes

20. Body Cavities • Many spaces within the body are separated by bones, muscles, ligaments and other structures. • This separation helps to support and protect the internal organs.

21. Body Cavities • Cranial cavity: formed by cranial bones, contains brain. • Vertebral cavity: formed by vertebral column, contains spinal cord protected by meninges.

22. Body Cavities • Thoracic cavity: formed by ribs, myo of chest, sternum, part of vertebral column. Contains: • Pleural cavity: surrounds lungs • Pericardial cavity: surrounds heart • Mediastinum: central part of thoracic cavity, runs from neck to diaphragm.

23. Body Cavities • Abdominal cavity: contains stomach, spleen, liver, gallbladder, small intestines, most of large intestines • Pelvic cavity: contains, urinary bladder, part of large intestines, reproductive organs

24. When the study of the human body first began, the only method to examine it was dissection or the careful cutting apart of the body. • Now there are many non invasive ways to image the inside of the body. Salmon dissection

25. Medical Imaging Procedures • Radiography • X-rays pass thru the body producing an image on film. • Dense structures don’t allow the rays to pass thru so the film does not get exposed and those areas appear white. • Hollow or soft structures allow more rays thru and appear in varying shades of black & gray. • Contrast dye can be injected into tissues to allow more detail to be seen. • Cheap, quick

26. Radiography Roentgen’s wife’s hand

27. Internal abdominal bleed shown with contrast dye

28. Magnetic resonance imaging (MRI) Strong magnetic field applied to body. Protons in body fluids line up with the field (particularly hydrogen). A pulse of radio waves specific to hydrogen make the protons spin in the other direction (this is where resonance comes in). When the radio waves are turned off, the protons slow their spinning. The energy they give off is detected by a computer and helps to form the image. The MRI system goes through the patient's body point by point, building up a 2-D or 3-D map of tissue types. It then integrates all of this information together to create 2-D images or 3-D models. Better for soft tissue

29. MRI

30. Computed tomography (CT) Uses x rays from multiple angles. A motor turns the X-ray tube and the X-ray detectors so that they revolve around the body. Each full revolution scans a narrow, horizontal "slice" of the body. Multiple “slices” can produced more detailed images. Useful for screen for cancers, heart, kidney and bone disease.

31. CT

32. Ultrasound scanning • High frequency sound waves are “bounced” off of body tissues and detected by the instrument. • The image may be moving and can be shown on a video monitor. • Non invasive way to fetus, vessels, etc.

33. Radionuclide scanning • Radioactive substance is injected into body & taken up by certain tissues. • Gamma rays are emitted and detected by a camera outside of the body. • Shows in color on video monitor. • Used to show activity of tissues, e.g. thyroid, kidney.

34. Radionuclide scan Metastatic prostate cancer

35. Endoscopy Uses light emitting scope to view the inside of organs & body cavities. Invasive, but relatively safe. Can view joints, abdominal organs, etc. Polyp in large intestine

36. We will be building on what you learned about cells in Bio1. • We will study many body systems in this course. • The focus will be on how they work together to keep the body’s internal environment within normal limits.

37. Body Systems • Integumentary • Skin, hair, nails, sweat and oil glands • Fxn: protection, temp. regulation, vit. D, sensory reception • Skeletal • Bones, joints, cartilage • Fxn: support, protection, movement, mineral deposit, blood cell production, triglyceride storage • Muscular • Skeletal muscles (attached to bone) • Fxn: movement, stabilizes, produces heat • Nervous • Brain, spinal cord, nerves, sensory organs • Fxn: collect, integrate, respond to stimuli inside and outside the body

38. Body Systems • Endocrine • Hormone producing organs and cells • Fxn: regulates body activities • Lymphatic/Immune • Lymphatic nodes, fluid, vessels & organs (spleen, thymus, tonsils) • Fxn: protein/fluid return, transport fats, cellular defense • Cardiovascular • Heart, blood vessels, blood • Fxn: pumping of blood, deliver nutrients, remove wastes, defense, regulation • Respiratory • Lungs, pharynx, larynx, trachea, bronchial tree • Fxn: gas exchange btwn inside and outside of body, acid/base balance

39. Body Systems • Digestive • Mouth, pharynx, esophagus, stomach, small & large intestines, anus. Also includes accessory organs (salivary glands, liver, gall bladder, pancreas). • Fxn: physical, chemical breakdown of food, absorption, eliminates solid waste • Urinary • Kidneys, ureters, bladder, urethra • Fxn: eliminates liquid waste, regulates blood volume and composition • Reproductive • Gonads & associated organs/tubes • Fxn: produce & store gametes, hormone release, maintain developing embryo

40. All systems work together to maintain homeostasis for the organism. • Examples?

41. Part 2--Tissues

42. Tissues • Contribute to homeostasis by providing support, protection & communication between cells.

43. Epithelial Tissue • These cells are arranged in continuous sheets of one or more layers. • They’re closely packed together. • The cells will have an apical surface. • This faces the body surface or the inside (lumen) of an organ or blood vessel. • May have specialized structures like villi

45. Epithelial Tissue • These cells are connected to each other on their lateral surfaces. • The basal surface is anchored in an extracellular matrix.

46. Epithelial Tissue • Some epithelial tissue may have glands for secretion of cellular products. • Hormones • Digestive juices

47. Connective Tissue • Most abundant & diverse: • Connects • Supports • Insulates • Compartmentalizes • Transports • Stores energy • Immune function

48. Connective Tissue • Has 2 basic parts: • Widely spaced cells • Extracellular matrix • Fluids, protein fibers & other substances produced by the cells • Determines quality of connective tissue (e.g. firm & pliable like cartilage or inflexible like bone)

50. Connective Tissue • Fibers of loose connective tissue are not tightly intertwined between cells. • Areolar (for strength, elasticity & support). • Adipose (cells store fat for insulation & energy reserve). • Reticular (form supporting framework of some organs).