notes for ana 209 PDF

Preview

Summary

notes...

Description

Study Guide for Exam 1 1. Define anatomy and some of its subdisciplines: -

Human anatomy is the study of the structure of the human body. It provides an essential foundation for understanding physiology, the study of function; anatomy and physiology together are the bedrock of the health sciences. You can study human anatomy from an atlas; yet as beautiful, fascinating, and valuable as many anatomy atlases are, they teach almost nothing but the locations, shapes, and names of things. This book is different; it deals with what biologists call functional morphology1—not just the structure of organs, but the functional reasons behind that structure.

-

Anatomy is studied from a variety of perspectives including gross anatomy (large-scale structure visible to the naked eye), surface anatomy (structure that can be seen without cutting, as in a routine patient examination), radiologic anatomy (use of imaging methods to view the internal anatomy of a living person), microscopic anatomy (histology) (microscopic study of the tissues), histopathology (examination of tissues for signs of disease), cytology (study at a cellular level), and ultrastructure (study at the cellular to molecular level, usually with the electron microscope). Systemic anatomy is the study of one organ system at a time, and is the approach of most introductory textbooks such as this one; regional anatomy is the study of all organs in a given body region such as the head or thorax, and is the usual approach in training doctors and surgeons. Comparative anatomy is the study of more than one species in order to understand common themes and evolutionary trends in body structure.

-

Microscopic Anatomy – microscopic analysis of cells o Histology o Histopathology – microscopic analysis of diseased tissue o Cytology Structure and function of individual cells Ultrastructure – fine details of cell

-

Methods of studying o Inspection – looking at surface appearance o Palpation – feeling a structure o Auscultation – listening to normal sounds o Percussion – tapping and listening o Dissection – cutting and separating of tissues  Use of cadavers  Before 1800’s referred to as “anatomizing” o Medical Imaging (Radiology) o Physicians examine the anatomy of patients by means of inspection (simple visual observation), palpation (touch), auscultation (listening to body sounds), and percussion (listening to sounds reverberating

from a tap on the surface). o Dissection is the careful cutting and separation of tissues and organs to study internal structure. Modern methods of medical imaging (radiology) have replaced most exploratory surgery for visualizing the internal structure of the living body. o Some methods of medical imaging use high-energy ionizing radiation and some do not. -

Radiography o X-ray or radiograph o Radiopaque – visualization of hollow organs o Angiography – blood vessels

-

Computed tomography (CT scan) o Formally CAT scan (computerized axial tomographic) o Cross section x-rays

-

Magnetic Resonance Imaging (MRI) o Soft tissue visualization o fMRI – functional moment-to-moment change

-

Positron Emission Tomography (PET) o Gamma ray detection o Nuclear medicine (use of radioisotopes)

-

In the past 100 years, new techniques have been developed to visualize internal structures in living patients. The oldest is radiography, which photographs internal structures with X-rays. X-rays are especially useful for seeing pathologies in dense tissues such as bones and teeth, and can be used to diagnose tumors. Computed tomography is a more sophisticated application of X-rays that relies on computer analysis to reveal three-dimensional, soft tissue anatomy. Sonography relies on sonar technology using ultrasound waves. Sonography is frequently used in obstetrics to assess fetal age and position. Magnetic Resonance Imaging (MRI) uses magnetic fields to visualize soft tissues, and has especially been effective in images of the spinal cord and brain. For example, functional MRI reveals moment to moment changes in tissue activity associated with brain function. Positron Emission Tomography (PET) is used to assess metabolic status of tissues. It produces color images that show which area is using the greatest amount of glucose. PET scans and functional MRI have revolutionized our understanding of brain function because images produced while a person is performing specific tasks such as movement or cognitive tests reveal what part of the brain is active during specific activities. Common methods of radiology are radiography (X-rays), computed tomography (CT scans), magnetic resonance imaging (MRI), and positron emission tomography (PET scans). Any medical use of radioisotopes for

-

-

imaging, diagnostic, or treatment purposes (such as PET scans or cancer radiation therapy) is called nuclear medicine Gross level 1. Dissection 2. X-ray 3. Computerized tomography (CT) scanning 4. Magnetic resonance imaging (MRI) 5. Positron emission tomography (PET) scanning Microscopic level 1. Light microscopy 2. Transmission electron microscopy 3. Scanning electron microscopy Molecular level 1. Nuclear magnetic resonance (NMR) 2. Crystallography 3. Numerous biochemical techniques

2. Describe the anatomical position: • Not all people have “normal” position of organs • Terminology o Situs solitus – normal arrangement o Situs inversus – reversed position of organs o Situs perversus – one organ malpositioned 

Standing erect with feet flat o Arms at the sides (supinated) o Palms, face, and eyes facing forward o Provides a constant reference of body position o Supine – face up o Prone – face down



All anatomical descriptions are expressed in relation to the anatomical position to ensure no ambiguity in description. Anatomical position is a body stance that provides a standard frame of reference and eliminates the ambiguity of saying, for example, that one structure is above or behind another. The feet are close together and flat on the floor, arms to the sides, forearms supinated, and the head and eyes directed forward. When the forearm is supinated, the palms face forward or upward; when it is pronated, the palms face rearward or downward. This is unrelated to the positions of prone (lying face downward) or supine (lying on the back).

• Sagittal – right/left portions – Median (midsagittal) plane – equal halves – Parasagittal – unequal portions • Frontal (coronal) plane – anterior/posterior portions • Transverse (horizontal) plane – superior/inferior portions

• • • • • • • • • •

Superior, cephalic, cranial- above or closer to the head Inferior, caudal- below or closer to the feet Anterior, ventral- toward front Posterior, dorsal- toward back Medial- toward midline Lateral- away from midline Proximal- closer to point of attachment or close to trunk Distal- farther from point of attachment or further from trunk Superficial, external- toward surface of body Deep, internal- toward center or core of body

3. List in proper order the levels of structural complexity of the body, from atom to organism: - Human structure is organized around a hierarchy of complexity. The major levels of human complexity from simplest to most complex are atoms, molecules, organelles, cells, tissues, organs, organ systems, and the whole organism. Gross anatomy is generally concerned with structure from the organismal to organ levels; microscopic anatomy from the organ to cellular level; cytology from the cellular to molecular level; and ultrastructure from the organelle to molecular level. 4. Know the medical imaging technique and what they are for: - See the answer to number 1. 5. Describe the structure of the plasma membrane: - Boundary of cell • Membrane lipids – Phospholipids – 75% • Bilayer • Hydrophilic • Hydrophobic • Amphiphilic – Cholesterol – 20% • Fluidity of the membrane – Glycolipids – 5% • Contribute to glycocalyx • Membrane Proteins – Transmembrane proteins • Pass through membrane • Glycoproteins – Peripheral proteins • Adhere to either face of membrane

A cell is enclosed by a plasma membrane. The material between the plasma membrane and nucleus is the cytoplasm; the material within the nucleus is the nucleoplasm. The cytoplasm contains a cytoskeleton, organelles, and inclusions, embedded in the gelatinous cytosol. The fluid within a cell is called intracellular fluid (ICF). All body fluids not contained in cells are collectively called extracellular fluid (ECF). The ECF amid the cells of a tissue is called tissue fluid. The fluid-mosaic model describes the structure of the plasma membrane. The vast majority (90–99%) of the molecules in the membrane are lipids, and of those, most (75%) are phospholipids. Phospholipids have a hydrophilic head that interacts with water and a hydrophobic tail composed of fatty acids. The phospholipids are arranged in two layers, creating a sandwich effect with the fatty acid tails inside. This arrangement means that fat-soluble molecules pass easily through the membrane but water-soluble molecules are restricted. In addition to phospholipids, cholesterol is found in all animal membranes, and is essential for maintaining the integrity, flexibility, and strength of the membrane fabric. Glycolipids in the membrane enable it to heal itself. If there is a breach, the lipids flow back together to seal the opening. 6. Explain the functions of the lipid, protein, and carbohydrate and the components of the plasma membrane such as glycocalyx; glycolipids; phospholipids; transmembrane proteins: - Functions of membrane proteins: o Receptor o Enzyme o Channel Proteins o Transport Proteins o Cell-identity Markers o Cell-adhesion Molecules Proteins associated with the membrane have varied structures and functions. Integral proteins may span the membrane (transmembrane), while peripheral proteins adhere to one side. Glycoproteins are integral proteins that have an attached carbohydrate chain. Transmembrane proteins penetrate from one side of the plasma membrane to the other. Most of these are glycoproteins. Peripheral proteins are attached to the intracellular or extracellular face of the membrane and do not penetrate into the phospholipid layer. Membrane proteins serve a variety of functions: receptors for chemical signals, enzymes, channel proteins, gates, transport proteins (carriers), cell-identity markers, and celladhesion molecules. Glycocalyx: • Carbohydrate component • Fuzzy, sugary coat • Functions – Protects – Cell identity

– Binds tissues • The glycocalyx is a spongy carbohydrate coating on every cell surface, formed by the carbohydrate components of glycolipids and glycoproteins. It functions in cell identity, in the body’s ability to distinguish its own tissues from foreign invaders, and in cell adhesion. 7. Definition of organ, tissue and organ system: - Tissue is made up of cells. - Organ is made up of tissues. - Organ system is a group of organs. 8. List the main organelles of a cell and explain their functions: - “little organs” - Metabolically active - Compartmentalize contents of cell • Nucleus • Largest organelle • Contains chromosomes • Genetic control center • Produce ribosomes • Nuclear envelope • Nuclear pores • Nucleoplasm • Chromosomes • Nucleoli • The nucleus is the largest organelle. It contains most of the cell’s DNA. It is bordered by a nuclear envelope composed of two unit membranes perforated with large nuclear pores. The nucleoplasm, or nuclear contents, contains 46 chromosomes and often one or more nucleoli. • The genetic material, DNA, is located in chromosomes in the nucleus and, therefore, it is “command central” because DNA directs cellular activity. Most cells have a single nucleus but some are multinucleate. Ribosomes, structures important in the process of protein synthesis, are produced in the nucleus, and are among the many substances that pass through nuclear pores. Nuclear pores are openings in the nuclear envelope that regulate traffic into and out of the nucleus. • Endoplasmic Reticulum • “little network within the cytoplasm” • Cisternae • Rough endoplasmic reticulum • Phospholipids • Proteins of plasma membrane • Lysosomes

• Smooth endoplasmic reticulum • Cells that detoxify • Cells that synthesize steroids • The endoplasmic reticulum (ER) is a system of interconnected channels called cisternae, which often occupy most of the cytoplasm. Areas called rough ER have relatively flat cisternae and are studded with ribosomes. Areas called smooth ER have more tubular cisternae and lack ribosomes. The ER synthesizes phospholipids, steroids, and other lipids; produces all the membranes of the cell; and detoxifies some drugs. The rough ER is a major site of protein synthesis. Smooth ER is scanty in most cells, but abundant in cells that synthesize steroids or engage in detoxification. It functions as a calcium reservoir in muscle cells and some others. • Ribosomes • Locations: • Cytosol • Rough Endoplasmic Reticulum • Nuclear envelope • Nucleoli • Mitochondria • Read genetic messages → assemble amino acids → synthesize proteins • Ribosomes are protein-synthesizing granules of RNA and enzymes, found free in the cytosol, attached to the rough ER and nuclear envelope, and in the mitochondria and nucleoli. • Golgi complex • Composed of cisternae • Transport vesicles from RER to Golgi complex • Golgi vesicles – packaged proteins • Lysosomes • To plasma membrane • Secretory vesicles • The Golgi complex: Like the endoplasmic reticulum, the Golgi complex consists of cisternae. It synthesizes carbohydrates and puts the finishing touches on proteins, sometimes attaching carbohydrate bits so that they become glycoproteins. The Golgi complex sorts proteins and packages them into Golgi vesicles that may be exported in the process of exocytosis. Some of the vesicles become lysosomes. • The functional interaction between the ribosomes, endoplasmic reticulum, and Golgi complex. Ribosomes link amino acids together in a genetically specified order to make a particular protein. This new protein threads its way into the cisterna of the rough ER, where enzymes trim and modify it. The altered protein is then shuffled into a little transport vesicle, a small, spheroidal organelle that buds off the ER and carries the protein to the nearest cisterna of the Golgi complex. The Golgi complex sorts these

proteins, passes them along from one cisterna to the next, cuts and splices some of them, adds carbohydrates to some of them, and finally packages the proteins in membrane-bounded Golgi vesicles. These vesicles bud off the swollen rim of the cisterna farthest from the ER. They are seen in abundance in the neighborhood of the Golgi complex. Some Golgi vesicles become lysosomes, the organelles discussed next; some migrate to the plasma membrane and fuse with it, contributing fresh protein and phospholipid to the membrane; and some become secretory vesicles that store a cell product, such as breast milk, mucus, or digestive enzymes, for later release by exocytosis. • Lysosomes • Enzymes in single unit membrane • Clean up cell • Autophagy – breaks down organelles • Apoptosis – programmed cell death • Lysosomes are membrane-enclosed packets of enzymes that break down macromolecules, expired organelles, and phagocytized foreign matter, and assist in programmed cell death (apoptosis). • Peroxisomes • Resemble lysosomes • Oxidize organic molecules • Produce hydrogen peroxide • Oxidize other molecules • Excess broken down to water and oxygen by catalase • Abundant in liver and kidney • Peroxisomes : contain enzymes that detoxify substances such as alcohol and other drugs and neutralize free radicals. They also break fatty acids into 2-carbon molecules that may enter metabolic pathways that ultimately produce ATP. They produce hydrogen peroxide as a by-product. • Mitochondria • Specialized for aerobic respiration • Most of body’s ATP • Outer membrane • Inner membrane • Cristae • Mitochondrial matrix • Mitochondrial DNA (mtDNA) • Mitochondria are sometimes called the “power-houses” of the cell because they are the primary source of ATP. A double membrane encloses them. The inner membrane has folds called cristae, surface area for enzymes associated with production of ATP. Mitochondria are fascinating partly

because they have their own DNA, probably because they were once (billions of years ago) an independent organism that was “hijacked” by larger cells. The mitochondrial DNA has been utilized in recent decades to explore genetic relationships among closely related species and populations. For example, studies of mtDNA suggest that all modern humans descended from a population in Sub Saharan Africa some 150– 200 thousand years ago. • Centrioles • Microtubules • Nine groups of three • Centrosome • Cytoplasm that contains perpendicular pair • Cellular division • Basal body • Cilium • A centriole is a short cylindrical array of nine triplets of microtubules. There are usually two centrioles in a clear patch of cytoplasm called the centrosome. Each cilium and flagellum also has a solitary basal centriole called a basal body, which gives rise to the axoneme. • Centrioles consist of an assembly of microtubules. Centrioles found in the centrosome, an area near the nucleus, play a role in cell division. The centrosome is a center for organization of microtubules, components of the cytoskeleton. Centrioles may also form cilia and flagella, structures which are made up of bundles of microtubules.

9. Describe the processes of endocytotic; distinguish the phagocytosis, pinocytosis and exocytosis:  Vesicular transport : Larger particles or droplets of water are moved in and out of the cell through the energy-requiring processes of endocytosis and exocytosis. Phagocytosis (literally, cell “eating”) occurs when a cell surrounds a substance and engulfs it. Pinocytosis (cell “drinking”) enables cells to engulf droplets of extracellular fluid. Receptor-mediated endocytosis allows a cell to take in specific molecules from the ECF such as insulin. Exocytosis is the process of expelling material from the cell by enclosing a cell product in a secretory vesicle and fusing the bubble with the plasma membrane.

10. Describe the differences of simple diffusion, osmosis, and active transport: - Simple diffusion is a process in which molecules move spontaneously down a concentration gradient from a point of high concentration to a point of lower concentration. Substances can diffuse through a plasma membrane if they are small enough to fit through channels in the membrane or are soluble in its phospholipid. - Osmosis

Special case of simple diffusion Movement of water High concentration to low concentration Osmosis is the net diffusion of water through a selectively permeable membrane from a side with less dissolved matter (where water is more concentrated) to the side with more dissolved matter (where water is less concentrated). Reverse osmosis is the net movement of water in the opposite direction because of a force, such as blood pressure, applied to one side of a membrane. - Facilitated diffusion: Carrier proteins ferry a molecule from one side of the membrane to another down the concentration gradient. Thus, ions and watersoluble molecules can still cross the membrane. This passive process does not require cellular energy. - Active transport requires ATP and moves molecules against their concentration gradient. An important example of active transport is the Na+K+ (sodium-potassium) pump that maintains an appropriate ion balance for nerve conduction and muscle excitation. • • • •

11. Describe function of epithelial, adipose, nervous, and connective tissue: Epithelial Tissue - to allow rapid diffusion or transport of substances through a membrane (e.g. simple squamous epithelium), to absorb and secrete substances (e.g. cuboidal epithelium in kidney tubules), to move substances by using cilia (e.g. bronchi), and to protect the body from the intrusion of microbes (e.g. epidermis). Epithelial tissue is often int...