Human structure and function course notes PDF

Preview

Summary

Warning: TT: undefined function: 32 Warning: TT: undefined function: 32 Human Structure and Function Course NotesHSF Compendium 1 NotesC1 L1 – The Human Body – iLecture Notes What is Anatomy? Anatomy: scientific discipline that investigates the structure of body parts and how they relate to each oth...

Description

Human Structure and Function Course Notes HSF Compendium 1 Notes C1 L1 – The Human Body – iLecture Notes What is Anatomy? - Anatomy: scientific discipline that investigates the structure of body parts and how they relate to each other. - Includes the study of systems, organs, tissues, the shapes of the organs, what the organs are made of, the position in the body and their locations. Levels of Anatomy - 1) Gross anatomy (macroscopic): structures examined without the aid of a microscope. - a) Systemic: body is studied system by system; e.g. integumentary system: skin, hair, nails and sweat glands, skeletal system: bones and cartilage, and muscular system: muscles - b) Regional: body is studied area by area or region by region; identify the relationship between different structures of an area; e.g. in the arm you can study the muscles, nerves and blood vessels. - 2) Surface: study of the external form of the body and its relation to deeper structures; e.g. using the sternum and the ribs you can identify where the heart sits. - Is a type of gross or macroscopic anatomy. - 3) Microscopic: structures examined with the aid of a microscope; common forms = cytology, histology. - Cytology: study of cells and their content; e.g. urine cytology = urine sample examined for the presence of abnormal cells. - Histology: study of tissues and the cells that make up the tissue; can be used for diagnostic purposes such as for the diagnoses of melanoma – a mole can be biopsied and viewed under a microscope to view the types of cells that make up that sample. - 4) Developmental: structural changes that occur in the body throughout the life span; may look at how different parts of the body develops from in utero to a fully grown adult. What is Physiology? - Physiology: study of the function of living things. Levels of Physiology - Molecular: examines the activity of molecules in a cell; e.g. proteins in a cell, protein channels in a cell membrane, receptors found on a cell membrane. - Cellular: examines how cells interact and communicate with each other. - Systemic: examines the physiology of the cells and tissues of the organs of body systems. - Neurophysiology: examines the physiology of the nervous system. - Renal: examines the physiology of the kidneys and urinary system. - Cardiovascular: examines the physiology of the heart, the blood circulation and the blood vessels. Examples of Anatomical and Physiological Studies - Measuring the electrical conductivity of the heart = physiological. - Viewing cells under a microscope = anatomical. - Using a vitalograph to test respiratory function = physiological. - Observing the interior and exterior structures of the brain = anatomical. - Measuring blood pressure after running a race = physiological. - Dissecting a heart = anatomical. Organisation of the Human Body - Atomic level -> molecular level - Atoms (e.g. carbon, hydrogen, oxygen, nitrogen) interact to form molecules (e.g. DNA, RNA, sugar, water). - Molecular level -> cellular level - Molecules (e.g. DNA, RNA) combine to form organelles (e.g. nucleus, mitochondria, endoplasmic reticulum, etc.) of a cell.

- Cellular level -> tissue level - Numerous cells and organelles (e.g. smooth muscle cells) join together to form a tissue (e.g. smooth muscle tissue). - Tissue level -> organ level - Tissues (can be more than one type, e.g. adipose, muscle, connective) form organs (e.g. bladder). - E.g. urinary bladder wall made up of epithelium, connective tissue, smooth muscle tissue and connective tissue. - Organ level -> system level - One or more organs (e.g. kidneys, ureters, bladder) make up a system (e.g. urinary system). - Other systems: integumentary, skeletal, muscular, lymphatic, respiratory, digestive, endocrine, cardiovascular, male reproductive, female reproductive, urinary. - Organ system level -> organism level - All different systems make up an organism; e.g. respiratory system, renal system, cardiovascular. - Organism Characteristics of Organisms - 1) Organisation: relationships among the parts of an organism and how those parts interact to perform specific functions; e.g. thousands of smooth muscle cells join up to make smooth muscle tissue which is just one component of those that make up the urinary bladder. - 2) Metabolism: chemical reactions taking place in an organism; e.g. chemical reaction to produce energy. - 3) Responsiveness: organism’s ability to sense changes in its environment and adjust to those changes; e.g. when you are feeling cold your body responds by trying to warm itself up – does this by moving blood away from skin to the core of your body to keep the core of the body warm. - 4) Growth: increase in the size or the number of cells; e.g. the growing of your hair or nails. - 5) Development: changes an organism undergoes through time; e.g. developmental changes that a human undergoes through puberty. - 6) Reproduction: formation of new cells or new organisms. Homeostasis - Homeostasis: the existence and maintenance of a relatively constant environment within the body. - Includes body temperature, blood pressure, pH, glucose, carbon dioxide, oxygen, etc. - Homeostatic mechanisms maintain the body near an ideal normal point called the set point. - Homeostasis is still maintained when small fluctuations occur above or below the set point = normal range. - The failure of homeostasis can result in disease or even death. C1 L2 – Anatomical Terminology – iLecture Notes The Anatomical Position - An erect person whose: - Face is directed forward - Arms are hanging by their side - Palms of their hands facing forward. - The purpose is to give us a point of reference to describe the different points of the body. Other Body Positions - Supine: person lying face up. - Prone: person lying face down. Directional Terms - Superior: toward the head; e.g. the head is superior to the neck, the knees are superior to the ankles. - Also known as cephalic or cranial. - Inferior: toward the tail; e.g. the pelvis is inferior to the stomach, the lips are inferior to the eyes. - Also known as caudal. - Anterior: toward the front; e.g. the breast is anterior to the spine, the nose is anterior to the ears. - Also known as ventral. - Posterior: toward the back; e.g. the ankles are posterior to the toes, the ears are posterior to the lips. - Also known as dorsal. - Proximal: nearest; e.g. the elbow is proximal to the wrist, the knees are proximal to the ankles.

- Distal: distant; e.g. the fingers are distal to the wrist, the elbow is distal to the shoulder. - Proximal and distal are used to describe linear structures such as the arms and legs. - Medial: toward the mid-line of the body; e.g. the nose is medial to the eyes, the naval is medial to the ears. - Lateral: away from the mid-line of the body; e.g. the ears are lateral to the lips, the shoulder is lateral to the sternum. - Superficial: close to the surface of…; e.g. the epidermis is superficial to the dermis, the dermis is superficial to the muscle. - Deep: towards the interior of…; e.g. the bone is deep to the adipose tissue, the muscle is deep to the dermis. Body Planes - Sagittal plane: runs vertically down the body separating the body into left and right portions. - A median plane is a sagittal plane that passes through the midline of the body, dividing it into equal right and left halves. - Frontal plane (coronal): runs vertically from right to left and divides the body into anterior and posterior parts. - Transverse plane (horizontal): runs parallel to the ground and divides the body into superior and inferior portions. - Oblique: a plane that does not run parallel to the frontal or transverse plane. - A cut through the long axis of the organ is a longitudinal section, and a cut at right angle to the long axis is a transverse (cross) section. If a cut is made across the long axis at other than a right angle, it is called an oblique section. Body Cavities - 1) Thoracic cavity: upper cavity; contains the lungs and the mediastinum (which consists of the esophagus, trachea, blood vessels, thymus, heart and nerves). - 2) Abdominal cavity: the largest cavity; enclosed anteriorly by the abdominal muscles; contains the stomach, intestines, spleen, liver, pancreas, and the kidneys. - 3) Pelvic cavity: enclosed by the pelvic bones; contains bladder, parts of the large intestine and reproductive organs. - Occasionally abdominal cavity and pelvic cavity grouped together as abdominopelvic cavity. Subdivisions of the Abdomen - Quadrants: right-upper quadrant, left-upper quadrant, right-lower quadrant, left-lower quadrant. - Regions: right hypochondriac region, epigastric region, left hypochondriac region, right lumbar region, umbilical region, left lumbar region, right iliac region, hypogastric region, left iliac region. - We divide the abdomen into quadrants or regions for descriptive or diagnostic purposes.

Body Parts and Regions

C1 L3 – Serous Membranes – iLecture Notes Serous Membranes - Also known as serosa. - Serous membranes line the cavities in the trunk of the body and cover the organ within these cavities. - 2 layers: parietal layer lines the trunk cavity whereas the visceral layer lines the organs. - Are continuous – visceral layer connects directly to parietal layer. - Serous fluid produced by the membrane fills the cavity between the two layers and acts as a lubricant between the organ and the body wall. - Three different serous membranes in the trunk of the body: - Heart = pericardium - Lungs and thoracic cavity = pleura - Abdominopelvic cavity = peritoneum. - Retro-peritoneum = behind the peritoneum. - We need serous membranes lining body cavities as they are a point of attachment to the body (hold organs to the body wall) and the serous fluid acts as a lubricant between the organ and the body wall which is important to prevent friction for organs that move.

HSF Compendium 2 Notes C2 L1 – The Cell and its Organelles – iLecture Notes The Cell - Structural and functional unit of all living things, including humans. Environment of a Cell - Intracellular: inside the cell. - Main components: Some similar components to the extracellular environment such as water, ions, hormones, dissolved gases, glucose but differing concentrations. Will also have intracellular proteins with various functions, cytoskeleton and various organelles - Extracellular: outside the cell. - Intravascular: inside the blood vessels. - Intercellular (interstitial): in between cells. Functional Characteristics of Cells - 1. Cell metabolism and energy use - Cell metabolism: the chemical reactions that take place in the cell. - Energy produced from chemical reactions used for other cellular processes, reactions and functions. - 2. Synthesis of molecules - Some of the molecule produced by cells: lipids (cholesterol, phospholipids), DNA, RNA, and various proteins. - Protein can be turned into receptors, hormones, cell membrane channels, antibodies, muscle proteins. - 3. Communication - Communicate with other cells be sending or receiving chemical or electrical signals. - Reasons for communication: cell division, cell growth, or to carry out specific functions. - 4. Reproduction and inheritance - Most cells contain genetic information, mainly DNA, and this DNA will direct how a cell functions and what it looks likes. - DNA can be passed into newer cells so the newer cells know how to carry out the same functions as older cells. Human Cell - Organelles: little organs that carry out particular functions within a cell. Plasma Membrane - Also known as the cell membrane. - Functions: - Encloses and supports cellular contents. - Controls what goes into the cell and what comes out. - Role in inter-cellular (cell-to-cell) communication; e.g. through the use of protein receptors. - Extracellular fluid = outside of the cell. - Cytoplasm/intracellular fluid = inside of the cell. - Structure: - Lipid bilayer (phospholipids bilayer and cholesterol) – 45-50%. - Provides flexibility to the cell. - Carbohydrates – 4-8%. - Proteins – 45-50%. - E.g. integral protein, membrane channel. - Glycocalyx (outer surface of cell membrane). - Establishes an extracellular micro-environment.

- Role in cell metabolism, cell recognition and cell association. - Molecules which make up glycocalyx: gycloproteins (carbohydrates and proteins), glycolipids (carbohydrates and lipids) and carbohydrates. Cytoplasm - Cellular fluid material outside the nucleus but within the boundaries of the plasma membrane. - Within the cytoplasm are the organelles. - Made up of cytosol. Cytosol - Fluid portion of the cytoplasm (ions and proteins in water). - Cytoplasmic inclusions – aggregates (clumps) of chemicals – e.g. pigments such as melanin, glycogen. - Cytoskeleton – supports the cell and its organelles. Responsible for changes to the shape of the cell and movement of its organelles. Cytoskeleton - Support the cell and its organelles. Responsible for changes to the shape of the cell and movement of its organelles. - Three types of cytoskeleton proteins: - Microtubules - Microfilaments - Intermediate filaments. Cytoplasm Cytosol Cytoskeleton

The cell components outside the nucleus but inside the plasma membrane. All the intracellular fluid plus all the organelles except the nucleus. Intracellular fluid, containing a mixture of water, salts, dissolved ions and organic molecules. Consists of structural protein filaments that give shape to a cell, provide strength, stabilise the position of organelles and assist in cell movement.

Nucleus - Function: - “Control centre” of the cell. - Deoxyribonucleic acid (DNA) in the nucleus determines the structural and functional characteristics of the cell. - Structure: - Nuclear envelope – a bilayer membrane surrounding the nuclear; porous – has pores/holes in it which allow molecules to pass through and out of the nucleus. - Nucleoplasm – fluid material inside the nucleus. - Nucleolus – primary produces ribosomes. - Cells that are multi-nucleated: skeletal muscle cells and osteoclasts (cells which break down bone) as these cells require more regulation e.g. muscle cells require the constant synthesis of enzymes and proteins for their function. Ribosomes - Function: - Site of protein synthesis. - Nucleolus, nucleus, cytoplasm. - Structure: - Composed of two subunits: large and small. - Free ribosomes and membrane-bound ribosomes (e.g. attached to organelles such as the endoplasmic reticulum). Endoplasmic Reticulum - Structure: - Flattened, interconnecting sacs and tubules. - Rough endoplasmic reticulum – with ribosomes.

- Smooth endoplasmic reticulum – without ribosomes. - Function: - Rough endoplasmic reticulum: - Synthesis and modification of proteins. - Smooth endoplasmic reticulum: - Site of lipid, steroid and carbohydrate synthesis. - Detoxification of harmful substances (e.g. drugs). - Breakdown of glycogen to glucose. - Cells that have large amount of SER: liver cells because they detoxify harmful substances and cells of the ovaries and testes because they produce the lipid-containing hormones estrogen and testosterone, Golgi Apparatus - Golgi spelt with a capital ‘G’ (1898, Camillio Golgi). - Structure: - Flattened membranous sacs, with cisternae. - Secretory vesicles – move the proteins from the Golgi apparatus to their appropriate destination. - Function: - “Traffic director” for cellular proteins. - Modifies, packages and distributes proteins and lipids that are made in the rough endoplasmic reticulum. - Cells that contain a well-developed and extensive Golgi apparatus: secretory cells in general e.g. goblet cells (mucus), pancreatic beta cells (insulin) or acinar cells (enzymes), stomach chief cells (digestive enzymes) and plasma cells (antibodies). Lysosomes - Structure: - Membrane-bound vesicles that form at the Golgi apparatus. - Contain enzymes within them. - Function: - “Demolish” unwanted substances. - Digestion of molecules (nucleic acids, proteins, lipids, carbohydrates, etc.) that are no longer needed by the cell. Mitochondria - Structure: - Outer membrane - Intermembrane space - Inner membrane - Matrix – gel-like substance where chemical reactions take place. - Changes shape continuously. - Has its own genetic material so is able to reproduce itself. - Function: - “Power plants” of a cell. - ATP (adenosine triphosphate) production and supply. - ATP is the unit of currency for energy. - Cells with a large numbers of mitochondria: kidney, liver and muscle cells because these cells have higher energy requirements and use energy at a higher rate.

Centrioles (and the Centrosome) - Structure: - Barrel-shaped organelles orientated at right angles to each other. - Wall of centrioles is composed of microtubules. - Two centrioles can be found in the centrosome (cell’s centre). - Function: - Cell division. Cilia - Structure: - Whip-like, motile cellular extensions which project from the outer surfaces of certain cells. - Function: - Movement of substances across the surface of cells. - E.g. cilia lining the respiratory tract which move mucus out of the lungs. - E.g. cilia in the fallopian tubes of the female reproductive system which moves the egg from the ovary to the uterus. - Cilia beat in an organised motion and move material across cell surface. This is important in areas such as the trachea where they whip up mucous with trapped particles to prevent them entering lower respiratory system. Flagella - Structure: - Similar to cilia but longer. - Found in humans on sperm cells only (one flagellum per sperm). - Unlike cilia which move substances across the cell surface, flagella move the actual cell itself. - Function: - Motility. Microvilli - Structure: - Extensions of the plasma membrane. - Each cell has many microvilli usually. - 1/10-1/20 size of cilia, hence micro. - Non-motile. - Function: - Increases the cell’s surface area. - E.g. absorptive cells of intestine or kidney tubules. Summary of Cell Parts and Functions Cell Parts Structure Plasma Lipid bilayer composed of phospholipids and membrane cholesterol; proteins extend across or are embedded in either surface of the lipid bilayer.

Nucleus

Ribosome

Enclosed by nuclear envelope, a double membrane with nuclear pores; contains chromatin (dispersed, thin strands of DNA and associated proteins), which condenses to become visible mitotic chromosomes during cell division; also contains one or more nucleoli, dense bodies consisting of ribosomal RNA and proteins. Ribosomal RNA and proteins form large and small subunits; some are attached to endoplasmic reticulum, whereas others are distributed throughout the cytoplasm.

Function Functions as the outer boundary of cells; controls the entry and exit of substances; receptor proteins function in intercellular communication; marker molecules enable cells to recognise one another. Is the control centre of the cell; DNA within the nucleus regulations protein (e.g. enzyme) synthesis and therefore the chemical reactions of the cell.

Serves as site of protein synthesis.

Rough endoplasmic reticulum Smooth endoplasmic reticulum Golgi apparatus Lysosome

Membranous tubules and flattened sacs with attached ribosomes.

Synthesises proteins and transports them to Golgi apparatus.

Membranous tubules and flattened sacs with no attached ribosomes.

Manufactures lipids and carbohydrates; detoxifies harmful chemicals; stores calcium.

Flattened membrane sacs stacked on each other.

Modifies, packages, and distributes proteins and lipids for secretion or internal use. Contains digestive enzymes.

Membrane-bound vesicle pinched off Golgi apparatus. Mitochondria Spherical, rod-shaped, or threadlike structures; enclosed by double membrane; inner membrane forms projections called cristae. Centrioles Pair of cylindrical organelles in the centrosome, consisting of triplets of parallel microtubules. Cilia Flagellum Microvilli

Extensions of the plasma membrane containing doublets of parallel microtubules; 10µ in length. Extension of the plasma membrane containing doublets of parallel microtubules; 55µ in length. Extension of the plasma membrane containing microfilaments.

Are major sites of ATP synthesis...