HAP Notes PDF

Preview

Summary

Lecture 1 - Human Body and cells 25/02/blackboard.aut.ac/bbcswebdav/pid-4669023-dt-content-rid-8942414_4/xid-8942414_THE HUMAN BODY - AN ORIENTATION (Chapter 1) Anatomy vs Physiology Anatomy = Structure The study of the structure and shape of the body and its parts and their relationship to one anot...

Description

Lecture 1 - Human Body and cells

25/02/19

https://blackboard.aut.ac.nz/bbcswebdav/pid-4669023-dt-content-rid-8942414_4/xid-8942414_4 THE HUMAN BODY - AN ORIENTATION (Chapter 1) Anatomy vs Physiology Anatomy = Structure The study of the structure and shape of the body and its parts and their relationship to one another. - Gross anatomy - Easily observable, what you can easily see. - Microscopic anatomy - Only seen at high magnification. Cells and tissues are microscopic. Physiology = Function The study of how the body and its parts work or function. - Many subdivisions e.g. neurophysiology (the function of the nervous system). - Cellular physiology - How cells work. Anatomy reflects physiology (complementary relationship). Structural organization that make up the human body: - Chemicals (Major 96.1% Carbon, Hydrogen, Oxygen, Nitrogen). - Molecules (Water, Sugar, Protein). - Organelles (Mitochondria, Ribosomes, ER) - Cells (Bone cell, Muscle cell, fat cell) - Tissue (four types). - Organs (Blood vessel, Lung, Heart) - Organ systems (x10) - Organism Chemicals > Molecules > Organelles > Cells > Tissue > Organs > Organ System > Organism. Tissue types 1. Epithelial tissue - Cells organised to form a covering/lining and glands - protection, absorption, secretion, filtration. 2. Connective tissue - Cells organised to provide protection, support and ‘holding together’. 3. Muscle tissue - A body tissue that contracts or shortens, making body parts move. 4. Nervous tissue - A body tissue that carries electrical messages back and forth between the brain and every other part of the body.mf Key Terms Homeostasis - maintaining a relatively stable internal environment. Elements of a homeostatic control system:

-

Receptor (to detect change). Control centre (to determine the ‘set point’). Effector (to carry out adjustments).

Feedback Negative - Reduces the intensity of the change or reverse the change (most common form of feedback). Positive - Increase the intensity of the change or magnify the change (rare). Human Body organ systems https://www.youtube.com/watch? v=Ae4MadKPJC0&feature=youtu.be Skeletal, Muscular, Cardiovascular and Nervous create an infrastructure that facilitates the other systems. Organ Systems Organ systems work together to maintain a healthy body. 1. Skeletal - Protects and supports the body’s organs. 2. Muscular - Allows manipulation of the environment. 3. Cardiovascular - Transport blood which carries nutrients and removes toxins. 4. Nervous - Control system, activates muscles and glands. 5. Endocrine - Secrete hormones that regulate processes such as growth and reproduction. 6. Lymphatic - Picks up fluid, filters it and returns it to blood. 7. Respiratory - Supplies blood with oxygen and removes carbon dioxide. 8. Digestive - Breaks food down to be absorbed into the blood. 9. Urinary - Eliminates waste, regulates water, electrolytes and acid balance. 10. Reproductive - Facilitates the production of offspring. 11. Integumentary - Forms external body covering.

Planes (Analysis of movement) a) Sagittal - Dissection of left and right. Movements of front and back. E.g Dumbbell Lifts. (Midsagittal - Dissection from the midline, even sides) b) Frontal - Dissection of front and back. Movements side to side. E.g. Star Jumps. c) Transverse - Dissection of upper and lower. Movement is Horizontal. E.g looking at a view. Why exercises typically involve only one plane? - Injury Prevention (No rotation) - Isolation of muscles - Balance

Orientation and Directional Movements Every term has an opposite in reference to the midline. 1. 2. 3. 4. 5. 6. 7.

Superior - Above Inferior - Below Anterior - Frontal Posterior - Back Medial - Toward Lateral - Away Proximal - Outside

8. Intermediate - In between 9. Superficial - External 10. Deep - Internal

BASIC CELLS (Chapter 3) Cells > Cells are single cell organisms > Humans are made of trillions of cells, but start off as just one. > The activity of an organism depends on the collective activity of its cells. > Cells come in many shapes and sizes - their anatomy complements their physiology. > Cells have three main parts - Nucleus, Cytoplasm and Plasma membrane.

Nucleus (Control centre) Contains the genetic material to make proteins (DNA - complete set of instructions). Surrounded by a double membrane containing pores. Without a nucleus, a cell cannot survive for very long.

Structure - Largest organelle. Surrounded by the nuclear envelope; contains fluid nucleoplasm, nucleoli and chromatin. Functions - Control centre of the cell; responsible for transmitting genetic information and providing the instructions for protein synthesis.

Structure of a generalised cell

Organelles of a cell(specialised structures within a cell to carry out specific function). Cell Part

Structure (Anatomy)

Functions (Physiology)

Mitochondria

Rodlike, double membrane structures; inner membrane folded into projections called cristae.

Site of ATP synthesis; powerhouse of the cell. Areobic respiration (Requires oxygen).

Ribosomes

Dense particles of two subunits, each composed of ribosomal RNA and protein. Free or attached to rough endoplasmic reticulum.

The site of protein synthesis.

Rough endoplasmic reticulum

Membrane system enclosing a cavity, the cistern and coiling through the cytoplasm. Externally studded with ribosomes.

Sugar groups are attached to proteins within the cisterns. Proteins are bound in vessels for transport to the Golgi apparatus and other sites. External face synthesises phospholipids.

Smooth endoplasmic reticulum

Membrane system of sacs and tubules; free of ribosomes.

Site of lipid and steroid (cholesterol) synthesis, lipid metabolism and drug detox.

Golgi apparatus

A stack of flattened membranes and associated vessels close to the nucleus.

Packages modify and segregate proteins for secretion from the cell. Inclusion in lysosomes and incorporation into the plasma membrane.

Lysosomes

Membrane sacs containing acid hydrolases (powerful digestive enzymes).

Sites of intracellular digestion.

Cell membrane Double layer of lipids and proteins that surround a cell and separates the cytoplasm from the surrounding environment. > Flexible barrier surrounding the cell. > Every cell has a membrane. > “Selectively permeable” - only allows some things in (K+) and some things out (Na+). > Separates the internal cellular environment from the extracellular environment. > Structure is a double layer of phospholipids with protein.

Phospholipid bilayer Phosphors - Hydrophilic (Likes water). Lipids - Hydrophobic (Doesn't like water).

Lecture 2 - Integumentary system and Skeletal system

04/03/19

https://blackboard.aut.ac.nz/bbcswebdav/pid-4669032-dt-content-rid-8475457_4/xid-8475457_4 INTEGUMENTARY SYSTEM (Chapter 5)

Cutaneous membrane - Covers the body’s surface. Integumentary system Includes skin, sweat glands oil glands, hair and nails. Integument - covering Skin is essential (waterproof, stretchable, self-repairing, tough surface). The skin has three main layers. 1. Epidermis 2. Dermis 3. Subcutaneous Hypodermis Epidermis Layer > The outermost layer. > Cellular but no blood supply or nerve fibres. > Composed of five layers. 1. Basale (deepest). 2. Spinosum 3. Granulosum 4. Lucidum 5. Corneum (outermost). Most cells are keratinocytes (produce keratin that makes the epidermis a tough protective layer), but there are also melanocytes (Produces melanin pigment to protect against light and radiation). Dendritic cells (Important to alert and active immune system to a bacterial or viral invasion - Phagocytosis). and Merkel cells (Associated with sensory nerve endings and serve as touch receptors). Phagocytosis - The ingestion of bacteria or other material by phagocytes and amoeboid protozoans.

Basale Constantly dividing, making new cells. Cells are pushed forward towards superficial layers which then go through the process of keratinisation (filling the cells with protein).

Dermis Layer The dermis has two layers the papillary layer (forms fingerprints) and the reticular layer. Appendage - extra parts in the dermis layers. Sebaceous oil gland - Oil gland that produces sebum, usually attached to a hair follicle. Exocrine gland - Respond to an temperature increase by producing more sweat. Release their secretions to the skin's surface via ducts. Apocrine gland - Sweat related to stress. Functions of the Integumentary system > Protects deeper tissue from - Mechanical damage - Chemical damage - Bacterial damage > Aids the body in heat loss or heat retention. > Synthesises inactive form of vitamin D (Cholesterol is modified in skin to form a precursor to vitamin D). > Waterproof surface.

SKELETAL SYSTEM (Chapter 5) Functions of the bone Support - Bones form an internal framework. Protection - Soft organs are protected by bones. Allow movement - Skeletal muscles attach to bones which act as levers, and joints between bones allow movement. Storage - Fat is stored in the bone marrow, calcium and phosphorus minerals stored in bones. Blood cell formation - ‘Hematopoiesis’ occurs in the bone marrow of certain bones.

Classification of bone by shape 1. Long bone (Humerus) 2. Irregular bone (Vertebrae) 3. Flat bone (Sternum) 4. Short bone (Talus) Features of a long bone Proximal Epiphysis - Close to point of attachment. Epiphyseal line - Important to bone growth. Cite of Ossification. Articular cartilage - Smoot white tissue found at end of long bones. No blood supply. Allows bones to slide over each other. Periosteum - A dense layer of vascular connective tissue enveloping the bones. Full of nerves. Bone Marrow - Forms new blood cells. Medullary cavity - Central cavity of the bone where bone marrow is stored. Type of bone Spongy - Lightens weight Compact - Surface.

Bone growth and remodelling - Cartilage is replaced by bone through a process called “ossification”. - Osteoblasts are cells which build new bone. - Osteoclasts are cells which break down bones. - Hormones influence the activity of both osteoblasts and osteoclasts. - Remodelling allows bones to strengthen where needed e.g. at the attachment site of large muscles. - Remodelling allows bones to heal after breaking. Skeleton Axial Skeleton (Green) - Central Axes, Fixed Point. (Dock) Appendicular Appendicular Skeleton (White) - Attachments (Boat)

Joints Cartilaginous - Bones connected by hyaline cartilage. Joint has limited movement. Fibrous - Bones connected by fibrous connective tissue. Joints have limited movement. Synovial - Ends of bone ‘connected’ with a joint cavity. Freely moveable.

-

Synovial Joint - Articular cartilage reduces friction by covers the ends of the bones. Joint capsule – ends of bones enclosed in a fibrous capsule lined with a synovial membrane. Joint cavity filled with synovial fluid Reinforcing ligaments to support joint. Synovial fluid helps to lubricate joints and is a source of nutrients for some cells within the joint.

Lecture 3 - Nervous System

11/03/19

https://blackboard.aut.ac.nz/bbcswebdav/pid-4669048-dt-content-rid-8517124_4/xid-8517124_4 PART ONE Functions of the nervous system - Controls all other systems. - Fast acting control system. - Responds to internal and external change. - Activates muscles and glands.

Three overlapping systems of the nervous system 1. Sensory Input - Information gathered by sensory receptors about internal and external changes. 2. Integration - Processing and interpretation of sensory input. 3. Motor Output - Activation of effector organs (muscles and glands) produces a response. Nervous system is divided into two principal parts 1. Central nervous system (CNS) - Essential. - Brain and spinal cord of the dorsal cavity. - Integration and control centre. (Intercepts sensory input and dictates motor output). 2. Peripheral nervous system (PNS) - The proportion of the nervous system outside CNS. - Consists mainly of nerves that extend from the brain and spinal cord. (Spinal nerves to and from the spinal cord) (Cranial nerves to and from the brain). The peripheral nervous system has two functional divisions Sensory (afferent) division. Recieve or transport sensory material towards the brain. - Somatic sensory fibres: convey impulses from skin, skeletal muscles and joints to CNS. - Visceral sensory fibres: convey impulses from visceral organs to CNS.

Nerve Classification Free nerve ending - Pain and temp receptors. Meissner’s corpuscle - Touch receptors. Lamellar corpuscle - Deep pressure receptors. Motor (efferent) division. Signal from brain towards muscles/glands. - Transmits impulses from CNS to effector organs (muscles and glands). - Two divisions (somatic and autonomic nervous systems). Autonomic Nervous System Sympathetic - Fight Parasympathetic - Flight Stimulated in a stressful situation. Organisation of the nervous system

Overview of nervous system function Receive a signal from the external environment (Sensory) > Signal to brain (Integration) Signal to muscles/glands > Instruction performed (Effector).

Structure of a Neuron Neurons = nerve cells. - Cells specialised to transmit messages. - Major regions of neurons. - Cell body - Nucleus and metabolic - center of the cell. - Processes - Fibres that extend from the cell body. Neuron Anatomy Extensions outside the cell - Dendrites - conducts impulses toward the cell body. - Axons - conduct impulses away from the cell body. Neuron Axon Coverings - Schwann cells - produce myelin sheaths in jelly-roll like fashion. - Nodes of Ranvier - gaps in the myelin sheath along the axon. Types of neurons Multipolar neurons - Many extensions from the cell body, most common. Unipolar neurons - Have a short single process leaving the cell body. Projected cell body. (Sensory neurons) Bipolar neurons - One axon and one dendrite, rare in adults. Eye and Ear.

Neuron cell body location - Most are found in the central nervous system. - Grey matter - cell bodies and unmyelinated fibres. - Nuclei - clusters of cell bodies within the white matter of the central nervous system. - Ganglia - collections of cell bodies outside the central nervous system. Neuron functional classification Sensory (afferent neurons). - Carry impulses from the sensory receptors. - Cutaneous sense organs. - Proprioceptors - detect stretch or tension. - Tells you what is happening in your body. Motor (efferent neurons). - Carry impulses from the central nervous system. - Signals muscles to move.

Interneurons (association neurons). - Found in neural pathways in the central nervous system. - Connect sensory and motor neurons. Neuron Functions - Irritability - ability to respond to stimuli. - Conductivity - ability to transmit an impulse (electrictly).

Axon -

The plasma membrane at rest in polarized.

Starts at the hillock. Ends in axonal terminals. Axonal terminals contain vesicles with neurotransmitters. Axonal terminators are separated from the next neuron by a gap. Synaptic cleft - gap between adjacent neurons. Synapse - junction between neurons.

PART TWO (ACTION POTENTIAL) https://blackboard.aut.ac.nz/bbcswebdav/pid-4669048-dt-content-rid-8517125_4/xid-8517125_4 Resting membrane > No changing in concentration > No fast movement of chemicals. Content of chemicals is reflected by size of element (Na+ and K+) Inside of cell - High concentration of Potassium Ions (negative). Outside of cell - High concentration of Sodium Ions (positive).

-

Electrochemical Gradient Ions flow along their chemical gradient when the move from an area of high concentration to an area of low concentration. Ions flow along their electrical gradient when they move toward an area of opposite charge. Electrochemical gradient - The electrical and chemical gradients taken together.

Signals > Used to integrate, send and receive information. > Membrane potential changes are produced by: - Changes in membrane to ions. - Alterations of ion concentration across the membrane. Types of membrane ion channels: Passive or leakage channels - always open. Chemically gated channels - open with the binding of a specific neurotransmitter.

Voltage-gated channels - open and close in response to membrane potential. Mechanically gated channels - Open and close in response to physical deformation of receptors. Resting membrane potential (Vr) > The potential difference (-70mV) across the membrane of a resting neuron. > It is generated by different concentrations of Na+, K+, Cl- and protein anions (A-). > Ionic differences are the consequences of: - Differential permeability of the neurilemma to Na+ and K-. - Operation of the sodium-potassium pump. The plasma membrane of a neuron at rest is polarized (negative on inside, positive on outside). > Major positive ion inside the cell is K+. > Major positive ion outside the cell is Na+. > Slightly more positive ion outside the cell compared to inside. > As long as the inside stays more negative compared to the outside the cell will be inactive. Importance of resting membrane potential - Generation and conduction of nerve impulses or an electrical current along the axon. - Without resting membrane potential the ability to send nerve impulses would not exist. Four stages of Action potential (Four main steps). https://www.youtube.com/watch?v=-h_kWFM2faQ 1. Resting state: All gated Na+ and K+ channels are closed, a high intracellular concentration of anionic proteins. ATP expenditure of the neuron, the actions of the sodium-potassium pump. 2. Depolarization: Na+ channels open. 3. Repolarization: Na+ channels are inactivating and K+ channels open. 4. Hyperpolarization: Some K+ channels remain open and Na+ channels rest. Action Potential (depolarization and repolarization). > Principle way neurons send signals. - Means of long-distance neural communication. > Occur only in muscle cells and axons of neurons. > Brief reversal of membrane potential with a charge in voltage of 100mV. > Action potentials (APs) do not decay over distance as graded potentials do. > In neurons also referred to as nerve impulse. Involves opening of specific voltage-gated channels. Generating an action potential

Depolarization: Na+ channels open > Depolarizing local currents open voltage-gated Na+ channels and Na+ rushes into cell. > Na+ activation and inactivation gates open. > Na+ influx causes more depolarization, which opens more Na+ channels. - As a result, ICF becomes less negative. > At threshold (-55 to -50mV), positive feedback causes opening of all Na+ channels. - Results in large action potential spike. - Membrane polarity jumps to +30 mV. The action potential If the action potential (nerve impulse) starts it is propagated over the entire axon and never goes part way along the axon. Immediately after Na+ rushes in the membrane permeability changes again. Membrane becomes impermeable to Na+ not permeable to K+ inside the cell than outside. K+ ions rush out of the neuron after Na+ ions rush in, which repolarizes the membrane. Repolarization restores the membrane electrical conditions to resting. - The sodium-potassium pump restores the original configuration of Na+ and K+. (Requires ATP). Speed of conduction > The impulse continues to move away from the cell body. > This show events in an unmyelinated axon. > Impulses travel faster when fibres have a myelin sheath.

Nerve impulse propagation - Nerve impulse jumps from the node of Ranvier to the node of Ranvier along the length of the axon. - No electrical current can flow across the membrane where there is fatty myelin insulation. This is called Saltatory conduction. Starting a nerve impulse (INSERT DIAGRAMS) > Different stimuli excite neurons to become active and produce an impulse. Examples incl...