Compendium 1, 2, 3 Flashcards
Define Anatomy
Scientific discipline that investigates the structure of body parts and how they relate to each other.
- E.g. shape and size of bones
Derived from the Greek word anatemnō = “I cut up, cut open”
Define Physiology
Study of the function of living things
Levels of Anatomy
- Gross anatomy (macroscopic): structures examined without the aid of a microscope
a) Systemic: body is studied system by system (respiratory)
- System is a group of structures that have one or more common functions, such as the cardiovascular, nervous, respiratory, skeletal, or muscular systems.
b) Regional: body is studied area by area
- Within each region, such as the head, abdomen, or arm, all systems are studied simultaneously
Surface
o
Study of external form of the body and its relation to deeper structures
•
Using surface landmarks which indicate deeper structures eg sternum and
ribs to identify different parts of the heart
o
A form of macroscopic/gross anatomy
Surface
o
Study of external form of the body and its relation to deeper structures
•
Using surface landmarks which indicate deeper structures eg sternum and
ribs to identify different parts of the heart
o
A form of macroscopic/gross anatomy - Surface: Study of the external form of the body and its relation to deeper structures
- Using surface landmarks which indicate deeper structures e.g. sternum and ribs to identify different regions of the heart
- A form of macroscopic/gross anatomy - Microscopic: Structures examined with the aid of a microscope e.g. cytology, histology
- Cytology examines the structural features of cells
- Histology examines tissues, which are composed of cells and the materials surrounding them. - Developmental: Structural changes that occur in the body throughout the life span
- studies the structural changes that occur between conception and adulthood
Levels of Physiology
Molecular Cellular Systemic Neurophysiology Renal Cardiovascular, etc
Cell physiology examines the processes occurring in cells, and systemic physiology considers the functions of organ systems.
Neurophysiology focuses on the nervous system, and cardiovascular
physiology deals with the heart and blood vessels.
Describe the six levels of organisation in the body
chemical Level:
- The chemical level involves interactions between atoms (tiny building blocks of matter)
- Atoms combine to form molecules, such as water, sugar, lipids, and proteins. The function of a molecule is intimately related to its structure.
- Atoms (e.g. carbon, hydrogen, oxygen, nitrogen) combine to form molecules (e.g. DNA, RNA, sugar, water)
Cellular Level:
- Cells are the basic structural and functional units of plants and animals. Molecules combine to form organelles
- Molecules (e.g. DNA, RNA) combine to form organelles (e.g. nucleus, mitochondria, endoplasmic reticulum, etc) of a cell
Tissue Level:
- A tissue is composed of a group of similar cells and the materials surrounding them. The characteristics of the cells and surrounding materials determine the functions of the tissue. The body is made up of four basic tissue types: epithelial, connective, muscle, and nervous.
- Numerous cells (e.g. smooth muscle cells) join together to form a tissue (e.g. smooth muscle tissue)
Organ Level:
- composed of two or more tissue types that perform one or more common functions.
- E.g. The urinary bladder, heart, stomach, lung
Organ System:
- group of organs that together perform a common function or set of functions and are therefore viewed as a unit. For example, the urinary system consists of the kidneys, ureter, urinary bladder, and urethra.
Organism Level:
- organism is any living thing considered as a whole—whether composed of one cell, such as a bacterium, or of trillions of cells, such as a human. The human organism is a network of organ systems, all mutually dependent on one another.
List the six characteristics of organisms
- Organisation: refers to the specific interrelationships among the parts of an organism and how those parts interact to perform specific functions.
- Metabolism: refers to all of the chemical reactions taking place in the cells and internal environment of an organism.
- Responsiveness: is an organism’s ability to sense changes in its external or internal environment and adjust to those changes.
- Growth: refers to an increase in the size or number of cells, which produces an overall enlargement of all or part of an organism.
- Development: includes the changes an organism undergoes through time, beginning with fertilization and ending at death. The greatest developmental changes occur before birth, but many changes continue after birth, and some go on throughout life.
- Reproduction: is the formation of new cells or new organisms. Without reproduction of cells, growth and development are not possible. Without reproduction of organisms, species become extinct.
Homeostasis
The existence and maintenance of a relatively constant environment within the body.
List the characteristics of the anatomical position
Anatomical position refers to a person standing erect with the face directed forward, the upper limbs hanging to the sides, and the palms of the hands facing forward.
Why?
- Gives us point of reference to describe different parts of the body
- To avoid confusion, relational descriptions are always based on the anatomical position, no matter the actual position of the body. Thus, the chest is always described as being “above” (superior to) the stomach, whether the person is lying down or is even upside down
Directional terms
Superior (cephalic)– Structure above another/higher
Inferior (Caudal)– Structure below another/lower
Anterior– The front of the body
Posterior– The back of the body
Dorsal – Towards the back
Ventral – Towards the belly
Medial– Towards the midline of the body
Lateral– Away from the midline of the body
Proximal– Used for limbs - Closer to the point of attachment
Distal– Used for limbs - Further from the point of attachment
Superficial– Toward or on the surface
Deep– Away from the surface, internal
Caudal– Closer to the tail
Cephalic– Closer to the cranium/head
What are the three planes in which the body or organs can be divided?
- Sagittal Plane:
- Runs vertically down the body separating the body into left and right portions
- Median = mid-sagittal
- A mid-sagittal plane will divide the body into two equal segments (e.g. through the nose). A parasagittal plane will divide the body into unequal segments (e.g. through a shoulder). - Frontal Plane:
- Aka coronal
- Runs vertically from right to left and divides the body into anterior and posterior - Transverse Plane
- Aka horizontal
- Runs parallel to the ground, dividing the body into superior and inferior portions.
Oblique:
- A plane that does not run parallel to the frontal or transverse plane
- Plane on an angle
Subdivisions of the abdomen
Right-Upper Quadrant (RUQ)
This Quadrant contains the following: Liver, Gall Bladder, Duodenum, Head of Pancreas, and
Hepatic Flexure of Colon.
Right-Lower Quadrant (RLQ)
This Quadrant contains the following: Cecum, Appendix, Ascending Colon, Right Ovary,
Fallopian Tube (Right Uterine Tube), and Right Ureter.
Le7-Upper Quadrant (LUQ)
This Quadrant contains the following: Stomach, Spleen, Left Lobe of Liver, Body of Pancreas,
Left Kidney, Adrenal Gland, Splenic Flexure of Colon, and Parts of Transverse and
Descending Colon.
Left-Lower Quadrant (LLQ)
This Quadrant contains the following: Descending Colon, Sigmoid Colon, Left Ovary, and
Fallopian Tube (Left Uterine Tube).
Right Hypochondriac Region
This Region contains the following: Liver, Gall Bladder, Small Intestine, Ascending Colon,
Transverse Colon, and Right Kidney.
Left Hypochondriac Region
This Region contains the following: Stomach, Liver (Tip), Pancreas (Tail of), Small Intestine,
Transverse Colon, Descending Colon, Left Kidney, and Spleen.
Epigastric Region
This Region contains the following: Oesophagus, Stomach, Liver, Pancreas, Small Intestine,
Transverse Colon, Right & Left Adrenal Glands, Right & Left Kidneys, Right & Left Ureters,
and Spleen.
Right Lumbar Region
This Region contains the following: Liver (Tip), Gall Bladder, Small Intestine, Ascending
Colon, and Right Kidney.
Right-Upper Quadrant (RUQ)
This Quadrant contains the following: Liver, Gall Bladder, Duodenum, Head of Pancreas, and
Hepatic Flexure of Colon.
Right-Lower Quadrant (RLQ)
This Quadrant contains the following: Cecum, Appendix, Ascending Colon, Right Ovary,
Fallopian Tube (Right Uterine Tube), and Right Ureter.
Left-Upper Quadrant (LUQ)
This Quadrant contains the following: Stomach, Spleen, Left Lobe of Liver, Body of Pancreas,
Left Kidney, Adrenal Gland, Splenic Flexure of Colon, and Parts of Transverse and
Descending Colon.
Left-Lower Quadrant (LLQ)
This Quadrant contains the following: Descending Colon, Sigmoid Colon, Left Ovary, and
Fallopian Tube (Left Uterine Tube).
Right Hypochondriac Region
This Region contains the following: Liver, Gall Bladder, Small Intestine, Ascending Colon,
Transverse Colon, and Right Kidney.
Left Hypochondriac Region
This Region contains the following: Stomach, Liver (Tip), Pancreas (Tail of), Small Intestine,
Transverse Colon, Descending Colon, Left Kidney, and Spleen.
Epigastric Region
This Region contains the following: Oesophagus, Stomach, Liver, Pancreas, Small Intestine,
Transverse Colon, Right & Left Adrenal Glands, Right & Left Kidneys, Right & Left Ureters,
and Spleen.
Right Lumbar Region
This Region contains the following: Liver (Tip), Gall Bladder, Small Intestine, Ascending
Colon, and Right Kidney.
Right-Upper Quadrant (RUQ)
This Quadrant contains the following: Liver, Gall Bladder, Duodenum, Head of Pancreas, and
Hepatic Flexure of Colon.
Right-Lower Quadrant (RLQ)
This Quadrant contains the following: Cecum, Appendix, Ascending Colon, Right Ovary,
Fallopian Tube (Right Uterine Tube), and Right Ureter.
Left-Upper Quadrant (LUQ)
This Quadrant contains the following: Stomach, Spleen, Left Lobe of Liver, Body of Pancreas,
Left Kidney, Adrenal Gland, Splenic Flexure of Colon, and Parts of Transverse and
Descending Colon.
Left-Lower Quadrant (LLQ)
This Quadrant contains the following: Descending Colon, Sigmoid Colon, Left Ovary, and
Fallopian Tube (Left Uterine Tube).
Right Hypochondriac Region
This Region contains the following: Liver, Gall Bladder, Small Intestine, Ascending Colon,
Transverse Colon, and Right Kidney.
Left Hypochondriac Region
This Region contains the following: Stomach, Liver (Tip), Pancreas (Tail of), Small Intestine,
Transverse Colon, Descending Colon, Left Kidney, and Spleen.
Epigastric Region
This Region contains the following: Oesophagus, Stomach, Liver, Pancreas, Small Intestine,
Transverse Colon, Right & Left Adrenal Glands, Right & Left Kidneys, Right & Left Ureters,
and Spleen.
Right Lumbar Region
This Region contains the following: Liver (Tip), Gall Bladder, Small Intestine, Ascending
Colon, and Right Kidney.
Right-Upper Quadrant (RUQ)
- This Quadrant contains the following: Liver, Gall Bladder, Duodenum, Head of Pancreas, and Hepatic Flexure of Colon.
Right-Lower Quadrant (RLQ)
- This Quadrant contains the following: Cecum, Appendix, Ascending Colon, Right Ovary, Fallopian Tube (Right Uterine Tube), and Right Ureter.
Left-Upper Quadrant (LUQ)
- This Quadrant contains the following: Stomach, Spleen, Left Lobe of Liver, Body of Pancreas, Left Kidney, Adrenal Gland, Splenic Flexure of Colon, and Parts of Transverse and Descending Colon.
Left-Lower Quadrant (LLQ)
- This Quadrant contains the following: Descending Colon, Sigmoid Colon, Left Ovary, and Fallopian Tube (Left Uterine Tube).
Right Hypochondriac Region
- This Region contains the following: Liver, Gall Bladder, Small Intestine, Ascending Colon, Transverse Colon, and Right Kidney.
Left Hypochondriac Region
- This Region contains the following: Stomach, Liver (Tip), Pancreas (Tail of), Small Intestine, Transverse Colon, Descending Colon, Left Kidney, and Spleen.
Epigastric Region
- This Region contains the following: Oesophagus, Stomach, Liver, Pancreas, Small Intestine, Transverse Colon, Right & Left Adrenal Glands, Right & Left Kidneys, Right & Left Ureters, and Spleen.
Right Lumbar Region
- This Region contains the following: Liver (Tip), Gall Bladder, Small Intestine, Ascending Colon, and Right Kidney.
Left Lumbar Region
- This Region contains the following: Small Intestine, Descending Colon, and Left Kidney (Tip).
Umbilical Region
- This Region contains the following: Stomach, Pancreas, Small Intestine, Transverse Colon, Right & Left Kidneys, and Right & Left Ureters.
Right Iliac Region
- This Region contains the following: Small Intestine, Appendix, Cecum, Ascending Colon, and Right Ovary (Females).
Left Iliac Region
- This Region contains the following: Small Intestine, Descending Colon, Sigmoid Colon, Left Ovary (Females), and Left Fallopian Tube (Females).
Hypogastric Region
- This Region contains the following: Small Intestine, Sigmoid Colon, Rectum, Right & Left Ovaries (Females), Right & Left Ureters, Uterus (Females), Right & Left Fallopian Tubes (Females), and Prostate (Male).
Describe the major body cavities and their divisions
- Thoracic Cavity:
- The rib cage surrounds the thoracic cavity, and the muscular diaphragm separates it from the abdominal cavity. The thoracic cavity is divided into right and left parts by a middle section called the mediastinum. - Abdominal Cavity:
- Abdominal muscles primarily enclose the abdominal cavity, which contains the stomach, the intestines, the liver, the spleen, the pancreas, and the kidneys. - Pelvic Cavity:
- Pelvic bones encase the small space known as the pelvic cavity, where the urinary bladder, part of the large intestine, and the internal reproductive organs are housed. The abdominal and pelvic cavities are not physically separated and sometimes are called the abdominopelvic cavity.
Describe the properties of serous membranes
Also known as serosa
Serous membranes line the cavities in the trunk of the body and cover the organs within these cavities
2 layers:
- parietal layer lines the trunk cavity (outer)
- visceral layer lines the organs (inner)
Serous fluid produced by the membrane fills the cavity between the two layers and acts as a lubricant between the organ and body wall
Heart = pericardium
Lungs and thoracic cavity = pleura
Abdominopelvic cavity = peritoneum
The cavity, or space, between the visceral and parietal serous membranes is normally filled with a thin, lubricating film of serous fluid produced by the membranes. As organs rub against the body wall or against
another organ, the combination of serous fluid and smooth serous membranes reduces friction.
The cell
Structural and functional unit of all living things, including humans
Functional characteristics of cells
- Cell metabolism and energy use
- Cell metabolism involves all chemical reactions that occur within a cell. These metabolic reactions often involve energy transfers, meaning the energy released by one reaction is then used in another reaction. - Synthesis of molecules
- The different cells of the body synthesize, or produce, various types of molecules, including proteins, nucleic acids, and lipids. The structural and functional characteristics of cells are determined by the types of molecules they produce. - Communication
- Cells communicate with each other by using chemical and electrical signals. - Reproduction and inheritance
- Most cells contain a complete copy of all the genetic information of the individual. This genetic information ultimately determines the structural and functional characteristics of the cell.
Distinguish between the cytoplasm, cytosol, and cytoskeleton
Cytoskeleton
- Consists of structural protein filaments that give shape to a cell, provide strength, stabilise the position of organelles and assist in cell movement.
Cytosol
- Intracellular fluid, containing a mixture of water, salts, dissolved ions and organic molecules.
Cytoplasm
- The cell components outside the nucleus but inside the plasma membrane. All the intracellular fluid plus all the organelles, except the nucleus.
Describe the structure and the role of the cell (plasma) membrane
Function:
- Encloses and supports cellular contents
- Controls what goes into the cell and what comes out
- Role in inter-cellular (cell-to-cell) communication Plasma membrane
Structure:
- Lipid bilayer (phospholipids bilayer and cholesterol) (45-50%)
- Provides flexibility to the cell
- Carbohydrates (4-8%)
- Proteins (45-50%)
- Glycocalyx (outer surface of cell membrane)
Glycoproteins (carbohydrates and proteins)
Glycolipids (carbohydrates and lipids)
Carbohydrates
The predominant lipids of the plasma membrane are phospholipids and cholesterol. Phospholipids readily assemble to form a lipid bilayer, a double layer of phospholipid molecules, because they have a polar (charged) head and a nonpolar (uncharged) tail. The polar heads are attracted to water molecules, so they are also called hydrophilic (water-loving) heads. The polar, hydrophilic heads are exposed to the aqueous extracellular and intracellular fluids of the cell. The tails of the phospholipids are nonpolar and are not attracted to water molecules, so the tails are also called hydrophobic (water-fearing). The nonpolar, hydrophobic tails face
one another in the interior of the plasma membrane. The fluid-mosaic model of the plasma membrane describes the plasma membrane as being neither rigid nor static in structure.
Cholesterol is the other major lipid. It is interspersed among the phospholipids and accounts
for about one-third of the total lipids in the plasma membrane. The hydrophilic hydroxyl (–OH) group of cholesterol extends between the phospholipid heads to the hydrophilic surface of the membrane, whereas the hydrophobic part of the cholesterol molecule lies within the hydrophobic region of the phospholipids. The amount of cholesterol in a particular plasma membrane is a major factor in determining the fluid nature of the membrane. Cholesterol limits the movement of phospholipids, providing stability to the plasma membrane.
Histology
The microscopic study of tissues
Preparation of Tissue
Step 1: Removal of tissue from the body via a biopsy or autopsy. A biopsy is taking a piece of tissue from the body where the person is still alive. For example, cutting a mole from the skin to check if it’s cancerous. An autopsy is taking a piece of tissue from the body where the person has passed away.
Step 2: Fixation of Tissue. The process of immersing the tissue into a mixture of chemicals to stop the metabolism or the chemical reactions that is occurring in this tissue. This fixation process preserves the cells and the extracellular components. The chemicals used for fixation are known as “fixatives”.”
Step 3: Embedding of the Tissue. The tissue must be embedded where the tissue is infiltrated with wax and allowed to set so it becomes hard. It’s this solidification of the tissue that allows us to cut it into thin sections.
Step 4: Slicing of the Tissue and Mounting tissue on a Slide. The slicing of the tissue is done on an instrument called the “microtome.” This instrument allows us to cut very thin slices of tissue so we can mount this tissue onto the slide and view it.
Step 5: Staining and Viewing using a Microscope. After the tissue is cut and placed onto the slide, the wax that had been infiltrated in the tissue is dissolved and the tissue is stained. Tissue is normally colourless, hence the reason why we stain the tissue.
Haematoxylin and Eosin: This chemical is usually abbreviated to H&E. This chemical is used to stain the tissue. This chemical is the most common chemical used in a histology lab. In the H&E stain, Nuclei is stained purple (from Haematoxylin) whereas other cell structures, including the cytoplasm, are stained pink (from Eosin)
4 tissue types
All organs in the body contain all four primary tissue types:
- Epithelial tissue - covers
- Connective tissue - support
- Muscle tissue - movement
- Nervous tissue – control
Epithelial tissue
Epithelial:
Characteristics of epithelial tissue:
- Covers and protects
Covering and lining epithelium
Glandular epithelium
- Distinct cell surfaces
Free surface- where cells are exposed and not attached to other cells.
Lateral surface- where cells are attached to other epithelial cells.
Basal surface (basement membrane or basal lamina)- attached to a basement membrane. It plays an important role in supporting and guiding cell migration during tissue repair. The basement membrane is typically porous, which allows substances to move to and from the epithelial tissue above it.
- Avascular but innervated- Blood vessels in the underlying connective tissue do not penetrate the basement membrane to reach the epithelium;
- Ability to regenerate- ability to replace damaged cells with new epithelial cells. Undifferentiated cells (stem cells) continuously divide and produce new cells
Avascular means that the Epithelia doesn’t have blood vessels running through it.
Innervated means that it does have nerve cells in it.
Avascular means that the Epithelia doesn’t have blood vessels running through it.
Innervated means that it does have nerve cells in it.
- Avascular means that the Epithelia doesn’t have blood vessels running through it. Innervated means that it does have nerve cells in it.
Simple squamous epithelium
Single layer of flattened cells with sparse cytoplasm
Functions:
- Diffusion, filtration and some secretion
Some locations:
- Alveoli of lungs, kidney glomeruli, serous membranes of pleura, pericardium and peritoneum
Simple cuboidal epithelium
Single layer of cubed-shaped cells.
- Some of these cells have microvilli or cilia
Functions:
- Absorption, secretion and movement
Some locations:
- Kidney tubules and terminal bronchioles
Simple columnar epithelium
Single layer of column-shaped or tall cells with round to oval nuclei.
- Some cells have cilia
Functions:
- Absorption, secretion and movement (similar to simple cuboidal!)
Locations:
- Intestines, stomach, fallopian tubes and lungs
Transitional epithelium
Resembles stratified squamous and stratified cuboidal cells depending on its state
Functions:
- Accommodate changes in fluid volume of the organs Locations: • Urinary bladder, ureter and upper part of urethra
Location:
- Lining of the urinary bladder, ureters, superior urethra
Stratified squamous epithelium
Basal cells are cuboidal or columnar and become progressively flatter (i.e. squamous) as you move to the surface. Several layers of cells
- Keratinized- primarily In the skin
- Non-keratinized - mouth, throat, larynx, esophagus, anus, vagina, inferior urethra, cornea
Functions:
- Protection against abrasion and loss of water
Locations:
- Keratinized: sole of feet, palm of hands, skin
- Non-keratinized: mouth, oesophagus, anus and vagina
Stratified cuboidal epithelium
Multiple layers of cubed-shaped cells. Rare tissue.
Functions:
- Absorption, secretion and protection
Locations:
- Ducts of sweat glands, ducts of salivary glands and developing ovum
Stratified columnar epithelium
Several layers of column-shaped cells. Also a rare tissue.
Functions:
- Secretion and protection
Locations:
- Ducts of mammary glands, larynx and part of the male urethra
Pseudo-stratified columnar epithelium
Single layer of column-shaped cells with differing heights where some cells may not extend all the way to the surface. Nuclei are all over the place and cells are ciliated.
Functions:
- Secretion and movement
Locations:
- Pharynx, trachea, male’s sperm carrying ducts
Exceptions to the rule These epithelial cell combinations do not exist….
- Simple transitional
- Stratified transitional
- Pseudostratified squamous
- Pseudostratified cuboidal
- Pseudostratified transitional
Where are epithelial tissues found?
line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs.
List the main characteristics of connective tissue
Most abundant and widely distributed primary tissue in the body
Function:
- Connects and binds together, supports, strengthens, protects, insulates, compartmentalise, transports, provides energy
1. Enclosing and separating other tissues: sheets of connective tissue form capsules around organs, such as the
liver and kidneys; also forms layers that separate tissues and organs, e.g. connective tissue separates muscles,
arteries, veins and nerves from one another.
- 2. Connecting tissues to one another: tendons attach muscles to bones and ligaments hold bones together.
- 3. Supporting and moving parts of the body: bones of the skeletal system provide rigid support for the body;
the semirigid cartilage supports structures such as the nose, ears, and joint surfaces; and joints between bones
allow one part of the body to move relative to other parts.
- 4. Storing compounds: adipose tissue stores high-energy molecules, and bones store minerals, such as calcium
and phosphate.
- 5. Cushioning and insulating: adipose tissue cushions and protects the tissue it surrounds and provides an
insulating layer beneath the skin that helps conserve heat.
- 6. Transporting: blood transports the gases, nutrients, enzymes, hormones, and cells of the immune system
throughout the body.
- 7. Protecting: cells of the immune system and blood protect against toxins and tissue injury, as well as against
microorganisms; bones protect underlying structures from injury.
1. Enclosing and separating other tissues: sheets of connective tissue form capsules around organs, such as the liver and kidneys; also forms layers that separate tissues and organs, e.g. connective tissue separates muscles, arteries, veins and nerves from one another.
2. Connecting tissues to one another: tendons attach muscles to bones and ligaments hold bones together.
3. Supporting and moving parts of the body: bones of the skeletal system provide rigid support for the body; the semirigid cartilage supports structures such as the nose, ears, and joint surfaces; and joints between bones allow one part of the body to move relative to other parts.
4. Storing compounds: adipose tissue stores high-energy molecules, and bones store minerals, such as calcium and phosphate.
5. Cushioning and insulating: adipose tissue cushions and protects the tissue it surrounds and provides an insulating layer beneath the skin that helps conserve heat.
6. Transporting: blood transports the gases, nutrients, enzymes, hormones, and cells of the immune system throughout the body.
7. Protecting: cells of the immune system and blood protect against toxins and tissue injury, as well as against microorganisms; bones protect underlying structures from injury.
Location:
- Found in all organs and parts of the body but its amount varies
Composition of connective tissue
- Cells – produce the ECM.
- Ground substance.
- Fibres.
Together the ground substance and fibres are known as the extracellular matrix (ECM).
Cells of Connective Tissue
- Adipose cells (adipocytes) – energy source and cushioning; contain a large amount of lipid and store nutrients.
- Fibroblasts – secrete fibers and ground substance (ECM).
- Mast cells – immunity; found around blood vessels; have role in detecting foreign bacteria and creating inflammatory response.
- White blood cells (also known as leucocytes) – repair injury and fight off infection, e.g. neutrophils, lymphocytes.
- Macrophages – phagocytose (destroy) foreign molecules, e.g. dust particles, injured cells and foreign bacteria.
Ground Substance of Connective Tissue
Gel-like fluid which fills the spaces between the cells of the connective tissue, and the space where the fibres are suspended.
Ground Substance of Connective Tissue
- Gel-like fluid which fills the spaces between the cells of the connective tissue, and the space where the fibres are
suspended.
Fibres of Connective Tissue
- Collagen fibres.
- Elastic fibres.
- Reticular fibres.
Collagen Fibers
- Fibers made of cross-linked collagen fibrils.
- Extremely tough and flexible.
- Many (20) classes of collagen exists with type 1 being most abundant
- Type 1 is found in Skin, Bone, tendons and Ligaments.
Elastic Fibers
- Long thin fibers that form branching networks.
- Able to stretch and recoil.
- Found in Skin, Lungs, and Blood Vessels.
Reticular Fibers
- Short, fine, and collagenous fibers.
- Continuous with collagen fibers and branch from them forming delicate networks.
- Found surrounding small Blood Vessels and support soft tissue of organs
Classes of connective tissue
- Connective tissue (CT) proper
- Cartilage
- Bone
- Blood
Areolar connective tissue (loose)
Functions:
- Loose packing, support and binding other tissues
Locations:
- Widely distributed throughout the body; substance on which epithelial basement membranes rest; packing between glands, muscles, and nerves; attaches the skin to underlying tissues
Adipose connective tissue (loose)
Functions: - Nutrient-storing ability - Shock absorption and protection - Insulation Locations: - Fat beneath the skin, surrounding kidneys, breasts, abdomen and hips
Reticular connective tissue (loose)
Function: - Forms a framework to support free blood cells (white blood cells, mast and macrophage cells) Location: - Lymph nodes - Spleen - Bone marrow
Regular connective tissue (dense)
Functions: - Attachment Locations: - Tendons (muscles to bones) - Most ligaments (bones to bones)
Irregular connective tissue (dense)
Functions:
- Provides strength and stretching capabilities
Location:
- Skin’s dermis
- Fibrous coverings surrounding bones, cartilages, muscles and nerves
Elastic connective tissue (dense)
Functions: - Capable of strength, with stretching and recoil in several directions Locations: - Walls of arteries - Ligaments between spinal vertebrate
Cartilage
- Made of cartilage cells within a rigid matrix
- Avascular and not innervated
Function: - Provides protection, flexibility, rigidity and capable of withstanding pressure
Types and their locations:
1. Hyaline cartilage: most abundant and found in the rib cage, trachea, articulating surfaces of bones and nose
2. Fibrocartilage: found in intervertebral discs and pubic symphysis
3. Elastic cartilage: found in the ear and epiglottis
Bone
- Supports and protects body structures.
- Composed of Cells and Matrix.
- Osteocytes (Bone Cells) reside in the Lacunae (la-koo-neigh) (Spaces, little cavities). Osteocytes sit in little holes known as Lacunae.
Two Types:
1. Spongy Bone: found at the ends of the Long Bone, Sternum, Vertebrate, and Pelvis. It has a lot of space in it, hence its name.
2. Compact Bone: found in the shaft of Long Bone and makes up the outer portions of all Bones.
blood
- Atypical Connective Tissue in that it does not provide support or “connect” anything.
- Mostly Red Blood Cells (Erythrocytes) and scattered White Blood Cells (Leucocytes) and Platelets (Blood Clotting).
- Transport of Nutrients, Wastes and Respiratory Gases around the Body.
Muscle tissue
- Highly cellular, well vascularised and responsible for most body movement Types of muscle: 1. Skeletal 2. Cardiac 3. Smooth
Skeletal muscle
- Muscles attached to the bones of the skeleton.
- Contracts, pulls on the bone, creates the movement.
- Muscle cells are called muscle fibres. –
- Multi-nuclei (each cell has more than one nucleic).
- Striated muscle (can see striations/lines going through each muscle cell). The striation are myofilaments.
- Mostly under voluntary control but involuntary movements can occur with skeletal muscle, e.g. twitching
Cardiac Muscle
- Only found in the walls of the heart where it is responsible for pumping blood around the body.
- Striated muscle with intercalated disks (areas which join one muscle cell to another; act to make sure all the muscle cells pump at the same time in a coordinated fashion).
- Under involuntary control.
Smooth Muscle
- Found mainly in the walls of hollow organs, e.g. stomach, bladder, uterus, blood vessels.
- No striations and single nucleus per muscle cell.
- Under involuntary control.
Nervous tissue
- Control Nervous system: - Brain - Spinal cord - Nerves Nervous tissue is the main component of the nervous system - Neurons (also known as nerve cells) - Supporting cells (also known as neuroglia)
enzyme
- A protein catalyst that increases the rate at which a chemical reaction proceeds, without the enzyme being permanently changed.
- Highly specific – active site on an enzyme can only bind to specific reactant.
- Many different enzymes needed in the body for different chemical reactions. • Often named by adding ‘ASE’ as a suffix to their reactant.
Lipase – enzyme that breaks down lipids
Protease – breaks down proteins
Anatomy of digestive system
- Oral cavity (mouth) with salivary glands
- Pharynx (throat)
- Esophagus
- Stomach
- Small intestine (duodenum, ileum, jejunum) with liver, gallbladder and pancreas as accessory organs
- Large intestine including cecum, colon, rectum and anal canal
- Anus
Functions of digestive system
- Ingestion: introduction of food into stomach (via mouth)
- Mastication: chewing. Chemical digestion requires large surface area so breaking down large particles mechanically facilitates chemical digestion
- Secretion: lubricate, liquefy, digest (e.g. Mucus: secreted along entire digestive tract, lubricates food, coats and protects lining)
- Digestion: Mechanical and chemical digestion of food into nutrients
- Absorption: Movement of nutrients out of digestive tract into cells
- Elimination: Waste products removed from body; feces. Defecation
Histology of digestive tract
One large tube from mouth to anus plus the accessory organs.
- Mucosa: innermost layer, secrets mucus.
- Submucosa: connective tissue layer, contains blood vessels, nerves etc.
- Muscularis: 2/3 muscle layers, movement & secretion.
- Serosa / Adventitia: outermost layer, connective tissue, stability.
Peritoneum
- The walls & organs of the abdominal cavity are lined with serous membranes.
1. Visceral peritoneum: Covers organs
2. Parietal peritoneum: Covers interior surface of body wall
3. Mesenteries: peritoneum (epithelial tissue) which connects organs together. Routes by which vessels and nerves pass from body wall to organs. - Greater omentum: connects stomach to transverse colon
- Lesser omentum: connects stomach to liver & diaphragm
Oral cavity
Digestion begins in the oral cavity (mouth).
- Hard Palate: Hard bone, anterior.
- soft palate: Soft muscle, posterior.
- Tongue
- Teeth
- Masticate (chew) food and turn it into a bolus.
The palate separates the oral and nasal cavities and prevents food from passing into the nasal cavity during chewing and swallowing.
teeth
Two sets: Primary, milk: Childhood Permanent or secondary: Adult (32)
Types: Incisors, canines, premolars and molars
Oral cavity -salivary glands
- Salivary glands– produce & secret saliva into the oral cavity.
- Saliva – protects oral cavity, moistens, lubricates and digests food.
- Amylase – enzyme found in saliva that breaks down carbohydrates into smaller sugars.
- Lysozyme – antibacterial enzyme
Pharynx and esophagus
Pharynx (throat) – connects oral cavity to the esophagus.
- Uvula (soft palate) prevents food/drink from entering the nasopharynx.
Esophagus – tube that connects pharynx to stomach. 25cm long, lies posteriorly to the trachea.
- Epiglottis prevents food/drink from entering the trachea.
Swallowing
- Voluntary phase: Tongue pushes bolus to back of oral cavity towards pharynx (oropharynx).
- Pharyngeal phase: Soft palate (Uvula) close off the nasopharynx. Bolus touches receptors on oropharynx and swallowing reflex moves bolus down pharynx and into esophagus. Epiglottis covers trachea.
- Esophageal phase: bolus is moved down esophagus towards stomach by peristalsis.
stomach
Located in abdomen, ‘holding point’ for food.
- Food comes from the esophagus as a bolus and the stomach mixes it (churns) into chyme (thick liquid).
- Produces mucus, hydrochloric acid, protein digesting enzymes (pepsin).
- Contains a thick mucus layer that lubricates and protects epithelial cells on stomach wall from acid pH 2-3.
Openings:
- Gastroesophageal (cardiac): to esophagus
- Pyloric sphincter: to duodenum.
Parts:
- Cardiac
- Fundus
- Body
- Pyloric: antrum and canal
Layers
- Visceral peritoneum or serosa
- Muscularis: three layers
Outer longitudinal
Middle circular
Inner oblique
- Submucosa
- Mucosa
Rugae: folds in stomach wall that allow stomach to stretch after eating.
Movements of the stomach
- 3 muscular layers enable churning of food. Make Chyme.
- Combination of mixing waves (80%) and peristaltic waves (20%)
- Both esophageal and pyloric sphincters are closed.
- Stomach empties every 4hrs (6-8 after a fatty meal)
Small Intestine
Very long ~6m, small diameter.
Large surface area for efficient absorption of nutrients.
Divisions:
- Duodenum – first 25cm beyond the pyloric sphincter.
- Jejunum – 2.5cm.
- Ileum – 3.5m. - ‘Folds’ increase surface area of small intestine 600 fold. Increase absorption.
- - 1. Plicae circulares – circular folds in the wall of the small intestine.
- - 2. Villi – folds of the mucosa that contain capillaries and lacteals.
- - 3. Microvilli – small folds on epithelial cell surface.
Liver
Gall bladder
Pancreas
makes bile ~100ml/day. Stores glucose (as glycogen) and lipids for energy. Detoxification.
stores concentrated bile.
produces digestive enzymes. Produces insulin and glucagon for blood sugar homeostasis.
Large intestine
- Absorption of water
- Extends from ileocecal junction to anus
- Consists of cecum, colon (ascending, transverse, descending, sigmoid), rectum, anal canal
- Bacteria / microbes synthesise vitamin B & K.
Nutrients
- Chemicals taken in to body to
produce energy
provide building blocks to build other molecules - 6 classes: carbohydrates, proteins, lipids, vitamins, minerals, water
- Carbohydrates, proteins & lipids are major organic nutrients (organic = contains carbon)
- Need large amounts of carbs, proteins, lipids & water
- Only need small amounts of vitamins & minerals
taken in to body without being digested - Essential nutrients – are chemicals that must be taken in to the body, because we can’t make them ourselves.
Include some amino acids/fatty acids/carbs, water, most vitamins & minerals
Six major classes of nutrients
Carbohydrates – mono / di / polysaccharides - plants, vegetables
Lipids – triglycerides - oils, dairy, animal fat, eggs
Proteins – chains of amino acids - meat, fish, poultry
Vitamins – organic molecules (vit A,B,E) – animal and plants products
Minerals – inorganic nutrients (calcium, iron) – animal and plant products
Water
Recommended Amounts
Carbohydrates - 45-65% of daily intake of kilocalories Lipids - 20-35% or less of total daily kilocalories Proteins - 10-35% of total kilocalories per day
60% 30% 10% Carbohydrates>Lipids>Proteins
