Section 1: Cells & Tissues Flashcards
Structural organisation of the body (6 levels)
Chemical < Cellular < Tissue < Organ < System < Organismal
Structural level: Chemical
Building blocks of the body
e.g. atoms and molecules
Structural level: Cellular
Basic structural and functional units of the body (~200 types)
e.g. cardiac muscle cells, smooth muscle cells
Structural level: Tissue
Groups of cells that work together to perform a particular function
e.g. cardiac muscle, muscle tissue
Structural level: Organ
Structures with specific functions composed of 2 or more types of tissue
e.g. stomach, heart
Structural level: System
Consists of related organs with a common function
e.g. circulatory, digestive
Structural level: Organismal
All parts of the body function together to constitute a living organism
e.g. the individual
Body systems (11 systems)
Integumentary Muscular Skeletal Nervous Endocrine Lymphatic and Immune Cardiovascular Respiratory Digestive Urinary Reproductive
Body system: Integumentary - principle function and major components
Principle function:
Protective
Major components: Cutaneous membrane (skin) Hair follicles Sweat glands - helps regulate body temperature Oil glands Nails Sensory receptors Hypodermis
Integumentary system: Cutaneous membrane (skin)
Epidermis:
Protects surface
Protects deeper tissues
Vitamin D production
Dermis:
Feeds epidermis; strength; glands
Integumentary system: Hair follicles
Hair follicles:
Sensation from innervation (nerves)
Hairs:
Protection
Sebaceous glands:
Lubricates hair shaft and epidermis - removes waste
Integumentary system: Sweat glands
Thermoregulation - evaporative cooling (sweat)
Type of merocrine gland
Breast tissue is modified sweat gland
Integumentary system: Nails
Stiffen and protect digits
Integumentary system: Sensory receptors
Detects sensations - touch, pressure, temp, pain
Integumentary system: Hypodermis
Fat stores - attaches skin to deeper layers
Body system: Muscular - principle function and major components
Principal function:
Movement
Major components: Skeletal muscles Axial muscles Appendicular muscles Tendons and aponeuroses
Muscular system: Skeletal muscles
Provide skeletal movement Control entrances and exits to digestive, respiratory, and urinary system Produce heat (shivering) Support skeleton Protect soft tissues
Muscular system: Axial muscles
Provide support and positioning of axial skeleton
Muscular system: Appendicular muscles
Support, move and brace limbs
Muscular system: Tendons and aponeuroses
Translate contractile forces into tasks
Tendon - muscle to bone connection
Aponeuroses - often muscle to muscle connection
Body system: Skeletal - principle function and major components
Principle function:
Support and protection
Major components:
Bones, cartilage and joints
Axial Skeleton (skull, vertebrae, sacrum, coccyx, sternum, supporting cartilages, ligaments)
Appendicular skeleton: limbs and supporting bones and ligaments
Bone
Bone marrow
Skeletal system: Bones, cartilage and joints
Connects bones together
Skeletal system: Axial skeleton
Protects brain, spinal cord, sense organs, and soft tissues of thorax
Supports body weight over lower limbs
Skeletal system: Appendicular skeleton
Provides internal support and positioning of external limbs; enables muscles to move the axial skeleton
Skeletal system: Bone
Stores minerals and lipids
Skeletal system: Bone marrow
Red blood cell production (flat bones, pelvis, sternum, skill, ribs; lose with aging)
Yellow: stores of fat cells / adipose (found medullary cavity of long bones; gain with aging, can change to red after major bleeding)
Body system: Nervous - principle function and major components
Principle function:
Produces nerve impulses to regulate body activities by generating action potentials
Major components: CNS (Central Nervous System) Brain Spinal cord Special senses (also considered part of PNS *except for optic nerve* which is part of CNS) PNS (Peripheral Nervous System)
Nervous system: CNS
Control center
Short term control over other systems
Nervous system: Brain
Complex integrative activities
Controls voluntary and involuntary
Nervous system: Spinal cord
Relays information to and from brain
Performs less complex integrative activities (reflex arc)
Nervous system: Special senses
Sensory input to brain relating to sight, hearing, smell, taste, and equilibrium
Nervous system: PNS
Links CNS with other systems and sense organs
Body system: Endocrine - principle function and major components
Principle function:
Release hormones to regulate body activities
Major components: Pineal gland Hypothalamus/Pitituary gland Thyroid gland Parathyroid gland Thymus Adrenal glands Kidneys (due to major hormone producing cells) Pancreas Gonads
Endocrine system: Pineal gland
Day night rhythms
Endocrine system: Hypothalamus/Pituitary gland
Control other endocrine glands
Regulate growth
Fluid balance
Endocrine system: Thyroid gland
Metabolic rate
Calcium levels
Endocrine system: Parathyroid gland
Calcium levels
Endocrine system: Thymus
Maturation of lymphocytes
Endocrine system: Adrenal glands
Water and mineral balance
Tissue metabolism
Cardio and respiratory function
Endocrine system: Kidneys
Red blood cell production
Blood pressure up
Calcium levels
Endocrine system: Pancreas
Glucose control
Endocrine system: Gonads
An organ that produces gametes
Body system: Lymphatic and Immune - principle function and major components
Principle function:
Defense
Transport of lipids, proteins, and lymphoid cells
Major components: Lymphatic vessels Lymphatic fluid B cells (mature in bone marrow) and T cells (mature in thymus) Lymph nodes including tonsils Thymus
Lymphatic and Immune system: Lymphatic vessels
Carry lymph fluid (water and protein) and lymphocytes from peripheral tissues to veins of cardiovascular system
Lymphatic and Immune system: Lymphatic fluid
Lipids from gut
Definition of lipids
Fats and fatty acids
Lymphatic and Immune system: B cells and T cells
Cells that carry out immune responses
Lymphatic and Immune system: Lymph nodes (incl tonsils)
Monitor composition of lymph
Defense - engulf pathogens
Stimulate immune responses (e.g. lymphadenopathy)
Lymphatic and Immune system: Spleen
Monitors circulation blood cells
Engulfs pathogens
Recycle RBCs
Stimulates immune response
Lymphatic and Immune system: Thymus
Controls development and maintenance of T cell lymphocytes
Body system: Cardiovascular - principle function and major components
Principle function:
Transport of O2 and CO2
Regulation of water content and temperature
Major components:
Heart
Blood vessels
Blood
Cardiovascular system: Heart
Propels blood
Maintains blood pressure
Cardiovascular system: Blood vessels
Arteries - conveys blood from heart to capillaries
Capillaries - diffusion between blood and interstitial fluids
Veins - return blood from capillaries to heart
Cardiovascular system: Blood
Transport of O2 and CO2 Transport nutrients and hormones Remove waste Regulate temperature Defense against illness (immune cells) Acid base balance (-HCO3)
Body system: Respiratory - principle function and major components
Principle function:
Transfer of O2 and CO2 between blood and air
Major components: Nasal cavity and paranasal sinuses Pharynx Larynx Trachea Bronchi Lungs
Respiratory system: Nasal cavity and paranasal sinuses
Filter warm humidified air
Detects smells
Respiratory system: Pharynx
Conducts air to larynx
Respiratory system: Larynx
Protects opening to trachea
Contains vocal cords for vocalisation
Respiratory system: Trachea
Conducts air
Cartilage keeps it open
Respiratory system: Bronchi
Conducts air between trachea and lungs
Respiratory system: Lungs
Air movement
Gas exchange of O2 and CO2 in alveoli
Acid base control
Body system: Digestive - principle function and major components
Principle function:
Digestion of food
Absorption of nutrients
Elimination of solid waste
Major components: Oral cavity Salivary glands Pharynx Oesophagus Stomach *Small intestine* Liver Gallbladder Pancreas Large intestine and anus
Digestive system: Oral cavity
Breaks up food working with teeth and tongue
Digestive system: Salivary glands
Buffers and lubricant
Enzymes that begin digestion
Type of merocrine gland - releases products via exocytosis
Digestive system: Pharynx
Carries food and liquids to oesophagus
Digestive system: Oesophagus
Deliver food to stomach
Digestive system: Stomach
Secretes acid
Hormones
Enzymes
Digestive system: Small intestine
Digestive enzymes
Buffers and hormones
Absorb nutrients
Digestive system: Liver
Secretes bile
Regulates nutrients in blood
Digestive system: Gallbladder
Concentrates bile
Digestive system: Large intestine and anus
Water removal
Waste storage and removal
Definition of bile
Alkaline fluid which aids digestion
Body system: Urinary - principle function and major components
Principle function: **Assist in production of blood cells and mineral balance** Urine production Storage and elimination Regulation of blood volume
Major components: Kidneys Ureters Bladder Urethra
Urinary system: Kidneys
- Form and concentrate urine*
- Endocrine function*
- Regulate pH* and ions
- Blood volume and blood pressure*
Urinary system: Ureters
Conduct urine to bladder
Urinary system: Bladder
Stores urine prior to elimination
Urinary system: Urethra
Conducts urine to exterior
EPO (Erythropoietin)
A glycoprotein hormone produced by interstitial fibroblasts in kidneys
Signals for erythropoiesis in bone marrow
Increased activity of hemocytoblasts (RBC stem
cell) –> more RBC production –> allows blood to have greater O2 carrying capacity
Body system: Reproductive - principle function and major components
Principle function:
Production of sperm or gametes
Hormones regulate many processes
Major components (male):
Testes
Accessory organs
External genitalia
Major components (female): Ovaries Uterine tubes Uterus Vagina and external genitalia Mammary glands
Reproductive system: Testes (male)
Produce sperm Produce hormones (also in endocrine system)
Reproductive system: Accessory organs (male)
Epididymis - sperm maturation Ductus deferens - sperm from epididymis Seminal glands - seminal fluid Prostate gland - seminal fluid Urethra - Sperm to exterior
Reproductive system: External genitalia (male)
Penis and scrotum - Reproduction and thermal control of testes
Reproductive system: Ovaries (female)
Oocytes and hormones (also in endocrine system)
Reproductive system: Uterine tubes (female)
Deliver oocyte
Location of fertilisation
Reproductive system: Uterus (female)
Embryonic development
Reproductive system: Vagina and external genitalia (female)
Lubrication
Sperm reception
Birth canal
Reproductive system: Mammary glands (female)
Nutrition of new-born
Modified sweat glands, so also part of the integumentary system
Histology
The microscopic study of tissues of the body
4 basic tissues
Epithelial
Connective
Muscle
Nervous
Epithelial tissue - description and major function(s)
Covers body surface
Lines hollow organs, tubes, cavities and ducts
Protects tissue beneath
Prevents water loss
*Protection (especially from abrasion) Filtration/Selective barriers Secretion (onto free surface)* Absorption Excretion
Connective tissue - description and major function(s)
Cells in a matrix of fibres and ground substance (incl. bone and blood)
Most diverse in appearance
Binds, supports and strengthens other body tissues and organs
Stores energy as fat
Transport (blood)
Main source of immune responses
Muscle tissue - description and major function(s)
Description: Contractile cells (muscle fibres/cells/myocytes)
Major function:
Generates physical force required to make body structures move
Force generated from hydrolysis of ATP from muscle fibres
Nervous tissue - description and major function(s)
Description:
Conducting nerve cells and supportive neuroglia
Major function:
Detects changes inside and outside the body and responds by generating nerve impulses
Anatomy vs physiology
Anatomy: the science of body structures and the relationships among them
Physiology: the science of body functions (how they work)
What is metabolism
The sum of all chemical processes that occur in the body
Two phases: catabolism (breakdown of complex chemical substances into simpler components) and anabolism (the building up of complex chemical substances from smaller, simpler components)
What is responsiveness
The body’s ability to detect and respond to changes
Movement includes…
Movement of the whole body, individual organs, single cells, as well as tiny structures inside cells
What is growth
An increase in body size that results from an increase in size of existing cells, increase in number of cells, or both
Note: tissues sometimes increase in size because the amount of material between cells increase
What is differentiation
The development of a cell from an unspecialised to a specialised state, i.e. stem cells
Stem cells
Precursor cells which can divide and give rise to cells which undergo differentiation
What is reproduction
Either:
- The formation of new cells for tissue growth, repair, or replacement (cell division), or
- The production of a new individual (fertilisation)
Homeostasis
The condition of equilibrium in the body’s internal environment due to constant interaction of body’s regulatory processes
Dynamic condition
Body’s equilibrium can shift in response to changing conditions
Intracellular fluid (ICF)
Fluid within cells
Extracellular fluid (ECF)
Fluid outside body cells
Differs depending on where it occurs in body
Interstitial fluid
Type of ECF that fills narrow spaces between cells of tissue
Often called body’s internal environment
Types of ECF
Blood plasma: within blood vessels Lymph: within lymphatic vessels Cerebrospinal fluid: around brain and spinal cord Synovial fluid: in joints Aqueous humor and vitreous body: in eyes
Abnormal fluid accumulation in the lungs would be detected during breathing by _____
Auscultation - the action of listening to sounds from the heart, lungs, or other organs (e.g. via stethoscope)
IGF
Insulin-like growth hormone - produced from anterior pituitary gland
Growth hormone (GH)
Gigantism: too much GH from childhood
Acromegaly: too much GH as an adult
Achieving maximum aerobic capacity
- Increased hb concentration and blood volume –> increased hemoglobin mass –> increased aerobic capacity
- Max heart rate and stroke volume –> max cardiac output –> max O2 uptake
- O2 affinity of the blood and mitochondrial respiratory capacity –> max O2 extraction –> max O2 uptake
How are cells of an epithelium arranged and held together?
In continuous sheets as single or multiple layers
Held together by variety of cell junctions
Types of cell junctions
Lateral junctions: Tight junction Adherens junction Gap junction Desmosome
Basal junction:
Hemidesmosome
Cytoskeleton
Microfilaments (e.g. actin): bundles beneath cell membrane and cytoplasm Provide strength Alter cell shape Link cytoplasm to membrane Muscle contraction Tie cells together
Intermediate filaments (e.g. keratin)
Provides strength
Moves materials through cytoplasm
Junctional complex
Combination of tight junction, adherens junction and desmosome
Basement membrane composed of…
- Basal lamina: secreted by epithelial cells, contains collagen, laminin. Composed of glycoproteins
- Reticular lamina: produced by fibroblasts, contains fibrous proteins, e.g. fibronectin, collagen
Where is basement membrane found
Between epithelium and connective tissue
Epithelia - nerves and blood vessels?
Contain nerves
Don’t contain blood vessels (avascular)
What occurs in the connective tissue
Exchange of nutrients and wastes via diffusion from vessels in connective tissue
Functions of basement membrane
Support overlying epithelium
Provide surface along which epithelial cells migrate during growth and repair
Act as physical barrier
Participates in filtration of substances in kidney
Basement membrane; melanoma
BM can act as barrier to invasion by malignant melanoma
Once barrier has been penetrated, chances of metastasis/spread occurring increase
Melanoma warning signs
Asymmetry - one half of a mole doesn’t match the other
Border irregularity - edges ragged or blurred
Colour: mix of brown, black, red, white or blue
Diameter: > 6mm
Types of epithelial tissue
- Epithelia - covers exposed surfaces and internal cavities, often have scattered secretory cells in them
a. Outer covering - of skin and some internal organs
b. Inner lining - of blood vessels, ducts and body cavities, and interior of respiratory, digestive, urinary and reproductive systems - Glands - secretory cells predominate
a. Endocrine - hormones or precursors into interstitial fluid/bloodstream
b. Exocrine - secrete onto external surfaces and into passages/ducts
Covering and lining epithelia classified according to…
- The arrangement of cells in layers
2. The shapes of the cells
Types of arrangement of epithelia
Simple: single layer
Secretion, absorption, filtration
Stratified: two or more layers
Protective
Pseudostratified: appears to have multiple layers
Pseudostratified arrangement of epithelia
Not all cells reach apical surface
All cells are in contact with basement membrane, i.e. actually a simple epithelium (secretion)
Types of shape of epithelia
Squamous: flat and thin
Helps allow passage by diffusion
Cuboidal: about as tall as they are wide
Secretion, absorption
Columnar: more tall than wide
Secretion, absorption
Transitional: stratified epithelium where cells can change shape from cuboidal to flat shape depending on organ shape (allow stretch)
Types of covering and lining epithelia
Simple:
Simple squamous
Simple cuboidal
Simple columnar (ciliated and non-ciliated)
Stratified: Stratified squamous (keratinized and non-keratinized) Stratified cuboidal Stratified columnar Transitional
Pseudostratified: Pseudostratified columnar (ciliated and non-ciliated)
Simple squamous epithelium: features and specialised subtypes
Most delicate epithelium
Filtration (kidney), diffusion (lung), secretion where slippery surface needed
Mesothelium - lines pericardial, pleural, peritoneal cavities
Endothelium - lines inside of heart, blood and lymphatic vessels
Simple cuboidal epithelium: features
Secretion and absorption into or from surface
Distance between adjacent nuclei approx height of epithelium
Simple columnar epithelium: features, specialised subtypes
More cytoplasm so more organelles
Major subtypes: non-ciliated and ciliated
Secretes mucous
Has oval nuclei near basal surface
Can have cilia or microvilli
Non-ciliated simple columnar epithelium: features
Microvilli on apical surface
Have goblet cells interspersed
Increase SA for absorption
Ciliated simple columnar epithelium: features
Single layer
Have goblet cells
Moves materials
Stratified squamous epithelium: features
Located where mechanical or chemical stresses are severe
Protect against microbes
Pseudo-stratified columnar epithelium: features and specialised subtypes
All cells contact base membrane but not all reach apical surface of tissue
Ciliated:
Cilia on some cells
Secrete mucus from goblet cells
Non-ciliated:
No cilia
No goblet cells
Absorption and protection
Glands consist of…
A single cell or a group of cells that secrete substances into ducts, onto a surface, or into blood
Glands classified according to…
Where they secrete their substances
Classification of glands
Endocrine gland Exocrine gland (apocrine, merocrine, holocrine)
Endocrine glands
Secrete directly into blood (often via traversing interstitial fluid)
e.g. pituitary, pineal, thyroid, parathyroid, adrenal
Exocrine gland
Secrete into ducts that empty onto the surface of a covering/lining epithelium
e.g. sweat, salivary, oil, wax, pancreas, sebaceous, mammary, goblet
Pancreas glands
Mixed secreting into ducts and into blood
Mucous cells
Individual secretory cells
Secrete mucin
Characteristics used to describe structure of multicellular glands
- Structure of duct
- Structure of secretory area
- Relationship between the two
How to tell if a gland is simple, branched, compound, or tubuloalveolar
Simple: has a single duct that doesn’t divide on it’s way to the gland cells
Branched: several secretory areas share a duct (refers to glandular areas, not to the duct)
Compound: duct divides one or more times onto its way to the gland cells
Tubuloaveolar: secretory cells form both tubes and sacs
Types of multicellular exocrine glands
Simple glands: Simple tubular Simple branched tubular Simple coiled tubular Simple acinar Simple branched acinar
Compound:
Compound tublar
Compound acinar
Compound tubuloacinar
Connective tissue is supplied with nerves with the exception of _______
Cartilage
Major types of connective tissues
Fibroblasts (in loose and dense connective tissue)
Adipocytes (under skin and around organs)
Chondroblasts (in cartilage)
Osteoblasts (in bones)
In cartilage and bone, once extracellular matrix is produced, immature cells differentiate into mature cells; fibrocytes, chondrocytes, osteocytes
Blast cells vs mature cells
Blast cells:
Retain capacity for cell division
Secrete ECM
Mature cells:
Reduced capacity for cell division
Reduced ECM formation
Mostly involved in monitoring and maintaining ECM
Fibroblasts
Large, flat cells with branching processes Found in all general connective tissues Often most numerous Migrate through connective tissues Secrete fibres Can be considered immature cells
Macrophages
Develop from monocytes (type of white blood cell) Irregular shape - short branching projections Perform phagocytis (engulf bacteria and cellular debris)
Fixed: reside in a particular tissue
Wandering: have ability to move throughout the tissue and gather at sights of inflammation to perform phagocytis
Plasma cells
Develop from B lymphocyte (type of WBC)
Secrete antibodies –> important part of immune response
Mostly found in connective tissue
Mast cells
Found in many connective tissues Produce histamine (dilates small blood vessels as part of inflammatory response)
Adipocytes (aka fat cells or adipose cells)
Connective tissue cells Store triglycerides (fats)
Leukocytes (white blood cells)
Not found in large numbers in normal connective tissue
Can migrate from blood into connective tissue in response to certain conditions (e.g. allergies, infections)
Connective tissue is composed of…
ECM (extracellular matrix) + Cells
ECM (extracellular matrix) is composed of…
GS (ground substance) + F (protein fibres; secreted by cells in ECM)
What determines the quality of connective tissues?
Structure of ECM
ECM: Ground substance is composed of…
H2O + proteins + polysaccharides (sugars; includes glycosaminoglycans (GAGS))
Proteoglycans are composed of…
Glycosaminoglycans (GAGS) + proteins
Glycosaminoglycans (GAGS)
Aka mucopolysaccharides
Long unbranched polysacchirides
Can be sulphated and non-sulphated
Sulphated GAGS
Dermatan sulphate
Heparin sulphate
Keratan sulphate
Chondroitin sulphate
Non-sulphated GAG
Hyaluronic acid (doesn’t bind directly to core protein)
GAG: hyaluronic acid
Slippery
Traps water to make ground substance more jelly-like
Binds cells together
Lubricates joint
Maintains shape of eyeball
Hyaluronidase
Produced by WBC, sperm and some bacteria
Makes ground substance more liquid so they can move easily in it or makes access to egg easier for sperm
GAG: Chondroitin sulphate
Support and provide adhesive features of cartilage, bone, skin, blood vessels
GAG: Keratan sulphate
Found in bone, cartilage, cornea of eye
GAG: Dermatan sulphate
Found in skin, tendons, blood vessels, heart valves
Types of connective tissue fibres in extracellular matrix (ECM)
Collagen fibres
Reticular fibres
Elastic fibres
Marfan syndrome
A hereditary defect in elastic fibres
Dominant mutation in chromosome 15 - codes for fibrillin
Body produces growth factor ‘Transforming Growth Factor beta’ (TGFb) - increases growth because does not bind normally to fibrillin to keep it inactive
Individuals often tall, long-limbed, chest deformity, normal lifespan, may have weakened heart valves and arterial walls
1/20,000 live births
Fibrillin
Large glycoprotein
Contributes to a structural scaffold for elastin
Types of fixed macrophages
Dust cells (lung) Kupffer cells (liver) Langerhan's cells (skin)
Types of embryonic connective tissues
Mesenchyme (embryonic)
Mucous
Embryonic connective tissues: Mesenchyme
Gives rise to all other connective tissues, e.g. reticular, bone, hyaline cartilage, dense irregular
Contains mesenchymal/CT cells in a semi-fluid ground substance containing reticular fibres
Embyronic connective tissues: Mucous CT
Has widely scattered fibroblasts embedded in jelly-like ground substance
Supports umbilical cord
Types of mature connective tissues
- Connective tissue proper
a. Loose
b. Dense - Fluid connective tissues (specialised CT)
a. Blood
b. Lymph - Supporting connective tissues (specialised CT)
a. Cartilage
b. Bone
Mature CT: Types of loose CT
Loose = many cells, fewer fibres
Areolar CT (most common form)
Adipose CT
Reticular CT
Types of dense CT
Dense = more fibres, fewer cells
Dense regular
Dense irregular
Dense elastic
Types of Supporting CT: Cartilage
Hyaline cartilage
Elastic cartilage
Fibrocartilage
Supporting CT: types of bone/osseous tissue
Compact bone
Spongy bone
Cell types found in bones
Osteogenic cells
Osteoblasts
Osteocytes
Osteoclasts
Parts of osteon
Lamellae
Lacunae
Canaliculi
Central (Haversian) canal
Osteon structure - Lamellae
Concentric rings of mineral salts for hardness and collagen
Osteon structure - Lacunae
Small spaces between lamellae that contain osteocytes
Osteon structure - Canaliculi
“minute canals”
Radiate from lacunae
Provides routes for O2, nutrients and waste
Osteon structure - Central (Harversian) canal
Blood, lymph, nerves
Process of bone formation after injury
Osteoclasts - reabsorb dead bone
Chondroblasts - lay down hyaline cartilage callus
Osteoblasts - lay down new bone
Osteoclasts - remodel new bone
Liquid CT: Blood
Consists of blood plasma (liquid ECM) and formed elements (red and white cells and platelets)
What do erythrocytes do
Transport O2 and CO2
Leukocytes combat disease:
- Neutrophils and monocytes and phagocytic
- Basophils and mast cells release substances that intensity inflammatory reaction
- Eosinophils effective against certain parasitic worms and accurate allergic response
- Lymphocytes involved in immune response
Platelets
Tiny blood cells which help body form clots to stop bleeding
Properties of muscle tissue
Electrical excitability
Contractility
Extensibility
Elasticity
What does ATP stand for
Adenosine triphosphate
Types of muscle
Skeletal muscle
Cardiac muscle
Smooth muscle
Skeletal muscles
Attached to bones by tendons
Long cells
Striated
Multinucleate
Voluntary
Fibres cylindrical - stapedius (smallest) and sartorius (longest)
Striations of skeletal muscle fibres are due to…
The highly organised arrangement of myofibrils within the cells
Myofibrils
Pretty much fill the cytoplasm of muscle fibre and extend its entire length within the cell
Composed of myofilaments; overlapping thin (actin) and thick filaments (myosin)
Myofilaments
Don’t extend the length of the muscle fibre
Arranged in compartments called sarcomeres
Sarcomere
Basic functional unit of a myofibril
What do Z discs/lines do
Separate sarcomeres
Connective tissue of skeletal muscle
Epimysium - surrounds anatomical muscle Perimysium - around fascicles Endomysium - around muscle fibres Sarcolemma - around plasma membrane Sarcoplasm - cell cytoplasm
Striations in myofibril
A band - dark, middle part; contains all thick filaments
I band - thin filaments (no thick)
H zone - thick filaments (no thin)
M line - middle of sarcomere (holds thick filaments together)
Z disc - passes through centre of I band (between sarcomeres) made up of actinins that link filaments of adjacent sarcomeres
Cardiac muscle tissue - location, structure, control
Heart
Striated
May be branched
Single central nucleus
Intercalated discs
Involuntary
Intercalated discs contain…
Desmosomes
Gap junctions
Smooth muscle tissue - location, structure, control
In walls of hollow internal structures
Non-striated, but still have bundles of thin and thick filaments, as well as intermediate filaments which connect to dense bodies
Single, central nucleus
Involuntary
Smooth muscle tissue - what happens during contraction?
Tension is transmitted to the intermediate filaments (which don’t contract), and the cell twists as it contracts about these stable ‘rods’
Nervous tissue: major functions
Sensory - detection of internal and external stimuli and transfer to CNS
Integrative - analysis and storing of information
Motor - stimulation of effectors through PNS
Nervous tissue: Types of cells
Neurons (nerve cells that can be very large)
Neuroglia (supportive cells - usually small)
Neurons
Longest cells in body Conscious and unconscious control Have a cell body, into which short, branched dendrites convey nerve impulses, and from which a longer, single axon conducts nerve impulses to another neuron or tissue Longevity High metabolic rate Specialised Not high mitotic rate
Neurons: Dendrites
The receiving/input part of the neuron
Neurons: Axon
Carries nerve impulse away from neuron
For our purposes, neurons…
Don’t divide
Have a high metabolic rate (die rapidly without O2)
Neuroglia
Found in CNS and PNS Make up around half the volume of CNS Smaller than neurons but more numerous Don't propogate action potentials, but can communicate Can divide within mature nervous system
Neuroglia: Functions
Physical structure of nervous tissue Repair framework of nervous tissue Undertake phagocytosis Nutrient supply to neurons Regulate interstitial fluid in neural tissue
Classification of neuroglia
- CNS neuroglia
a. Astrocytes
b. Oligodendrocytes
c. Microglia
d. Ependymal cells - PNS neuroglia
a. Schwann cells
b. Satellite cells
Electrical excitability
The ability to respond to certain stimuli by producing electrical signals, e.g. action potentials
Repair and growth of cartilage
Interstitial growth - growth from within the tissue
Appositional growth - growth at outer surface of tissue
Plaque
Dense layer of proteins inside plasma membrane
Purpose: to join cells together by allowing transmembrane glycoproteins from opposite side of plasma membrane into it
Lymphatic system carries lipids from ______ to ______
Lymphatic system carries lipids from gastrointestinal tract to blood
Biopsy
A procedure that removes living tissue for examination
What structures contain vascular tissues
Bone, adipose, cardiac muscle, areolar
To reach gall bladder via abdominal wall into peritoneal cavity, you must cut through…
Dense irregular tissue Simple squamous Keratinised stratified squamous Skeletal muscle Adipose
Squamous cell carcinoma found in…
Epithelium
Carcinoma (cancer of epithelia) affects desmosomes
Cell junctions allow…
Communication between adjacent cells by electrical and chemical signalling
If skin can’t firmly attach to each other, antibodies are being produced against ______
Integrin
Which connective tissue does epithelial depend on to survive?
Blood
Is epithelial tissue or blood better equipped for diffusion of hormones into ECF?
Epithelial tissue
Where are phagocytes more commonly found
In connective tissue as they move freely
Feature of keratin
Water-resistant
If no holocrine glands…
Skin becomes excessively dry for lack of oil from sebaceous glands
Davidson’s disease; baby has severe watery diarrhea and malabsorption - this is due to….
Due to microvilli not fully developed
Of the cell types found in CT, the most numerous and found in all general CTs are _______
Fibroblasts
Classification of exocrine glands
Serous secretion
Mucous secretion
In order to move mucous from respiratory tract, it requires…
Cilia, goblet cells, and elastic fibers
Intima
Inner-most layer of blood vessels
Epithelial tissue lining kidney tubules regulate…
Passage of water, salt, and urea
Merocrine glands
Secretes substances without any part of the gland being lost or damaged
Releases ribosomal products from cell in secretory vesicles by exocytosis
Epithelial tissue lining small intestine regulates…
Passage of amino acids and glucose
What type of exocrine gland are mammary glands
Apocrine
Compound/branched acinar
Holocrine glands require…
Higher rate of mitosis based on how secretion occurs
Purpose of cilia
Allows ability to move mucous, in conjunction with elastic fibers and goblet cells
Hormones are produced in ____________ and are moved into ECF via ______
Hormones are produced in epithelial cells and are moved into ECF via diffusion
What type of gland is a sebaceous gland
Holocrine gland
Apocrine glands - function
Accumulates secretory product at apical surface of secreting cells
Purpose of microvilli
Assist epithelial tissue in nutrient absorption
Goblet cells and tight junctions produce…
A continuous layer of mucous
Golgi complex and secretion
Golgi complex packages and modifies material into vesicles via merocrine secretion
Apical cells of _________ are alive if tissue lacks _______
Apical cells of stratified squamous epithelia are alive if tissue lacks keratin
What types of cells are often packed with keratin
Exposed epithelial cells that have potential for dehydration
Goblet cells - hyperplasia
Increased mucous production
Goblet cells and cilia are modifications of…
Columnar epithelial tissue
If epidermis was burned, what tissue was damaged?
Keratinised stratified squamous tissue
Amino simple squamous
Allows for easy passage of material but no protection
_____ increase in number when the body has an infection
Leucocytes
Heart valves, tendons, lung tissue, and blood vessels have ________ in common
Dermatan sulphate
Reticular region of dermis provides…
Strength in numerous directions
Back injury - slipped disc
Damaged fibrocartilage
If vitamin C is present in low amounts, it affects…
Dense regular tissue
Fibrocartilage
Elastic CT
If proportion of organic material in bone increases compared to inorganic material…
Bones become more flexible
In a mobile joint, ______ covers the bone surface
Hyaline cartilage
Structures affected by GAG defects
Blood
Bone
Tendons
Cartilage
Once a clot forms, _____ invade the area to lay down a ______
Fibroblasts
Collagen matrix
Lacunae/lacuna can hold what types of cells?
Osteocytes
Chondrocytes
Cell body of neuron aka…
Soma
Skeletal and cardiac muscles - sacromere
Skeletal and cardiac muscles have thick and thin filaments in their sacromeres
A cell with predominance of RER is likely to produce large quantities of…
Proteins for secretion
Main characteristic component of myelin
Lipid
Goblet cells are… and have a high quantity of…
Unicellular exocrine glands - secrete onto surface of epithelium
Have a high quantity of golgi apparatus
Where do hair follicles originate from
Dermis
Multi-cellular endocrine glands - secretion
Secrete directly into blood (CT)
Pseudostratified columnar epithelium is associated with its own…
Nerve supply
Which layer in the duodenum wall contains the lamina propria
Mucosa
The primary major component of marrow in the long bones of the adult body is…
Adipose
What do fibroblasts secrete
Fibres (collagen, reticular and elastic fibres) and ground substance)
