Week 2 - Tissues and blood Flashcards
What are the general functions of epithelial tissue?
Epithelial tissue line body surfaces and cavities and thus are involved in: • Protection • Absorption • Secretion • Sensation
List and describe the functional significance of the 5 main characteristics of epithelial tissue
1) Specialized contacts - helps cells fits together to form continuous sheets
2) Supported by connective tissue - help resist stretching and tearing and enables blood supply
3) Avascular & Innervated - prevents excessive bleeding and enables sensation
4) Regeneration - to withstand abrasion
5) Polar cells - Apical and basal surface to allow for specialized functions (absorption).
What are the two ways that epithelia can be classified?
- Number of layers (simple, stratified)
* Cell shape (squamous, cuboidal, columnar)
Give an example of where simple squamous epithelial cells may be found in the body
Sites where rapid exchange is required - Alveolar of the lungs
Give an example of where simple cuboidal epithelial cells may be found in the body
Kidney tubules
Give an example of where simple columnar epithelial cells may be found in the body
Digestive tract
Give an example of where pseudo stratified columnar epithelial cells may be found in the body
Trachea and upper respiratory tract
Give an example of where stratified squamous epithelial cells may be found in the body
Skin, mouth & vagina
Give an example of where stratified cuboidal epithelial cells may be found in the body
Sweat, saliva and mammary glands
Give an example of where stratified columnar epithelial cells may be found in the body
male urethra and some glandular ducts
Give an example of where transitional epithelial cells may be found in the body
Bladder
What is the difference between endocrine and exocrine glands?
Endocrine glands secrete directly into the bloodstream, whereas endocrine glands secrete into ducts that lead lead to the target tissue.
Distinguish between unicellular and multicellular glandular epithelium giving an example for each.
Unicellar are single scattered cells (eg. golbet cells), whereas multicellar(eg. sweat, sebaceous glands) contain multiple cells.
Are endocrine or exocrine glands ductless?
endocrine
What is the function endocrine glands?
Secrete hormones into the extracellular space and subsequently the bloodstream via exocytosis.
What is the function of exocrine glands?
Secrete products onto the skin or into body cavities.
What is the difference between a simple and compound gland?
- Simple - unbranched duct
* Compound - branched duct
What is the difference between a alveolar and tubular duct?
- Tubular - secretory cells form tubular structures
* Alveolar - secretory cells form a sac like structure
What are the three basic components of connective tissue?
- Specialised cells
- Ground substance
- Fibers
Describe ground substance
Its a clear viscous fluid that fills the space between the cells and fibers
Distinguish between the structure and function of the 3 different connective tissue fibers
- Collagen - hard and fibrous to provide strength
- Elastic - long and thin which allows them to stretch and recoil to allow for elasticity
- Reticular - short and fine to act as a supporting mesh
Distinguish between the suffix -blast and -cyte when referring to cells of the connective tissue.
- Blast (immature) - actively proliferating cells that secrete ground substance and fibers
- Cytes (mature) - maintain the health of the matrix
Name some other cell types found in connective tissue
- Macrophages
- White blood cells
- Fat cells
- Mast cells
What do mast cells secrete?
- Histamine
* Heparin
List the 4 main categories of connective tissue and their respective sub types
- Connective tissue proper
* Dense CT
* Dense regular
* Dense irregular
* Elastic
* Loose CT
* Areolar
* Adipose
* Reticular - Blood
- Bone
- Cartilage
* Hyaline
* Fibro
* Elastic
Areolar connective tissue • Ground substance: • Fibres: • Cells: • Function: • Location:
- Ground substance: Majority if it ground substance
- Fibres All three (collagen, elastin, reticular)
- Cells: Fibroblasts, leukocytes
- Function: Holds organs in place, attaches epithelial tissue to other underlying tissue and acts as a reservoir for nutrients, water and salts
- Location: located in the skin and binds the outer layer ofthe skin to the muscles beneath.
Adipose connective tissue • Fibres: • Cells: • Function: • Location:
- Fibres: reticular
- Cells: adipocytes, leukocytes, fibroblasts
- Function: Stores fat, cushions and insulates the body
- Location: Subcutaneous tissue
Reticular connective tissue • Fibres: • Cells: • Function: • Location:
- Fibres: reticular
- Cells: fibroblasts, leukocytes
- Function: Internal framework that can support immune cells.
- Location: Internal frameworks such as spleen, lymph nodes and bone marrow
Dense regular connective tissue • Fibres: • Cells: • Function: • Location:
- Fibres: Collagen
- Cells: fibroblasts
- Function: Resist pulling forces in one direction
- Location: Joints, bone ends and attached to muscles
Dense irregular connective tissue • Fibres: • Cells: • Function: • Location:
- Fibres: Collagen
- Cells: Fibroblasts
- Function: Resists tension in multiple directions
- Location: Dermis of the skin, deep fascia
Elastic connective tissue • Fibres: • Cells: • Function: • Location:
- Fibres: elastin + collagen
- Cells: fibroblasts
- Function: Allow tissues to recoil after stretching
- Location: Blood vessel walls, bronchial tubes
Hyaline cartilage • Fibres: • Cells: • Function: • Location:
- Fibres: Collagen
- Cells: chondrocyte
- Function: Provides support and acts as a shock absorbing pad.
- Location: joints, epiphyseal plate, ventral ends of ribs
Elastic cartilage • Fibres: • Cells: • Function: • Location:
- Fibres: Elastin + Collagen
- Cells: Chondrocytes
- Function: Maintain shape of structures whilst also maintaining flexibility
- Location: External ear and epiglottis
Fibrocartilage • Fibres: • Cells: • Function: • Location:
- Fibres: Collagen (Blend of hyaline and dense regular CT)
- Cells: Chondrocytes
- Function: Compressible and act as a cushion
- Location: Intervertebral discs.
Bone (osseous) tissue • Fibres: • Cells: • Function: • Location:
- Fibres: Collagen
- Cells: Osteocytes, Osteoblasts
- Function: Support and protection, blood cell production and storage
- Location: Bones
Blood • Fibres: • Cells: • Function: • Location:
- Fibres: None
- Cells: Red blood cells, white blood cells
- Function: Delivers nutrients and gases around the body
- Location: circulatory system
Distinguish between the functions of the three different types of muscle tissue
- Skeletal - contract to produce movement
- Cardiac - contract to pump blood around the body
- Smooth - changes shape to facilitate body functions.
Skeletal muscles • Shape: • Control: • Striation: • Nucleus: • Branched:
- Shape: Long and cylindrical
- Control: Voluntary
- Striation: Striated
- Nucleus: Multinucleated
- Branched: Unbranched
What causes the striated appearance of cardiac and skeletal muscles?
The regular/repeating arrangement of actin and mysosin filaments.
Why aren’t smooth muscles striated?
Smooth muscles have a more irregular arrangement of filaments - arranged in sheets instead of bundles
Smooth muscles • Shape: • Control: • Striation: • Nucleus: • Branched:
- Shape: Spindles shaped
- Control: Involuntary
- Striation: Non-striated
- Nucleus: Uni nucleated
- Branched: Unbranched
Cardiac • Shape: • Control: • Striation: • Nucleus: • Branched:
- Shape: Branched structures with intercalated discs
- Control: Involuntary
- Striation: Striated
- Nucleus: Uninucleated
- Branched: Branched
What is the function of intercalated discs?
They help to synchronize cardiac muscle contraction
What is the difference between neurons and neuroglial cells?
Neurons are involved in the transmission of neural impulses , whereas neuroglial cells support the neurons and aren’t actually involved in transmission.
Describe the structure and function of the different parts of the neuron.
- Dendrites - Carry signals towards the cell body
- Cell body - Contains the organelles necessary to control the cell
- Axon Hillock - Region where the nerve impulse is generated
- Axon - carries nerve impulses away from the cell body
What are is the difference between oligodendrocytes and schwann cells?
oligodendocytes myelinate axons in the CNS whereas scwann cells myelate axons in the PNS
List the basic components of blood and the relative percentages of each
1) Plasma (55%)
2) Formed elements (45%)
• Red blood cells
• White blood cells
• Platelets
List the main components of blood plasma
- Proteins
- Electrolytes
- Gases
- Wastes
- Nutrients
- Amino acids
What are the important structural features that aid in the function of red blood cells?
- Contain the protein haemoglobin to transport O2 and CO2
- Biconcave shape to maximize surface area
- Surface proteins to determine blood type
What is the function of red blood cells?
• Deliver O2 and remove CO2 from cells
What is the most abundant leukocyte?
Neutrophile
Describe the appearance and function of neutrophiles
- Appearance: Very fine granules with lobulated nucleus
* Function: Phagocytose and destroy foreign particles
Describe the appearance and function of eosinophils
- Appearance: Contain granules that stain red
* Function: Multi-cellular parasites, infection and allergic responses.
Describe the appearance and function of basophils
- Appearance: Purple stained granules
* Function: Secrete heparin and histamine and thus are involved in inflammatory and allergic responses.
Describe the appearance and function of monocytes / macrophages
- Appearance: purple kidney shaped nucleus
* Function: Phagocytosis and antigen presentation
Describe the appearance and function of lymphocytes
- Appearance: Large purple nucleus
* Function: Involved in the active and passive immune response
Describe the appearance and function of platelets
- Appearance: Small cell fragments
* Function: Prevent excessive bleeding by initiating blood clotting
