Tissues Of The Body Flashcards
To cover all aspects of Tissues of the Body for ESA 1 Note: You will still need to go through histological slides and be able to name different parts I take no responsibility for any of the flashcards featured here...mistakes/shit happens.
Define epithelia.
Epithelia are sheets of contigous tissue of varying embryonic origin that cover the external surfaces and line the internal surfaces of the body.
An increase of muscle mass from work performed against load results in what? What is this described as?
More contractile proteins, increase in fibre diameter - Hypertrophy
Describe keratinocyte differentiation
1) Keratinocyte mitosis occurs in BASAL layer 2) Daughter keratinocytes move into prickle cell layer where terminal differentiation occurs meaning the cells can no longer divide 3) Then in the granular layer cells lose plasma membrane and become corneocytes 4) FInally in the stratum corneum they are flattened corneocytes
Cardiac muscle cannot be regenerated, what happens instead?
Fibroblasts invade, divide and lay down scar tissue
How does calcium allow for the binding of myosin to actin?
-Increased amounts of calcium bind to the TnC part of troponin -Conformational change moves tropomyosin away from the actin binding site -This displacement allows for the binding of myosin to the actin site
Describe the mechanism of innervation of muscle and excitation contraction coupling. (6 points)
-Action potential arrives at the pre synaptic neurone causing influx of Ca2+ -Causes vesicles containing acetylcholine to fuse with membrane and release Ach -Binds to nicotinic receptors on the motor end plate -Binding leads to depolarisation of the sarcolemma by an influx of sodium -Proteins in T tubule change conformation causing calcium to be released from the terminal cisternae into the sarcoplasm -Ca2+ binds to Tnc on troponin casuing contraction
Define the term “limit of resolution”
Limit of resolution is the minimum distance that two objects can be distinguished at.
Describe the two different types of bone.
-Compact (dense) bone made up of vertical osteons with horizontal Volkmann’s canals and vertical Haversian canals -Cancellous (spongy) bone - Meshwork of trabeculae filled in with marrow
Describe the process of endochondral ossification
-Cartilage is reabsorbed and replaced with bone (e.g. long bones) -Begins at the primary centre in the shaft (diaphysis) and later at each end (epiphysis – secondary centre) -Growth in length is at epiphyseal growth plates
Describe the process of intramembranous ossification
-Begins as highly vascularised loose connective tissue. -Mesenchymal cells differentiate into osteoblasts surrounded by collagen fibres and ground substance. -Osteoblasts secrete uncalcified matrix (osteoid) and then become osteocytes
How can skeletal muscle be repaired?
-Tissue regenerates by the mitotic activity of satellite cells which fuse with muscle cells to increase mass
Give two examples of cholinergic transmitters of the post ganglionic nerve fibres of the sympathetic nervous system.
-Perspiration -Ejaculation
Describe what a muscle is made of, with each component in order of size?
-Fascicles -Muscle fibres (cells) -Myofibrils -Myofilaments (actin and myosin)
Give some examples, other than blood, of loose connective tissue.
Forms the septa (walls) and trabeculae (rods) that make up the framework inside organs and adipose tissue.
Describe the histological structure of tendons.
-Collagen fibres interspersed with flattened fibroblasts in bundles -> fascicles -Fasiciles have endotendineum (loose CT) inside and held together by peritendineum. A fibrous sheath surrounds the whole tendon
Describe the cellular processes involved in bone repair following a fracture
-Matrix is destroyed - bone cells adjoining the fracture will die -Inflammatory cells invade and form a pre-callus which contains a blood clot (haematoma) and fibrous tissue -Osteocallus of primary bone is made which is then calcified to secondary -Tendons pull and pressure the bone until it matches the contours of the surrounding bone until it fully heals
How many days does it take for skin to be renewed?
28 Days
How many days does it take for small intestine epithelia to be renewed?
4-6 Days
In the CNS what maintains the myelin coating?
Glial cells called oligodendrocytes
How does demyelination relate to a slowing of conduction velocity?
The impulse can no longer jump from Node of Ranvier by saltatory conduction and therefore cannot be propagated as quickly meaning the impulse moves slower
In rare cases some post ganglionic transmitters of the sympathetic nervous system are not noradrenergic, what transmitter are they?
Cholinergic transmitters
In general terms outline the process of haemopoiesis
-Proliferation: Starting with a stem cell, the cell divides into two. One to replace the original stem cell (self-renewal) and one that differentiates. -Differentiation of haemopoietic progenitor (under influence of cytokine) to form either a myeloid blast (RBC, WBC, platelets) or a lymphoid blast (immunoresponse cells)
In the parasympathetic nervous system what type of receptors do the post ganglionic neurones express?
Nicotinic receptors
List the 4 types of skin appendage
-Hair Follicles -Nails -Sebaceous glands -Eccrine and apocrine sweat glands
In the parasympathetic nervous system what type of transmitter is used in the post ganglionic nerve fibre?
Cholinergic transmitters
In the parasympathetic nervous system what type of transmitter is used in the pre ganglionic nerve fibre?
Cholinergic transmitters
In the sympathetic nervous system what type of receptors do the post ganglionic neurones express?
Nicotinic receptors
In the sympathetic nervous system what type of transmitter is used in the pre ganglionic nerve fibre?
Cholinergic transmitters
In the sympathetic nervous system what type of transmitter (mainly) is used in the post ganglionic nerve fibre?
Noradrenergic transmitters
Name the five cellular components of the innate immunity system and describe what each of them do?
-Macrophages and Monocytes – phagocytosis and antigen presentation to lymphocytes. Phagocytosis is enchanced by the coating of antibodies or complement to render it recognisable as foreign (opsonisation). -Neutrophils – Phagocytic and anti-bacterial -Eosinophils – Anti-parasite and allergic response -Basophils & Mast Cells – Allergic response -Natural Killer Cells – Recognise and kill abnormal cells, e.g. tumours
Name the seven humoral components of the innate immunity system and describe what each of them do?
-Transferrin/Lactoferrin – deprive microorganisms of iron -Interferons – Inhibit viral replication -Lysozyme – Breaks down peptidoglycan in bacterial cell walls -Antimicrobial peptides -Fibronectin – opsonises bacteria and promotes their phagocytosis -Complement – Cause destruction of microorganisms directly or with the help of phagocytic cells -TNF-α - Suppresses viral replication and activates phagocytes
Name the three humoral components of the adaptive immunity system and describe what each of them do?
-Cytokines – Promote the differentiation and proliferation of lymphocytes -Perforin – Released by T killer cells and destroy cell walls -Antibodies – Protect host by neutralisation (prevents binding to epithelia), opsonisation and complement activation (enhances opsonisation and lysis)
Name the two cellular components of the adaptive immunity system and describe what each of them do?
-T cells: +T Helper – Become activated when CD4 binds to a specific antigen on the MHC/antigen complex of an APC (antigen presenting cells). Once activated, it clones itself to form active T-helper cells and T-memory cells. +T Killer – Releases perforin when cell is already infected -B Cells – Divide to form plasma cells and memory cells when activated by T-helper ells and release cytokines. Plasma cells produce specific immunoglobulin for non-self antigen.
What 5 cell constituents make up the dermis?
-Fibroblasts -Blood vessels -Lymphatic vessels -Mast Cells -Nerves
Name two places in the body where you could find dense regular connective tissue?
-Ligaments -Tendons
Outline the 5 stages of the sliding filament model of muscle contraction, starting with attachment.
-Attachment of the myosin head to the actin molecule -Release of the myosin head when ATP binds -Cocking of the myosin head due to hydrolysis of ATP -Force generation as the myosin weakly binds and the phosphate is released leading to the power stroke -Reattachment of the myosin head to the actin
The autonomic nervous system is made up of which two neurones?
Pre-ganglionic and post-ganglionic
What are entrapped chondroblasts known as?
Chondrocytes
What are fascicles made of?
Muscle fibres
What are fibroblasts?
Synthesise and maintain extra-cellular materials. Synthesise collagen, elastic and reticular fibres and ground substance.
What are ligaments made up of?
Dense regular connective tissue: -Collagen fibres interspersed with fibroblasts -Elastic ligaments - mainly elastin.
What are muscle fibres made of?
Myofibrils
What are mast cells?
Near blood vessels containing granules (histamine and heparin). They release pharmacologically active molecules.
What are neurones with multiple dendrites known as?
Multi-polar
What are neurones with one axon and one dendrite known as? Where are they usually found?
Bi-polar neurones usually found in the retina of the eye
What are neurones with one axon only known as? Give an example of one type.
Unipolar - the primary sensory neurone
What are the 4 main features of the perikaryon?
-Nucleus -Nucleolus -Nissl substance (aggregation of RER) -Dendrite
What are the 4 main functions of skin?
-Barrier -Sensation -Thermoregulation -Psychosexual communication
What are the 4 regions of the epidermis is descending depth?
Stratum Corneum Granular Layer Prickle Cell Layer Basal Layer (SGPB)
What are the 4 types of tissue classification?
-Muscle -Epithelial -Connective -Nervous
What are the 5 layers of stomach?
-Epithelium -Gastric Mucosa -Muscularis Mucosa -Submucosa -Muscularis Externae
What are the 6 layers of the oesophagus?
-Epithelium -Lamina Propria -Muscularis Mucosa -Submucosa -Muscularis Externa -Adventitia
What are the 5 types of white blood cells that circulate in the blood and lymphatic system? What type of nucleus does each have?
-Neutrophils (Multi-lobed nucleus) -Eosinophils (Bi-lobed) -Monocytes (Kidney shaped) -Basophils (Bi- or Tri-lobed) -Lymphocytes (Deep staining)
What are the benefits of smooth muscle?
-Contraction is more sustained -Contraction requires less ATP -Capable of being stretched
What are the components of the extracellular matrix in the dermis?
-Ground Substance -Fibres (Type 1 Collagen and Elastin)
What are the features of innate immunity which make it different to adaptive immunity?
-Present from birth -Non-specific -No memory -Not enhanced by secondary exposure
What are the features of Purkinje fibres?
-Abundant glycogen -Sparse myofilaments -Extensive gap junction sites -Rapid conduction of action potentials
What are the four layers of the ailmentary tract?
-Mucosa -Submucosa -Muscularis externa -Serosa
What are the gaps between Schwann cells called?
Nodes of Ranvier
What are the main features of mucous connective tissue? Where is it found?
-Large stellate fibroblasts (which fuse with similar adjacent cells), few macrophages and lymphocytes and soft ground substance full of hylauronic acid -Loose connective tissue -Only found in the umbilical cord and subdermal CT of the embryo.
What are the main functions of bone?
-Support -Protection -Mineral storage -Haemopoiesis.
What are the meninges?
The system of membranes which envelops the central nervous system
What are the relative sizes of the pre and post ganglionic nerve fibres in the parasympathetic nervous system?
Long pre-ganglionic and short post-ganglionic
What are the meninges?
The system of membranes which envelops the central nervous system
What are the three histological forms of muscle?
-Skeletal -Cardiac -Smooth
What are the relative sizes of the pre and post ganglionic nerve fibres in the sympathetic nervous system?
Short pre-ganglionic and long post-ganglionic
What are the three layers of meninges in increasing depth?
-Dura mater -Arachnoid -Pia mater
What are the three layers of meninges in increasing depth?
-Dura mater -Arachnoid -Pia mater
What are the three major types of cartilage?
-Hyaline -Elastic -Fibrocartilage
What are the two remnants of the hyaline cartilage (that made up the foetal skeleton) in the child?
-Growth plates -Articular cartilage
What are the two colours of marrow and what is their respective function?
-Red: red blood cell synthesis -Yellow: contains adipose tissue
What are the two types of ossification called? What do they give rise to?
-Intramembranous - flat bones created from loose connective tissue/mesenchyme -Endochondral - most skeletal bones, made from the hyaline cartilage of foetus
What can a smear be used for?
-Cervix -Buccal cavity
What can curettage be used for?
-Testing endometrial lining of uterus
What can direct incision be used for?
-Skin -Mouth -Larynx
What can endoscopic methods be used for?
-Lung -Intestine -Bladder
What can needle methods be used for?
-Brain -Breast -Liver -Kidney -Muscle
What can transvascular methods be used for?
-Heart -Liver
What causes differentiation to platelet cells?
Thrombopoietin
What causes differentiation to red blood cells?
Erythropoietin
What do melanocytes produce?
Melanin N.B. More melanin production leads to darker skin - not more melanocytes
What do many fascicles make up?
Muscles