Homeostasis Flashcards
Give three examples of exocrine glands
Sweat glands
Salivary glands
Mammary glands
What is the somatic nervous system?
Under our control - voluntary muscle.
Receives sensory input
What neurotransmitter is involved in the somatic nervous system?
Acetyl Choline
What is the autonomic nervous system?
Involuntary - self regulating
Influences the function of internal organs
Give some examples of things the autonomic nervous system effects
Heart rate
Respiratory rate
Digestion
Pupil dilation
What are the two branches of the autonomic nervous system?
Sympathetic
Parasympathetic
What is the sympathetic response?
Fight or flight
Neurotransmitter - noradrenaline
What is the parasympathetic response?
Rest and digest
Neurotransmitter - acetyl Choline
What is normal body temperature?
36.5-37.5 degrees Celsius
How can core temperature be measured?
Oral cavity Rectum Axilla Temporal artery External auditory canal
What temperature is considered hyperthermia?
Less than 35 degrees
Where are B cells made and where do they mature?
Made in the bone marrow
Mature in the spleen and other lymphoid tissues
What are the functions of B cells?
Produce specific antibodies
Act as antigen presenting cells (APC)
Secrete cytokines
Where are T cells made and where do they mature?
Made in the bone marrow
Mature in the thymus
What are functions of antibodies? (3)
Complement activation
Opsonisation
Blocking receptors
Preventing growth
What three ways can cells be attached in the lateral domain?
Tight junctions
Desmosomes
Gap junctions
What is a tight junction? And where are they found?
Fused plasmalemma of 2 cells - forms a seal
Seen in cells lining the intestine
What are desmosomes and where are they found?
Seen next to tight junctions - formed of protein - provides resistance to stretching and twisting
Found between epithelial cells that need to withstand physical stress e.g. Skin
What are gap junctions?
Connexons form channels that allow small ions/molecules to move back and forth through cells - communication
What is the basal domain?
Anchorage for cells onto a basement membrane.
Acts as a structural site for overlaying calls and underlying connective tissue
How to cells attach to the basement membrane?
- hemidesmosomes - found on tissue subject to abrasion - skin/oral cavity
- focal adhesions - anchor intracellular actin filaments to basement membrane - predominant role in cell movement
What is an intigrin?
Transmembrane proteins that attach the cell cytoskeleton to the extracellular matrix (mechanical).
And have a role in signal transduction between the ECM and the cell
What is autocrine communication?
Cell communication with itself - positive feedback
What is paracrine communication?
Communication with adjacent cells - regulator diffuses to nearby cells
What is Neurocrine communication?
Nerve cells secrete into the bloodstream to target cells - e.g. Pituitary gland, adrenal medulla
What are the two ways cells can die?
Necrosis
Apoptosis
What is necrosis?
Following physical disruption of the cell through injury/toxins/deprivation the cell loses functional control. Osmotic pressure causes swelling or organelles, chromatin clumps and the cell bursts.
The cytotoxic cellular components induce tissue damage and inflammation.
What is apoptosis?
Programmed cell death - catabolic processes begin throughout cell, enzymes digest cytosolic components and fragment DNA. Cell is repackaged for safe removal. Chromatin condenses, cell shrinks and fragments into small membrane bound apoptosis bodies which are phagocytosed.
How did the mitochondria become an organelle?
An early anaerobic eukaryote engulfed and aerobic bacterium - live in endosymbiosis
What are the four types of tissue
Muscle
Nerve
Connective
Epithelial
What is epithelium?
Cells that cover the exterior body surface, line internal closed cavities and body tubes fear communicate with the exterior. Also form secretory portion of glands and line their ducts.
What are epithelioids? And give some examples?
Cells without a surface
Islets of langerhans
Leydig cells in the testes
Parenchyma cells of adrenal gland
Why do necrotic cells swell and burst?
Failure of the Na/K ATPase
What is osmolality?
Concentration of solutes/proteins in solution
More proteins/solutes = ______ osmolality
High
What is normal plasma osmolality?
285-295 mOsmol/kg
What is the result of lowering intracellular K?
Means lower resting membrane potential therefore cell is less excitable (needs larger stimulus for activation)
What are the main causes of an abnormal plasma pH?
Major organ dysfunction - especially lungs, kidneys, liver
Poor tissue perfusion - shock
Define shock
A state of global cellular and tissue hypoxia due to reduced oxygen delivery (commonly due to hypoperfusion)
How does shock lower plasma pH?
When tissue poorly perfused, anaerobic glycolysis leads to lactic acid production and lactic acidosis which lowers ph
What are starling forces?
Govern whether fluid moves into capillaries (absorption) or out of capillaries (filtration)