Basics Of Human Physiology And Homeostasis Flashcards
Physiology
Study of the mechanism maintaining the life on an organism.
Focuses on: organ systems, organs, anatomy, cells and biomolecules that carry out chemical or physical functions
Chemical level: molecules and the functions
Protein:
Structural, signalling, metabolic role
Nucleic acid:
Genomic information, energy store, signalling
Lipids:
Membrane organisation, energy storage
Ions:
Body fluids
Cellular level- membrane
Membranes create compartmentalisation- each compartment sustains integrity/survival of cell
They act as barriers and controls movement of chemicals in and out of the cell
Advantageous as each organelle has their own specific function and pH/chemical environment
Basic cell function
Obtain food and oxygen from the environment
Use food and oxygen which provides cellular energy
Eliminate waste, i.e. carbon dioxide
Control of exchange with outside environment
Senses change and then has an appropriate response to it
Specialised cell function: glands
Glands synthesises/ secrete enzymes or hormones
Specialised cell functions: muscle cells
Muscle cells can contract or relax through the movement of internal structures
There is a specific organisation i.e. elastic properties allow contraction or relaxation of muscles. For example: blood vessels, the gut and stomach
Specialised cell function: controlling the body’s needs
Controls body’s needs for substances which control the exchange they do with the environment. i.e. the kidneys response to Na2+
If the bodies salt levels are unbalanced, the specialised cells in the kidney (located in the nephron- specialised tubule cells) that sense Na2+ levels in the body. They adjust the body’s Na2+ levels by reabsorbing Na2+ into them and then they pass into the capillaries. These then transport Na2+ ions into the bloodstream.
Specialised cell functions: sensory cells
Specialised cell functions:
Responding to sound, temperature, light and touch
Neurones relay environmental information which helps the body adjust.
Tissue levels: 4 primary types of tissues
Connective tissues
Epithelial tissues
Muscle tissues
Nervous tissue
Muscle type:
Skeletal muscles: accomplish movements of the skeleton ( muscles are linked to the bone) These can be controlled
Cardiac muscle: pump blood out of the heart
These cannot be controlled
Smooth muscle: enclose ams control movement of contents through hollow tubes and organs (e.g. food in diegestive tracts and blood in blood vessels)
Tubes in your body have smooth muscles to control movement, i.e. urinary tract, reproductive tract
Nervous tissue
Specialised cells for initiating and conducting electrical impulses. These nervous impulses determine muscle contraction/ hormone secretion.
Examples of nervous cells: brain, spinal cord- these send nervous impulses about external environment and internal environment.
Epithelial tissue
Cells specialised for the exchange of materials between cells and the environment of the cell. It allows the passing of materials between two environments.
Examples of epithelial cells: epithelial sheets- present in the gut
Epithelial sheets
Cells are tightly joined together
Serve as a boundary to separate- the body from external environment (skin)
Contents of cavities from neighbouring organs- intestine epithelium (separates food from organs- allows it to be processed)
Controls the movement of substances in and out of the body- differences exist dependent on the type of epithelium.
For example: the skin has little exchange whereas in the digestive tract, cells are specialised to absorb nutrients.
Secretory glands
2 different types of specialised glands/cells that secrete substances that they synthesise; endocrine and exocrine.
They are formed at embryonic development- pockets of epithelial tissue dip inwards from the surface.
Exocrine glands
Release hormones directly into the surface of the epithelium through a duct, i.e. sweat glands and digestive glands
Endocrine glands
Release hormones directly into the bloodstream, which is then transported to the target cells/ site of action.
For example, aldosterone secreted by adrenal glands act on the kidneys. It’s very vascularised.
Connective tissue:
Connect, support and anchor various body parts- tendons attaching skeletal muscles to bones
Composed of cells dispersed in an abundance of extra cellular cells which are Sudetenland by the cells- basically making the base of the connective tissue.
Fibrous connective tissue:
Composed of:
Collagen fibres
Cartilage:
Composed of:
Cells and matrix
Bone:
Composed of:
Central canal, matrix, cells
Blood:
White blood cells, red blood cells, plasma
Adipose (fat) cells:
Composed of:
Fat droplets
Loose connective tissues:
Composed of: disorganised cells, collagen fibres and other fibres.
Body system:
A collection of organs that interact and preorder a similar function which is essential for the survival of the body.
For example: the digestive system breaks down food into smaller molecules which can be absorbed into the blood, and then distributed to the cells ( which are respiring or need nutrients).
Circulatory system:
Consists of:
Heat, blood, blood vessels (arteries, arterioles, veins and capillaries)
Digestive system:
Consists of:
Mouth, pharynx, oesophagus, stomach, small and large intestine, salivary glands, pancreas, liver, gall bladder and the anus
