Unit 3 Anatomy Flashcards
Anterior
towards the front of the body, in front of.
Posterior
towards the back of the body, behind.
Superior
above, on top of.
Inferior
below, underneath.
Lateral
Away from the midline of the body, towards the sides.
Medial
Towards the middle/midline of the body.
Superficial
Towards the external surface of the body (skin)
Deep
Away from the body surface, towards the inner body.
Anatomical position
Person stands upright with their legs straight (shoulder width apart) and arms down by their sides.
Their eyes, palms of their hands and toes should point forwards
What is the integumentary system?
Skin, hair, nails, sweat glands
What are indications that something might be wrong w integumentary system?
First indication you will see of visible disease or illness
Could be red, pale, sweating, jaundiced
Could have dry skin, swelling, bruising or a rash
Main functions of the skin
· Protection
· Thermoregulation
· Cutaneous sensation (touch)
· Excretion
· Absorption
· Vitamin D synthesis
Transdermal/topical drug delivery- what is it?
Very useful, particularly for slow-release drugs, or for poorly-soluble suspensions.
Very convenient and usually painless delivery system
Bypasses first-pass metabolism by the liver
Examples of drugs administered transdermally/topically
· Nicotine (transdermal patches)
· Clotrimazole (anti-fungal medication)
· Lidocaine (local anaesthetic)
Intramuscular drug delivery (IM)- what is it and which muscles are involved?
Provides an easily-accessible route of administration, either for fast absorption of aqueous solutions, or slower release of “depot” preparations (often non-aqueous).
Muscles used for intra-muscular injections deltoid (shoulder), gluteus maximum (buttocks), and quadriceps muscles (anterior thigh)
Where are the lungs situated?
Situated in the thoracic cavity, on either side of the heart
Protected by the thoracic cage.
Base of each lung rests on the diaphragm
Apex of the lungs is slightly above/behind the clavicle.
What is on the medial surface of each lung?
A region called the hilus, through which pass the bronchi (carrying air), the pulmonary arteries and veins (carrying blood from and to the heart, respectively), the lymph vessels, and the pulmonary plexus (autonomic nerves).
What do the airways consist of?
Nose, pharynx, larynx, trachea and a branching tree of bronchi and bronchioles, leading to the alveolar ducts and the alveoli
How does drug delivery occur in lungs?
Via mucous membranes of the respiratory tract and pulmonary epithelium- effective and rapid (almost as fast as IV delivery)
Bronchodilators (salbutamol for asthma), inhalational anaesthetics (nitrous oxide), and corticosteroids (fluticasone) all delivered through respiratory system
How do the main arteries work in moving blood away from the heart?
From the left ventricle of the heart, blood moves into the aorta
Curving up and back behind the heart
Then dropping down through the thorax and abdomen, supplying the organs.
The abdominal aorta splits into two, to supply the pelvic structures and continuing down to supply the legs.
How do the veins work in returning blood to the heart?
Superior and inferior vena cava drain into the right atrium, then into the right ventricle, and to the lungs (via the pulmonary arteries).
From the lungs, blood travels back via the pulmonary veins, into the left atrium and then the left ventricle, to begin its journey around the body once more.
How is the superior vena cava formed?
Veins carrying blood from the head, neck, and upper limbs merge to form the superior vena cava, which travel towards the heart.
How is the inferior vena cava formed?
The veins from the legs, pelvic structures and abdomen travel upwards and merge to form the inferior vena cava, which lies next to the abdominal aorta in the abdominal cavity.
The inferior vena cava continues up towards the heart, and veins join from the thorax.
What forms of administration are linked to the digestive/gastrointenstinal system and why are they useful ?
Enteral adminisatration (by mouth)–> most common, safest and most convenient.
- Sublingual= placing drug under tongue
- Buccal= placing drug between gums and cheek
Provide useful route for rapid absorption and onset of action
Useful for nausea medication, painkillers, or drugs for acute symptoms (angina)
What happens to drugs administered from the mouth?
Subject to first-pass metabolism
First pass metabolism
Drugs pass through oesophagus–>stomach and are exposed to harsh environments where they may be inactivated.
Then nutrients are absorbed through the intestines into the bloodstream.
Upon absorption into the intestinal bloodstream, the blood is carried to the liver via the hepatic portal system. (not directly back to heart)
Positives of rectal drug administration
Providing better bioavailability than oral route- avoids the stomach and also first pass metabolism (the venous return from the rectum to the heart, not the liver) Reduces side-effects such as gastric irritation, nausea, vomiting.
Explain the hepatic portal systems route
Blood drains from the intestines via the mesenteric veins,
Into the splenic vein,
Moving across towards the liver in the hepatic portal vein.
Blood passes through the hepatocytes of the liver
Drain into the hepatic veins
THEN returns to the systemic circulation.
Use of renal system
Filtration and excretion of substances from the body
Provides an easily-accessible point of testing for drugs excreted from the body, and metabolic diseases such as diabetes.
What is the renal system composed of?
Paired kidneys and ureters, with a single urinary bladder and urethra.
Explain the positioning of the kidneys
The kidneys lie laterally to the vertebral column, with the left kidney at the level of the T12-L3 vertebrae, and the right kidney slightly lower due to the large size of the liver.
Which glands lie superiorly on each kidney?
Adrenal glands
How is blood supplied and removed from the kidneys?
Blood supply comes from the heart via the descending abdominal aorta and the renal arteries, and is removed by the renal veins to the inferior vena cava.
What is the CNS surrounded and protected by, and what does it consist of?
Meninges
Consists of three layers (the dura mater, the arachnoid and the pia mater).
Importance of blood brain barrier
Extremely important in terms of protection and also accessibility
Adaptions of blood brain barrier
Tightly-connected endothelial cells in the BBB ensure that only substances which are capable of passing through the endothelial capillary cells, or which are actively transported, can cross into the central nervous system.
Lipid-soluble drugs can cross readily (dissolve in the cell membrane and diffuse across the endothelial cell layer) whereas polar or ionised drugs cannot. These rely on an active transporter system (ie levodopa).
What fluid is the brain surrounded by?
Cerebrospinal fluid (CSF)
Points about cerebrospinal fluid (CSF)
· is a clear colourless liquid found in the brain and spinal cord;
· acts as a cushion/buffer for the cortex providing protection of the brain inside the skull;
· contains small amounts of protein, glucose and potassium;
· contains relatively large amounts of sodium chloride;
· has no cellular components;
· is produced within the brain;
· can be sampled to aid diagnosis of certain conditions (e.g. meningitis);
· maintains its own pressure, which can be measured to diagnose or treat illness.
What is a lumbar puncture and when is it needed?
Sample of cerebrospinal fluid
Required to diagnose infections (ie meningitis), cancer or CNS disorders (multiple sclerosis, Guillain-Barre syndrome).
May also be used to introduce drugs directly into the CSF
How is a lumbar puncture conducted?
A needle must be inserted into the spinal column, whilst trying to avoid all important structures.
Performed at the lumbar region (lower back) as this is where the spinal cord ends and becomes a collection of nerve roots rather than a solid structure.
Epidural
Administration of drugs into the epidural space. (outside dura mater)
Intrathecal
Administration of drugs directly into the CSF into the intrathecal (subarachnoid) space.
Primary components of endocrine system
Hypothalamus
Pituitary gland
Pineal gland
Thyroid
Parathyroids
Adrenal glands
Pancreas
Hypothalamus
Located in brain
Bridge between nervous and endocrine system
Recieves signals from areas of brain and translates them into hormones which are transported to the pituitary gland.
Pituitary gland
Has anterior and posterior lobe
Produces ADH and oxytocin- stored in posterior lobe for later release into blood
Hormones from hypothalamus regulate release of hormones from anterior pituitary hormones- regulating other glands
Anterior pituitary gland secretes HGH
Pineal gland
Located at back of the diencephalon
Secretes melatonin- regulates sleep patterns
Thyroid gland
Located in neck
Regulates metabolism- secretes T3 and T4
Secretes calcatonin- regulates blood calcium levels
Parathyroids
Secrete PTH- also regulates blood calcium
Adrenal glands
Have outer cortex and inner medula
Cortex secretes steroid hormones like cortisol, aldosterone, androgens and estrogens
Medulla secretes epinephrine and norepinephrine (stress/FF response)
Pancreas
Digestive organ and endocrine gland
Cells in pancreatic eyelets secrete insulin and glucagon- regulate blood glucose
Four types of tissues
Epithelial
Connective
Muscular
Nervous