Unit 3 Anatomy Flashcards
1
Q
Anterior
A
towards the front of the body, in front of.
2
Q
Posterior
A
towards the back of the body, behind.
3
Q
Superior
A
above, on top of.
4
Q
Inferior
A
below, underneath.
5
Q
Lateral
A
Away from the midline of the body, towards the sides.
6
Q
Medial
A
Towards the middle/midline of the body.
7
Q
Superficial
A
Towards the external surface of the body (skin)
8
Q
Deep
A
Away from the body surface, towards the inner body.
9
Q
Anatomical position
A
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
10
Q
What is the integumentary system?
A
Skin, hair, nails, sweat glands
11
Q
What are indications that something might be wrong w integumentary system?
A
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
12
Q
Main functions of the skin
A
· Protection
· Thermoregulation
· Cutaneous sensation (touch)
· Excretion
· Absorption
· Vitamin D synthesis
13
Q
Transdermal/topical drug delivery- what is it?
A
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
14
Q
Examples of drugs administered transdermally/topically
A
· Nicotine (transdermal patches)
· Clotrimazole (anti-fungal medication)
· Lidocaine (local anaesthetic)
15
Q
Intramuscular drug delivery (IM)- what is it and which muscles are involved?
A
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)
16
Q
Where are the lungs situated?
A
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.
17
Q
What is on the medial surface of each lung?
A
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).
18
Q
What do the airways consist of?
A
Nose, pharynx, larynx, trachea and a branching tree of bronchi and bronchioles, leading to the alveolar ducts and the alveoli
19
Q
How does drug delivery occur in lungs?
A
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
20
Q
How do the main arteries work in moving blood away from the heart?
A
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.
21
Q
How do the veins work in returning blood to the heart?
A
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.
22
Q
How is the superior vena cava formed?
A
Veins carrying blood from the head, neck, and upper limbs merge to form the superior vena cava, which travel towards the heart.
23
Q
How is the inferior vena cava formed?
A
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.
24
Q
What forms of administration are linked to the digestive/gastrointenstinal system and why are they useful ?
A
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)
25
What happens to drugs administered from the mouth?
Subject to first-pass metabolism
26
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)
27
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.
28
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.
29
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.
30
What is the renal system composed of?
Paired kidneys and ureters, with a single urinary bladder and urethra.
31
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.
32
Which glands lie superiorly on each kidney?
Adrenal glands
33
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.
34
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).
35
Importance of blood brain barrier
Extremely important in terms of protection and also accessibility
36
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).
37
What fluid is the brain surrounded by?
Cerebrospinal fluid (CSF)
38
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.
39
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
40
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.
41
Epidural
Administration of drugs into the epidural space. (outside dura mater)
42
Intrathecal
Administration of drugs directly into the CSF into the intrathecal (subarachnoid) space.
43
Primary components of endocrine system
Hypothalamus
Pituitary gland
Pineal gland
Thyroid
Parathyroids
Adrenal glands
Pancreas
44
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.
45
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
46
Pineal gland
Located at back of the diencephalon
Secretes melatonin- regulates sleep patterns
47
Thyroid gland
Located in neck
Regulates metabolism- secretes T3 and T4
Secretes calcatonin- regulates blood calcium levels
48
Parathyroids
Secrete PTH- also regulates blood calcium
49
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)
50
Pancreas
Digestive organ and endocrine gland
Cells in pancreatic eyelets secrete insulin and glucagon- regulate blood glucose
51
Four types of tissues
Epithelial
Connective
Muscular
Nervous
52
Epithelial tissue
Line the body cavities, form the outside surfaces of the internal organs, line the gut and can be modified to form glands.
53
Connective tissue
Connect one tissue to another and/or provide a framework on which tissues can be supported to function as an organ.
54
Muscular tissue
Three types.
Cardiac muscle is restricted to the heart,
Skeletal muscle allows joint movement and
Smooth muscle is found in the tubular structures such as the gut, blood vessels and in the eye.
55
Nervous tissue
In the central nervous system (CNS) and peripheral nervous system specialised cells are used for processing information and integrating functions of the body.
56
Epithelial cell functions
Physical protection
Sensation- senses come from specially evolved neuroepithelia
Control absorption and uptake of material- cells alter permability
Secretion- gland cells can be dotted amongst regular epithelial cells.
57
Glandular epithelium.
involved in the production and release of different secretory products
Their secretions can coat the surface of the tissue providing lubrication and physical protection or if systemically absorbed can act as chemical messengers to other parts of the body.
58
Simple squamous epithelium description and function/location
Description- Single layer of thin, flat cells which have a central nucleus
Location/function- Found in lung alveoli, lining blood vessels and kidney glomeruli; the shape allows effective diffusion of material, where physical protection is not important.
59
Simple cuboidal epithelium description and function/location
Description- Single layer; shaped like a cube; have a large central nuclei
Location/function- Found in the kidney tubules, small glands and the ovary. Involved in secretion and absorption.
60
Simple columnar epithelium- ciliated description and location/function
Description- Single layer of tall, thin and rectangular cells, with cilia
Location/function- Found in the bronchi, the Fallopian tubes and some parts of the uterus. Often bathed in mucus from glands in the epithelium, to maximise ciliary function.
61
Simple columnar epithelium- non ciliated description and location/function
Description- Single layer of tall, thin and rectangular cells, without cilia
Location/function- Found in the gastrointestinal tract, from the stomach to the anal canal; allow absorption to occur.
62
Stratified squamous epithelium description and location/function
Description- Several layers of cells: those at the free surface are squamous.
Location/function- Forms the epidermis of the skin and also lines (e.g.) the oesophagus and mouth protecting the underlying tissues from physical forces/damage.
63
Stratified cuboidal epithelium description and location/function
Description- Usually two layers of cuboidal cells
Location/function- Found in the largest ducts of the salivary, sweat and mammary glands where they have a protective role.
64
Stratified columnar epithelium description and location/function
Description- Several layers of cells: those at the free surface are columnar.
Location/function- Rare, but found in the epiglottis, anus, ducts of the salivary glands, and the male urethra where they have a protective and secretory role.
65
Transitional epithelium description and location/function
Description- Basal cells are cuboidal or columnar and the surface cells are either cube-like or squamous-like depending on degree of stretching
Location/function- Lines the ureters, bladder, and part of urethra as it easily and repeatedly stretches (e.g. permitting urinary bladder distension as it fills with urine). The epithelia can undergo repeated stretching (becoming flat and thin, like squamous cells) before returning to a more cuboidal shape (as the tissue relaxes).
66
How are epithelial cells arranged?
Bound tightly together with very little extracellular matrix.
Cells have polarity
They have an exposed free surface, the apical side of the cell, and an opposite surface (basal side) which can be attached to a second layer of epithelial cells or a basement membrane, which in turn attaches to connective tissue cells found below the membrane
67
Why are epithelia termed avascular?
Epithelial cells are usually tightly bound together completely covering the underlying surface.
This tight arrangement leaves no space for blood vessels.
Their nutritional requirements have to travel either downwards from the exposed apical surface or up through the basal lamina.\
68
4 types of specialised cell junctions
Tight junctions
Gap junctions
Desmosomes
Hemidesmosomes
69
Tight junctions
Bind cells closely together
Prevent water passage
Useful in small intestine- isolates them from liquid present in lumen
70
Gap junction
Enable small molecules to pass between connected cells
Can be used to coordinate various activities (beating of cilia)
Occur as interlocking connexon proteins which act as transport channels.
71
Desmosomes
Junctions involved in intercellular adhesion of epithelial cells
Enable epithelium to withstand mechanical stresses e.g. twisting, stretching and squeezing
72
Hemidesmosomes
Junctions involved in adhesion of epithelia to basement membranes
73
Role of basement membrane
Stick epithelium to connective tissue.
74
Feature of basement membrane
Porous- allows material to move between epithelial and connective tissue layers.
75
2 layers that basement membrane is comprised of
Layer closest to epithelial cells= basal lamina
Layer connecting directly to connective tissue= reticular lamina
76
Outer layer of skin
Keratinised endothelium
77
4 types of membrane
Cutaneous membrane
Mucous membrane
Serous membrane
Synovial membrane
78
Cutaneous membrane
External membrane- skin
Comprised of stratified squamous epithelium, on top of a layer of areolar and adipose tissue (superficial fascia) that is connected to the layer of dense, fibrous connective tissue (deep fascia)
important role in protection of the body against trauma and also prevents excessive water loss.
79
Mucous membrane
Class of internal membranes that line body cavities in direct contact with the outside world (e.g. digestive, reproductive, respiratory)
Layer of epithelium connected to a thick layer of loose connective joined via a basement membrane.
Ability to secrete mucus as a lubricant, protective lining or to improve digestion and absorption
80
Serous membrane
A type of internal membrane that lines cavities that do not make direct contact with the outside world and do not contain glands
Comprise of a layer of simple squamous epithelium connected to a thin layer of loose connective tissue via a basement membrane.
Secrete seorus fluid- decreases friction between adjacent surfaces and act as a water-tight barrier preventing fluid accumulation.
81
Examples of serous membrane
pericadial membrane covers heart
pleaural membrane covers outside of lungs
peritoneum lines abdominal cavity
82
Synovial membranes
Class of internal membrane that line moving joints
Contain no epithelia, just connective tissue (predominantly areolar) cell which secretes synovial fluid.
Lubricates joints- keeps movement free and easy
83
Endocrine glands
Secrete hormones directly into surrounding interstitial fluid
Diffuses into blood- influences cell function
Examples include thyroid, pancreas and thymus
Endocrine cells scattered in gastrointestinal tract
Also caled ductless glands
84
Exocrine glands
Produce secretions that travel through a duct to be released onto an endothelial surface.
Examples include tears, sweat, and breast milk.
Release their secretions via a process called exocytosis e.g. sweat glands
85
What process do exocrine glands release their secretions by and what type of secretion is this?
Process of exocytosis
Known as merocrine secretion
86
Three types of secretions
Merocrine
Apocrine
Holocrine
87
Apocrine secretion
Occurs when apical side of each cell bud splits from main cell taking a large proportion of cytoplasm with it.
88
Apocrine secretion is considered more damaging than merocrine secretion. However..
the cells can repair themselves, replace their secretatory products and release them again
89
Example of a mixture of merocrine and apocrine secretion
Mammary glands use a mixture if both to release breast milk
90
Holocrine secretion
Entirely destructive process
Where mature cells burst to release their products
Eventually replaced with new cells
91
Skeletal muscle structure
Multinucleated- more than one nucleus
Very thin
Extremely long
Myocytes referred to as muscle fibres
92
Skeletal muscle fibre structure
Each fibre consists of several cytoskeletal filaments of actin and myosin, arranged in repeating bands known as sarcomeres.
93
Sliding filament theory
Once a signal to contract is received, myosin proteins pull on actin filaments, causing temporary shortening in length of overall fibre.
94
What does skeletal muscle contracting look like under a microscope
Alternating arrangement of actin and myosin is striated
95
How are skeletal muscles formed by their fibres?
Each fibre is wrapped in a layer of collagen and bundled together with other fibres in a fascicle.
These bundle together to form individual muscles, which are connected to tendons, connected to the skeleton.
Skeletal muscles contract only on receiving a voluntary nervous signal- referred to as striated voluntary muscle
96
Cardiac muscle structure
Myocardiocytes have limited ability to divide.
Striated with actin and myosin filaments and typically contain a single nucleus and much shorter than skeletal muscle cells.
Well connected cells
Branched arrangment of cells joined with intercalated disks.
97
What is the importance of intercalated disks in cardiac muscle?
2 neighbouring cell membranes are joined tight together with intercellular cement, desmosomes and also gap junctions
Allows the cardiac muscle cells to contract in a wave-like pattern so that the heart can work as a pump/pacemaker.
This tissue is referred to as striated involuntary muscle
98
Where does smooth muscle occur?
In hollow organs such as bladder, gastrointestinal and reproductive tracts and in walls of blood vessels
99
Smooth muscle structure
Contain actin and myosin. Not appearing striated.
Coordination of contraction is limited to local area, via gap junction, and usually under the control of the autonomic nervous system.
Tissue referred to as striated involuntart muscle
100
2 cell types of nervous tissue
Neurons
Glial cells
101
How are messages sent along a neurone and what happens when they are sent to a muscle or gland cell?
Information passes as electrical impulses known as action potentials, to the axon terminus. This releases neurotransmitters which pass signals to the receptors on target cells. This is usually other nerve cells which continue to electrically transmit the message.
However, if the target is a muscle cell, the signal results in muscular contraction or gland cell causing secretion
102
Glial cells
Neurons cant reproduce- so are maintained by variety of cells called neuroglia or glial cells.
These cells surround neurons, fixing them in place, insulating them from eachother.
Glial cells provide nutrients to the neurons, mop up invading pathogens, and can tidy away dead neurons.
E.G. myelin consists of a variety of different types of glial cells in a matrix.
103
Connective tissue structure
Contains variety of specialised cells surrounded and supported by matrix of extracellular protein fibres between which there is a gel like fluid referred to as ground substance.
104
Role of connective tissue
Vascularised- recieving nutrients from the blood, and make the framework on which organs and tissues sit, enclosing and separating organs from eachother.
Protective role- physically and in the immune system. Certain connective tissues contain fat as an energy substrate for later use
105
Examples of permanent/resident cells
Mesenchymal cells
Fibroblasts
Elastic fibres
Reticular fibres
Collagen fibres
Adipocytes
Melanocytes
Mast cells
106
What are cells surrounded by in classical connective tissue
Both extracellular proteins and viscous gel ground substance
107
What does loose connective tissue act as
Filler material, packing out gaps between organs and epithelia, holding them in place
E.G. areolar, adipose, reticular
108
Areolar tissue
Separates skin from muscle underneath-allows muscle to bulge/flex without stretching/tearing skin above
109
Adipose tissue
Majority underlies skin- particularly in butt, breasts, flanks. Referred to as subcutanous fat.
Insulates body from heat loss, protets organs from physical shock and acts as energy store.
110
Reticular tissue
Used to build complex structures referred to as stroma that can support action of functional cells found in liver, kidneys, spleen, lymph nodes and bone marrow
111
What is dense connective tissue
Usually referred to as collagenous tissue
Has less ground substance in matrix than loose
112
Types of dense connective tissue
Regular- fibres run in parallel directions e.g. tendons/ligaments
Elastic- elastic fibres are domnant- tough yet springy, cushiosn surrounding material from physical shock
Irregular- collagen, laid down in branched interconnected network. encapsulates liver, kidney and spleen, surrounds joint cavities and coats outside of cartillage and bones
113
What is bone made out of and why is this good?
Made of flexible collagen-fibre matrix filled with hard mineral substance called hydroxylapatite.
Material has rigidity and strength- flexibility afforded by the collagen means bone isnt brittle.
114
Structure of bone
Bone/osseous tissue appears as series of small holes (lacunae), containing bone cells (osteocytes), surrounded by bone matrix.
Laccunae arranged around blood vessels which supply nutrients and building material.
Solutes cannot diffuse through bone matrix hence osteocytes are connected to eachother through long thin canals called canaliculi.
115
How can bone tissue be subcategorised?
Based on density of matrix material.
Ends of long bones, and centers of thick bones (e.g. skull, vertebrae and pelvis) are less densely packed with matrix, with obvious gaps between rods of bone matrix.
Spongy bone (cancellous/trabecular) is highly vascularised, and is known as site of bone marrow.
More densely packed areas of bone known as cortical bone.
116
Cells in cartilage
Chondrocyte cells
117
Types of cartilage
Hyaline
Elastic
Fibrocartilage
118
Hyaline cartilage structure and function
Tightly packed collagen fibres- flexible and strong
Form cartilage of respiratory tract and nose, and bone surfaces in joints- prevents friction and wearing
Cartilage protected by synovial fluid produced by synovial membrane when present in a joint cavity
119
Elastic cartilage
Comparatively high amount of elastin fibres allow structures to return to their oringal shape following compression
Form outer ear, aural tube, epiglottis, parts of larynx.
120
Fibrocartilage
Comprised of tightly compact collagen fibres with little ground substance- material rsilient to mechanical stress, but difficult to repair after injury.
Used to make pads in between verterbrae, pubic bones and inside knee joints.
121
Blood
known as fluid connective tissue comprising of plasma and cells known as formed elements.
122
What is the creation of formed elements in blood and where does it occur
Haematopoiesis- occurs through differentiation of stem cells in bone marrow
123
Granulocytes
Contain small granules of proteins.
Three types- basophils (increase in number after allergic reaction), eosinophils (general immune and inflammatory response) and neutrophils (make up majority of WBC in body)
124
Monocytes
Agranular
Move from blood to tissue then undergo structural changes to become macrophages
Fixed macrophages stay in tissue for a long time (Chronic illness) providing defence by englufing offending material (phagocytosis)
125
Lymphocytes
Agranular
B cells and T cells can recognise antigens on either invading pathogen/body materials that have been innapropriately modified/damaged.
Natural killer cells are another type- identify and kill invaders without antibodies- sppeds up immune response
126
How is lymphatic fluid formed?
Tissue is surrounded by interstital fluid which can accept material which passes through capillary endothelial junctions.
Cells= too big to get through junctions so erythrocytes, platlets and plasma proteins cant cross
Once through the barrier, around 85% travels back through the capillaries into veins and becomes blood
However some interstitial fluid enters lymphatic vessels and becomes lymph.
127
Why was lymphatic system designed?
Partly designed as alt pathway for intertitial fluid to re-enter circulation as blood, and bring lymph back to large veins in neck.
128
What does lymph contain and where does it pass through?
Contains material from tissues it has been in contact w (inc fatty acid, signalling molecules, toxins, pathogens).
Lymph passes through lymph nodes on its way back to heart- which are packed with lymphocytes and macrophages which screen for signs of infection.
